JOURNAL

OF EXPERIMENTAL

CHILD

54, 121-146

PSYCHOLOGY

(1992)

The Dissociation of Repetition Priming and Recognition Memory in Language/Learning-Disabled Children THOMAS Depurtment

C. LORSBACH AND JANETTE SODORO

of Special

Education

and Communication

Disorders

AND

JOSEPH S. BROWN University

of Nebraska

at Omaha

Recent research has found that the performance of learning-disabled and nondisabled children is dissociated on explicit and implicit tests of memory (Lorsbach & Worman, 1989). The current study further examined this phenomenon by comparing language/learning-disabled (L/LD) and nondisabled children (NLD) on tasks measuring primed picture-naming and item recognition. Included within the design of the experiment was the manipulation of both presentation format (pictures or words) and retention interval (immediate or 1 day). Children were initially presented with pictures and words. Performance was measured both immediately and following a l-day retention interval on a picture naming task. an item recognition task. and a supplementary measure of memory for presentation format. The magnitude of facilitation associated with primed picture-naming was found to be independent of item recognition performance. In addition, the effects of population (L/LD and NLD) and retention interval (immediate test or 1 day) each produced dissociations between the magnitude of naming facilitation and item recognition performance. Results were discussed in terms of their implications for our understanding of the nature of memory difficulties in L/LD children. ,c’ IW? Academx

Press. Inc.

When presented with traditional episodic memory tasks, the performance of children with learning disabilities rarely equals that of nondisThe present research was supported by a fellowship awarded to the first author by the University Committee on Research, University of Nebraska at Omaha. and was based on a Master’s thesis that was completed by the second author. The authors acknowledge David Mitchell who provided helpful comments on an earlier draft of this article. Address correspondence and reprint requests to Tom Lorsbach. Department of Special Education and Communication Disorders, 11.5 Kayser Hall. University of Nebraska at Omaha, Omaha. NE 68182-0054. 121 0022~0965192

$5.00

Copyright ICI 1492 hy Acadrm,c Prc\\. Inc All rqhtz ot reproductwn in any tcrrm reervrd

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abled children. Compared to their nondisabled peers, children with Iearning disabilities have been found to perform poorly on tasks measuring free recall (Lorsbach, 198(I), cued recall (Ceci, Lea, & Ringstrom, 1980). serial recall (Torgesen, 1978), story recall (Weaver & Dickinson, 1982). item recognition (Lorsbach & Gray, 1985). and short-term memory (Torgesen & Houck. 1980). These memory difficulties have been attributed to a variety of deficits, including deficient rehearsal (Bauer. 1977) and organization (Suiter 6i Potter, 1978). as well as a failure to engage in “purposive” (effortful) forms of semantic processing (Ceci, 1983, 1984). In recent years, our conceptualization of what constitutes “memory” has been expanded to include performance on tasks that do not require conscious awareness on the part of the subject (c$ Richardson-Klavehn Bi Bjork, 198X; Schacter. 1987). In this case. memory is revealed implicitly through performance on tasks that do not require the conscious recollection of a recently experienced event. Such implicit measures of memory often yield results that are often dissociated from those obtained with more traditional measures. In an attempt to gain a more thorough understanding of the nature of memory difficulties in learning-disabled children, the present study used tasks that explicitly and implicitly assessed memory. E.xplicit and Implicit

Tests of Memoq

When an event is experienced, memory for that event later may bc expressed with or without one’s conscious awareness. Memory with conscious awareness is manifested on traditional memory tasks, such as recognition or recall, where the individual is explicitly asked to bring to mind aspects of a prior experience. Such memory tasks have been referred to variously as “episodic” (Tulving. 1972). “explicit” (Graf 8r Schacter, 1985: Schactcr. 1987). and “direct” (Johnson & Hasher, 1987; Richardson Klavehn & Bjork. 1988). In contrast are those measures that do not make explicit rcfercnce to a prior experience. In this case. instructions make no reference to a prior experience and the individual is asked to perform a task that implicitly reveals memory for the stimulus cvcnt. Under these circumstances, memory is demonstrated when performance reveals facilitation in the identification of old, relative to new, stimuli. Terms such (Graf 6i Schacter, 1985; as “procedural” (Tulving, 1983, 1985). “implicit” Schacter, 1987). and “indirect” (Johnson & Hashcr. 1987; RichardsonKlavehn & Bjork. 1088) have been used to refer to these latter memory tasks. The present study uses the terms “explicit” and “implicit” to refer to these alternate forms of testing memory. Repetition priming has been the most common method used in the implicit measurement of memory. In the typical priming experiment. subjects are exposed initially to a series of target items such as words or pictures. Memory is subsequently tested by asking the subject to perform

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a task that does not require the deliberate retrieval of study-list items. A variety of tasks have been used to measure repetition priming, including the completion of word stems (e.g., Graf, Mandler, & Haden, 1982) and word fragments (e.g., Tulving, Schacter, & Stark, 1982), lexical decision tasks (e.g. Scarborough, Gerard, & Cortese, 1979), word identification tasks (e.g., Jacoby & Dallas, 1981). picture naming tasks (e.g., Mitchell & Brown, 1988), and picture-fragment completion tasks (e.g., Warrington & Weiskrantz, 1968). In repetition priming, memory is expressed through the facilitation that accompanies the processing of old, relative to new, stimulus events (e.g., Graf & Schacter, 1985; Schacter, 1987). Facilitation, for example, may be revealed when old items are named faster or identified more readily than new stimulus items. The relationship between explicit and implicit tests of memory has been examined extensively in recent years (See reviews by Lewandowsky, Dunn, & Kirsner, 1989; Richardson-Klavehn & Bjork, 1988; Schacter, 1987). What has captivated the interest of so many investigators is that performance on explicit and implicit tests is often dissociated. A number of variables that have an effect on explicit tests of memory have either no effect, or an opposite effect on implicit tests of memory. The most dramatic example of this dissociation has been research that has examined patients with severe memory disorders. Although amnesic patients exhibit profound memory deficits when tested with traditional measures, their memory is “preserved” when implicit measures are utilized (e.g., Cohen 6i Squire, 1980; Graf, Squire, & Mandler, 1984; Shimamura, 1986). Dissociations between explicit and implicit tests also appear as a result of developmental comparisons. For example, while older adults may recognize fewer study-list items than younger adults, these age differences are often absent when memory is tested implicitly through tasks such as word-fragment completion (Light, Singh, & Capps, 1986) or repeated picture-naming (Mitchell, 1989). Studies that have compared children at different age levels have similarly found a developmental dissociation between explicit and implicit tests of memory. Although older children may recall or recognize more information than younger children, these developmental differences are absent when memory is tested implicitly through picture-fragment completion (Lorsbach & Worman. 1989; Parkin & Streete, 1988) or repeated picture-naming tasks (Carroll, Byrne, & Kirsner, 1985; Lorsbach & Morris, 1991). Changing stimulus characteristics between study and test is another manipulation that often dissociates performance on explicit and implicit tests of memory. Changing stimulus characteristics between study and test significantly reduces the amount of priming, relative to a condition in which there are no study-test alterations. The negative effect of stimulus alterations on the amount of priming has been demonstrated with a variety of methods that have changed modality of presentation (e.g., Kirsner,

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Milech, & Stander-r, 1983; Kirsner & Smith, 1974) or altered the surface form of the stimuli (e.g., Blaxton, 1989; Jacoby & Hayman, 1987). In contrast, the alteration of stimulus characteristics often has no impact upon performance on explicit tests of memory. Recent studies that have compared the effects of stimulus alterations on explicit and implicit measures have found the two measures to be dissociated, with only the implicit measures showing a negative effect of stimulus change (Jacoby & Dallas, 1981; Graf. Shimamura, & Squire, 1985; Roediger & Blaxton. lY87a). Another variable that may produce dissociations between explicit and implicit measures is length of retention interval. Studies that have compared performance on explicit and implicit tasks tend to find that while performance on explicit measures declines as retention interval is lengthened. performance on implicit measures often remains stable (e.g., Mitchell & Brown, 1988; Tulving et al., 1982). In their review of those studies that have examined the effects of retention interval, Mitchell. Brown, and Murphy (1990) indicate that performance on implicit measures generally shows an initial decline at brief intervals, followed by a stabilization in performance at longer retention intervals. Performance on explicit measures, on the other hand. manifests a steady decline as retention interval is lengthened. It is important to note that although explicit and implicit measures often may be dissociated. there are several instances in which the two measures respond similarly to the manipulation of a given variable. For example, both explicit and implicit measures appear to be sensitive to repeated presentations of a stimulus (Graf & Mandler, 1Y84), as well as to the overlap of contextual information in study and test materials (Jacoby. 1983). Theoretical

Approaches

According to Schacter (19X7), three theoretical frameworks have been used to explain the relationship between explicit and implicit tests of memory. The first position is referred to as the “activation” view and is exemplified by the writings of Mandler and his colleagues (Graf & Mandler. 1984; Mandlcr, 1980; Mandler, Graf. & Kraft. 1986). When facilitation is observed on an implicit test such as repetition priming, it presumably occurs as the result of the momentary activation of preexisting representations. These representations contain no contextual information and are activated automatically. In contrast, performance on explicit tests requires the formation of new representations and involves a process known as “elaboration.” The explicit recollection that is required of explicit tests is made possible because elaborative processing incorporates contextual information of the prior learning episode. The transfer-appropriate processing framework represents the second theoretical position and is reflected in the works of Roediger and his

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colleagues (Blaxton, 1989; Roediger & Blaxton, 1987a, b; Roediger, Srinivas, & Weldon, 1989; Roediger, Weldon, & Challis, 1989). This position begins with the assumption that efficient memory performance depends upon transfer-appropriate processing, where memory performance is maximized when there is a match between the operations used during study and test. In addition, memory tests are considered to vary in their processing demands. Explicit tests of memory are considered to be conceptually driven, in that the subject actively engages in a variety of mental activities (e.g., organization in free recall) to assist in the conscious reinstatement of prior experiences. In contrast, implicit tests are considered to be largely data driven in that there is no deliberate attempt to retrieve prior information and because performance of the subject is guided by the characteristics of the stimuli. Dissociations between explicit and implicit tests emerge as the result of a mismatch between the conceptually driven and data driven processing requirements study and test materials. The third theoretical approach to the relationship between explicit and implicit tests of memory is the multiple-memory systems account. Under this approach, dissociations between explicit and implicit measures of memory are attributed to the operation of different memory systems. A variety of multiple-memory distinctions have been offered in an attempt to explain the dissociations between explicit and implicit tests of memory. including “procedural” versus “declarative” memory (Cohen, 1984; Squire & Cohen, 1984), “semantic memory” versus “cognitive mediation” (Warrington & Weiskrantz, 1982), and “taxon” versus “locale” (O’Keefe & Nadel, 1978). Tulving (1985, 1987) has proposed a ternary classification scheme that involves three interrelated systems: Procedural memory, semantic memory, and episodic memory. Procedural memory, the lowest level of the hierarchical scheme, has semantic memory as its subsystem, which in turn has episodic memory as its subsystem. Thus, semantic memory is dependent upon procedural memory, and episodic memory is dependent upon semantic memory. Different forms of consciousness accompany the three systems; although the episodic and semantic memory systems are subject to introspection, the contents of procedural memory may not be examined consciously. The Current Study

To our knowledge, only two published studies have directly compared explicit and implicit measures of memory performance with learning-disabled children. Lorsbach and Worman (1989) compared third- and sixthgrade learning-disabled children with third- and sixth-grade nondisabled children on explicit and implicit measures of picture memory. The explicit tests of memory consisted of both free recall and cued recall tasks, while the implicit measure involved the completion of old and new picture fragments. When memory was tested explicitly with free or cued recall,

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older children remembered more pictures than younger children and nondisabled children remembered more pictures than learning-disabled children. These developmental and individual differences, however. were absent when memory was measured implicitly with the fragment completion task. In a subsequent investigation, Lorsbach and Worman (1990) compared learning-disabled children and nondisabled children by using explicit and implicit measures of paired-associate learning ability. Memory for new associations was tested explicitly with a cued recall task and implicitly with an item recognition priming procedure. Compared to nondisabled children, learning-disabled children had significantly greater difficulty when paired-associate learning was tested explicitly on the cued recall task. On the other hand, the two populations exhibited equal amounts of priming on the item recognition priming task. Dissociations between learning-disabled and nondisabled children were examined further in the present study by using different explicit and implicit tests of memory. Children were presented with words and pictures and were later presented with naming/recognition tasks. The repetition priming associated with naming repeated pictures provided the implicit measure of memory. Picture naming was chosen as an implicit measure for several reasons. First. Mitchell and Brown (198X) have noted that naming repeated pictures is an everyday activity and therefore is more natural than other measures (e.g., fragment completion). Second, naming repeated pictures avoids a potential confound of fragment completion tasks; i.e., the fragment may be used covertly as a cue for the deliberate retrieval of a prior stimulus event (Schacter, 1987). Finally, Mitchell and Brown (1988) have observed that repeated picture-naming typically yields a large priming effect and does not appear to be affected by retention interval. An old/new item recognition task provided the explicit measure of memory. In addition, a supplementary task was used that measured memory for presentation format (picture or word). Memory for presentation format was examined in an attempt to determine whether learning-disabled and nondisabled children differ in their memory for an item’s physical details. Such information is valuable in that it is one of the many dimensions that one may use to consciously retrieve an item from memory. Given the results of Lorsbach and Worman (19X9), the performance of learning-disabled children and nondisabled children should produce a dissociation, with differences being observed on the explicit measures, but not on the implicit measure of naming facilitation. Memory was also examined as a function of both retention interval (immediate or 1 day) and presentation format (pictures or words). Previous research (e.g.. Mitchell & Brown, 1988) suggests that different retention intervals should produce a dissociation between recognition

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memory and repetition priming. Of interest is whether the retention of information on the explicit and implicit measures is different for learningdisabled and nondisabled children. Presentation format was manipulated to determine whether there are differences in priming between learningdisabled and nondisabled children and whether those differences vary with the format of the prime. The results of previous studies with adults indicate that pictures should be remembered better than words (e.g., Weldon & Roediger, 1987), and pictures should produce greater repetition priming than word primes (e.g., Durso & Johnson, 1979). Based on the observation that learning-disabled children experience semantic processing difficulties (Ceci. 1983, 1984; Lorsbach, 1980), and assuming that the word presentation format is “conceptually driven” (cf Roediger & Weldon. 1987), any differences between learning-disabled and nondisabled children should be more apt to appear when words are used as a presentation format. METHOD Subjects

Twenty-four language/learning disabled (L/LD) and 24 nondisabled (NLD) fourth graders were selected randomly from a predominantly white, surburban school district in the midwest. There were 19 boys and 5 girls in the L/LD group, with a mean chronological age of 10.43 years (SD = .39). L/LD children were selected who had been previously identified by school district personnel as both learning disabled and language impaired. Verification of a learning disability by school district personnel was based primarily upon two criteria. First, the child’s full scale IQ was above the - 1 standard deviation level on an individually administered intelligence test. For those children who had a discrepancy between composite scores that was greater than 1 standard deviation, the higher score was used as an index of ability. Second, the child’s standard score in one or more academic areas was 1.3 standard deviations or more below the child’s ability level. Furthermore, the standard score fell at or below 90 standard score points. Similar criteria were used to verify a language impairment. Again, at least average intellectual ability was documented and the child’s communication performance yielded scores greater than 1.3 standard deviations below the child’s overall ability level. The mean Verbal, Performance, and Full Scale scores on the Wechsler Intelligence Scule for Children-Revised (Wechsler, 1974) were 96.3 (SD = 12.3), 106.2 (SD = 13.7), and 100.X (SD = 11.6). respectively. The mean standard scores in reading and math on the Wide Range Achievement Test-Revised (Jastak & Wilkinson, 1984) were 80.6 (SD = 12.4) and 85.1 (SD = 13.9), respectively. Finally, the mean standard scores for receptive and expressive language on the Clinical Evaluation of Language

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(Semel & Wiig, 1987) were, respectively, 77.9 (SLI = 8.7) and 75 (SD = 9.7). The selection of NLD students excluded those students who were receiving remedial services, as well as those who were enrolled in programs for gifted and talented students. The NLD group consisted of 9 boys and 15 girls, with a mean chronological age of 10.15 years (SD = .35). Performances on the Wide Range Achievement Test-Revised yielded a mean standard score of 102.2 (SD = 7.4) in reading and 96 (SD = 9.6) in math. No standardized test scores were available that measured the cognitive abilities of the NLD children. Fundamentals-Revised

Material.7

Stimuli were presented in both a visual and an auditory condition. In the visual condition, stimuli consisted of black-and-white line drawings of common objects that were obtained from the norms of Snodgrass and Vanderwart (1980). Pictures were photographed and mounted on slides for presentation. One hundred twenty-eight pictures were randomly selected, with the restriction that they possess an H value that did not exceed 1.77. The H statistic has a range of O-2.55 and reflects both the name agreement and the percentage of subjects who provided the same name for a given picture. The smaller the N value, the higher the name agreement and the proportion of subjects providing the same name for a given picture. For example, with an H value of 0 the picture of a “balloon” has perfect name agreement, whereas the picture of a “doll” has an H value of 1.42 and elicits alternate names (e.g.. “baby” or “little girl”). Stimuli that were presented in the auditory condition consisted of the dominant name for each of the 128 pictures in the norms of Snodgrass and Vanderwart (1980). Picture names were tape-recorded for presentation using the voice of an adult female. The 128 items within the pool were randomly assigned to one of four 32-item Sets: A, B. C. and D. The items in each set served two separate functions: they were presented either as (a) critical items in a 64-item study list or (b) foils in one of two 64-item naming/recognition tasks. The four sets were equated on mean H value (Set A = 43.5, Set B = 43.6, Set C = 43.1, and Set D = 42.8). Each of the four sets was used equally often as study-list items and as foils in the naming/recognition tasks. In addition, the use of the four sets was counterbalanced perfectly across the factors of population (L/LD or NLD), naming/recognition test (immediate or delayed), and presentation format (picture or word). Four 64-item study lists were formed by combining the four sets of pictures: A + B. B + C, C + D. D + A. Two sets of stimuli composed each 64-item study list, with one set being presented as pictures and the other as spoken words. Items from each set were presented randomly in

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a series of eight 4-item blocks. The blocks representing each of the two sets were presented in an alternating manner (i.e.. 4 pictures, 4 words, 4 pictures, and so on). The immediate and the delayed naming/recognition tasks each consisted of 64 items: 32 targets and 32 foils. Unlike the preceding study lists, all items in the naming/recognition tasks were presented as pictures. The 32 targets used in the immediate test list consisted of 16 items that had been presented in the visual condition and 16 items that had been presented in the auditory condition. Sixteen items from each of the two unused Sets served as foils. The remaining 32 untested targets and 32 foils from the unused Sets were used to form the delayed test. Test items were presented in a random manner, but with the restriction that no more than 4 “old” or 4 “new” items be presented successively. Procedure

und Apparatus

Each child was tested individually at his or her own school. During the initial session, subjects were told that they would be seeing pictures, as well as hearing the names of common objects. Subjects were presented with a 64-item study list and asked to name each picture aloud and to listen as each word was presented. Each subject was also asked to provide a use for the object immediately following the presentation of each stimulus: “Whenever you see a picture or hear a word, think quickly of something you could do with the object.” This task served two functions. First, indicating the use of each object served as a semantic orienting task. Second, providing a use for the object enabled the examiner to verify that the subject has in fact heard the intended word and not a similar sounding word (e.g., box for fox). Subjects were not given any information regarding the nature of the forthcoming memory tests, nor when they would occur. Both pictures and words were presented using a 5-s presentation rate, with a 10-s pause between blocks. Timing of events within and between trials was accomplished by synchronizing the projector with inaudible tones occurring on the Wollensak tape recorder. Pictures were projected onto a screen that was approximately 2 m directly in front of the child by means of a Kodak carousel projector. A stimulus duration of approximately 1 s was used in the presentation of the pictures. Picture names were presented by means of a Wollensak tape recorder. One 64-item test list was presented immediately following the presentation of the study list, and a second test list was administered following a 24-h delay. Each test list was presented as a picture naming/recognition task and was subject paced. Subjects were informed that some of the pictures would be the same ones they had just seen, some would be pictures of words they had just heard, and others would be completely new pictures (i.e., they had not seen the picture, nor had they heard the

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TABLE

MEANS

BROWN

1

ok MEDIAN NAMING LAENCIES POK OLD AND NEW PKKJRES ACCORDING RETF.NIION INTERVAL. PRIMING FVRMA.I.. AND POPUI.A~~ON Pictures ~~~~~~

Item

type

Words

Immediate

I Day Language/learning

Old New

us I ( 196) 1048 (319)

Old

x.31 (131) 912 (100)

Immediate disabled

and

No@. Withln auditorily

interval. presented

each retention presented items

YY?. (IYh) 104x (210)

l(IIH 111Y

(221) (237)

YOO ( 148) Yl? (IOU)

X18

(111)

x54,

(142)

children

798 (12.5) XSY ( 143) interval. the mean were hased on the

the mean lutencies of new items arc items. The numbers in parentheses

I Day

children

Y93 (247) 1 I IY (277) Nondisablcd

New

IO

latencies of new items for hoth visually same pictures. Thus. for each retention

the \ame represent

for

visually standard

presented deviations.

and

auditorily

word). Subjects were instructed to provide the name and a recognition decision for each of 64 pictures. Each subject was requested to name each picture as rapidly as possible without sacrificing naming accuracy. Naming latencies were obtained through the use of a Gerbrands millisecond clock (Model G1271) and voice-operated relay (Model G1341T). Naming latencies were measured from the onset of the slide until the subject’s vocal response. Immediately following the naming of each picture, they were asked to decide whether or not that item had been presented on the preceding study list by responding “old” or “new.” In addition, for pictures that were judged to be “old” items the subject was also asked to render a decision about the format of presentation for that remembered item. Memory for presentation format was measured by asking the subject to decide if the remembered item had been presented originally as a picture or as a word. In this case, subjects were asked to respond by indicating whether they “saw it” or “heard it.” The experimenter recorded the speed and accuracy of naming and the memory decisions for each picture. RESULTS

Median naming latencies were computed for each subject for pictures named on each of the naming/recognition tests. Table 1 provides the means of the median naming latencies according to each experimental condition. Excluded from analysis were those trials in which there occurred either a machine/procedural error or a naming error. Of the 128 trials that were presented to each subject. a mean of 11.47 trials were eliminated

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as a result of either machine/procedural errors or naming errors. Thus, the subsequent analyses of the naming latencies is based upon a mean of 90.75% of the trials. Machine/procedural errors occurred when there was an equipment malfunction (e.g., slide did not advance from the carousel into the projector), when the timer was terminated prematurely (e.g., subject touched the microphone, made a vocal noise, coughed), or when the timer was not terminated (e.g., subject moved further away from the microphone or spoke in a voice that was not loud enough to activate the voice key). Machine/procedural errors were analyzed in a 2 x 2 x 2 mixed analysis of variance (ANOVA), with population (L/LD or NLD) as the betweensubjects factor, and presentation format (pictures or words) and retention interval (immediate or 1 day) as the within-subjects factors. All effects described as significant in this article involve an (Y level of 0.05, unless otherwise specified. A significantly greater number of machine/procedural errors occurred with L/LD children (M = 2.98) than with NLD children (M = 1.50), F(1, 46) = 9.93, MS, = 10.575. In addition, a greater number of machine/procedural errors appeared on the immediate test (M = 2.59) than on the test that occurred on the following day (M = 1.88). F(1, 46) = 4.33, MS, = 5.558. The criteria used in identifying naming errors on the naming/recognition test depended on whether a given item had been previously presented as a picture or a word. Two criteria were used to identify naming errors of items that had been previously presented as pictures: (1) failing to provide either a dominant or nondominant name in the norms of Snodgrass and Vanderwart (1980). and (2) providing different, yet normatively correct, names for items that were presented on both the study and test lists (old items). For those items that were initially presented as a word, naming errors involved providing a name that differed from that which was used on the preceding study list. Analysis of naming errors revealed that items that had been presented originally as words produced a significantly greater number of naming errors (M = 3.84) than items that had been presented as pictures (M = 3.16), F(1, 46) = 14.094, MS, = 1.561. There were no significant differences in the number of naming errors between L/LD and NLD children, F(1, 46) = 2.187, MS, = 11.336, or between the immediate test and the test on the following day (F < 1). An analysis of overall median naming latencies for old and new pictures was performed (i.e., disregarding hits, misses, correct rejections, and false alarms.)’ Naming latencies were analyzed in a 2 x 2 x 2 x 2 mixed ’ As we note below. there are significant differences between the overall naming latencies of the L/LD and NLD populations. Therefore, one might wish to analyze priming effects as a proportion of overall naming latency, rather than as raw reaction times. Such a decision would be based upon one’s assumption about the performance curves of the two groups.

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ANOVA, with population (L/LD or NLD) as the between-subjects factor, and item type (old or new), presentation format (pictures or words), and retention interval (immediate or 1 day) as the within-subjects factors. The effects of population, F(1, 46) = 14.0, MS, = 209731.22. and item type, F(1, 46) = 51.54, MS, = 9629.431, were each significant, as was their interaction, F(1. 46) = 5.30. MS, = 9629.431. The population x item type interaction was examined further by testing separately the effects of item type with each population. Simple effects tests revealed that both L/LD and NLD children named old items significantly faster than new items, F(1, 95) = 42.11, MS, = 10282.8 and F(1, 95) = 32.69. MS, = 350.955, respectively. As will be shown in the forthcoming analysis of the magnitude of priming, this two-way interaction was the result of a greater priming effect with L/LD children (M = 95 ms) than with NLD children (M = 48 ms). The population variable also interacted with retention interval, F( 1, 46) = 14.89. MS, = 18449.914. The population x retention interval interaction was examined by testing separately the effects of retention interval with each population. Simple effects tests indicated that, relative to naming Iatencies on the immediate test, the latcncies of NLD children became faster on the following day, F( 1, 95) = 26.56, MS, = 5445.921. In contrast, the naming latencies of L/LD children became slower on the following day, F(1, 95) = 10.61, MS, = 12281.91. These changes in performance may reflect motivational differences between the two populations. Despite these differences in naming speed across retention interval, the amount of priming was stable for both groups, with L/LD continuing to show greater amounts of priming than NLD children on the following day (the population x retention interval x item type interaction yielded an F < 1). The effect of presentation format was significant, F(1. 46) = 12.46, MS, = 2863.863, and interacted with item type, F(1, 46) = 12.46. MS, On the one hand. one might belicvc that the two groups share the same cognitive processes and simply occupy different places on the performance curve at a given point in time. Thus, equal changes in activation of central representations as a result of priming might lead to greater changes in reaction time for L/LD than for NLD children. This is similar to a Hoor effect in which the faster naming latencies of NLD children make it impossible for them to benefit as much as L/LD children from identical effects of priming. Alternatively, one might believe that the two groups occupy two different performance curves. That is, in addition to different overall reaction times. the two groups share different floors. Thus. one might expect the changes in reaction times to he the same across groups in spite of their different means. We feel uncomfortable asserting either position on the basis of the present state of theory on the nature of differences between LD and NLD populations. Therefore. we prefer to analyze the data directly. rather than run the risks inherent in interpreting transformed data. However, if an analysis is conducted using the proportion of mean reaction times as a dependent variable. the results are substantially the same, with one exception. The effect of population on the magnitude of priming effects that is significant in our analysis becomes a trend, F(l. 16) = 2.73. MS, = .OlS. 11 = .I())

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120 i; I !t

110

.-!? .-E L

60

%

50

B 3 .Zc

30

2

20

I

n

Immediate

100 90 70 60

40

10 0 LlLD

Nm

POPULATION

FIG. 1. Repetition priming (new minus old picture naming latencies) as a function of population and retention interval.

= 2863.868. The presentation format x item type interaction was analyzed further by testing separately the effects of item type with both pictures and words. Simple effects tests indicated that old items were named significantly faster than new items with both presentation formats (F(1, 95) = 68.42, MS, = 5833.446, for pictures and F(1, 95) = 16.38, MS, = 8112.591, for words). As will be shown in the analysis of the magnitude of priming, this presentation x item type interaction is the result of pictures priming pictures (M = 91 ms) more that words priming pictures (M = 53 ms). The magnitude of priming was assessed by subtracting the median naming latencies of old pictures from the median latencies of new pictures for each subject (e.g., Mitchell et al., 1990). An analysis of these difference scores again revealed that the magnitude of the priming was significantly greater with L/LD children than with NLD children, F(1, 46) = 5.45, MS, = 19141.922. As with the preceding analysis, pictures primed pictures significantly more than words primed pictures, F(1, 46) = 12.65, MS, = 5791.181. No other main or interactive effects were significant. With the exception of the presentation format x retention interval interaction, F( 1, 46) = 2.15, MS, = 5639.21, p < .15, all remaining Fs were less than 1. Notable here is that retention interval did not have a significant effect upon the magnitude of repetition priming for either L/LD or NLD children. Figure 1 plots the magnitude of priming that was observed with L/LD and NLD children at each retention interval. Recognition Memory

Recognition performance was analyzed within the framework of signal detection theory. Table 2 provides the means of the various signal de-

134

LORSBACH,

MEANS ANU STANDARII

DEVIAIWNS

SODORO,

AND BROWN

TABLE 2 (IN PARENTHESES)

OF SIGNAL

DETWTION

Pictures Recognition score

Hit rate False alarm d' score beta scow

Word:.

Immediate

rate

I Day

Language/learning .‘)I (.I()) .I0 (.Il) 7.87

(.7(b)

.lY (1.05)

disabled (.I’)) ,I3 (.I?) I.YX (.7X) .6X ( I .()I ) .7'

Nondisablcd Hit rate False alarm d'

rate

score

(.07)

.os

(.OS)

3.35

beta score Nore.

.Yh

Means

.I7

(52)

SCORU

2.61

for the beta scores arc based

I Day

children .7' (-19) .I(1 (.II) 2. I4 (.77)

.x5 (.YY)

.is (.7S, .I3 (.l7) .X6 .h7

(.X5) (.97)

children .xs .(IX

(.72)

Immediate

.s3

(.I?) (47)

.XI (.l5)

.4x (3)

.os (.OS)

.0x

(.SY)

2.67 (.6S) .YO (.73)

(.77)

on natural

logarithm

(47)

I.44 (.6’) .YX (.hl)

values

tection measures according to presentation format and retention interval for both L/LD children and NLD children. The critical measure in signal detection analysis involves the calculation of d’ which provides a measure of the subject’s ability to discriminate old from new items. The higher the d’ value, the more sensitive the subject’s memory in detecting old items in the presence of new items. The d’ scores were submitted to a 2 x 2 x 2-mixed-design ANOVA. with population (L/LD or NLD) as the between-subjects factor, and presentation format (pictures or words) and retention interval (immediate or 1 day) as the within-subjects factors. The recognition performance of NLD children produced d’ scores (M = 2.52) that were significantly larger than those of L/LD children (A4 = 1.96), F(1, 46) = 13.02. MS, = 1.154. The effects of presentation format, F( 1, 46) = 165.40, MS, = .247, and retention interval, F(1, 46) = 133.58, MS, = ,385, were each significant, as was their interaction. E( 1. 46) = 14.38, MS, = 163. This interaction was examined further by testing separately the effects of retention interval with each presentation format. Simple effects tests revealed that as retention interval was lengthened there were significant amounts of forgetting with both pictures, F(1, 47) = 68.96. MS, = .231, and words, F(1, 47) = 122.67, MS, = ,309. The presentation format x retention interval interaction is therefore due to the fact that the magnitude of the retention interval effect is greater with words than with pictures. The differences in recognition performance between L/LD and NLD children may be seen in Fig. 2 which plots the the d’ scores of each population according to presentation format and retention interval. Rc-

PRIMING

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IN L/LD

ULD 4.0

135

CHILDREN

NLD

4.0

1

3.5 30 25 20

00 lmmedlale

FIG. interval

2. and

Recognition presentation

performance format.

(8)

for

each

population

1

as a function

clay

of

retention

gardless of presentation format or retention interval, the recognition performance of L/LD children was reliably lower than that of NLD children. These results are in direct contrast to those obtained with priming, where the magnitude of repetition priming was larger with L/LD children than with NLD children. The recognition and the priming results also differ in that recognition performance declined as retention interval was lengthened, whereas the magnitude of priming remained stable. Priming and Recognition Memory Perceptual fluency (i.e., the ease with which a picture is named) may form the basis of recognition decisions (Johnston, Dark, & Jacoby, 1985). If perceptual fluency is used as a guide for recognition decisions, then items judged “old” should be named faster than those judged to be “new,” regardless of whether the item was a repetition. That is to say, for pictures that are readily named, subjects should tend to judge them as “old” regardless of whether that item had been presented previously. Therefore, naming latencies should be faster for hits than for misses and for false alarms than for correct rejections (Johnston et ul., 1985). The relationship between naming speed and recognition memory was examined following the procedures that were used by Mitchell et al., (1990). In the first set of analyses, the naming speed of old items (hits and misses) were compared to determine whether the recognition decisions of either L/LD or NLD children were based on perceptual fluency. In addition, the magnitude of priming associated with hits and misses was compared to determine if a dissociation exists between priming and recognition memory for L/LD or NLD children. The second analysis examined whether naming speed varied with the accuracy with which new pictures were detected. Table 3 provides the naming latencies of both old (hits and misses) and new (correct rejections and false alarms) items.

136

LORSBACH,

MEAN

OF MEDIAN

NAMING

SODORO,

LA~ENCIES

TABLE 3 ot L/LD

RECOGNITION

Old Population

Hits

L/LD Trials NLD Trials _~-

Y93 (213) 3h.3 (X.9) x40 (126) 43 (S.0) ~~~~ ~~

~~-

-~

AND

AND

BROWN

NLD

CHILDREN

items

New Misses 0x2 17.4 x20 12.4

ACCORDING

TO

DECISION

(lY6) (X.7) (17Y) (5.6)

NOW. The numbers in parentheses rcprcsent standard FA, false alarms; Trials. mean number of trials.

items

CR 1043 ‘IS.4 ‘)2x 51.81 deviations.

FA

(151 ) (7.5) (X9) (3.7) CR.

1042 Y.? Y74 5.x correct

(264) (43) (210) (2.5)

rejections;

Priming in hits a& Moses. Consistent with Mitchell et (11. (199(I), only those subjects who had at least four reaction times for both hits and misses were included in the analysis. All of the subjects in each population met this criterion. However, in order to obtain the minimum number of observations for each subject, it was necessary to collapse across the variables of presentation format and retention interval. The means of the medians for old latencies were submitted to a 2 x 2 mixed ANOVA, with population (L/LD or NLD) as the between-subjects factor and old item type (hit or miss) as the within-subjects variable. As expected. L/LD children named old items significantly slower than NLD children, F( 1,46) = 11.47, MS, = 51947.49. Neither the effect of old item type or the population x old item type interaction was signihcant (both Fs < 1). Thus, for both L/LD children and NLD children naming latencies did not vary according to whether old items were remembered or forgotten.

G

110

x

100

5

90

.-P

80

.-E 2

70 60

z

50

G x .$

40

IF I

20

30

10 0

POPULATION FIG.

3.

Repetition

priming

as a function

of population

and old item

type

(hit or miss).

PRIMING

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RECOGNITION

MEMORY

IN L/LD

CHILDREN

137

The relation between priming and recognition memory was examined by comparing the amount of priming that occurred with hits (new latencies minus hit latencies) and misses (new latencies minus miss latencies). These priming values are graphically displayed in Fig. 3. Overall, LD children exhibited a significantly greater amount of priming (A4 = 96 ms) than did NLD children (M = 56 ms), F(1, 46) = 4.14, MS, = 9428.6. However, the magnitude of priming did not depend on whether old items were remembered or forgotten (F < 1). In addition, the population x old item type interaction failed to reach significance (F < 1). Together, these results indicate that the magnitude of priming did not vary significantly with the conscious recognition of old items for either L/LD or NLD children. Naming speed for correct rejections and false alarms. Consistent with the criterion used in the preceding analysis, each subject needed at least four correct rejection latencies and four false alarm latencies to be included in the analysis. It was necessary to again collapse across the variables of presentation format and retention interval in order to obtain a sufficient number of subjects in each population. Because of so few false alarms, only a total of 11 L/LD and 14 NLD children could be used in this comparison. There were no significant main or interactive effects of population or type of new item. Because of the relatively few subjects used in this analysis, a lack of power may have contributed to the failure to find significant differences. Mernory for Presentation

Format

Each subject’s ability to remember presentation format was based upon a discrimination score. These discrimination scores were calculated by adding the number of items that were correctly identified as ones that had been previously seen plus the number of items that the subject correctly identified as ones they had previously heard and dividing this sum by the total number of old items that were remembered by the subject (hits). L/LD and NLD children did not differ significantly in their memory for presentation format, F(1, 46) = 1.34, MS, = 0.13, M = .85 and .88, respectively. For both populations, there was a decline in memory for presentation format between the immediate test (M = .91) and the test administered on the following day (M = .82), F( 1, 46) = 24.46, MS, = ,007.

False positives and new items that somehow seem familiar to the subject and are mistakenly judged as being old. When making source attributions of false positives, children appear to develop certain decision rules that are similar to those used by adults (Foley, Johnson, & Raye, 1983). Rather than indicating that they had generated the item, both children and adults tend to attribute “familiar” items to an external source. Lorsbach, Melendez, and Carroll-Maher (1991) recently found that LD and NLD children exhibit a similar developmental pattern in their source attributions

138

LORSBACH,

SODORO.

AND

BROWN

of false alarms. The attributions of false positives were analyzed in the current study to provide additional information about the decision rules that are used by L/LD and NLD children when dealing with false positives. The number of false positives for each subject was computed for each subject and submitted to a 2 (population) x 2 (retention interval) x 2 (presentation format) ANOVA. L/LD children (M = 1.63) committed a significantly greater number of false positives than NLD children (M = .Y7), F(1, 46) = 3.99, MS, = 5.34. All subjects committed more false positives following a l-day retention interval (M = 1.54) than when tested immediately (M = 1.06). F(1, 46) = 6.38, MS, = 1.726. For both L/LD and NLD children, false positives were misidentified significantly more often as words (M = 1.64) than as pictures (M = .YS), F(1, 46) = 9.09, MS, = 2.494. DISCUSSION

The present investigation found that repetition priming and recognition memory were dissociated in several important ways. First, the comparison of L/LD children and NLD children revealed a crossover dissociation between repetition priming and recognition memory. Although L/LD children exhibited a significantly greater amount of priming than NLD children, the reverse was true on the recognition task, where the performance of NLD children was superior to that of L/LD children. Second, repetition priming and recognition memory were dissociated as a function of retention interval. For both L/LD children and NLD children, rccognition performance declined between the two retention intervals, whereas the magnitude of repetition priming remained stable. A similar dissociation emerged between repetition priming and memory for presentation format. Third, the amount of priming was independent of recognition memory in both groups of children. Population

Effects

Finding that the performance of L/LD children and NLD children is dissociated on tasks measuring repetition priming and recognition memory is consistent with the results of a previous study by Lorsbach and Worman (1989). These investigators found that LD children remembered significantly less information than NLD children when memory was measured “explicitly” (cued recall and free recall), but not when memory was measured “implicitly” (picture-fragment completion). A possible criticism of their study is that such a dissociation could have been due to differences in the amount of retrieval support between the explicit tasks and the implicit task. Craik (1986) has argued that traditional memory tasks require retrieval efforts that are initiated by the subject, whereas implicit measures demand little effort in that retrieval is determined largely by the stimuli and their characteristics. The dissociation found by Lorsbach

PRIMING

AND RECOGNITION

MEMORY

IN L/LD

CHILDREN

139

and Worman (1989) between LD and NLD children could have been due to the fact that the recall tasks and the fragment-completion task used different stimuli and required different amounts of retrieval effort. Such a criticism may not be directed at the present study because the same stimulus (picture) was used for measuring priming effects and recognition memory (cf Mitchell et al., 1990). Perhaps the most general conclusion about the dissociation between L/LD children and NLD children on explicit and implicit measures of memory is that the memory problems of L/LD children are not general in nature, but rather are restricted to more traditional measures of memory. Such a conclusion, however, needs to be qualified by the fact that L/LD and NLD children did not differ in their memory for presentation format. Performance on this task required the conscious examination of information held in memory and thus qualifies as an explicit measure of memory. The relatively high level of performance by both groups of children suggests that a ceiling effect may have played a role in the failure to find differences between L/LD and NLD children. The task of discriminating pictures and spoken words may be too easy and therefore insensitive to individual differences. The deficits of L/LD on traditional memory tasks may be limited more difficult tasks that demand relatively greater amounts of retrieval effort. Retention Interval Effects

The results of the present study suggest that primed picture-naming is a relatively long-lasting and stable phenomenon for both L/LD and NLD children. Noteworthy is that the priming effect was equally persistent for both L/LD and NLD children. A persistent and stable priming effect is consistent with much of the research with adults. In particular, studies that have examined the stability of primed picture-naming in adults have found that although the priming effect may decline at very brief intervals, ranging from seconds to minutes, priming remains stable from 1 day to as long as 6 weeks (Durso & Johnson, 1979; Mitchell, 1989; Mitchell & Brown, 1988; Mitchell et al., 1990). Based on the previous studies of adults, and given the present findings, it would appear that the stability of primed picture-naming is a phenomenon that is developmentally insensitive. In addition, our results further indicate that primed picturenaming is stable over time for both L/LD children and NLD children, regardless of whether primes are presented in the form of pictures or words. Future research will want to determine whether the magnitude of priming remains stable or declines at longer retention intervals with children of different ages and whether such priming effects have a different developmental course in L/LD children. The stability of the priming effect over time is in marked contrast to the decline that was observed on the explicit measures of recognition

140

LORSBACH,

SODORO,

AND

BROWN

memory and memory for presentation format. Such declines in performance over time are typical for both adults and children on explicit measures of memory. The fact that retention interval had a comparable effect on the memory performances of both L/LD and NLD children indicates that the accessibility of information declines at a similar rate in both populations. Independence

of Primed Picture-Naming

and Recognition

Memory

The analysis of the relationship between repetition priming and recognition memory revealed that for both L/LD children and NLD children, the magnitude of priming was independent of whether old items were remembered (hits) or forgotten (misses). Such independence between priming and recognition memory has previously been found with younger adults (e.g., Jacoby & Witherspoon, 1982; Mitchell & Brown, 1988; Tulving et al., 1982) and in comparisons of younger and older adults (Mitchell et af., 1990). The present findings extend the results of these earlier studies and suggest that priming and recognition memory are independent in children as well as adults. There are occasions in which priming may influence recognition decisions. If a picture’s name is retrieved rapidly, the subject may use this information to decide that the item had been seen previously. Jacoby has argued that the ease with which an item is processed may be used in a form of recognition memory that he refers to as “perceptual fluency.” Recognition judgments that are based on an item’s perceptual fluency are characterized by fast, automatic modes of responding that are subject to error and are not easily justified (Jacoby & Brooks, 1984). Several studies of adults have provided evidence for such a fluency effect in adults by finding that, relative to correct rejections, false alarms are associated with faster naming latencies (Johnston et al., 198.5; Mitchell & Brown, 1988; Mitchell et al., 1990). Earlier in this paper, we indicated that perceptual fluency may also be manifested when “hits” are named faster than “misses.” The influence of perceptual fluency might have been more likely in the present study because an item-by-item procedure was used in which recognition decisions immediately followed naming responses. However, there was no evidence that either L/LD children or NLD children based their recognition decisions on perceptual fluency in the present study. Rather, both groups of children appear to have been using a second form of recognition memory that Jacoby refers to as “autobiographical.” Judgments based on the autobiographical component focus on conscious efforts to retrieve details of the original episode. Given the relatively poor performance of L/LD children in the present study, it would appear that the autobiographical component of recognition memory is deficient in L/LD children.

PRIMING

AND

Effects of Presentation

RECOGNITION

MEMORY

IN L/LD

CHILDREN

141

Format

As expected, pictures produced a greater amount of priming and were remembered better than words in both populations. Of particular interest in the present study was the effect of presentation format on repetition priming. The fact that pictures yielded more priming than words is consistent with studies of adults (e.g., Brown, Neblett, Jones, & Mitchell, 1991; Durso & Johnson, 1979; Durso & O’Sullivan, 1983). Although the magnitude of priming was substantially reduced, words also produced a significant amount of priming at each retention interval and with both populations. This latter finding is significant in that it indicates that transfer effects in repetition priming are not only durable in children, but are insensitive to the effects of a language/learning disability. Theoretical

Implications

We believe that the present findings are interpreted best within Tulving’s (1985, 1987) multiple-memory systems framework. According to Tulving (1985). memory consists of the monohierarchical arrangement of procedural memory, semantic memory, and episodic memory. An important implication of this monohierarchical arrangement is that “more specialized systems should be most affected by factors detrimental to memory” (Mitchell et al., 1990, p. 265). Thus, rather than having a generalized effect on all three memory systems, variables that have an adverse effect on memory may only involve the more specialized subsystems of episodic memory or semantic memory. The dissociations that were found in the present study support this observation. Performance on an episodic memory task (item recognition) was reduced by the presence of a language/learning disability, as well as by an increase in retention interval, whereas performance on procedural memory task (primed picture-naming) was unaffected. In addition, the dissociation between recognition memory and repetition priming indicates that episodic and procedural memory systems are independent. Neither of the two remaining theories provides an adequate account of the current data. The activation position cannot explain why the magnitude of repetition priming remained at the same level across the two retention intervals. Because level of activation is presumed to decay with time, activation theory would have predicted a decline in the magnitude of priming. The transfer-appropriate processing view (e.g., Roediger & Blaxton, 1987a, b; Roediger et al., 1989a, b) also has difficulty explaining the current findings. For example, the processing view cannot explain why priming and recognition memory were dissociated in L/LD children and NLD children, nor can it account for the dissociation between repetition priming and recognition memory as a function of retention interval. It would seem that the processing view offers a reasonable explanation

142

LORSBACH.

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AND

BROWN

for the effects of stimulus variation on the magnitude of priming. The processing view is based on the premise that the match of processing operations during study and test is critical, especially for performance on data driven tests. The current study seems to reinforce this observation by finding that the magnitude of priming was greater when pictures primed pictures, than when words primed pictures. In addition, alterations of the study-test presentation format exerted a similar effect upon recognition performance. Although such results are common in the literature and are often used to support the processing viewpoint, a recent series of experiments by Brown et al. (1991) suggests that such a conclusion may be limited to a within subjects design. Brown and his colleagues used both within- and between-subjects designs to examine how stimulus variations between study and test (words and pictures) affect repetition priming and recognition memory. When a within-subjects design was used the typical results were obtained, with the magnitude of priming being greater when the prime and test stimuli matched each other physically, compared to when they were mismatched. However, when a between-subjects design was employed the type of format that was used to present the prime had no effect on the magnitude of priming. These differences in priming were unrelated to recognition memory; picture primes were always remembered better than word primes. In interpreting their results, Brown et al. (1991) suggested that priming may consist of both perceptual and lexical dimensions. Attention to the perceptual or lexical dimensions of the primng stimuli often is determined by the manner in which the primes arc presented in a given study. When a study (such as the present one) varies the format of prime stimuli within the same presentation list, the perceptual differences among the different primes are presumably highlighted. Consequently, performance on “the subsequent test will yield transfer-appropriate asymmetries that are related to the physical match or mismatch between prime and test stimuli” (Brown et al., 1991, p. 523). The observations of Brown et ul. (1991) suggest, therefore, that the within-subjects manipulation of presentation format was responsible for the asymmetrical transfer effects in the current study. As the result of using a blocked presentation format, the attention of both L/LD children and NLD children was presumably directed at the perceptual dimensions of primes. Consequently. performance on the subsequent test lists resulted in greater priming when there was a perceptual match between primes and test stimuli (i.e., pictures primed pictures more than words primed pictures). On the other hand, performance was not entirely based on priming of the perceptual dimension. The fact that word primes facilitated the subsequent naming of pictures suggests that the lexical activation of word units was also involved. Noteworthy is that these perceptual and lexical dimensions affected the priming performance of L/LD and NLD children in a comparable manner. In fact. L/LD children actually cxperienced more priming than NLD children.

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Finding that L/LD children demonstrate more priming than NLD children was an unexpected result. Assuming that this difference is real (see Footnote l), we are unaware of any theoretical position that would have predicted greater priming in L/LD children. However, results of this sort are not entirely without precedence in the individual differences literature. For example, Howard (1988) found a nonsignificant trend toward superior procedural memory performance with older adults compared with younger adults. CONCLUSIONS

The memory dissociations that were found in the present investigation provide further evidence for the existence of a multiple-memory system (Tulving, 198.5, 1987). In addition, the present findings indicate that although procedural memory is unaffected, episodic memory is impaired in L/LD children (cf Lorsbach & Worman, 1989, 1990). In this case, L/LD children apparently are able to reaccess perceptual and lexical dimensions of prior stimulus events, but experience significant difficulty in accessing information that pertains to an event’s prior occurrence. Applying Donnelly’s (1988) distinction between procedural and episodic memory, L/LD children gain knowledge from prior stimulus events, but they may not always display knowledge of those events. REFERENCES Baucr, R. H. (lY77). Memory processes in children with learning disabilities: Evidence for deficient rehearsal. Journal of E.xprrimental Child I’sycholog.y, 24, 415-430. Blaxton, T. A. (1989). Investigating dissociations among memory measures: Support for a transfer-appropriate processing framework. Journal of Experimental Psychology: Leurnkg, Memory, and Cognition, 15, h57TMS-4. Brown. A. S., Neblett, D. R.. Jones. T. C., & Mitchell. D. B. (1YYl). Transfer of processing in repetition priming: Some inappropriate findings. Journal of Experimental P.~ycholo,q~y: Leurning, Memory. and Cognition, 17, 513-525. Carroll. M.. Byrne, B., & Kirsner, K. (108). Autobiographical memory and perceptual learning: A developmental study using picture recognition. naming latency, and perceptual identification. Memory & Cognition. 13. 273-27’3. Ceci, S. J. (1983). Automatic and purposive semantic processing characteristics of normal and language/learning disabled (L/LD) children. L)evelopmentocll Ps~holo~~, 19, 427‘x39. Ccei. S. J. (1984). A developmental study of learning disabilities and memory. Jourrud of Experimental Psychology. 38, 352-37 1 Ccci. S. J., Lea, S. E. G., & Ringstrom. M. D. (1980). Coding characteristics of normal and learning disabled IO-year olds: Evidence for modality-specific pathways to the cognitive system. Journui of Experimental I?~ychology: Human Lrurning and Mamory. 6, 7X5-797. Cohen. N. J. (IYX4). Preserved learning capacity in amnesia: Evidence for multiple memory systems. In L. R. Squire & N. Butters (Eds.). Nertropspcholop of memory (pp. H3103). New York: Guilford Press. Cohen, N. J., & Squire, L. R. (19X0). Preserved learning and retention of pattern-analyzing skill in amnesia: Dissociation of knowing how and knowing that. Science. 210. 207210.

144

LORSBACH.

SODORO.

AND

BROWN

Craik,

F. I. M. (1986). A functional account of age differences in memory. In F. Klix Sr H. Hagendorf (Eds.), Human memory and cognitive capahiliries. Amsterdam: Elsevier. Donnelly, R. E. (1988). Priming across modaliry in implicit memory: Fucilitution from auditory presentatiotz lo v&al Tess of word frugmenf complefion. Unpublished Doctoral dissertation, University of Toronto. Durso, F. T., & Johnson. M. K. (1979). Facilitation in naming and categorizing repeated pictures and words. Journal of Experimental Psychology: Human Learning and Memory. 5, 449-459. Durso. F. T., & O’Sullivan, C. S. (1983). Naming and rememhcring proper and common nouns and pictures. Journal of‘Experimmtu1 Psychology: Learning, Memory, and C’ogtfifion,

9, 497-510.

Foley,

M. A.. Johnson. M. K.. & Raye, C. L. (lY83). Age-related changes m confusion between memories for thought and memories for speech. Child Developmenl, 54, Sl60. Graf, P., & Mandler, G. (1984). Activation makes words more accessible, but not ncccssarily more retrieveable. Journal of Verhul Leurning and Verbal Behavior. 23, 553-561;. Graf. P., Mandler. G.. & Haden, P. (1982). Simulating amnesic symptoms in normal subjects. Science, 218, 1243-1244. Graf, P.. & Schacter. D. L. (1985). Implicit and explicit memory for new associations in normal and amnesic subjects. Journal of E.rperimental Pqchology: Leurning, Memory, and Cognirion. 11, 501-51X Graf, P.. Shimamura, A. P., & SquIrc, L. R. (19X5). Priming acruss modalities and priming across category levels: Extending the domain of preserved function in amnesia. Jourtzuf of Experimentul Psychology: Leurning, Memorv. und Cognirion. 11, 386-396. Graf, P.. Squire. L. R.. & Mandler. G. (IYX4). The information that amnesic patients do not forget. Journal of Experitnenlal I’sychology: Learning, Memory. rmd Cogtzibon. LO, 164-17X. Howard. D. V. (1988). Implicit and explicit assessment of cognitive aging. In M. L. Howe & C. J. Brainerd (Eds.), Cognilive developmettr in ad&hood: Progress in cqtziriw de,~elopment research (pp. 3-37). New York: Springer-Verlag. Jacoby. L. L. (1983). Perceptual enhancement: Persistent effects of an expericncc. Jourtud of E.xperitnental P.yychology Learning, Memory, and Cognition, Y, 71-3X. Jacoby, L. L.. Sr Brooks. L. R. (1’184). Nonanalytic cognition: Memory, perception. and concept learning. In G. H. Bower (Ed.), The psychology of Learning und tno~ivuriot~: Advances in reJearclz and theory (Vol. 18, pp. l-47). New York: Academic Press. Jacoby, L. L.. Kr Dallas. M. (1981). On the relationship between autobiographical memory and perceptual learning. Journul of Experimentul Psychology: Getteral, 110, 336-340. Jacoby, L. L.. & Hayman. C. A. G. (19X7). Specific visual transfer in word identification. Journal of Experimental Psychology: Learning. Metnorv. und (‘ognirion. 13, 456-46.X Jacoby, 1.. L.. & Witherspoon. D. (1982). Remembering without awareness. Cunudrurl Journul

Jastak,

of Psychology.

36.

XJO-324.

S.. & Wilkinson. G. S. (1984). Admitbtrutiott mamud: Wide Range Achwwmrw Te.wRevised. Wilmington. DE: Jastak Assoc. Johnson, M. K.. & Hashcr. L. (lYX7). Human learning and memory. Ann& Rrvlc,rra o/ Psychology. 38, 631-66X. Johnston, W. A.. Dark, V. J., & Jacuby. Ia. I,. (IYXS). Perceptual fluency and recognition judgments. Jourrml of Experimenlul I’swhology: l,earnin,g. Memory. and Cognitiotz. Il. 3-11. Kirsner, K.. Milech, D.. & Standcn, P. (IYX3). Common and modality-spccilic procrssc\ in the mental lexicon. Memory & (‘ogt~ikm, 11, 621-630 Kirsner. K.. & Smith, M. C. (lY74). Modality cffccts in word identitication. Metnor~ & c’ogtliiiotl. 2, 637-640.

PRIMING

AND

RECOGNITION

MEMORY

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CHILDREN

145

Lewandowsky, S., Dunn, J. D., & Kirsner, K. (1989). Implicit memory: Theoretical issues. Hillsdale, NJ: Erlbaum. Light, L. L., Singh, A., & Capps, J. L. (1986). Dissociation of memory and awareness in young and older adults. Journal of Clinical and Experimental Neuropsychology, 8, 6274. Lorsbach. T. C. (1980). Individual differences in semantic encoding processes. Journal of Learning Disabilities, 15, 476-480. Lorsbach, T. C., & Gray, J. W. (1985). The development of encoding processes in learning disabled children. Journal of Learning Disabilities, 18, 222-227. Lorsbach. T. C., Melendez, D. M.. & Carroll-Maher, A. (1991). Memory for source information in children with learning disabilities. Learning and Individual Dijference.s. 3, 135-147. Lorsbach, T. C.. c(c Morris, A. K. (1991). Direct and indirect testing of picture memory in second and sixth grade children. Contemporary Educational Psychology, 16, 18-27. Lorsbach. T. C., & Worman. L. J. (1989). The development of explicit and implicit forms of memory in learning disabled and nondisabled children. Contemporary Educational Psychology, 14, 67-76. Lorsbach, T. C.. & Worman. L. J. (1990). Episodic priming in children with learning disabilities. Contemporary Educational Psychology, 15, 93-102. Mandler, G. (1980). Recognizing: The judgment of previous occurrence. P.yychoioglcal Review. 87. 252-271. Mandler, G.. Graf, P.. & Kraft, D. (1986). Activation and elaboration effects in recognition and word priming. Quarterly Journal of Experimental Psychology, 38, 645-662. Mitchell. D. B. (1989). How many memory systems? Evidence from aging. Journal of Experimental Psychology: Learning, Memory, and Cognition, 15. 3 I-49. Mitchell, D. B., & Brown. A. S. (1988). Persistent repetition priming in picture naming and its dissociation from recognition memory. Journal of Experimental Psychology: Learning. Memory. and Cognition, 14, 213-222. Mitchell, D. B., Brown, A. S.. & Murphy, D. R. (1990). Dissociations between procedural and episodic memory: Effects of time and aging. Psychology and Aging, 5, 264-276. O’Kcefe. J., & Nadel, L., (1978). The Hippocampus as a cognitive map. Oxford: Clarendon Press. Parkin, A. J., & Streete. S. (1988). Implicit and explicit memory in young children and adults. British Journal of Psychology, 79, 363-369. Richardson-Klavehn. A., & Bjork. R. A. (1988). Measures of memory. Annual Review of Psychology, 39, 475-543. Roediger. H. L.. & Blaxton, T. A. (1987a). Effects of varying modality, surface features. and retention interval on priming in word-fragment completion. Memory & Cognition,

15, 379-388. Roediger. H. L., & Blaxton. T. A. (1987b). Retrieval modes product dissociations in memory for surface information. In D. S. Gorfein & R. R. Hoffman (Ed%), Memory und learning: The Ebbinghaus centennial conference (pp. 349-379). Hillsdale, NJ: Erlbaum. Roediger. H. L., Srinivas. K., & Weldon, M. S. (1989a). Dissociations between implicit measures of retention. In S. Lewandowsky. J. C. Dunn. and K. Kirsner (Eds.). Implicit memory.. Theoretical issues (pp. 67-84). Hillsdale. NJ: Erlbaum. Roediger. H. L.. Weldon, M. S., & Challis, B. H. (lY8Yb). Explaining dissociations between implicit and explicit measures of retention. In H. L. Roediger & F. 1. M. Craik (Eds.), Varieties of memory and consciousness: Essays in honor of Endel Tulring (pp. 3-41). Hillsdale, NJ: Erlbaum. Roediger. H. L.. Kr Weldon. M. S. (lY87). Reversing the picture superiority effect. In

146

LORSBACH. M.

A.

McDaniel

Theories.

individual

&

M.

Psychology:

Pressley

differences,

Verlag. Scarborough, D. L.. Gerard, transfer of word repetition 3-12. Schacter. D. L. (IYX7). Implicit Leurning,

SODORO.

and

AND

BROWN

(Eds.), Imugery and reluted upplications (pp. 15 1- 174).

mnemomc New York:

processes:

Springer-

L., & Cortesc, C’. (107’)). Accessing lexical memory: effects across task and modality. Mamory & Cognition. memory:

Memory.

History und

Chgnition,

and current status. Jottrnul 13, 501p5 1X.

The 7,

of.!kpertmentul

Semel, E.. & Wiig. E. (1987). Clinical Evaluation of Lunguage ~tlndarnr,ntuls-Revi.~rd. San Antonio: The Psychological Corp. Shimamura. A. P. (1986). Priming effects in amnesia: bvidencc for a dissociable memory function. Quarterly Journal of Experimented Psychology. 38A, hlY~h44. Snodgras5, J. G.. & Vanderwart, M. (19X0). A standardized set of 760 pictures: Norms fol name agreement, image agreement. familiarity, and visual complexity. Jorrrnul of I% perimentul Psychology: Human Lectrning und Memory, 6, 174-2 15. Squire. L. R.. Kr Cohen. N. J. (19X4). Human memory and amnesia. In