The Journal of General Psychology

ISSN: 0022-1309 (Print) 1940-0888 (Online) Journal homepage: http://www.tandfonline.com/loi/vgen20

Visual Similarity Effects in Detecting Letter Rhymes Steven G. Zecker To cite this article: Steven G. Zecker (1990) Visual Similarity Effects in Detecting Letter Rhymes, The Journal of General Psychology, 117:2, 171-179, DOI: 10.1080/00221309.1990.9921134 To link to this article: http://dx.doi.org/10.1080/00221309.1990.9921134

Published online: 06 Jul 2010.

Submit your article to this journal

Article views: 6

View related articles

Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=vgen20 Download by: [NUS National University of Singapore]

Date: 06 November 2015, At: 23:53

The Journal a/General Psychology. 117(2), 171-179

Downloaded by [NUS National University of Singapore] at 23:53 06 November 2015

Visual Similarity Effects in Detecting Letter Rhymes STEVEN G. ZECKER

Program in Learning Disabilities Northwestern University

ABSTRACT. Previous demonstrations of "visual" effects in auditory tasks have been largely restricted to orthographic effects with word stimuli. As a result, explanations of such effects have centered around a shared orthography-the similarity of the spelling patterns at the ends of the words. In the present study, these effects were extended to single-letter stimuli. Subjects made rhyming decisions about pairs of letters presented auditorily. Visually similar letter pairs facilitated responses to rhyming pairs and inhibited responses to nonrhyming pairs. The results indicate that visual effects are not restricted to word stimuli and suggest that additive effects of visual similarity and shared orthography may be responsible for these findings.

RECENT RESEARCH in memory and word identification has pointed to the existence of multiple codes that become activated during various types of linguistic processing. Such codes presumably contain or provide access to information about a word's orthographic, phonological, and semantic characteristics. One kind of evidence supporting the existence of multiple codes has been the counterintuitive finding that a code can be activated even though it is in a modality different from that which the task seemingly requires. For example, Conrad (1964, 1972) showed that subjects exhibited sound-based confusion about visually presented letters and words during both recall and recognition

This research was partially supported by Northwestern University Research Grant 0100-51O-05XA.

1 thank Michael K. Tanenhaus, Douglas J. Herrmann, Seth Greenberg, and an anonymous reviewer for their helpfulcomments. Requestsfor reprints shouldbe sent to Steven G. Zecker, Northwestern University, Program in Learning Disabilities, The Frances SearleBuilding, 2299 Sheridan Road, Evanston, 1L 60208. 171

172

The Journal of General Psychology

Downloaded by [NUS National University of Singapore] at 23:53 06 November 2015

tasks. Phonological coding in the perception or memory of visually presented stimuli has been found in many other types of tasks: short-term memory (Baddeley, 1966; Hintzman, 1967; Glassman, 1972), lexical decisions (Meyer, Schvaneveldt, & Ruddy, 1974), and reading (Baron, 1976). More recently, a complementary effect has been demonstrated: An orthographic code becomes available during an auditory task that requires a purely acoustic analysis of the stimulus. In the first demonstration of this orthographic effect, Seidenberg and Tanenhaus (1979) required subjects to detect, from a set of three target words, the word that rhymed with a cue word. They found that response latencies were slower for orthographically dissimilar rhymes (e.g., dune-moon) than for orthographically similar rhymes (e.g., dune-tune). Subsequent research examining the orthographic code has demonstrated that the magnitude of the effect correlates positively with reading ability (Zecker, 1989; Zecker & Zinner, 1982), that the effect obtains only when real words are used as cues and targets (Zecker & Nicklaus, 1984), and that the locus of the effect is in the left cerebral hemisphere (Zecker, Tanenhaus, Alderman, & Siqueland, 1986). Thus, considerable evidence exists to support the notion that multiple codes are made available in word recognition tasks, regardless of the presentation modality. There have been numerous attempts to explain the processes underlying multiple-code activation. Because this study was concerned with visual effects in an auditory task, the present discussion will focus on this code; much of what is presented also applies to phonological codes observed in visual tasks. Seidenberg and Tanenhaus ( 1979) proposed two broad interpretations for the source of an effect based on orthography. Both interpretations explained the effect in terms of shared spelling patterns; one interpretation localized the effect in the decision processes, and the other, in the encoding processes (see also Donnenwerth-Nolan, Tanenhaus, & Seidenberg, 1981). The encoding explanation holds that the orthography effect occurs early in processing, at the stimulus encoding stage. According to this interpretation, hearing the first word leads to the activation of other words that share a similar orthography. Such a process is consistent with the word-recognition models of Collins and Loftus (1975) and Morton (1969). The encoding-stage explanation assumes that the orthographic effect is due to facilitation in similar-orthography conditions. The decision explanation, which places the orthographic effect at a comparison stage in processing, holds that both orthographic and phonological information is accessed and that subjects make their decisions by attempting to match word pairs on both of these dimensions. An orthographic mismatch would require an additional stage of processing, providing a double-check on the phonological match. Thus, the orthographic effect is attributed to inter-

Downloaded by [NUS National University of Singapore] at 23:53 06 November 2015

Zecker

173

ference in dissimilar-orthography conditions. This interpretation is similar to that given by Meyer et al. (1974) in their demonstration of phonological effects in a visual lexical decision task. Both the encoding and decision explanations hold that orthographic information becomes available automatically, without conscious attention. The two explanations differ with respect to the stage in processing where the effect occurs, and whether the effect is due to inhibition or facilitation. Nonetheless, both assume that orthographic effects are based on shared spelling patterns between words. An alternative to the Seidenberg and Tanenhaus (1979) interpretation, suggested by Donnenwerth-Nolan et al. (1981), is that orthographic effects in a rhyming task are found because the cue stimulus activates visual features for letters. Donnenwerth-Nolan et al. suggested that the activation of sensory feature analyzers for the letters that two words have in common may explain the orthographic facilitation that has been attributed to the configuration of words; in other words, the effect is due to visual similarity in a more purely perceptual sense. A similar explanation for visual effects (although not using a rhyme decision task) comes from Schreuder, Flores d'Arcais, and Glazenborg (1984), who extended the generality of these findings by demonstrating that lexical decisions about concrete nouns were facilitated when the two words represented objects that were perceptually similar and conceptually dissimilar (for example, ball-orange and pencil-nail) as opposed to both perceptually and conceptually dissimilar. Related results from Nelson and Borden (1977) indicated that lexical decisions about word pairs that are both visually and semantically related to each other (e.g., cost-cash) are facilitated more than lexical decisions about pairs that are only semantically related (e.g., pricecash). The results of these two studies can be interpreted as due only to similarity in the perceptual sense and not to any abstract verbal code. Although Schreuder et al.'s results do require additional mechanisms (for example, visualization of the objects represented by the two words), they are at least suggestive of the hypothesis that shared visual similarity in a purely perceptual sense may facilitate processing of lexical items in the task. Both of these explanations could be correct; that is, visual effects could result from both a shared pattern of spelling (at the encoding or decision stage) and perceptual similarity, either at the feature level or in a gestalt sense. These lexical (orthographic) and nonlexical (visual-perceptual) explanations of visual effects are by no means mutually exclusive; support of one explanation does not rule out the other. It is certainly possible that the orthographic and visual facilitative effects are additive in nature. The present study was designed to extend the demonstration of visual facilitation effects in rhyming to nonword stimuli, specifically, letters. If

Downloaded by [NUS National University of Singapore] at 23:53 06 November 2015

174

The Journal of General Psychology

letter-rhyme decisions elicit the same facilitation and inhibition results demonstrated in previous studies (Donnenwerth-Nolan et al., 1981; Seidenberg & Tanenhaus, 1979; Zecker et al., 1986), this would indicate that the effect is more general than originally believed and must involve a perceptual component because the results could in no way be due to a shared spelling pattern. Although the design of this study does not allow for a determination of whether the predicted perceptual effects are due to a feature comparison process or a gestalt matching procedure, either explanation would mean that visual effects are more general than proposed by past researchers, involving both lexical and nonlexical processes.

Method Subjects Forty undergraduate and graduate students participated in the study. All subjects had self-reported normal hearing.

Materials The stimuli were selected from the set of 16 monosyllabic letters that have at least one rhyme. From this set, 16 rhyming pairs (i.e., T-B) and 16 nonrhyming pairs (i.e., J-B) were selected. Within both the rhyming and nonrhyming sets, half (8) of the pairs consisted of visually similar letters. For each target position, a given letter occurred in all four types of pairs. Similarity was determined by means of a confusion matrix for tachistoscopially presented uppercase letters taken from Gilmore, Hersh, Caramazza,and Griffin (1979). Pairs that were confused less than .8% of the time were considered visually dissimilar by Gilmore et al., whereas pairs that were confused at least 2% of the time were considered visually similar. For rhyming, confusib1e pairs, (i.e., C-G), the mean confusibility was 6.1%. For rhyming, nonconfusible pairs (i.e., P-G), the mean confusibility was .56%. For nonrhyming, confusib1e pairs (i.e., Q-G), the mean confusibility was 5.2%, and for nonrhyming, nonconfusible pairs (i.e., J-G), the mean confusibility was .46%. (The mean confusibility in the Gilmore et al. norms is 1.9%).

Procedure Stimuli were presented by means of a cassette recorder. Subjects were instructed that on each trial they would hear a cue letter followed 2 s later by a target letter. The task was to indicate whether or not the two letters rhymed

Downloaded by [NUS National University of Singapore] at 23:53 06 November 2015

Zecker

17S

by pressing the appropriate telegraph key. There was approximately a 7-s interval between trials. Cues were visually similar or dissimilar to the target letter. On half of the trials, the cue and target rhymed, and on half they did not. Response latencies were measured by a digital reaction timer. When the acoustic energy from the target letter began, an impulse from an electronic voice key triggered the reaction timer. The subject's press response stopped the reaction timer. The experimenter recorded the response latency as well as the accuracy of the response and then reset the reaction timer and voice key prior to the start of the next trial. The hand used to indicate each response (rhyme or nonrhyme) was counterbalanced across subjects. Results Out of a possible 1,280 responses, there were 35 errors (2.73%). Error rates did not approach significance for any of the main effects or interactions involving visual similarity and rhyming condition. Analyses were performed on the latency data for correct responses only. Excessively long responses (less than 1% of all responses), defined as more than two standard deviations from the condition mean, were dropped from the analyses. Figure 1 presents the means for the four conditions used in the study. As inspection of the figure shows, the overall difference between rhyming conditions was negligible (12 ms difference, F < 1), as was the difference between visual similarity conditions (3 ms difference, F < 1). Reaction times for visually similar rhyming pairs were 71 ms faster than reaction times for visually dissimilar rhyming pairs. The opposite pattern was obtained for nonrhyming pairs: Reaction times for visually similar pairs were 65 ms longer than for dissimilar pairs. An analysis of variance revealed that the interaction of the visual similarity and rhyming conditions was significant, F(1, 39) = 33.60, p < .001. An analysis of the overall pattern of results indicated that the results were highly consistent across subjects. Twenty-nine out of 40 subjects showed longer reaction times for visually similar nonrhyming pairs, and 33 out of 40 showed longer reaction times for visually dissimilar rhyming pairs. Discussion Visual similarity facilitated responses to rhyming letter pairs and inhibited responses to nonrhyming pairs. This result replicates the previously documented orthographic effect for word stimuli (Donnenwerth-Nolan et al., 1981; Seidenberg & Tanenhaus, 1979; Zecker et al., 1986). Because the stim-

176

The Journal of General Psychology

Reaction time

Downloaded by [NUS National University of Singapore] at 23:53 06 November 2015

in msec

675 650 625

Nonrhymes

600 575

Rhymes

550

.,....._----''-------~----Dissimilar

Similar

Visual similarity of letter pairs FIGURE 1. Reaction time as a function of visual similarity for rhyming and nonrhyming letter pairs.

uli in the present study consisted of only individual letters, shared orthography cannot be the basis for the observed effects. At least two explanations for the observed findings can be considered tenable. One explanation is that, whereas orthographic effects using word stimuli are due to a shared orthography, the visual effects obtained in the present study are due to shared features of letters, a possibility raised by Donnenwerth-Nolan et al. (1981). They suggested that using a feature code might be beneficial because of the auditory modality being taxed in the rhyme monitoring task. Tanenhaus, Flanigan, and Seidenberg (1980), however, observed orthographic effects that did not make any demands on auditory memory (a color-naming Stroop task), making an explanation based on a limitation of resources in the auditory modality seem doubtful. Another potential explanation for the present findings is that the effect of visual similarity is due to overall perceptual characteristics of the letters (the gestalts) rather than to individual shared features. Such an explanation is consistent with the results of Schreuder et al. (1984) because visual similarity in

Downloaded by [NUS National University of Singapore] at 23:53 06 November 2015

Zecker

177

that study could have been based only on overall shape; that is, the cue ball could have facilitated lexical decisions about apple only because of gross visual similarity. Both of these explanations can be considered nonlexical in nature; neither require that the stimulus items be lexical items. Given that Zecker and Nicklaus (1984) demonstrated that letter strings must form words to elicit orthographic effects (e.g., bope-hope and zing-ring do not result in facilitation using an auditory presentation), the present result is suggestive of two separate mechanisms for visual effects: one based on shared spelling patterns (as demonstrated by Donnenwerth-Nolan et al., 1981; Seidenberg & Tanenhaus, 1979; and Zecker et al., 1986) and another on perceptual similarity (as shown by Schreuder et al., 1984, and the present study). These two different visual effects are presumably additive; that is, a match on both dimensions should result in more facilitation than a match on either dimension alone. The presence of separate, additive effects also means that differences between individuals are likely, based on their reliance on or ability to use these lexical and nonlexical codes. For example, individuals who are learning-disabled in terms of language might show a greater reliance on the visual similarity of two words because their ability to automatically generate orthographic codes is limited. There is some support for this idea. Zecker (1989) found that reading-disabled children show significantly less orthographic facilitation than do their normally achieving peers when words are presented auditorally, indicating an impaired lexical code for orthography. Conversely, Rack (1985) found that dyslexic readers showed a larger orthographic effect than normal readers on a recall task when the stimuli were presented visually. Rack claimed that his results indicated that dyslexic readers are more able to use the orthographic code. These seemingly contradictory results can perhaps be explained by nonlexical (e.g., perceptual) processes, which may have been used by Rack's dyslexic subjects. Because Rack's (1985) dyslexic subjects were necessarily poor at grapheme-to-phoneme correspondence (they were poor decoders), they had a slow and difficult time deciding whether two words rhymed when forced to read them. Given the visual presentation modality, however, the subjects could also base their decisions purely on the visual similarity of the two words. All words were in the same type face, which would be conducive to such a visual strategy. The error patterns of dyslexics in Rack's study strongly suggest that a visual, not orthographic, process was employed. The results of Rack's (1985) and Zecker's (1989) studies of disabled readers, along with the present results, support the hypothesis that there are two separate sources for visual effects in rhyme detection-a lexical effect based on shared orthography, and a nonlexical effect based on perceptual similarity. These two effects, additive for most individuals, may not be present in those with deficits that preclude efficient use of one of the processes. Addi-

178

The Journal of General Psychology

tional research seems warranted to determine the generality and importance of these dual visual codes in linguistic processing.

Downloaded by [NUS National University of Singapore] at 23:53 06 November 2015

REFERENCES Baddeley, A. (1966). The influence of acoustic and semantic similarity in short term memory for word sequences. Quarterly Journal of Experimental Psychology. 18. 362-365. Baron, 1. (1976). Mechanisms for pronouncing printed words: Use and acquisition. In D. LaBerge & S. 1. Samuels (Eds.), Basic processes in reading: Perception and comprehension. Hillsdale, NJ: Erlbaum. Collins, A. M., & Loftus, E. F. (1975). A spreading activation theory of semantic processing. Psychological Review. 82. 407-428. Conrad, R. (1964). Acoustic confusions in irnrnediate memory. British Journal of Psychology. 55. 75-84. Conrad, R. (1972). Speech and reading. In 1. F. Kavanaugh & I. G. Mattingly (Eds.), Language by ear and by eye. Cambridge, MA: MIT Press. Donnenwerth-Nolan, w., Tanenhaus, M. K., & Seidenberg, M. S. (1981). Multiple code activation in word recognition: Evidence from rhyme monitoring. Journal of Experimental Psychology: Human Learning and Memory. 7, 170-180. Gilmore, G. C., Hersh, H., Caramazza, A., & Griffin, J. (1979). Multidimensional letter similarity derived from recognition errors. Perception and Psychophysics, 25(5),425-431. Glassman, W. F. (1972). Subvocal activity and acoustic confusion in short term memory. Journal of Experimental Psychology. 96. 164-169. Hintzman, D. L. (1967). Articulatory encoding in short term memory. Journal of Verbal Learning and Verbal Behavior. 6.312-316. McClelland,1. L., & Rumelhart, D. E. (1981). An interactive activation model of context effects in letter perception: Part I. An account of basic findings. Psychological Review, 88(5), 375-407. Meyer, D. E., Schvaneveldt, R. W., & Ruddy, M. G. (1974). Functions of graphemic and phonemic codes in visual word recognition. Memory and Cognition. 2. 309-321. Morton, J. (1969). Interaction of information in word recognition. Psychological Review. 76, 163-178. Nelson, D. L., & Borden, R. C. (1977). Encoding and retrieval effects of dual sensory semantic cues. Memory and Cognition. 5. 457-461. Rack, J. (1985). Orthographic and phonetic-coding in developmental dyslexia. British Journal of Psychology, 76. 325-340. Schreuder, R .• Flores d'Arcais, G., & Glazenborg, G. (1984). Effects of perceptual and conceptual similarity in semantic priming. Psychological Research, 45. 339354. Seidenberg, M. S., & Tanenhaus, M. K. (1979). Orthographic effects on rhyme monitoring. Journal of Experimental Psychology: Human Learning and Memory, 5,546-554. Tanenhaus, M. K., Flanigan, H. P., & Seidenberg, M. S. (1980). Orthographic and phonological priming in auditory and visual word recognition. Memory and Cognition, 8. 513-520. Zecker, S. G. (1989). The development of the orthographic code in normal and

Downloaded by [NUS National University of Singapore] at 23:53 06 November 2015

Zecker

179

learning disabled children. Paper presented at Orton Dyslexia Society Convention, Dallas, TX. Zecker, S. G., & Nicklaus, K. J. (1984). Lexical access and orthographic priming. Paper presented at Eastern Psychological Association Convention, Baltimore, MD. Zecker, S. G., & Zinner, T. E. (1982). Word recognition codes in dyslexic and normal readers. Paper presented at Northeast Educational Research Association Convention, Ellenville, NY. Zecker, S. G., Tanenhaus, M. K., Alderman, L., & Siqueland, L. (1986). Lateralization of lexical codes in auditory word recognition. Brain and Language, 29, 372-389. Received October 16, 1989

Visual similarity effects in detecting letter rhymes.

Previous demonstrations of "visual" effects in auditory tasks have been largely restricted to orthographic effects with word stimuli. As a result, exp...
842KB Sizes 0 Downloads 0 Views