Journal of Learning Disabilities http://ldx.sagepub.com/
Sustained and Selective Attention in Children with Learning Disabilities Gail P. Richards, S. Jay Samuels, James E. Turnure and James E. Ysseldyke J Learn Disabil 1990 23: 129 DOI: 10.1177/002221949002300210 The online version of this article can be found at: http://ldx.sagepub.com/content/23/2/129
Published by: Hammill Institute on Disabilities
and http://www.sagepublications.com
Additional services and information for Journal of Learning Disabilities can be found at: Email Alerts: http://ldx.sagepub.com/cgi/alerts Subscriptions: http://ldx.sagepub.com/subscriptions Reprints: http://www.sagepub.com/journalsReprints.nav Permissions: http://www.sagepub.com/journalsPermissions.nav Citations: http://ldx.sagepub.com/content/23/2/129.refs.html
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Sustained and Selective Attention In Children with Learning Disabilities Gail P. Richards, S. Jay Samuels, James E. Turnure, and James E. Ysseldyke
Sustained and selective attention of 30 fourth-, fifth-, and sixth-grade students with learning disabilities (LD) and 20 controls were compared. A continuous performance test (CPT) yielded no differences for students with LD and controls, suggesting similar ability for both groups in sustaining attention and inhibiting impulsive responding. Subjects with LD made more errors than controls on a selective attention task when letter distractors were adjacent to the target letter but not when they were distant, and more correct responses than controls when facilitating letters were adjacent to the target, suggesting that students with LD are less able to narrow the focus of their attention. Longer response times by students with LD indicate that they have slower information-processing skills than controls. Regrouping students according to teacher ratings for attention deficit-hyperactivity disorder (ADHD) yielded the customary impulsive response set on the CPT and more errors on the selective attention task, but no differences on response times for students with ADHD. LD students with ADHD made more errors than LD students without ADHD when letter distractors were adjacent to the target letter.
R
esearch with children with learning disabilities (LD) and children with attention disorders has identified a variety of attention deficits, which are viewed by some investigators as definihg characteristics of many children with LD (e.g., Dykman, Ackerman, Clements, & Peters, 1971; Ross 1976). Studies have shown that the characteristics of the two groups overlap very frequently (Holborow & Berry, 1986; Lambert & Sandoval, 1980). Children identified as having specific learning disabilities have been found to have increased rates of attention deficits, hyperactive behavior, and impulsivity; similarly, children with attention deficithyperactivity disorder (ADHD) have been found to have rates of learning difficulties well above those in the general population. Estimates of the percentage of children with ADHD that are likely to have learning problems range from 25% to 60% (Barkley, 1981; Holborow & Berry, 1986). Research investigating attention in populations with LD has focused on whether or not the attention of children with LD is similar to or worse than that of nonhandicapped children. While it is suggested in the bulk of the published
literature that there are differences in performance between these two populations, recently investigators have been examining performance deficits more carefully to understand the basis, scope, and magnitude of the differences, and some conflicting findings have emerged. For example, Blackwell, Mclntyre, and Murray (1983) described three experiments that indicate decreased spans of apprehension in boys with LD. They relate this decrease in performance to greater distractibility, slower pickup of information, or both. In contrast, Samuels and Miller (1985) found no differences in the number of errors or response times for children with LD and controls on a selective attention task involving a target letter flanked by distracting letters. Tarnowski, Prinz, and Nay (1986) compared the performance of children with LD, children with ADHD, and children with both disorders on measures of sustained attention, selective attention, and span of apprehension and found that unique patterns of deficits in attention were associated with each group. One explanation for the conflicting results in the LD attentional literature might be due to diagnostically mixed
samples. While impairments in two aspects of attention, sustained and selective attention, have been associated with LD (e.g., Copeland & Reiner, 1984; Douglas, 1983; Kupietz & Richardson, 1978; Swanson, 1981, 1983), in some of the LD groups studied, children with hyperactive behavior disorders were not excluded. Samuels and Miller (1985) did not identify or exclude children with ADHD from their investigation, which yielded no differences between children with LD and controls. As children with a diagnosis of ADHD perform poorly on tests of attention, specifically those requiring continuous vigilance (Michael, Klorman, Salzman, Borgstedt, & Dainer, 1981; Sostek, Buchsbaum, & Rapoport, 1980; Sykes, Douglas, & Morgenstern, 1972), they might bias results when investigating the attentional performance of students with LD. It is important to measure several aspects of attention within the same subjects to see whether patterns of attention deficits emerge, and if there are pattern differences in different diagnostic groups. An explanation that has been suggested for the poorer performance of children with LD on distraction tasks is their poorer performance on the task even when distractors are not present. Douglas and Peters (1979) recommended that baseline performance be assessed to rule out the possibility that children with LD are less successful than nonhandicapped peers on the basic task. The present study investigated further the extent to which students with LD are able to sustain attention or are distractible and whether or not they process information at a different rate than other students. Students with ADHD were identified in both the LD and control groups. The performance of all groups was compared on four measures of attention that assessed sustained attention, selective attention, and information processing speed. The students with LD were expected to be the most distractible and to have slower response times than the students in the other groups. The students with ADHD were expected to have deficits in sustaining attention, while the children with concurrent diagnoses of both LD and ADHD were expected to show impairments in all aspects of attention measured. 129
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METHOD Subjects Subjects were students in Grades 4, 5, and 6 from four St. Paul, Minnesota, elementary schools. The 30 students with LD (12 girls, 18 boys) were selected from children receiving special education services for LD, placed by the district's child study team on the basis of referral and assessment information. They ranged in age from 9.65 to 13.8 years (mean age, 11.5 years). The students were chosen from three service levels offered by the district: mainstream placement with teacher consultation and monitoring, mainstream placement with daily small group tutoring, and self-contained placement with selected mainstreaming. The 20 controls (8 girls, 12 boys) were selected to match the sample of children with LD as closely as possible on measures of ability and achievement, except for the academic area that qualified the students with LD for services. They ranged in age from 9.75 to 12.65 years (mean age, 11.5 years). They were in the same mainstream classrooms as the children with LD. Black, Asian, and Hispanic children were included in each group; there were 5 minority children in the LD group and 3 in the control group. School nurses, social workers, and other building professionals provided information to exclude children who had recently received or who were currently receiving prescription medication (such as methylphenidate) shown to improve performance on attentional measures (Barkley, 1977; Michael et al., 1981; Sostek et al., 1980; Swanson & Kinsbourne, 1979; Werry, Aman, & Diamond, 1980). School nurses also provided results of visual acuity screening in order to rule out visual impairment as a reason for poor performance on the measures of attention. All students in the study have vision or corrected vision within the normal range. Measures of ability and achievement are reported in Table 1 for the LD and control groups, along with results of t tests to determine if the differences between the groups are significant. The ability quotient scores for both the groups are within the average range, although they differ. This difference is not
unexpected, because some of the children with LD are performing poorly in certain areas, which could have affected scores on group-administered measures. Differences were also found in some, but not all, of the measures of achievement. All subjects were assessed for ADHD using the revised Conners Teacher Rating Scale (Goyette, Conners, & Ulrich, 1978) to determine if this factor contributed to group differences on the measures of attention. Subjects receiving a mean score greater than or equal to 1.5 on the Hyperkinesis Index (Conners, 1982) were designated as having ADHD. The distribution of children with ADHD by group and by grade is described in Table 2. The mean score on the Hyperkinesis Index for the entire sample was .97, suggesting that the overall sample is similar to a sample of normally achieving public school children on this dimension (M= .60, SD = .40 for 9- to 11-year-olds) (Conners, 1982). The mean Hyperkinesis Index scores for each group and grade are
shown in Table 2. Higher hyperkinesis ratings were found for students with LD for control, underscoring the need to examine data for the LD students with and without the ADHD subsample.
Procedure Laboratory measures of sustained and selective attention were administered to the 30 students with LD and the 20 control students. The examiner administered the series of experimental tasks individually to each student at school in a single session lasting approximately one-half hour. An AT&T Model 6300 microcomputer was used to display the stimuli and record responses. Letters were displayed in a 40-column format. Response keys were highlighted to facilitate recognition. The vigilance task given as a measure of sustained attention is a variation of the continuous performance test (CPT) (Rosvold, Mirsky, Sarason, Bransome, & Beck, 1956). Ten similar uppercase letters
TABLE 1 Ability and Achievement Characteristics of Subjects with Learning Disabilities (LD) and Controls LD(n == 30) M SD
Control (n = 20) M SD
Educational Abilities Series Ability Quotient (standard scores)
90.0
14.4
100.0
10.9*
SRA Achievement Test Composite score (national percentiles) Reading score Math score Language Arts score
19.4 28.3 19.3 19.9
16.6 28.1 14.0 16.6
40.3 40.9 40.2 39.1
29.5* 30.7 23.0** 29.9*
*p
Sustained and Selective Attention in Children with Learning Disabilities Gail P. Richards, S. Jay Samuels, James E. Turnure and James E. Ysseldyke J Learn Disabil 1990 23: 129 DOI: 10.1177/002221949002300210 The online version of this article can be found at: http://ldx.sagepub.com/content/23/2/129
Published by: Hammill Institute on Disabilities
and http://www.sagepublications.com
Additional services and information for Journal of Learning Disabilities can be found at: Email Alerts: http://ldx.sagepub.com/cgi/alerts Subscriptions: http://ldx.sagepub.com/subscriptions Reprints: http://www.sagepub.com/journalsReprints.nav Permissions: http://www.sagepub.com/journalsPermissions.nav Citations: http://ldx.sagepub.com/content/23/2/129.refs.html
>> Version of Record - Feb 1, 1990 What is This?
Downloaded from ldx.sagepub.com at UNIV TORONTO on October 23, 2014
Sustained and Selective Attention In Children with Learning Disabilities Gail P. Richards, S. Jay Samuels, James E. Turnure, and James E. Ysseldyke
Sustained and selective attention of 30 fourth-, fifth-, and sixth-grade students with learning disabilities (LD) and 20 controls were compared. A continuous performance test (CPT) yielded no differences for students with LD and controls, suggesting similar ability for both groups in sustaining attention and inhibiting impulsive responding. Subjects with LD made more errors than controls on a selective attention task when letter distractors were adjacent to the target letter but not when they were distant, and more correct responses than controls when facilitating letters were adjacent to the target, suggesting that students with LD are less able to narrow the focus of their attention. Longer response times by students with LD indicate that they have slower information-processing skills than controls. Regrouping students according to teacher ratings for attention deficit-hyperactivity disorder (ADHD) yielded the customary impulsive response set on the CPT and more errors on the selective attention task, but no differences on response times for students with ADHD. LD students with ADHD made more errors than LD students without ADHD when letter distractors were adjacent to the target letter.
R
esearch with children with learning disabilities (LD) and children with attention disorders has identified a variety of attention deficits, which are viewed by some investigators as definihg characteristics of many children with LD (e.g., Dykman, Ackerman, Clements, & Peters, 1971; Ross 1976). Studies have shown that the characteristics of the two groups overlap very frequently (Holborow & Berry, 1986; Lambert & Sandoval, 1980). Children identified as having specific learning disabilities have been found to have increased rates of attention deficits, hyperactive behavior, and impulsivity; similarly, children with attention deficithyperactivity disorder (ADHD) have been found to have rates of learning difficulties well above those in the general population. Estimates of the percentage of children with ADHD that are likely to have learning problems range from 25% to 60% (Barkley, 1981; Holborow & Berry, 1986). Research investigating attention in populations with LD has focused on whether or not the attention of children with LD is similar to or worse than that of nonhandicapped children. While it is suggested in the bulk of the published
literature that there are differences in performance between these two populations, recently investigators have been examining performance deficits more carefully to understand the basis, scope, and magnitude of the differences, and some conflicting findings have emerged. For example, Blackwell, Mclntyre, and Murray (1983) described three experiments that indicate decreased spans of apprehension in boys with LD. They relate this decrease in performance to greater distractibility, slower pickup of information, or both. In contrast, Samuels and Miller (1985) found no differences in the number of errors or response times for children with LD and controls on a selective attention task involving a target letter flanked by distracting letters. Tarnowski, Prinz, and Nay (1986) compared the performance of children with LD, children with ADHD, and children with both disorders on measures of sustained attention, selective attention, and span of apprehension and found that unique patterns of deficits in attention were associated with each group. One explanation for the conflicting results in the LD attentional literature might be due to diagnostically mixed
samples. While impairments in two aspects of attention, sustained and selective attention, have been associated with LD (e.g., Copeland & Reiner, 1984; Douglas, 1983; Kupietz & Richardson, 1978; Swanson, 1981, 1983), in some of the LD groups studied, children with hyperactive behavior disorders were not excluded. Samuels and Miller (1985) did not identify or exclude children with ADHD from their investigation, which yielded no differences between children with LD and controls. As children with a diagnosis of ADHD perform poorly on tests of attention, specifically those requiring continuous vigilance (Michael, Klorman, Salzman, Borgstedt, & Dainer, 1981; Sostek, Buchsbaum, & Rapoport, 1980; Sykes, Douglas, & Morgenstern, 1972), they might bias results when investigating the attentional performance of students with LD. It is important to measure several aspects of attention within the same subjects to see whether patterns of attention deficits emerge, and if there are pattern differences in different diagnostic groups. An explanation that has been suggested for the poorer performance of children with LD on distraction tasks is their poorer performance on the task even when distractors are not present. Douglas and Peters (1979) recommended that baseline performance be assessed to rule out the possibility that children with LD are less successful than nonhandicapped peers on the basic task. The present study investigated further the extent to which students with LD are able to sustain attention or are distractible and whether or not they process information at a different rate than other students. Students with ADHD were identified in both the LD and control groups. The performance of all groups was compared on four measures of attention that assessed sustained attention, selective attention, and information processing speed. The students with LD were expected to be the most distractible and to have slower response times than the students in the other groups. The students with ADHD were expected to have deficits in sustaining attention, while the children with concurrent diagnoses of both LD and ADHD were expected to show impairments in all aspects of attention measured. 129
Volume 23, Number 2, February 1990 Downloaded from ldx.sagepub.com at UNIV TORONTO on October 23, 2014
METHOD Subjects Subjects were students in Grades 4, 5, and 6 from four St. Paul, Minnesota, elementary schools. The 30 students with LD (12 girls, 18 boys) were selected from children receiving special education services for LD, placed by the district's child study team on the basis of referral and assessment information. They ranged in age from 9.65 to 13.8 years (mean age, 11.5 years). The students were chosen from three service levels offered by the district: mainstream placement with teacher consultation and monitoring, mainstream placement with daily small group tutoring, and self-contained placement with selected mainstreaming. The 20 controls (8 girls, 12 boys) were selected to match the sample of children with LD as closely as possible on measures of ability and achievement, except for the academic area that qualified the students with LD for services. They ranged in age from 9.75 to 12.65 years (mean age, 11.5 years). They were in the same mainstream classrooms as the children with LD. Black, Asian, and Hispanic children were included in each group; there were 5 minority children in the LD group and 3 in the control group. School nurses, social workers, and other building professionals provided information to exclude children who had recently received or who were currently receiving prescription medication (such as methylphenidate) shown to improve performance on attentional measures (Barkley, 1977; Michael et al., 1981; Sostek et al., 1980; Swanson & Kinsbourne, 1979; Werry, Aman, & Diamond, 1980). School nurses also provided results of visual acuity screening in order to rule out visual impairment as a reason for poor performance on the measures of attention. All students in the study have vision or corrected vision within the normal range. Measures of ability and achievement are reported in Table 1 for the LD and control groups, along with results of t tests to determine if the differences between the groups are significant. The ability quotient scores for both the groups are within the average range, although they differ. This difference is not
unexpected, because some of the children with LD are performing poorly in certain areas, which could have affected scores on group-administered measures. Differences were also found in some, but not all, of the measures of achievement. All subjects were assessed for ADHD using the revised Conners Teacher Rating Scale (Goyette, Conners, & Ulrich, 1978) to determine if this factor contributed to group differences on the measures of attention. Subjects receiving a mean score greater than or equal to 1.5 on the Hyperkinesis Index (Conners, 1982) were designated as having ADHD. The distribution of children with ADHD by group and by grade is described in Table 2. The mean score on the Hyperkinesis Index for the entire sample was .97, suggesting that the overall sample is similar to a sample of normally achieving public school children on this dimension (M= .60, SD = .40 for 9- to 11-year-olds) (Conners, 1982). The mean Hyperkinesis Index scores for each group and grade are
shown in Table 2. Higher hyperkinesis ratings were found for students with LD for control, underscoring the need to examine data for the LD students with and without the ADHD subsample.
Procedure Laboratory measures of sustained and selective attention were administered to the 30 students with LD and the 20 control students. The examiner administered the series of experimental tasks individually to each student at school in a single session lasting approximately one-half hour. An AT&T Model 6300 microcomputer was used to display the stimuli and record responses. Letters were displayed in a 40-column format. Response keys were highlighted to facilitate recognition. The vigilance task given as a measure of sustained attention is a variation of the continuous performance test (CPT) (Rosvold, Mirsky, Sarason, Bransome, & Beck, 1956). Ten similar uppercase letters
TABLE 1 Ability and Achievement Characteristics of Subjects with Learning Disabilities (LD) and Controls LD(n == 30) M SD
Control (n = 20) M SD
Educational Abilities Series Ability Quotient (standard scores)
90.0
14.4
100.0
10.9*
SRA Achievement Test Composite score (national percentiles) Reading score Math score Language Arts score
19.4 28.3 19.3 19.9
16.6 28.1 14.0 16.6
40.3 40.9 40.2 39.1
29.5* 30.7 23.0** 29.9*
*p
