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Biomedical subjects

P T Ackerman

Publications and source records attributed to P T Ackerman.

11 recordsLinked to original sources

Attention deficit disorder and specific reading disability: separate but often overlapping disorders.

Within a large (N = 182) heterogeneous sample of clinic-referred children with DSM-III-diagnosed attention deficit disorder (ADD), three behavioral subgroups were identified via cluster analysis of teacher ratings: 40% of the children had ADD with hyperactivity (ADDH), 30% had ADD with hyperactivity and aggressivity (ADDHA), and 31% had ADD without hyperactivity or aggressivity. Proportionally more girls were in the ADD-only subgroup. Over half the sample (n = 94) were poor readers, with 82 meeting discrepancy criteria for specific reading disability (RD). Proportionately more boys than girls met the RD criteria (9.2:1.0), whereas the sex ratio of males to females for the whole sample was 5.1 to 1.0. Focusing just on white males, the three behavioral subgroups were significantly different on convergent validity measures, such as other teacher ratings, parent ratings, and interview-elicited ratings of externalizing behavior, but were not different on such divergent validity measures as IQ and achievement scores, self-ratings, and laboratory performance tasks. Boys in the ADD sample who did not meet criteria for RD had significantly higher IQs than those who did, but subgroups with and without RD still differed significantly on WRAT-R reading and spelling scores with IQ covaried out. Both groups with and without RD could be differentiated from a control group on laboratory measures of sustained attention and impulse control. Methylphenidate benefited all subgroups equally, whether RD or not, and whether given a low (0.3 mg/kg) or high (0.6 mg/kg) dose.

Arousal

A trial of piracetam in two subgroups of students with dyslexia enrolled in summer tutoring.

Sixty children with dyslexia (41 boys, 19 girls; ages 9 to 13) were enrolled in a 10-week summer tutoring program that emphasized word-building skills. They were randomly and blindly assigned to receive either placebo or piracetam, a purportedly memory-enhancing drug that has been reported to facilitate reading skill acquisition. The children were subtyped as "dysphonetic" or "phonetic" on the basis of scores from tests of phonological sensitivity and phoneme-grapheme correspondence skills. Of the 53 children who completed the program, 37 were classified as dysphonetic and 16 as phonetic. The phonetic group improved significantly more in word-recognition ability than the dysphonetic group. Overall, the children on medication did not improve more than the nonmedicated ones in any aspect of reading. The phonetic subgroup on piracetam gained more in word recognition than any subgroup but did not improve significantly more than the phonetic subgroup on placebo. Results are discussed in relation to findings from previous studies of piracetam in children with dyslexia.

Adolescent

The frequency and significance of additional self-reported psychiatric diagnoses in children with attention deficit disorder.

The frequency of additional self-reported diagnoses in a large, heterogeneous sample of attention deficit disorder (ADD) children (N = 182) was determined using the Diagnostic Interview for Children and Adolescents (DICA). Over half the children had additional DICA diagnoses, with oppositional disorder and anxiety/mood disorders the most frequent. ADD boys with internalizing-type diagnoses had lower verbal IQs and arithmetic scores and performed more poorly on attention tasks than those without; parents also rated them more adversely. Those with externalizing-type diagnoses were rated as more aggressive by teachers and had sociopathic, thrill-seeking profiles on paper-pencil self-ratings. Over 40% of the children were dyslexic or slow learners but they had no higher rate of DICA diagnoses than those who read adequately.

Achievement

ADD students with and without dyslexia differ in sensitivity to rhyme and alliteration.

Children with attention deficit disorder (ADD) and dyslexia (n = 82) made significantly more errors than normally reading children with ADD (n = 83) on a simple auditory test of phonological sensitivity to rhyme and alliteration (Bradley, 1984). A subgroup of children with dyslexia who were sensitive to rhyme and alliteration had higher scores on the Wechsler Intelligence Scale for Children-Revised (WISC-R) Spatial factor than a dyslexic subgroup who were phonologically insensitive. In multiple regression analyses, age-corrected phonological sensitivity scores contributed significantly to the prediction of both reading and spelling Wide Range Achievement Test (WRAT) scores, this beyond the contribution of WISC-R variables. Of interest for dyslexia subtyping theories, Spatial factor scores had a subtractive effect in these regression analyses.

Achievement

Counting rate, naming rate, phonological sensitivity, and memory span: major factors in dyslexia.

Children with severe dyslexia were slower in counting from memory and naming alternating digits and letters than those with milder reading impairment. The children most disabled also had poorer phonological sensitivity, shorter digit spans, and lower Verbal IQs, but these variables accounted for no additional variance in prediction of scores on the Wide Range Achievement Test-Revised (R = 0.89).

Achievement

A psychosocial study of hyperactive and learning-disabled boys.

Adequately reading hyperactive boys, normally behaved learning-disabled (LD) boys, and normal controls were contrasted on tests measuring personality traits, cognitive role taking, and moral resoning. Additionally, parents and teachers rated all children on a number of behaviors, and parents were interviewed in a process-oriented fashion to assess home stimulation potential. Hyperactive boys were rated more aggressive and anxious than LD boys and controls and had not been encouraged as much by parents to achieve. Hyperactives had been born to younger parents, on the average, and 25% lived with their mothers and stepfathers. None of the LD or control boys had stepfathers. The groups did not differ significantly in moral reasoning ability, cognitive role taking, or locus of control; on the Junior Personality Inventory hyperactives tended to have elevated scores on the neuroticism scale while LD boys had higher scores on the lie scale.

Aggression

Heart rate reactivity in attention deficit disorder subgroups.

Beat-to-beat heart rate (HR) was analyzed for 9 contiguous seconds in a warned reaction time (RT) paradigm. Imperative stimuli were tones of three intensity levels (55, 78, and 100 db); a visual warning signal occurred 5 sec before tone onset. Baseline and reward conditions were run. Normal controls were contrasted with three Attention Deficit Disorder (ADD) subgroups: ADD-only, ADD with hyperactivity (ADDH), ADD with hyperactivity and aggression (ADDHA). The ADD subgroups were predicted to show less deceleration in HR because of their problem sustaining readiness to respond. Significant sex x group differences in HR levels and change scores were found. Overall, girls had higher HR levels than boys and the ADD-only group (boys and girls) had lower HRs than the other ADD groups. But, the ADD-only boys had more marked deceleration to the warning signal and acceleration to the tones than the other ADD boys, whereas the ADD-only girls were no more reactive than the ADDH and ADDHA girls. Control girls had the highest HR levels and were the most reactive to stimuli. Control boys and ADD-only boys had similar HR levels and reaction patterns. ADD-only girls appear to be underaroused, whereas ADD-only boys do not. Results suggest that cardiac measures can provide external validation of disruptive and nondisruptive ADD subtypes.

Attention Deficit Disorder with Hyperactivity

Auditory stimulus intensity gradients and response to methylphenidate in ADD children.

Using an auditory stimulus intensity paradigm, we obtained both event related potentials (ERPs) and press and release reaction times (RT) from a large sample of children with Attention Deficit Disorder (ADD). The ERP gradients to three tone intensities were used to classify the children as augmenters (steep gradients), moderates, or reducers (shallow or negative gradients). The RT data were used to classify the children as strong or sensitive, following neo-Pavlovian guidelines. The children were then cross-classified on these two dimensions and compared on cognitive, behavioral, and performance measures. The groups were also compared in response to two dosage levels of methylphenidate. Based on prior studies, we hypothesized that: 1. ERP augmenters would respond as well to the low as high dose but that reducers would respond better to high than low dose; and II. sensitive types (RT measure) would do better on the higher dose and strong types on the low dose. The first hypothesis was confirmed on a performance task but not on behavioral ratings. At the lower dose, augmenters improved most and reducers least on a 10-minute coding task presumed to require sustained attention. There was no support for the second hypothesis either in ratings or performance. The ERP augmentation measure was significantly related to teacher rated attentiveness; i.e., reducers and moderates were rated more adversely. The RT sensitivity measure tended to be related to achievement; i.e., strong types had lower reading and spelling scores. The ERP and RT sensitivity measures were not significantly correlated.

Arousal