Ivan L. Beale

Performance of disabled and normal readers on the continuous performance test

Twelve-year-old reading-disabled children of normal intelligence were compared on the Continuous Performance Test with two control groups of normal intelligence and reading ability either of the same age or of the same reading age as the reading-disabled group. Signal-detection analysis showed that the reading-disabled were more conservative than chronological-age controls in their willingness to identify the target letter sequence. Although this conservative performance was shared by the reading-age controls, the readingdisabled suffered an additional handicap of relatively frequent anticipatory errors. Groups also differed on a sensitivity measure, suggesting a deficit in working memory in the reading-disabled children.

EEG biofeedback vs. placebo treatment for Attention- Deficit/Hyperactivity Disorder: A pilot study

Method: Seven children diagnosed with attention-deficit hyperactivity disorder (ADHD) were trained using a standard EEG biofeedback treatment protocol designed to alter SMR/theta ratios and reduce behavioral symptomatology diagnostic of ADHD. During alternate periods they were also trained using a placebo protocol that was identical to the treatment protocol, save that the association between EEG patterns and feedback to the participants was random. Single-case design elements were used to control for the effects of internal validity threats such as maturation, history, and treatment order. Two participants failed to complete all training sessions, and the effects of training on behavior were analyzed both including and excluding these non-completers. Results: When all participants were included in analyses that controlled for overall trend, EEG biofeedback was found to be no more effective than the placebo control condition involving non-contingent feedback, and neither procedure resulted in improvements relative to baseline levels. When overall behavioral trends unrelated to training were not controlled for and noncompleters were excluded from the analysis, it could be mistakenly concluded that EEG biofeedback is significantly more effective than placebo and that the effect sizes involved are moderate to large. These results indicate that many previous reports of the efficacy of EEG biofeedback for ADHD, particularly those presenting series of single cases, might well have been based on spurious findings.

Eye contact in children's social interactions: What is normal behaviour?

Most remediation programmes for children with autism include training of eye contact behaviours, yet little data exist regarding levels of gaze behaviours in the social interactions of children without developmental disorders. Three behaviours were conventionally defined: (a) eye gaze, (b) joint attention, and (c) object engagement. Normative data were collected from children aged 5 to 10, who were observed in child-to-child social interactions (small playgroups). Joint attention was positively related to age and type of activity engaged in. Object engagement was consistently high across all age groups. Eye gaze was low relative to joint attention and object engagement, and was not significantly related to age. Eye gaze, as observed in small group interactions, was found to be significantly less than what has been reported for adult-child and adult-adult dyads. The implications of these findings for remedial training are discussed. Eye Contact in Childrens Social Interactions: What is Normal Behaviour?

Behavioural Assessment of Pharmacotherapy

There is growing recognition of the need for adequate procedures for evaluation of the effects of psychotropic drugs on the behaviour of individuals. Traditional methodology for drug evaluation is group based and therefore inappropriate for use with only one or a few subjects. Alternative procedures are described that are suitable for use with even a single subject, based on single-case research designs developed by researchers in applied behaviour analysis. Guidelines are given for choosing designs and methods of measurement that control for the common threats to internal and external validity and will enable clear and unambiguous conclusions to be reached regarding drug effects.

Relationship between the delay task and rating scale measures of inattention and hyperactivity.

A group of 187 elementary school children were administered a microcomputer version of the Delay Task (Gordon, 1979) in which responses were reinforced only when they followed the preceding response by at least 6 seconds. They were also rated on the Conners Teacher Rating Scale (CTRS) by their classroom teacher. Performance on the Delay Task was not correlated with any of the CTRS subscales for the overall sample. Sex differences were found in the Conduct, Inattention, and Hyperactivity factors of the CTRS. No sex difference was found for performance on the Delay Task. When performance on the Delay Task was correlated with the four CTRS factors by sex, correlations between the Delay Task and the inattention subscale and hyperactive subscale were significant only for the male subsample. Implications of the findings for assessment of hyperactivity are discussed.

Effects of methylphenidate on attention in children with moderate mental retardation

Six children with moderate mental retardation participated in a double-blind, placebo-controlled, crossover study of the effects of methylphenidate on performance on simultaneous two-choice discrimination learning problems, a sustained attention task, and classroom activity. Dependent measures were compared for: (1) % correct on discrimination learning problems; (2) sensitivity and bias on a sustained attention task; and (3) time on-task during classroom activities. Only the sustained attention task and the classroom measure showed a clear effect of methylphenidate. Two children performed better on the drug, one performed better on the placebo, and three showed no systematic effects. The two children who responded favorably to the drug spent more time on task in the classroom, showed higher sensitivity on the sustained attention task and adopted a more efficient, less conservative, criterion on this test. These results are inconsistent with the idea that methylphenidate improves the manageability of some children by decreasing behavior levels, in general, or by reducing impulsivity, in particular. Methylphenidate increased response output and the degree of environmental control of this output. The improvement in sensitivity demonstrates an attentional effect that cannot, in this case, be confounded by response bias factors.

Effects of chlorpromazine and thioridazine on discrimination learning in children with mental retardation

Four boys living in an institution for individuals with mental retardation participated in a study of the effects of chlorpromazine and thioridazine on discrimination learning. While on their previously prescribed drug, either chlorpromazine or thioridazine, the boys were trained on visual discrimination problems using multiple and concurrent schedules until their rate of learning new problems was stabilized. They then learned a series of new problems while taking only placebo tablets, and finally learned a further series of problems while receiving the alternative drug. Results showed that both drugs elevated discriminative performance relative to placebo. On multiple schedules the drugs increased a discriminative index based on response rate; on concurrent schedules they increased a discriminative index based on stimulus duration.

Comparison of Alternative Schedules for Producing Productive Workshop Behaviour in a Person with an Intellectual Handicap.

An intellectually handicapped man was studied in a workshop setting where he was employed to ‘detip’ ear tags. Productive behaviour was reinforced on either a variable ratio (VR) schedule or a variable duration (VD) schedule and the relative effectiveness of these schedules was compared using an alternating treatments design. Results showed that rate of detipping was higher, and time on task shorter, on the VR rather than the VD schedule. This indicates that the VR schedule was more effective than the VD schedule in producing efficient behaviour.