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PubMed1975

The recall of digits by normal, deaf and autistic children.

Normal, autistic and deaf children were tested for their immediate memory of visually presented digits. The digits were exposed either with or without a left to right spatial display arrangement, and had to be recalled forewards as well as backwards. Normal and deaf children tended to be sensitive to both display conditions and recall requirements whereas autistic children were mainly affected by direction of recall. Serial position effects in the normal and deaf groups were more dependent on order of retrieval than on input order.

Autistic Disorder↗
PubMed1980

Modality differences in relation to grouping in immediate recall.

An earlier study of auditory grouped presentation of digit strings had shown recall to be impaired by recalling the last group first. From this, it has been concluded that the item codes formed at Stage 1 of processing, and before conversion to a group code at Stage 2, were not yet in an output buffer. The present paper employs visual presentation for two similar studies, with results opposite to the earlier one; in a third experiment, ungrouped auditory stimulation gave results which were a compromise between those for vision and those for grouped auditory stimulation. These results suggest a use of echoic storage, over long intervals; in the visual case this is not so and an output buffer is employed.

Adult↗
PubMed1992

The relationship between individual differences in defensive style and concept formation.

The relationship between defensive style and concept formation with aggressive and neutral stimuli was investigated. Very strong relationships were found between the use of avoidant and repressive defenses and the number of errors made in acquiring and utilizing an aggressive concept. This relationship was not found for the neutral concept. The results suggest the importance of directing attention to the relevant stimulus dimension in efficient concept formation. Insofar as defensive style involves a particular way of deploying attention (e.g. avoidance of a particular content) and insofar as the affective nature of the stimulus material lends itself to the elicitation of defensive reactions, individual differences in defensive style can serve as a robust predictor of efficiency of concept formation.

Adolescent↗
PubMed1978

Reversal of the physiological effects of brief periods of monocular deprivation in the kitten.

1. Five normally reared kittens were monocularly deprived from day 32 to day 42 and then subjected to varying periods (from 6 to 14 days) of deprivation reversal using the technique of reverse suturing. Data obtained from single unit recordings in striate cortex of these kittens were compared to control data from seven normal kittens (aged 32 days to 22.5 weeks) and three normally reared kittens given monocular deprivation from day 32 to day 42. 2. Analysis of cortical ocular dominance patterns in these reverse-sutured kittens revealed a progressively greater shift of influence away from the originally experienced eye and toward the originally deprived eye as the duration of the period of deprivation reversal increased. Most cortical cells were monocularly driven in these animals, but at each stage of the reversal process some binocular neurones were found. 3. The distribution of interocular differences in preferred orientation for binocular cells from these kittens was not significantly different from that for normal kittens, indicating that the pattern of connexions established by the originally deprived eye during reinnervation of striate cortex was very similar to that present before deprivation. 4. Previous studies on reversal of the effects of longer periods of monocular deprivation have indicated that during reinnervation of cortex by fibres representing the originally deprived eye an entirely new and different pattern of connexions is formed. On the basis of these results, it is hypothesized that short-term monocular deprivation causes a reversible silencing of otherwise intact synapses, while terminals are physically disrupted when deprivation is prolonged. 5. This hypothesis is supported by the results of an additional set of experiments in which receptive fields, many of which were highly specific, could be demonstrated for about one-half of the cells studied after removal of the non-deprived eye in two normally reared kittens given 10 days of monocular deprivation beginning on day 32. Similar experiments in two kittens deprived from eye opening to day 42 revealed functional input to less than 20% of the cells studied and no evidence of response specificity.

Afferent Pathways↗
PubMed1995

Comparison of executive and visuospatial memory function in Huntington's disease and dementia of Alzheimer type matched for degree of dementia.

Groups of patients with Hungington's disease and probable dementia of Alzheimer type (DAT) matched for level of dementia on the basis of mini mental state examination scores were compared in several tests of visual memory and tests sensitive to frontal lobe dysfunction. Whereas recall of patients with DAT tended to be worse on the Kendrick object learning test, the two groups were equivalent on tests of sensorimotor ability and delayed matching to sample performance. By contrast, the patients with Huntington's disease were significantly worse on tests of pattern and spatial recognition, simultaneous matching to sample, visuospatial paired associates, and on three tests sensitive to frontal lobe dysfunction--namely, the Tower of London test of planning, spatial working memory, and a visual discrimination learning and reversal paradigm. The impairments in these tests, however, did not always qualitatively resemble those seen in patients with frontal lobe damage and may be more characteristic of primary neostriatal deficit. In the visual discrimination paradigm the patients with Hungtington's disease were significantly worse than the patients with DAT at the simple reversal stage, where they displayed significant preservation to the previously rewarded alternative. The results are consistent with the hypothesis that patients with Huntington's disease exhibit deficits in tests sensitive to frontostriatal dysfunction and that this form of intellectual deterioration is qualitatively distinct from that seen in Alzheimer's disease.

Aged↗
PubMed2003

The importance of hippocampus-dependent non-spatial tasks in analyses of homology and homoplasy.

The hippocampus or a homologous region plays a role in spatial tasks in a large number of vertebrate species. This result, in combination with recent findings of adaptive specializations of the hippocampus for spatial demands, has led to the conclusion that the prominent selective force behind hippocampal evolution was a need for spatial abilities. However, a review of non-spatial hippocampus-dependent tasks shows that many vertebrate species also share non-spatial functions of the hippocampus. Placed in the appropriate phylogenetic context, it becomes clear that non-spatial facets of hippocampal function were just as likely to be present in our vertebrate ancestors as spatial ones. In addition, the absence of spatial strategy use in three lineages suggests divergence of this feature. Divergence in this character and other characteristics of hippocampal function are meaningful indicators of lineage specific functions. Studies of the evolution of the hippocampus must include examination of spatial and non-spatial functions of the hippocampus and consider both conserved, as well as derived, features.

Animals↗
PubMed1994

Pattern reversal visual evoked potentials in minor head injury.

Pattern reversal visual evoked potentials (PR-VEPs) have been recorded in 50 patients with minor head injury (MHI) on days 1 and 30 after trauma and the data compared to 20 normals. None of the patients had visual complaints. The aim was to investigate a possible visual pathway affection in MHI and test the usefulness of PR-VEPs as an objective noninvasive tool in the detection of a possible subclinical affection of the visual system in MHI. P100 latency and amplitude had no significant difference compared to normals. Comparison of patient data on days 1 and 30 after trauma showed a significant latency decrease and amplitude increase on day 30, compared to day 1. These alterations were not age dependent. Our data suggest affection of the human visual pathway in MHI. PR-VEP recording seems to be a useful, objective, noninvasive tool, helping to identify possible subclinical affections of the visual pathway in MHI.

Adolescent↗
PubMed1991

Recombination of automatic processing components: the effects of transfer, reversal, and conflict situations.

This research was conducted to evaluate the effects of compatible and incompatible automatic processes on performance. Subjects were trained for 8400 trials of consistent mapping practice in a semantic category visual search task and then transferred for 2352 trials to conditions that utilized the trained component processes in various ways. Results indicate that if the components were reused in a compatible fashion (target and distractor transfer), there was positive transfer. Target and distractor reversal resulted in equivalent and severe performance disruption that persisted for the entire retraining period. Target conflict produced disruption equivalent to the reversal conditions. Distractor conflict resulted in less initial disruption, which dissipated before the end of the retraining period. The results are discussed in terms of agreement with strength-theoretic views of visual search and in terms of practical training and retraining issues.

Adult↗
PubMed2006

Habit reversal as a treatment for chronic skin picking: a pilot investigation.

The purpose of this study was to compare the effectiveness of habit reversal (HR) to a wait-list control as a treatment for chronic skin picking in adults. Twenty-five adults with a chronic skin-picking problem were randomly assigned to a wait-list control or HR group. At pretreatment, posttreatment, and a 3-month follow-up, self-reported skin picking was assessed, and photographs were taken of the damaged areas and later rated by independent observers. Treatment acceptability data were collected at posttreatment only. Results showed that HR produced a greater decrease in skin picking at posttreatment and follow-up when compared to the wait-list control group. Data from the independent raters confirmed these findings. HR was also viewed as an acceptable intervention by the participants.

Adolescent↗
PubMed2006

Behavioral therapy for treatment of stereotypic movements in nonautistic children.

Although typically described in autistic, mentally retarded, and sensory-deprived individuals, motor stereotypies also occur in normal children. In this preliminary report, the behavior modification techniques of habit reversal and differential reinforcement of other behavior were evaluated as a therapeutic modality for the suppression of stereotypic movements in nonautistic subjects. Twelve children, ages 6 to 14 years, with physiologic stereotypies were treated using a standardized treatment protocol. Clinical outcomes were based on differences between assessments obtained at baseline and on telephone follow-up. Evaluation scales included measures of the frequency, intensity, interference, and number of stereotypies (Stereotypy Severity Scale motor portion and Stereotypy Linear Analog Scale) and assessment of global function (Child Global Assessment Scale and Stereotypy Severity Scale global portion). The results were correlated with the child's level of motivation and the number of treatment sessions. After a mean follow-up of 12.1 months, motor stereotypies showed significant improvement on the Stereotypy Linear Analog Scale and Stereotypy Severity Scale total score, P = .009 and P = .046, respectively. Both scales showed a relationship between the number of treatment sessions attended and a reduction in movements. The Child Global Assessment Scale also improved with therapy, but there was no correlation with the number of treatment sessions. Highly motivated patients had greater improvement on the Stereotypy Linear Analog Scale and Stereotypy Severity Scale scales compared with less motivated patients, but motivation had no impact on the Child Global Assessment Scale. The combined use of habit reversal and differential reinforcement of other behavior is beneficial in reducing motor stereotypies in nonautistic children.

Adolescent↗
PubMedDate not supplied

Serial sevens versus world backwards: a comparison of the two measures of attention from the MMSE.

This paper reports on a comparison of the two alternative tests of attention in the Mini-Mental State Examination (MMSE), a well-known cognitive screening tool. The two tests, serial subtraction by seven and backwards spelling of the word world, are often used interchangeably. In a large population-based sample, the two tests were found to be weakly associated with each other, with the former test appearing more difficult, although both were strongly associated with educational level. The authors discuss the implications of this finding in clinical and research settings, and make recommendations for more consistent use of the instrument.

Aged↗