Rate and accuracy of vowel recognition as a function of spoken reinforcers and age

Developmental differences among the effectiveness of three spoken reinforcers were evaluated by measuring rate and accuracy of performance on a vowel recognition task. Eighty-seven males were selected from grades 1 to 3, 6 to 7, and 11 to 12 of a predominantly urban, Black, parochial school. The effectiveness of approval and affirmation of correctness was related to grade level for accuracy of performance, but not for rate. For accuracy of performance a decreasing linear trend was found when approval effectiveness was evaluated across grades. For correctness, an increasing linear trend was found. The results were discussed in terms of a developmental hierarchy of reinforcers and information processing.     

The preparation of reach-to-grasp movements in adults, children, and children with movement problems

This study explored the use of advance information in the control of reach-to-grasp movements. The paradigm required participants to reach and grasp illuminated blocks with their right hand. Four target blocks were positioned on a table surface, two each side of the mid-saggital plane. In the complete precue condition, advance information precisely specified target location. In the partial precue condition, advance information indicated target location relative to the midsaggital plane (left or right). In the null condition, the advance information was entirely ambiguous. Participants produced fastest responses in the complete precue condition, intermediate response times in the partial condition, and the slowest responses in the null condition. This result was observed in adults and four groups of children including a group aged 4-6 years. In contrast, children with Developmental Coordination Disorder (DCD, n = 11, aged 7-13 years) showed no advantage of partial precueing. Movement duration was determined by target location but was unaffected by precue condition. Movement duration was a clear function of age apart from children in the DCD group who showed equivalent movement times to those of the youngest children. These findings provide important insights into the control of reach-to-grasp movements and highlight that partial cues are exploited by children as young as 4 years but are not used in situations of abnormal development.     

Some Results from an Automated Statewide Comparison among Attempted,Committed, and Nonsuicidal Patients

ABSTRACT: In the Missouri Division of Mental Health statewide automated Standard System of Psychiatry, 151 patients who had attempted suicide were compared with 424 who had not and with 97 who had committed suicide. Much of the data was provided from relatives using an automated history. Compared with nonattempters, attempters were younger and more often female, depressed, assaultive, and had a family history of suicide. Actual suicides were more often male, better educated, and in general more resembled the attempters than nonattempters.     

Functional and anatomical profile of visual motion impairments in stroke patients correlate with fMRI in normal subjects

We used six psychophysical tasks to measure sensitivity to different types of global motion in 45 healthy adults and in 57 stroke patients who had recovered from the initial results of the stroke, but a large subset of them had enduring deficits on selective visual motion perception tasks. The patients were divided into four groups on the basis of the location of their cortical lesion: occipito-temporal, occipito-parietal, rostro-dorsal parietal, or frontal-prefrontal. The six tasks were: direction discrimination, speed discrimination, motion coherence, motion discontinuity, two-dimensional form-from-motion, and motion coherence – radial. We found both qualitative and quantitative differences among the motion impairments in the four groups: patients with frontal lesions or occipito-temporal lesions were not impaired on any task. The other two groups had substantial impairments, most severe in the group with occipito-parietal damage. We also tested eight healthy control subjects on the same tasks while they were scanned by functional magnetic resonance imaging. The BOLD signal provoked by the different tasks correlated well with the locus of the lesions that led to impairments among the different tasks. The results highlight the advantage of using psychophysical techniques and a variety of visual tasks with neurological patients to tease apart the contribution of different cortical areas to motion processing.