Biomedical subjects

M Woodin

Publications and source records attributed to M Woodin.

4 recordsLinked to original sources

PubMed1999

Hand-centred coding of target location in visuo-spatial working memory.

The aim of the present experiment was to determine the frame of reference used to encode a visually specified target location, in a simple, visuo-spatial short-term-memory task, using delayed manual pointing. Subjects were required to remember the location of a single, visually presented stimulus, over delays of 3 and 30 s, and to recall its location by pointing to it with the tip of a stylus with eyes closed. There were two starting positions for the hand: one near the body, proximal to the target area, the other far from the body, i.e., beyond the target area. Two groups of twelve subjects participated in the experiment. One group observed the target locations in the light, the other group observed the target LEDs in the dark. The results showed a large (between 10-30%) and consistent undershoot of the remembered target location with respect to the hand's starting position, in the sagittal axis, both when the hand started from the near and from the far position. That is, from the far starting position. pointing errors lay consistently beyond the actual target location as seen from the subject's viewpoint. Further, this undershoot error in the remembered target location increased over time delay. These results are in favour of the hypothesis that the visual target locations were encoded in a hand-centred frame of reference in spatial short-term memory. They also implicate the use of motor- or action-related representations in visuo-spatial working memory.

Adult↗

PubMed1998

Circadian rhythms in diving behavior and ventilatory response to asphyxia in canvasback ducks.

Underwater feeding behavior was measured in 10 captive canvasback ducks (Aythya valisineria) for 12 days under a 12:12-h light-dark photoperiod. Feeding activity exhibited a daily rhythm, with 76% of dives occurring at night. In separate experiments on six of these ducks, a circadian rhythm was observed in the duration of voluntary dives. Dives at night (14.7 +/- 0.7 s) were significantly longer than those during the day (10.7 +/- 0.7 s). These day-night differences in diving behavior were accompanied by day-night differences in respiratory responses to progressive asphyxia. In the same six ducks, ventilation increased exponentially as a function of inspired CO2 concentration during rebreathing in a closed-circuit barometric plethysmograph. The exponential rate constant for inspired ventilation was significantly smaller at night (0.23 +/- 0.02) than during the day (0.26 +/- 0.01). We suggest that intermittent apneic exercise is facilitated by reduced respiratory chemosensitivity and that the respiratory and behavioral control systems are synchronized by the circadian timing system in diving ducks.

Animals↗

PubMedDate not supplied

Neuropsychological profile of children and adolescents with the 22q11.2 microdeletion.

PURPOSE: Patients with one of the 22q11.2 deletion syndromes provide a unique opportunity to research the interface between genetics and brain-behavior relationships. This study investigates the neuropsychological characteristics and behavioral phenotype of children with this deletion syndrome. METHODS: We report updated findings from descriptive and nonparametric analyses of neuropsychological data from 80 children with the 22q11.2 deletion. RESULTS: The subjects showed higher verbal than nonverbal IQ scores, assets in verbal memory, and deficits in the areas of attention, story memory, visuospatial memory, arithmetic performance relative to other areas of achievement, and psychosocial functioning. CONCLUSION: Children with 22q11.2 deletion syndromes exhibit a behavioral phenotype reflective of nonverbal learning disabilities, concomitant language deficits, and social-emotional concerns.

Adolescent↗

PubMedDate not supplied

Communication issues in 22q11.2 deletion syndrome: children at risk.

PURPOSE: The purpose of this investigation is to describe the communication profile of children with the 22q11.2 deletion syndrome from infancy through school age and to examine the influence of other medical aspects, such as palate anomalies, learning disorders, and cardiac defects of the syndrome to communication. METHODS: Seventy-nine children were examined using standardized tests of speech and language and perceptual measures of resonance and voice. RESULTS: Results show significant delay in emergence of speech and language milestones with delay/disorder in speech-language processes persisting into the school aged years, including those children diagnosed with nonverbal learning disabilities. Persistent articulation and resonance disorders were also present, presumed to be related in part to palatal anomalies. No correlation was found between cardiac status, learning disorders, palate anomalies and communication disorders. CONCLUSION: The need for early identification and management of communication skills is crucial in the care of children with the 22q11.2 deletion.

Adolescent↗