Emma Gowen | PubMed Health

PubMed2006

Eye-hand interactions in tracing and drawing tasks.

We report a preliminary analysis of the interactions between eye and hand during tracing and drawing of four simple shapes. Eye and hand movements were recorded using the ASL 504 system and the Flock of Birds system, respectively. During tracing, pen tip and eye were tightly coupled, with participants making a series of small saccades just in front of the moving pen, interspersed with periods of smooth pursuit. During drawing, saccades were fewer and larger and pursuit was less frequent. Observed eye-hand interactions suggested a bidirectional relationship between the eye and hand. These findings are explained in terms of the differing degree that the two tasks employ visual detail, external or internal cues and eye-hand coordination.

Adult↗

PubMed2005

Behavioural aspects of cerebellar function in adults with Asperger syndrome.

Aside from social deficits, Asperger and autistic individuals also exhibit motor control abnormalities such as impaired gait, balance, manual dexterity and grip. One brain area that has consistently been reported on autopsy and imaging studies to be abnormal in such individuals is the cerebellum. As the cerebellum controls sensorimotor coordination and lesions here typically cause hypotonia, dysmetria and dyscoordination, we performed a series of quantitative tests aimed at investigating cerebellar function in Asperger individuals. Tests examining visually guided movement (rapid pointing), speeded complex movement (finger tapping, rapid hand turning), muscle tone (catching dropped weight), prediction, coordination and timing (balance, grip force and interval timing) were conducted on 12 Asperger subjects and 12 age and IQ matched controls. In comparison to control subjects, Asperger subject's demonstrated: (i) decreased pointing accuracy and rate, (ii) increased postural instability, and (iii) decreased timing accuracy. IQ was found to co-vary with some parameters of each of these tasks and no further impairments were found on the remaining tests. We suggest that these specific deficits reflect impairment in the ability to integrate sensory input with appropriate motor commands and are consistent with cerebellar dysfunction in Asperger syndrome.

Adolescent↗