Handedness and cognitive functions in pervasive developmental disorders

Area of Science:

• Neuroscience
• Developmental Psychology
• Child Psychiatry

Background:

• Abnormal handedness is observed in Pervasive Developmental Disorders (PDD).
• Previous research suggests a link between handedness, cerebral dysfunction, and developmental disorders.
• Handedness patterns may indicate the presence, lateralization, and severity of neurological issues in PDD.

Purpose of the Study:

• To investigate the relationship between abnormal handedness and cognitive/motor performance in children with PDD.
• To compare the cognitive and motor functioning of left-handed, right-handed, and mixed-handed children with PDD.
• To explore potential explanations for observed handedness patterns in PDD, considering cerebral dysfunction and lateralization.

Main Methods:

• Administered a battery of cognitive and motor tests to a group of children diagnosed with PDD and autistic symptoms.
• Compared performance on these tests across subgroups based on handedness: left-handed, right-handed, and mixed-preference.
• Utilized an extended model (Satz, 1972) and proposed alternative theories to interpret findings related to brain damage and lateralization.

Main Results:

• Left-handed children with PDD generally outperformed right-handed children on cognitive measures.
• Mixed-preference children with PDD exhibited the lowest performance across all cognitive measures.
• No significant differences in motor performance were observed between the handedness groups.

Conclusions:

• Handedness in PDD is associated with cognitive performance, with left-handedness potentially indicating different underlying neurological processes.
• Mixed-handedness in PDD appears to correlate with more significant cognitive impairments.
• Findings support theories involving early brain damage or anomalous cerebral lateralization in explaining handedness variations within the PDD population.