Gesture imitation in schizophrenia.

Recent evidence suggests that individuals with schizophrenia (SZ) are impaired in their ability to imitate gestures and movements generated by others. This impairment in imitation may be linked to difficulties in generating and maintaining internal representations in working memory (WM). We used a novel quantitative technique to investigate the relationship between WM and imitation ability.

Sex differences in the acquisition of complex skilled movements.

The praxis system comprises a network of brain regions dedicated to complex skilled movements. Following suggestions of a female advantage on learned movements (Chipman and Hampson in Neuropsychologia 44(12):2315-2329, 2006), we investigated how males and females acquire skilled movements. Subjects viewed and imitated sequences of hand movements, which were repeated ten times.

A new way to quantify the fidelity of imitation: preliminary results with gesture sequences.

Imitation is a common and effective way for humans to learn new behaviors. Until now, the study of imitation has been hampered by the challenge of measuring how well an attempted imitation corresponds to its stimulus model. We describe a new method for quantifying the fidelity with which observers imitate complex series of gestures.

Learning to imitate novel motion sequences.

Many imitative behaviors entail complex sequences of component actions that must be recalled and performed in the proper order. It is well known that imitation of complex actions tends to improve with repeated opportunities to observe and execute the target behavior. But what actually makes this practice-based improvement possible? To address this question, we had subjects view and then reproduce sequences of connected, randomly directed motions of a disc.