Impact of Handedness Consistency on Bimanual and Unimanual Continuous Movements

Bimanual coordination is an essential human function requiring efficient interhemispheric communication to produce coordinated movements. Previous research suggests a “bimanual advantage” phenomenon, where completing synchronized bimanual tasks results in less variability than unimanual tasks. Additionally, of hand dominance has been shown to influence coordinated performance. The present study examined the bimanual advantage in individuals with consistent and inconsistent handedness. It was predicted that participants with consistent handedness would not display a bimanual advantage unlike those with inconsistent handedness. Fifty-six young adults completed a finger-tapping paradigm in five conditions: unimanual tapping with either left or right hand, in-phase bimanual tapping, and out-of phase bimanual tapping led by either left or right hand. Results were not consistent with the hypothesis that participants with consistent handedness displayed the “bimanual advantage”. However, the “bimanual advantage” was not evident for the inconsistent handers when the temporal consistency was measured with either the left or right hand only. Overall, the “bimanual advantage” may be dependent upon consistency of hand preference, as well as the direction of hand dominance.     

What happened in kindergarten? Mother-child conversations about life story chapters

ABSTRACT

Research indicates that adults form life story chapters, representations of extended time periods that include people, places and activities. Life chapter memories are distinct from episodic memories and have implications for behaviour, self and mental health, yet little is known about their development during childhood. Two exploratory studies examined parent–child conversations about life chapters. In Study 1, mothers recorded naturalistic conversations with their 5–6 year old children about two chapters in the child’s life. In Study 2, mothers recorded conversations with their 6–7 year old children about a particular life chapter—the child’s kindergarten year—and also about a specific episode of their choice. The results indicated that young children are able to recall and discuss information about life chapters and that parents actively scaffold children’s discussion of general information in chapters as well as specific events. Mothers’ conversational style when discussing chapters (e.g., elaborativeness) predicted children’s memory contributions, and was also positively correlated with their style when discussing specific events. The results suggest new avenues for research on the ontogeny of life chapters, the factors that shape them, and their role in development.