motivation and motor control hemispheric specialization for approach motivation reverses with handedness动力和电动机控制半球专业化与构型方法动机逆转.pdfVIP

Motivation and Motor Control: Hemispheric Specialization for Approach Motivation Reverses with Handedness Geoffrey Brookshire1,2, Daniel Casasanto 1,2,3* 1 Department of Psychology, The New School for Social Research, New York, New York, United States of America, 2 Neurobiology of Language Department, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands, 3 Donders Institute for Brain, Cognition, Behaviour, Radboud University, Nijmegen, The Netherlands Abstract Background: According to decades of research on affective motivation in the human brain, approach motivational states are supported primarily by the left hemisphere and avoidance states by the right hemisphere. The underlying cause of this specialization, however, has remained unknown. Here we conducted a first test of the Sword and Shield Hypothesis (SSH), according to which the hemispheric laterality of affective motivation depends on the laterality of motor control for the dominant hand (i.e., the ‘‘sword hand,’’ used preferentially to perform approach actions) and the nondominant hand (i.e., the ‘‘shield hand,’’ used preferentially to perform avoidance actions). Methodology/Principal Findings: To determine whether the laterality of approach motivation varies with handedness, we measured alpha-band power (an inverse index of neural activity) in right- and left-handers during resting-state electroencephalography and analyzed hemispheric alpha-power asymmetries as a function of the participants’ trait approach motivational tendencies. Stronger approach motivation was associated with more left-hemisphere activity in right-handers, but with more right-hemisphere activity in left-handers. Conclusions: The hemispheric correlates of approach motivation reversed between right- and left-handers, consistent w