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The way we use our hands may determine how emotions are organizedin our brains, according to a recent study published in PLoS ONE bypsychologists Geoffrey Brookshire and Daniel Casasanto of The NewSchool for Social Research in New York. Motivation, the drive to approach or withdraw from physical andsocial stimuli, is a basic building block of human emotion. Fordecades, scientists have believed that approach motivation iscomputed mainly in the left hemisphere of the brain, and withdrawmotivation in the right hemisphere. Brookshire and Casasanto's study challenges this idea, showing thata well-established pattern of brain activity, found across dozensof studies in right-handers, completely reverses in left-handers. The study used electroencepahlography (EEG) to compare activity inparticipants' right and left hemispheres during rest. After havingtheir brain waves measured, participants completed a surveymeasuring their level of approach motivation, a core aspect of ourpersonalities. In right-handers, stronger approach motivation was associated withgreater activity in the left hemisphere than the right, consistentwith previous studies. Left-handers showed the opposite pattern:approach motivation was associated with greater activity in theright hemisphere than the left. A New Link Between Motor Action and Emotion Most cognitive functions do not reverse with handedness. Language,for example, is mainly in the left hemisphere for the majority ofright- and left-handers. However, these results were notunexpected. "We predicted this hemispheric reversal because we observed thatpeople tend to use different hands to perform approach- andavoidance-related actions," says Casasanto. Approach actions areoften performed with the dominant hand, and avoidance actions withthe non-dominant hand. "Approach motivation is computed by the hemisphere that controlsthe right hand in right-handers, and by the hemisphere thatcontrols the left hand in left-handers," says Casasanto. "We don't think this is a coincidence. Neural circuits formotivation may be functionally related to circuits that controlhand actions - emotion may be built upon neural circuits foraction, in evolutionary or developmental time." The authors caution that these data show a correlation betweenemotional motivation and motor control, and that further studiesare needed to establish a causal link. Implications for the treatment of depression and anxiety disorders To treat depression and anxiety disorders, brain stimulation isused to increase neural activity in the patient's left hemisphere,long believed to the 'approach hemisphere." "Given what we show here," says Brookshire, "this treatment, whichhelps right-handers, may be detrimental to left-handers - the exactopposite of what they need." The discovery that approach motivation reverses with handedness maylead to safer, more effective neural therapies for left-handers,according to Brookshire, "it's something we're investigating now." Brookshire, G. and Casasanto, D. (2012). Motivation and Motor Control: Hemispheric specialization forapproach motivation reverses with handedness. PLoS ONE. The e-commerce company in China offers quality products such as China RFID Laundry Tag , RFID UHF Reader Manufacturer, and more. For more , please visit RFID UHF Reader today!
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