For decades, scientists believed that approach motivation is processed in the brain’s left hemisphere while withdraw motivation is in the right hemisphere. But in a new study, experts from the New School for Social Research in New York found that a well-established pattern in the brain activity of right-handers reverses in the case of left-handers.
Hemispheric Reversal in Between Left and Right Handers
Psychologists Geoffrey Brookshire and Daniel Casasanto from the New School for Social Research in New York challenged the long-established facts about motivation. In the said study, they also found out that the way people use their hands may determine how emotions are organised in their brains.
Motivation has been a subject of various scientific studies. In psychology, it is defined as the process that initiates, guides, and maintains goal-oriented behaviours. It serves as the ‘drive’ to either approach or withdraw from physical and social stimuli. To prove whether their theory was right, the researchers recruited left- and right-handers in their experiment. Using electroencephalography (EEG), they compared the participants’ brain activities in the left and right hemispheres while on rest. Then, the researchers measured the participants’ level of approach motivation through a survey. The results show that in right-handers, stronger approach motivation is reflected in their brain’s left hemisphere while the left-handers have the opposite pattern. The EEG showed that in left-handers, the right hemisphere is responsible for approach motivation.
Motor Control and Emotional Motivation
The study suggests that emotional motivation and motor control is related but researchers warned that more studies must be made to support this claim. While most cognitive functions are not affected with motor actions, Casasanto and Brookshire revealed that motor action and emotions are linked. As pointed out by Casasanto – ‘We predicted this hemispheric reversal because we observed that people tend to use different hands to perform approach- and avoidance-related actions’. They observed that in most cases, approach motivation is often executed with the dominant hand while the withdraw motivation is performed using the non-dominant hand.
They also explained that neural circuits for motivation may be linked to circuits that control an individual’s hands. ‘Emotions may be built upon neural circuits for action, in evolutionary or developmental time’, said Casasanto.
At present, therapies used to treat anxiety and depression involve stimulating the brain’s left hemisphere which is believed to be the ‘approach’ hemisphere. But because their study shows that it reverses in the case of left-handers, such treatment may be detrimental to some. The researchers further suggest that their findings can be used as basis for more effective neural therapies for the left-handers.
Source of this article:
PLoS ONE, by psychologists Geoffrey Brookshire and Daniel Casasanto of The New School for Social Research in New York