A research conducted by Wim Vanduffel from KU Leuven and John Arsenault of Massachusetts General Hospital has shown that the choices of primates could be altered by stimulating an area of their brain with electrical pulses. The research is the first to confirm a causal link between activity in the ventral tegmental area and the choice behaviour in primates.
The ventral tegmental area of the brain is responsible for reinforcing the brain’s reward system. This area produces dopamine, a neurotransmitter that plays an important role in reinforcing positive feelings. This implies that when the reward is larger or smaller than expected, the behaviour is reinforced or discouraged accordingly. During the research, any two macaques were allowed to choose multiple times between two images namely a star or a ball. Their choice indicated their natural preference. Later when macaques’ ventral tegmental area was stimulated with mild electrical currents, they went against their natural preference to choose the non–preferred image. Researchers, however, were able to manipulate their altered preference back to their natural preference.
The study being the first of its kind can open new doors for research related to the brain’s reward network such as an addiction or a disability. It shows that our choices could be manipulated through non–invasive methods. At present, more invasive methods are followed to stimulate brain by placing electrodes in order to treat Parkinson’s disease or depression.