Activity in the left auditory cortex is associated with individual impulsivity in time discounting

Impulsivity dictates individual decision-making behavior. Therefore, it can reflect consumption behavior and risk of addiction and thus underlies social activities as well. Neuroscience has been applied to explain social activities; however, the brain function controlling impulsivity has remained unclear. It is known that impulsivity is related to individual time perception, i.e., a person who perceives a certain physical time as being longer is impulsive. Here we show that activity of the left auditory cortex is related to individual impulsivity. Individual impulsivity was evaluated by a self-answered questionnaire in twelve healthy right-handed adults, and activities of the auditory cortices of bilateral hemispheres when listening to continuous tones were recorded by magnetoencephalography. Sustained activity of the left auditory cortex was significantly correlated to impulsivity, that is, larger sustained activity indicated stronger impulsivity. The results suggest that the left auditory cortex represent time perception, probably because the area is involved in speech perception, and that it represents impulsivity indirectly.