Goal-directed rewarded behavior and goal-directed non-rewarded behavior are concerned with motivation. However, the neural substrates involved in goal-directed non-rewarded behaviors are unknown. Using functional magnetic resonance imaging, we investigated the brain activities of healthy individuals during a novel tool use (turning a screwdriver) to elucidate the relationship between the brain mechanism relevant to goal-directed non-rewarded behavior and motivation. We found that our designed behavioral task evoked activities in the orbitofrontal cortex, striatum, anterior insula, lateral prefrontal cortex, and anterior cingulate cortex compared with a meaningless task. These results suggest that activation in these cerebral regions play important roles in motivational behavior without tangible rewards.
aDepartment of Neurosurgery, Faculty of Medicine, University of the Ryukyus
bDepartment of Occupational Therapy, Okinawa College of Rehabilitation and Welfare, Okinawa
cDepartment of Neurosurgery, Tsukuba Memorial Hospital, Ibaragi
dWaseda Institute for Advanced Study, Waseda University, Tokyo, Japan
Correspondence to Masahiko Nishimura, Department of Neurosurgery, Faculty of Medicine, University of the Ryukyus, 207-Uehara, Nishihara-cho, Okinawa 903-0215, Japan
Tel: +81 98 895 1171; fax: +81 98 895 1423; e-mail: firstname.lastname@example.org
Received 6 July 2009 accepted 8 July 2009