Influence of dopaminergically mediated reward on somatosensory decision-making.
Reward-related dopaminergic influences on learning and overt behaviour are well established, but any influence on sensory decision-making is largely unknown. We used functional magnetic resonance imaging (fMRI) while participants judged electric somatosensory stimuli on one hand or other, before being rewarded for correct performance at trial end via a visual signal, at one of four anticipated financial levels. Prior to the procedure, participants received either placebo (saline), a dopamine agonist (levodopa), or an antagonist (haloperidol).


RESULTS
higher anticipated reward improved tactile decisions. Visually signalled reward reactivated primary somatosensory cortex for the judged hand, more strongly for higher reward. After receiving a higher reward on one trial, somatosensory activations and decisions were enhanced on the next trial. These behavioural and neural effects were all enhanced by levodopa and attenuated by haloperidol, indicating dopaminergic dependency. Dopaminergic reward-related influences extend even to early somatosensory cortex and sensory decision-making.
Pleger
Burkhard
B
Wellcome Trust Centre for Neuroimaging at UCL, London, United Kingdom. bpleger@cbs.mpg.de
Ruff
Christian C
CC
Blankenburg
Felix
F
Klöppel
Stefan
S
Driver
Jon
J
Dolan
Raymond J
RJ
D000328:Adult; D001931:Brain Mapping; D003657:Decision Making; D004298:Dopamine / Q000378:metabolism*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D011597:Psychomotor Performance; D011930:Reaction Time; D012201:Reward; D013003:Somatosensory Cortex / Q000502:physiology*
D004298:Dopamine