Andrew Westbrook - Dopamine Promotes Cognitive Effort

The Future of Dopamine - ViDA Symposium - Nov 19, 2020

Andrew Westbrook
Frank Lab, Brown University & Cools Lab, Donders Institute

Striatal Dopamine Promotes Cognitive Effort by Biasing the Benefits versus Costs of Cognitive Work

Stimulants like methylphenidate are increasingly used to treat ADHD-like symptoms, and for cognitive enhancement, but the precise mechanisms of action are unknown. Prior theories have alternately pointed to cortical or subcortical effects and modulation of either dopamine or norepinephrine. In this study, we show that striatal dopamine increases willingness to expend cognitive effort for reward, by amplifying the subjective benefits versus the subjective costs of action. Our study utilized convergent evidence including PET measures of dopamine synthesis capacity, methylphenidate, and sulpiride, a D2 receptor agent, to implicate striatal dopamine, in particular. Gaze patterns reveal that attention to benefit versus cost information also promotes cognitive motivation. Furthermore, both methylphenidate and higher dopamine synthesis capacity increase the effect of benefits on the evidence accumulation process. In addition, we find dynamic effects of gaze on choice, where gaze early in a trial magnifies the influence of attended-versus-unattended information while late gaze instead reflects an emerging preference. These findings help resolve conflicting accounts of how gaze impacts economic decision-making more broadly, beyond decisions about cognitive effort.