Neural Mechanisms of Post-error Adjustments of Decision Policy in Parietal Cortex

• DOI: 10.1016/j.neuron.2015.12.027
• Publication Date: 2016-01-21T22:05:05Z
• Authors: Braden A. Purcell; Roozbeh Kiani
• Keywords: Male; Neurons; 0303 health sciences; Neuroscience(all); Decision Making; Models, Neurological; Motion Perception; Macaca mulatta; 03 medical and health sciences; Discrimination, Psychological; Parietal Lobe; Reaction Time; Saccades; Animals; Humans; Photic Stimulation

Humans often slow down after mistakes (post-error slowing [PES]), but the neural mechanism and adaptive role of PES remain controversial. We studied changes in the neural mechanisms of decision making after errors in humans and monkeys that performed a motion direction discrimination task. We found that PES is mediated by two factors: a reduction in sensitivity to sensory information and an increase in the decision bound. Both effects are implemented through dynamic changes in the decision-making process. Neuronal responses in the monkey lateral intraparietal area revealed that bound changes are implemented by decreasing an evidence-independent urgency signal. They also revealed a reduction in the rate of evidence accumulation, reflecting reduced sensitivity. These changes in the bound and sensitivity provide a quantitative account of choices and response times. We suggest that PES reflects an adaptive increase of decision bound in anticipation of maladaptive reductions in sensitivity to incoming evidence.