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

Abstract

SUMMARY Humans often slow down after mistakes (post-error slowing, PES), but the neural mechanism and adaptive role of PES remains 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 (LIP) 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.

Using experience to improve: How errors shape behavior and brain activity in monkeys

“…These behavioral 21 adjustments have been replicated in animal models, such as rodents (Narayanan, primates (Purcell & Kiani, 2016), also showing that their neural mechanisms seem to be 24 well preserved across species. Therefore, the brain substrate of post-error behavioral 25 adjustments can be studied with single cell recordings that allow a deeper understanding 26 of the neuronal mechanisms responsible.…”

“…In perceptual decision-making, however, the outcomes and their influence in future 6 behavior have received less attention (Purcell & Kiani, 2016). This may be due to the 7 fact that, once participants are trained up to their psychophysical thresholds, there is 8 little room for learning and performance is assumed to depend mainly on sensory 9 factors that do not change dramatically from trial to trial (Gold & Shadlen, 2007).…”

“…10 However, it is known that, even under these circumstances, the outcomes of the adjustments have been mostly studied in humans, using EEG and imaging techniques 18 (Danielmeier & Ullsperger, 2011b). Although these methods have provided relevant 19 information on this topic, they lack the temporal and spatial resolution to reveal changes 20 in the neural mechanisms of decision-making (Purcell & Kiani, 2016). These behavioral 21 adjustments have been replicated in animal models, such as rodents (Narayanan, primates (Purcell & Kiani, 2016), also showing that their neural mechanisms seem to be 24 well preserved across species.…”

“…Although these methods have provided relevant 19 information on this topic, they lack the temporal and spatial resolution to reveal changes 20 in the neural mechanisms of decision-making (Purcell & Kiani, 2016). These behavioral 21 adjustments have been replicated in animal models, such as rodents (Narayanan, primates (Purcell & Kiani, 2016), also showing that their neural mechanisms seem to be 24 well preserved across species. Therefore, the brain substrate of post-error behavioral 25 adjustments can be studied with single cell recordings that allow a deeper understanding 26 of the neuronal mechanisms responsible.…”

“…In perceptual tasks, single neurons from the ventral premotor cortex (PMv) represent 28 many of the components of the decision-making process that lead to a choice, in 2008). If this is indeed the case, it is expected that neuronal responses during a given 39 trial will carry information of the preceding outcomes.…”