Neural Mechanisms That Make Perceptual Decisions Flexible

Abstract

Neural mechanisms of perceptual decision making have been extensively studied in experimental settings that mimic stable environments with repeating stimuli, fixed rules, and payoffs. In contrast, we live in an ever-changing environment and have varying goals and behavioral demands. To accommodate variability, our brain flexibly adjusts decision-making processes depending on context. Here, we review a growing body of research that explores the neural mechanisms underlying this flexibility. We highlight diverse forms of context dependency in decision making implemented through a variety of neural computations. Context-dependent neural activity is observed in a distributed network of brain structures, including posterior parietal, sensory, motor, and subcortical regions, as well as the prefrontal areas classically implicated in cognitive control. We propose that investigating the distributed network underlying flexible decisions is key to advancing our understanding and discuss a path forward for experimental and theoretical investigations. Expected final online publication date for the Annual Review of Physiology, Volume 85 is February 2023. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Neural Manifold Capacity Captures Representation Geometry, Correlations, and Task-Efficiency Across Species and Behaviors

“…The three effective manifold alignments suggest the curve-shaped organization of decision manifolds (Fig. 4f), agreeing with previous findings in other brain areas related to decision making [46]. Furthermore, the difference in effective radius and dimension between manifolds with different coherence level indicates that there is a stronger compression when the monkey has more evidence (Fig.…”

A new theoretical framework jointly explains behavioral and neural variability across subjects performing flexible decision-making

“…Under the simplifying assumptions that the response to a pulse does not depend on time within a trial nor on previously presented evidence (assumptions supported by the good fit to the data of a model built with these assumptions, Figs. 4 and Extended Data Fig. 9b), the theory predicts a specific relationship between differential behavioral kernels and differential pulse responses: If T is the time at which position on the choice axis is read out to commit to a Right vs Left choice, then the impact on choices of a pulse at time t will follow the pulse-evoked movement along the choice axis after an interval T-t. For direct input modulation, with a differential pulse response that is immediate and sustained (Fig.…”

“…For example, if we hear our name called in a crowded room and our goal is to respond based on the identity of the caller, the frequencies in the sound will be an important part of driving our actions; but if we wish to first turn towards to the caller, regardless of who they might be, information about location , of the very same sound, will be the most relevant to our actions. As with other types of decisions, when the evidence for or against different choices is noisy or uncertain, accumulation of many observations over time is an important strategy for reducing noise 1–4 . To study the neural basis of such context-dependent selection and accumulation of sensory evidence, we trained rats on a novel auditory task where, in alternating blocks of trials, subjects were cued to determine either the prevalent location (“LOC”) or the prevalent frequency (“FRQ”) of a sequence of randomly-timed auditory pulses (Fig.…”

Abstract deliberation by visuomotor neurons in prefrontal cortex

“…Our investigation is the first to offer unequivocal evidence that circuits involved in action selection can also reflect deliberation among abstract propositions in a representational space that is uncoupled from specific motor plans [13]. Previous attempts to determine whether action-planning circuits in the macaque brain also support abstract deliberation were inconclusive for a variety of reasons.…”

“…But natural behavior occurs under many different contexts and therefore generally requires a flexible association between perceptual interpretation and motor response. It has been hypothesized that when such flexibility is required, deliberation may consist of a competition among possible interpretations of the sensory environment rather than among possible action plans [10, 11, 12, 13].…”