Large-scale Dynamics of Perceptual Decision Information across Human Cortex

Abstract

During perceptual decisions, agents accumulate sensory evidence for a particular choice towards an action plan. It is commonly held that sensory cortical areas encode evidence, which is accumulated on the way to downstream cortical regions that encode the action plan. This exclusively feedforward framework contrasts with the existence of powerful feedback connections within sensory-motor cortical pathways. We used behavioral analysis and magnetoencephalography to disentangle decisionrelated feedforward and feedback signals in human cortex. We isolated choice-dependent feedback signals by comparing choice-predictive signals across cortical regions to the weighting of sensory evidence on choice. Feedback signals were prominent in the lowest processing stage (primary visual cortex), expressed in a narrow frequency-band (around 10 Hz), and built up during decision formation, following the choice-predictive dynamics in downstream cortical regions. Our results challenge current, pure feedforward accounts of perceptual decision-making, and yield a computational interpretation of frequency-specific cortical oscillations.

Multiple timescales of sensory-evidence accumulation across the dorsal cortex

“…Decisions under uncertainty can be potentially solved in the brain through a chain of largely feedforward computations progressing from stimulus processing to accumulation of evidence to post-accumulation categorization and decision, with different brain areas implementing different steps of the process (Brincat et al, 2018;Brody and Hanks, 2016;Erlich et al, 2015;Gold and Shadlen, 2007;Hanks et al, 2015;Yartsev et al, 2018) . On the other hand, neural correlates of decisions relying on evidence accumulation have been found in a number of cortical and subcortical structures, in both primates and rodents (Ding and Gold, 2010;Hanks et al, 2015;Horwitz and Newsome, 1999;Kim and Shadlen, 1999;Koay et al, 2020;Krueger et al, 2017;Murphy et al, 2020;Orsolic et al, 2019;Scott et al, 2017;Shadlen and Newsome, 2001;Wilming et al, 2020;Yartsev et al, 2018) . Likewise, we have previously shown that, when mice must accumulate evidence over several seconds to make a navigational decision, the inactivation of widespread dorsal cortical areas leads to behavioral deficits, and that these areas encode multiple behavioral variables, including evidence (Pinto et al, 2019) .…”

Dynamics of visual perceptual decision-making in freely behaving mice

“…Exploring the temporal dynamics of perceptual decisions from onset of the sensory input through the initiation of behavioral responses affords a key window into the underlying cognitive processes [1-3]. Investigations of such dynamics have led to rich insights into human visual decision-making [4,5], and other species/modality [6][7][8]. They have revealed distinct stages in perceptual processing, their timing, and their interactions, and have highlighted the importance of conditional accuracy analysis (over just conventional reaction time analyses) for investigating dynamics of perception and decision-making [9][10][11].…”

Abstract neural choice signals during action-linked decisions

“…Perceptual decisions involve a complex interaction of feedforward and feedback processes throughout the brain 18,40 . Here, we found that the spatial peak of abstract choice information shifted throughout the trial, reflecting the currently relevant stage 18,41 .…”

“…A growing body of evidence has related the formation of action-linked sensorimotor decisions to activity in motor- and premotor areas 2,3,5,23,33,40 . Our findings are well compatible with these results: the presence of an abstract choice stage does not preclude the simultaneous planning and competition of multiple response options 23,42 .…”