A Role for the Superior Colliculus in Decision Criteria

Abstract

Simple decisions arise from the evaluation of sensory evidence. But decisions are determined by more than just evidence. Individuals establish internal decision criteria that influence how they respond. Where or how decision criteria are established in the brain remains poorly understood. Here, we show that neuronal activity in the superior colliculus (SC) predicts changes in decision criteria. Using a novel "Yes-No" task that isolates changes in decision criterion from changes in decision sensitivity, and computing neuronal measures of sensitivity and criterion, we find that SC neuronal activity correlates with the decision criterion regardless of the location of the choice report. We also show that electrical manipulation of activity within the SC produces changes in decisions consistent with changes in decision criteria and are largely independent of the choice report location. Our correlational and causal results together provide strong evidence that SC activity signals the position of a decision criterion. VIDEO ABSTRACT.

Simultaneous multi-area recordings suggest that attention improves performance by reshaping stimulus representations

“…MT 67 contributes to motion perception 12,13 . The SC is thought to play many roles in visually guided 68 tasks including gaze control [14][15][16] , decision-making [17][18][19] The two predominant attention hypotheses make different predictions about how attention should 98 affect MT and the SC in our task. The first (information coding) hypothesis predicts that 99 attention improves the motion direction information encoded in MT.…”

“…32 We evaluated these hypotheses using the responses of groups of simultaneously recorded 33 neurons in multiple stages of visuomotor processing, psychophysics, and data analysis methods 34 that leverage that unique combination. We recorded simultaneously from groups of neurons in 35 area MT, which encodes motion information 12,13 and the superior colliculus (SC), where 36 neuronal responses are either visual, oculomotor, or intermediate, contribute to gaze control 14-16 37 and are involved in computing perceptual decisions [17][18][19] . When we analyzed the responses of 38 single neurons or pairs of neurons, we replicated previous observations, including the results 39 from two of our previous studies, which focus on visual area V4 in two different tasks with 40 spatial attention components: an orientation change detection task 5 and a contrast discrimination 41 task 6 .…”

Weber’s law is the result of exact temporal accumulation of evidence

“…Our results show that explicit level invariance in neural representations is not necessary for level-invariant accuracy at the behavioral level, and can instead be a property of the discrimination mechanism itself, with neither neurons encoding the evidence, nor neurons integrating it, displaying ABL-independent activity. Regarding non-sensory components of the model, the parietal cortex (77–79), and the striatum (80), are candidates for evidence accumulation, and the superior colliculus (SC) has been suggested as a possible site where a threshold-like mechanism might be implemented (81, 82). Future studies should address the involvement of these areas in tasks probing the effect of stimulus intensity on sensory discrimination.…”

Functional Organisation and Connectivity of the Dorsal Column Nuclei Complex Reveals a Sensorimotor Integration and Distribution Hub

“…The SC is a midbrain structure involved in a multitude of functions including attention, decision making, planning, and orienting an organism toward stimuli of interest (Basso & May, 2017;Crapse, Lau, & Basso, 2018;Gandhi & Katnani, 2011;Krauzlis, Lovejoy, & Zénon, 2013). Most of these functions require or are dominated by visual inputs in most vertebrates.…”