Causal role for the primate superior colliculus in the computation of evidence for perceptual decisions

Abstract

Trained monkeys performed a two-choice perceptual decision-making task in which they reported the perceived orientation of a dynamic Glass pattern, before and after unilateral, reversible, inactivation of a brainstem area involved in preparing eye movements, the superior colliculus (SC). Surprisingly, we found that unilateral SC inactivation produced significant decision biases and changes in reaction times consistent with a causal role for the primate SC in perceptual decision-making. Fitting signal detection theory and sequential sampling models to the data revealed that SC inactivation produced a decrease in the relative evidence for contralateral decisions, as if adding a constant offset to a time-varying evidence signal for the ipsilateral choice. The results provide causal evidence for an embodied cognition model of perceptual decision-making and provide compelling evidence that the SC of primates, a brainstem structure, plays a causal role in how evidence is computed for decisions, a process usually attributed to the forebrain.

Express detection and discrimination of visual objects by primate superior colliculus neurons

“…More recently, a series of studies explored the roles of the SC and pulvinar in the processing of face and snake images [11][12][13][14][15][16][17], and concluded that the SC may be part of a fast detection network for visual threats and ecologically-relevant faces that can influence emotions [6]. Because the SC is also shown to contribute to a variety of important cognitive processes like target selection, visual attention, and perceptual decision making [18][19][20][21][22][23][24], and given that SC activity can influence cortical areas through different thalamic circuits [25][26][27][28], it stands to reason that the SC may be involved in object processing in a more general way than being specifically tuned for processing snakes and faces. In fact, experimental manipulation of SC activity is associated with altered object selectivity in a patch of the ventral visual processing stream of the cortex [29], and, similarly, the SC has a dedicated primary cortical area in mice…”

Single-Cell RNA Sequencing Characterizes the Molecular Heterogeneity of the Larval Zebrafish Optic Tectum

“…The superior colliculus (SC) is a highly laminated multisensory processing hub located in the mammalian midbrain that receives sensory input of various modalities and is involved in visual, motor, and sensory pathways ( Krauzlis et al, 2013 ; Stein and Stanford, 2013 ), as well as perceptual decision-making ( Jun et al, 2021 ). Despite studies dating back to the 1970s ( Basso and May, 2017 ), knowledge concerning the different neuronal cell types comprising SC microcircuitries and their respective functions is limited.…”

Pyramidal cell types drive functionally distinct cortical activity patterns during decision-making

“…This argues against models in which task-relevant sensory information is directly transmitted from parietal to frontal cortex during decision formation 40,58,60 and instead highlights the importance of subcortical projection pathways via PT neurons [61][62][63] . A likely subcortical target is the SC, which receives inputs from PT neurons 18,26 and has been implicated with somatosensory 18 and visual 61,63 perception, and decision-making 38,62,64 . Parietal CStr neurons were not required for sensory perception and may thus serve a different function, such as tracking task history 65 .…”