Neural Substrates and Models of Omission Responses and Predictive Processes

Abstract

Predictive coding theories argue that deviance detection phenomena, such as mismatch responses and omission responses, are generated by predictive processes with possibly overlapping neural substrates. Molecular imaging and electrophysiology studies of mismatch responses and corollary discharge in the rodent model allowed the development of mechanistic and computational models of these phenomena. These models enable translation between human and non-human animal research and help to uncover fundamental features of change-processing microcircuitry in the neocortex. This microcircuitry is characterized by stimulus-specific adaptation and feedforward inhibition of stimulus-selective populations of pyramidal neurons and interneurons, with specific contributions from different interneuron types. The overlap of the substrates of different types of responses to deviant stimuli remains to be understood. Omission responses, which are observed both in corollary discharge and mismatch response protocols in humans, are underutilized in animal research and may be pivotal in uncovering the substrates of predictive processes. Omission studies comprise a range of methods centered on the withholding of an expected stimulus. This review aims to provide an overview of omission protocols and showcase their potential to integrate and complement the different models and procedures employed to study prediction and deviance detection.This approach may reveal the biological foundations of core concepts of predictive coding, and allow an empirical test of the framework’s promise to unify theoretical models of attention and perception.

Stimulus novelty uncovers coding diversity in visual cortical circuits

“…Stimulus omissions are another form of contextual novelty in which expectation is violated, i . e ., a predicted input does not occur (Braga and Schönwiesner, 2022). In sessions with familiar stimuli, we found that Vip activity showed ramping behavior during the inter-stimulus interval and continued to ramp up during unexpected omissions.…”

“…Instead, ramping activity in Vip cells could represent more general information about task timing (Rabinovich et al, 2022), temporal expectation (Nobre et al, 2007), prediction error (Orlova et al, 2021;Wacongne et al, 2011), salience (Itti and Koch, 2001), stimulus contrast (Millman et al, 2020) or a combination of these (Braga and Schönwiesner, 2022).…”

“…The neural effects of novelty are widespread, affecting cortical, subcortical, and neuromodulatory systems (Braga and Schönwiesner, 2022; Kafkas and Montaldi, 2018; Ranganath and Rainer, 2003; Schomaker and Meeter, 2015; Tapper and Molas, 2020). A common observation across species and sensory modalities is that novel stimuli evoke larger sensory responses compared to familiar stimuli (Ranganath and Rainer, 2003; Schomaker and Meeter, 2015).…”

“…This novelty effect (or it’s inverse, the familiarity effect) is observed both at the macro-level using techniques such as EEG and fMRI in humans (Courchesne et al, 1975; Daffner et al, 2000; Hawco and Lepage, 2014), and at the single cell level using single unit recordings in animals (Li et al, 1993; Meyer and Rust, 2018; Xiang and Brown, 1998; Zhang et al, 2022). Contextual novelty effects such as repetition suppression, mismatch negativity, and deviance detection are thought to arise through adaptation (Braga and Schönwiesner, 2022; Garrido et al, 2009; Grill-Spector et al, 2006; Hu et al, 2021; Nelken and Ulanovsky, 2007). However, the cell types and circuits that underlie the lifetime history-dependent effects of absolute stimulus novelty are unknown.…”

“…Contextual novelty arises when a rare or unexpected stimulus appears among more common, repeated stimuli, thus deviating from local stimulus context. The omission of a stimulus from an expected or predictable sequence is a second form of novelty or surprise (Braga and Schönwiesner, 2022). Finally, absolute stimulus novelty is defined as the exposure to a stimulus that has not been experienced before.…”