Top-down specific preparatory activations for Selective Attention and Perceptual Expectations

Abstract

SummaryProactive cognition brain models are mainstream nowadays. Within these, preparation is understood as an endogenous, top-down function that takes place prior to the actual perception of a stimulus and improves subsequent behavior. Neuroimaging has uncovered the existence of such preparatory activity in different cognitive domains, however no research to date has sought to uncover their potential similarities and differences. Two of these domains, often confounded in the literature, are Selective Attention (information relevance) and Perceptual Expectation (information probability). We used EEG to characterize the mechanisms that support preparation in Attention and Expectation. In different blocks, participants were cued to the relevance or to the probability of target categories, faces vs. names in a gender discrimination task. Multivariate Pattern (MVPA) and Representational Similarity Analyses (RSA) during the preparation window showed that both manipulations led to a significant, ramping-up prediction of the relevant or expected target category. However, classifiers trained on data from one condition did not generalize to the other, indicating the existence of different anticipatory neural patterns. Further analyses pointed to a differential involvement of specific frequency bands in each condition. Finally, a Canonical Template Tracking procedure showed that there was stronger perceptual reinstatement for Attention than for Expectation. Overall, results indicate that preparation during attention and expectation acts through different, although partially overlapping, neural mechanisms. These findings have important implications for current models of brain functioning, as they are a first step towards characterizing and dissociating the neural mechanisms involved in top-down anticipatory processing.

Canonical template tracking: Measuring the activation state of specific neural representations

“…Finally, while locating the localizer(s) at the beginning or the end of the experimental session is straightforward to implement, it can be subject to contaminating effects that evolve over time, such as participants' fatigue or practice, or low-frequency noise from the neuroimaging technique employed. To prevent that, the main paradigm blocks can be alternated with the localizer(s) during the experimental session (e.g., Peñalver et al, 2022 ). In that case, further control on task (localizer, main paradigm) order should be implemented.…”