The Inferior Frontal Junction Jointly Encodes Target Identity and Feature Uncertainty

During visual search, one must hold in memory a representation of the target, called the attentional template. How such attentional templates are represented by the brain has been at the core of research on attention mechanisms for decades. The vast majority of visual search studies measured neural responses to fixed targets, whereby the task-relevant dimensions were cued reliably to provide a veridical target representation (Witkowski and Geng, 2019). However, typically we are required to search for items that have variable appearances that oftentimes can't be fully known in advance. Thus, understanding how the brain flexibly encodes variable and uncertain target features may be of fundamental importance in modeling search behavior in ecological conditions (Witkowski and Geng, 2019). Previous neuroimaging studies identified the prefrontal cortex (PFC), and in particular the inferior frontal junction (IFJ), as a prominent source of top-down signals in feature- and object-based attention (Baldauf and Desimone, 2014). While the IFJ and the dorsolateral PFC (DLPFC) likely share information during search behavior, as suggested by consistent coactivations between these regions, it is still unclear what their respective roles are (Witkowski and Geng, 2023). Increases in the BOLD signal have been associated with uncertainty in perceptual information and choice outcomes in PFC regions (Badre et al., 2012), and their multivariate patterns are hypothesized to reflect the encoding of target identity, as supported by several fMRI studies that were able to decode this information from the IFJ (Bedini and Baldauf, 2021). But how does the PFC integrate information about the target features and their uncertainty, and what are the specific roles of the IFJ and the DLPFC? A recent study by Witkowski and Geng (2023) addressed these questions by collecting fMRI data while subjects performed a visual search task. Their task builds upon previous evidence … Correspondence should be addressed to Marco Bedini at marco.bedini{at}fulbrightmail.org.