Object or cake? Selective processes in the human brain for the recently discovered specialized food area in the ventral visual stream

Abstract

The human ventral visual cortex shows category-selective organization to recognize and discriminate between ecologically important categories like faces, words, body parts, and places. The food image selective region in the ventral stream has been discovered by recent data-driven studies, which is called the ventral food stream. The overarching goal of this study is to investigate the ventral food stream by employing a novel object-food illusion: a hyper-realistic cake. In hyper-realistic cake videos, the initial object perception shifts to a perception of cake throughout the video. We conducted two different experiments. In Experiment 1, we collected behavioral data from 22 participants to validate the hyper-realistic cake videos. In Experiment 2, we first applied a functional localizer one-back task and employed validated object-food illusion videos with fMRI. Consistent with the recent findings of food selectivity, we identified the foodselective response in the ventral food stream by using a functional localizer task. During the video session, the ventral food stream exhibits a significant increase in activity when the object perception shifts to perception of a cake. Despite showing spatial variability between participants, there is a selective response to visual food cues in the fusiform cortex. This study shows the food-selective activity in the ventral visual cortex in response to illusory visual stimuli in a hypothesis-driven manner. Future studies should conduct functional connectivity analysis to investigate how activity in the ventral food stream is correlated with activity in the gustatory cortices.