AUTHOR=Maksimenko Vladimir A. , Kuc Alexander , Frolov Nikita S. , Khramova Marina V. , Pisarchik Alexander N. , Hramov Alexander E. 

TITLE=Dissociating Cognitive Processes During Ambiguous Information Processing in Perceptual Decision-Making

JOURNAL=Frontiers in Behavioral Neuroscience

VOLUME=Volume 14 - 2020

YEAR=2020

URL=https://www.frontiersin.org/journals/behavioral-neuroscience/articles/10.3389/fnbeh.2020.00095

DOI=10.3389/fnbeh.2020.00095

ISSN=1662-5153

ABSTRACT=Decision-making requires accumulating sensory evidence. However, in everyday life, sensory information is often ambiguous and contains decision-irrelevant features. It requires the brain to disambiguate sensory input and extract decision-relevant features.  The sensory information processing and decision-making represent two subsequent stages of the perceptual decision-making process. While sensory processing relies on the occipito-parietal neuronal activity during the earlier time window, decision-making lasts for a prolonged time involving parietal and frontal areas.  Although perceptual decision-making is actively studied, its neuronal mechanisms under the ambiguous sensory evidence lack detailed consideration. Here, we analyzed the brain activity of subjects accomplishing a perceptual decision-making task involving ambiguous stimuli classification. We demonstrated that ambiguity induced high frontal $\theta$-band power for 0.15~s post-stimulus onset, indicating increased reliance on top-down processes such as expectations and memory. Ambiguous processing also caused high occipito-parietal $\beta$-band power for 0.2~s and high fronto-parietal $\beta$-power for $0.35-0.42$~s post-stimulus onset. We supposed that the former component subserved the disambiguation process, while the latter one reflected the decision-making phase. Our findings complemented the existing knowledge about the ambiguous perception by providing additional information regarding the temporal discrepancy between the different cognitive processes during the perceptual-decision making.