Top-down and bottom-up processes in auditory preception
Abstract
Auditory perception and decision-making are mediated by both bottom-up (feedforward) and top-down (feedback) processes. Bottom-up processes interpret incoming sensory information to form a categorical perceptual decision (e.g., did I hear ~bing~ or ~boing~?). In contrast, top-down processes such as cued or expectation-driven attention improve auditory perception by enhancing the neural representations of behaviorally relevant stimuli, while simultaneously suppressing neural representations of irrelevant stimuli. As a consequence of this interaction between bottom-up and top-down processes, a listener can flexibly direct his/her perceptual and cognitive resources in the pursuit of goal-directed behavior.The PI will conduct two experiments to identify and characterize the functional relevance of bottom-up and top-down processing in the context of an auditory perceptual decision about the frequency content of an acoustic stimulus stream. In Experiment #1, the PI will characterize if and how neural activity at several stages of the ventral pathway is modulated by a monkey~s perceptual reports. In Experiment #2, the PI will test how neurons in (1) auditory cortex, which provides evidence for the decision, and (2) vPFC, which represents the outcome of the decision, respond to auditory input when governed by a bottom-up decision process (e.g., interpret the sensory evidence to form the decision) or a top-down postdecision process (e.g., enhance responses to stimuli that are consistent with the decision and suppress responses to other stimuli).The experiments are complementary, choice-related modulations identified in the first experiment are expected to be predictive of the effects on selectivity identified in the second experiment. However, the experiments also stand alone, because any new information about choice modulations and decision-related changes in stimulus selectivity will enhance our understanding of how neural processing in the ventral auditory pathway relates to auditory perception and decision-making. These experiments also set the stage for planned future work to more precisely identify the oscillatory circuit mechanisms responsible for interacting bottom-up and top-down processes in the context of auditory decision-making and perception. The experiments in this research proposal are executed through a unique combination of quantitative auditory psychophysics and neurophysiological techniques in behaving monkeys and computational modeling.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 23, 2016
- Source ID
- N000141612539
Entities
People
- Yale Cohen
Organizations
- Office of Naval Research
- United States Navy
- University of Pennsylvania