The role of dorsal premotor cortex in decision-making and action selection

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Abstract/Contents

Abstract
Why do we do the things we do? Understanding cognition is a key step towards understanding our diverse perspectives and behaviors. Over the years, the study of decision-making in neuroscience has shed light on the black box of cognition. Decision-making is the process of arriving at one choice out of multiple alternatives, and correlates of this process have been found in many sensory- and motor-related brain structures. However, we do not have a full account of the way in which brain regions participate in this process, especially given the many potential forms that decision-making can take. Here, we focus in on the dorsal premotor cortex (PMd), a frontal brain region involved in motor preparation and execution, decision-making, and goal-oriented action. We use a perceptual decision-making task in which the subject reports the perceived dominant color of a red-and-green checkerboard by reaching to the corresponding colored target. Studies have previously found that the activity of PMd neurons correlate with the choice report, the evidence supporting that choice, and the time taken to deliberate upon the choice. We now ask: To what extent is PMd involved in the perceptual aspect of decision-making, and how do motor costs affect the decision-making process? First, we separate the perceptual process (whether the checkerboard is mostly red or green) from the motor process (to reach left or right) by presenting a checkerboard decision cue without providing information on how to report. We found that PMd neurons did not encode information about the perceptual color choice, but did exhibit decision-related activity when the subject was able to report the choice. We next randomly assign the positions of the target choices to be near or far relative to the hand's starting position. We found that performance was biased towards the choice that was closer to the animal, and that these target configurations were reflected in neural activity during the report epoch as well. These findings suggest that PMd involvement in the decision process is primarily in an action-decision space, and that relevant motor and perceptual information are combined at the same time. These results provide stepping stones towards understanding how brain regions drive our perception and behavior.

Description

Type of resource text
Form electronic resource; remote; computer; online resource
Extent 1 online resource.
Place California
Place [Stanford, California]
Publisher [Stanford University]
Copyright date 2019; ©2019
Publication date 2019; 2019
Issuance monographic
Language English

Creators/Contributors

Author Wang, Megan
Degree supervisor Shenoy, Krishna V. (Krishna Vaughn)
Thesis advisor Shenoy, Krishna V. (Krishna Vaughn)
Thesis advisor Baccus, Stephen A
Thesis advisor Moore, Tirin, 1969-
Thesis advisor Newsome, William T
Degree committee member Baccus, Stephen A
Degree committee member Moore, Tirin, 1969-
Degree committee member Newsome, William T
Associated with Stanford University, Neurosciences Program.

Subjects

Genre Theses
Genre Text

Bibliographic information

Statement of responsibility Megan Wang.
Note Submitted to the Neurosciences Program.
Thesis Thesis Ph.D. Stanford University 2019.
Location electronic resource

Access conditions

Copyright
© 2019 by Megan Wang
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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