Dynamics of payoff and stimulus effects on decisions under time pressure : combined behavioral, EEG and model-based analysis
Abstract/Contents
- Abstract
- It is well established that prior knowledge about payoff can bias decisions toward higher-paying alternatives. However, little is known about how payoff information affects the neural mechanism underlying these biased choices in humans. We address this question by recording electroencephalography (EEG) signals from 13 participants while they performed a two-alternative forced-choice task. On each trial, the participant judged whether a rectangle was shifted to the right or to the left of the fixation point and responded by squeezing the right- or left-hand dynamometer. Participants were cued about the payoff of each choice before stimulus onset and had to respond correctly before a short deadline (375-475 ms) to obtain the payoff. We show that payoff information influences participants' choices and response times: the frequency and speed of choices toward the higher-paying alternative increases. Moreover, we show that payoff bias is represented in the lateralized readiness potential (LRP), a response-related brain potential reflecting the preparation of motor activity in a specific hand. The representation of payoff bias in LRP has two components: a static component that shifts the LRP baseline toward the higher-paying alternative for hundreds of milliseconds before stimulus onset; and a dynamic component that causes an abrupt rise in LRP toward the higher-paying alternative after stimulus onset (but before stimulus information influences the decision). These components seem to reflect different processes; while the static component is not predictive of participants' choices or response times, the dynamic component predicts both. We also provide evidence showing that the static and dynamic LRP components propagate down to the muscles and can generate isometric forces measurable by dynamometers. Finally, drawing on both the LRP and motor responses, we present a new model for the effects of payoff information on the decision-making process. This model is based on a competition between a fast- guess process that is informed solely by payoff information and an evidence accumulation process that is informed by the sensory stimulus.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2013 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Noorbaloochi, Sharareh |
|---|---|
| Associated with | Stanford University, Department of Electrical Engineering. |
| Primary advisor | McClelland, James L |
| Primary advisor | Shenoy, Krishna V. (Krishna Vaughn) |
| Thesis advisor | McClelland, James L |
| Thesis advisor | Shenoy, Krishna V. (Krishna Vaughn) |
| Thesis advisor | Widrow, Bernard, 1929- |
| Advisor | Widrow, Bernard, 1929- |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Sharareh Noorbaloochi. |
|---|---|
| Note | Submitted to the Department of Electrical Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2013. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2013 by Sharareh Noorbaloochi
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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