Projects per year
Abstract
According to sequential sampling models, perceptual decision-making is based on accumulation of noisy evidence towards a decision threshold. The speed with which a decision is reached is determined by both the quality of incoming sensory information and random trial-by-trial variability in the encoded stimulus representations. To investigate those decision dynamics at the neural level, participants made perceptual decisions while functional magnetic resonance imaging (fMRI) was conducted. On each trial, participants judged whether an image presented under conditions of high, medium, or low visual noise showed a piano or a chair. Higher stimulus quality (lower visual noise) was associated with increased activation in bilateral medial occipito-temporal cortex and ventral striatum. Lower stimulus quality was related to stronger activation in posterior parietal cortex (PPC) and dorsolateral prefrontal cortex (DLPFC). When stimulus quality was fixed, faster response times were associated with a positive parametric modulation of activation in medial prefrontal and orbitofrontal cortex, while slower response times were again related to more activation in PPC, DLPFC and insula. Our results suggest that distinct neural networks were sensitive to the quality of stimulus information, and to trial-to-trial variability in the encoded stimulus representations, but that reaching a decision was a consequence of their joint activity.
Original language | English |
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Pages (from-to) | 190-200 |
Number of pages | 11 |
Journal | Neuropsychologia |
Volume | 111 |
DOIs | |
Publication status | Published - 1 Mar 2018 |
Keywords
- Decision difficulty
- Evidence accumulation
- Functional magnetic resonance imaging
- Perceptual decision-making
- Sequential sampling models
Projects
- 1 Finished
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ARC Centre of Excellence for Integrative Brain Function
Egan, G., Rosa, M., Lowery, A., Stuart, G., Arabzadeh, E., Skafidas, E., Ibbotson, M., Petrou, S., Paxinos, G., Mattingley, J., Garrido, M., Sah, P. K., Robinson, P. A., Martin, P., Grunert, U., Tanaka, K., Mitra, P., Johnson, G., Diamond, M., Margrie, T., Leopold, D., Movshon, J., Markram, H., Victor, J., Hill, S. & Jirsa, V. K.
Australian National University (ANU), Eidgenössische Technische Hochschule Zürich (ETH Zürich) (Federal Institute of Technology Zurich), Australian Research Council (ARC), Karolinska Institutet (Karolinska Institute), Council of the Queensland Institute of Medical Research (trading as QIMR Berghofer Medical Research Institute), Ecole Polytechnique Federale de Lausanne (EPFL) (Swiss Federal Institute of Technology in Lausanne) , Monash University, University of Melbourne, University of New South Wales (UNSW), University of Queensland , University of Sydney, Monash University – Internal University Contribution, NIH - National Institutes of Health (United States of America), Cornell University, New York University, Francis Crick Institute, Scuola Internazionale Superiore di Studi Avanzati (International School for Advanced Studies), Duke University, Cold Spring Harbor Laboratory, RIKEN
25/06/14 → 31/12/21
Project: Research