Dissociating representations of time and number in reinforcement rate learning by GluA1 AMPAR subunit deletion in mice

Austen, J. M.; Pickering, C.; Sprengel, R.; Sanderson, D. J.

Abstract

Theories of learning differ in whether they assume that learning reflects the strength of an association between memories or symbolic encoding of the statistical properties of events. We provide novel evidence for symbolic encoding of informational variables by demonstrating that sensitivity to time and number in learning is dissociable. Whereas responding in normal mice was dependent on reinforcement rate, responding in mice that lacked the GluA1 AMPA receptor subunit was insensitive to reinforcement rate and, instead, dependent on the number of times a cue had been paired with reinforcement. This suggests that GluA1 is necessary for weighting numeric information by temporal information in order to calculate reinforcement rate. Sample sizes per genotype varied between seven and 23 across six experiments and consisted of both male and female mice. The results provide evidence for explicit encoding of variables by animals rather than implicit encoding via variations in associative strength.

Citation

Austen, J. M., Pickering, C., Sprengel, R., & Sanderson, D. J. (2021). Dissociating representations of time and number in reinforcement rate learning by GluA1 AMPAR subunit deletion in mice. Psychological Science, 32(2), 204-217. https://doi.org/10.1177/0956797620960392

• Journal Article Type: Article
• Acceptance Date: Jul 17, 2020
• Online Publication Date: Jan 4, 2021
• Publication Date: Feb 1, 2021
• Deposit Date: Jul 17, 2020
• Publicly Available Date: Feb 12, 2021
• Journal: Psychological Science
• Print ISSN: 0956-7976
• Electronic ISSN: 1467-9280
• Publisher: SAGE Publications
• Peer Reviewed: Peer Reviewed
• Volume: 32
• Issue: 2
• Pages: 204-217
• DOI: https://doi.org/10.1177/0956797620960392
• Public URL: https://durham-repository.worktribe.com/output/1266128