Cortical recruitment determines learning dynamics and strategy

• Published in: Nature communications 2019-04, Vol.10 (1), p.1479-1479, Article 1479
• Main Authors: Ceballo, Sebastian, Bourg, Jacques, Kempf, Alexandre, Piwkowska, Zuzanna, Daret, Aurélie, Pinson, Pierre, Deneux, Thomas, Rumpel, Simon, Bathellier, Brice
• Format: Article
• Language: English
• Subjects: 631/378/1595/1395; 631/378/1595/1396; 631/378/1595/2618; 631/378/2619/2618; Acoustics; Activity patterns; Animals; Auditory Cortex; Auditory Cortex - physiology; Auditory discrimination; Auditory Perception; Auditory Perception - physiology; Cerebral Cortex; Cerebral Cortex - physiology; Cognitive Sciences; Conditioning; Cortex (auditory); Cortex (temporal); Cues; Discrimination Learning; Discrimination Learning - physiology; Frequency; Go/no-go discrimination learning; Humanities and Social Sciences; Learning; Learning - physiology; Life Sciences; Machine learning; Mice; multidisciplinary; Nervous system; Neurobiology; Neurons and Cognition; Optogenetics; Psychology and behavior; Recruitment; Reinforcement; Reinforcement, Psychology; Salience; Science; Science (multidisciplinary); Temporal variations
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-09450-0

Salience is a broad and widely used concept in neuroscience whose neuronal correlates, however, remain elusive. In behavioral conditioning, salience is used to explain various effects, such as stimulus overshadowing, and refers to how fast and strongly a stimulus can be associated with a conditioned event. Here, we identify sounds of equal intensity and perceptual detectability, which due to their spectro-temporal content recruit different levels of population activity in mouse auditory cortex. When using these sounds as cues in a Go/NoGo discrimination task, the degree of cortical recruitment matches the salience parameter of a reinforcement learning model used to analyze learning speed. We test an essential prediction of this model by training mice to discriminate light-sculpted optogenetic activity patterns in auditory cortex, and verify that cortical recruitment causally determines association or overshadowing of the stimulus components. This demonstrates that cortical recruitment underlies major aspects of stimulus salience during reinforcement learning. Sounds vary in the strength of behavioural conditioning they can evoke, a property attributed to stimulus salience. Here, the authors show that stimulus salience the overall level of neuronal activity recruited in the auditory cortex is strongly related with its reinforcing strength.