Purkinje cell activity during classical conditioning with different conditional stimuli explains central tenet of Rescorla–Wagner model [corrected].
A central tenet of Rescorla and Wagner's model of associative learning is that the reinforcement value of a paired trial diminishes as the associative strength between the presented stimuli increases. Despite its fundamental importance to behavioral sciences, the neural mechanisms underlying the model have not been fully explored. Here, we present findings that, taken together, can explain why a stronger association leads to a reduced reinforcement value, within the context of eyeblink conditioning. Specifically, we show that learned pause responses in Purkinje cells, which trigger adaptively timed conditioned eyeblinks, suppress the unconditional stimulus (US) signal in a graded manner. Furthermore, by examining how Purkinje cells respond to two distinct conditional stimuli and to a compound stimulus, we provide evidence that could potentially help explain the somewhat counterintuitive overexpectation phenomenon, which was derived from the Rescorla-Wagner model.
Associative Learning Group, Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden; The Linnaeus Centre Thinking in Time: Cognition, Communication and Learning, Lund University, 221 00 Lund, Sweden; anders.rasmussen@med.lu.se.
Anders
A
Rasmussen
Laboratory for Synthetic Perceptive, Emotive, and Cognitive Systems (SPECS), N-RAS, DTIC, Universitat Pompeu Fabra, 08018 Barcelona, Spain.
Riccardo
http://orcid.org/0000-0003-4808-6010
R
Zucca
Associative Learning Group, Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden; The Linnaeus Centre Thinking in Time: Cognition, Communication and Learning, Lund University, 221 00 Lund, Sweden;
Fredrik
http://orcid.org/0000-0001-5942-0606
F
Johansson
Associative Learning Group, Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden; The Linnaeus Centre Thinking in Time: Cognition, Communication and Learning, Lund University, 221 00 Lund, Sweden;
Dan-Anders
DA
Jirenhed
Associative Learning Group, Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden; The Linnaeus Centre Thinking in Time: Cognition, Communication and Learning, Lund University, 221 00 Lund, Sweden;
Germund
G
Hesslow
D000704:Analysis of Variance; D001245:Association Learning / Q000502:physiology*; D001767:Blinking / Q000502:physiology; D003214:Conditioning, Classical / Q000502:physiology*; D005108:Extinction, Psychological; D006801:Humans; D008960:Models, Psychological; D011689:Purkinje Cells / Q000502:physiology*; D012054:Reinforcement, Psychology
Rescorla–Wagner model; climbing fibers; eyeblink conditioning; inferior olive; nucleo-olivary pathway