Informativeness, contingency and time scale invariance in associative learning

Contemporary theories guiding the search for neural mechanisms of learning
and memory assume that associative learning results from the temporal
pairing of cues and reinforcers resulting in coincident activation of
associated neurons, strengthening their synaptic connection. While
enduring, this framework has limitations: Temporal-pairing-based models of
learning do not fit with many experimental observations and cannot be used
to make quantitative predictions about behavior. Here we present
behavioral data that supports an alternative, information-theoretic
conception: The amount of information that cues provide about the timing
of reward delivery predicts behavior. Furthermore, this approach accounts
for the rate and depth of both inhibitory and excitatory learning across
paradigms and species. We also show that dopamine release in the ventral
striatum reflects cue–predicted changes in reinforcement rates consistent
with subjects understanding temporal relationships between task events.
Our results reshape the conceptual and biological framework for
understanding associative learning.