Integrating unsupervised and reinforcement learning in human categorical perception: A computational model

PLoS One. 2022 May 10;17(5):e0267838. doi: 10.1371/journal.pone.0267838. eCollection 2022.

Abstract

Categorical perception identifies a tuning of human perceptual systems that can occur during the execution of a categorisation task. Despite the fact that experimental studies and computational models suggest that this tuning is influenced by task-independent effects (e.g., based on Hebbian and unsupervised learning, UL) and task-dependent effects (e.g., based on reward signals and reinforcement learning, RL), no model studies the UL/RL interaction during the emergence of categorical perception. Here we have investigated the effects of this interaction, proposing a system-level neuro-inspired computational architecture in which a perceptual component integrates UL and RL processes. The model has been tested with a categorisation task and the results show that a balanced mix of unsupervised and reinforcement learning leads to the emergence of a suitable categorical perception and the best performance in the task. Indeed, an excessive unsupervised learning contribution tends to not identify task-relevant features while an excessive reinforcement learning contribution tends to initially learn slowly and then to reach sub-optimal performance. These results are consistent with the experimental evidence regarding categorical activations of extrastriate cortices in healthy conditions. Finally, the results produced by the two extreme cases of our model can explain the existence of several factors that may lead to sensory alterations in autistic people.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Computer Simulation
  • Humans
  • Perception
  • Reinforcement, Psychology*
  • Reward*

Grants and funding

GG: received funding from the European Union’s Horizon 2020 Research and Innovation Program, under Grant Agreement No 713010 of the project ‘GOAL-Robots -- Goal-based Open-ended Autonomous Learning Robots’ FD: received funding from the H2020-MSCA-IF-2017, under Grant Agreement No 796135 of the project ‘INTENSS’. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.