Conditioning with spatio-temporal patterns: Constraining the contribution of the hippocampus to configural learning

- The hippocampus has been implicated in learning about spatio-temporal patterns.
- Retrieval-mediated learning about such patterns depends on the hippocampus.
- Here, direct learning about the same patterns did not depend on the hippocampus.

The conditions under which the hippocampus contributes to learning about spatio-temporal configural patterns are not fully established. The aim of Experiments 1-4 was to investigate the impact of hippocampal lesions on learning about where or when a reinforcer would be delivered. In each experiment, the rats received exposure to an identical set of patterns (i.e., spotted + morning, checked + morning, spotted + afternoon and checked + afternoon); and the contexts (Experiment 1), times of day (Experiment 2), or their configuration (Experiments 3 and 4) signalled whether or not a reinforcer would be delivered. The fact that hippocampal damage did not disrupt the formation of simple or configural associations involving spatio-temporal patterns is surprising, and suggests that the contribution of the hippocampus is restricted to mediated learning (or updating) involving spatio-temporal configurations.