Object representations and the influence of learning: Insights from single neurons in the human brain

Abstract

Objectives Learning associations between co-occurring events enables us to extract structure from our environment. However, the neuronal processes underlying the formation of new associations in the human brain are not yet well understood. Here I will present evidence for sparse representations of concepts in the human medial temporal lobe (MTL) and show how these representations can be modified by short-term learning. Methods and results Human participants, implanted with depth electrodes, learned arbitrary associations between images presented in an ordered, predictable sequence. During learning we recorded from MTL neurons and found that single MTL neurons showed asymmetric shifts in activity and started firing earlier in the sequence in anticipation of their preferred stimulus. In contrast, neurons in temporal cortex did not show anticipation effects as a result of this short-term learning. Conclusion These results demonstrate flexible representations in the MTL that could support rapid learning.