PT  - JOURNAL ARTICLE
AU  - Kenneth W. Latimer
AU  - David J. Freedman
TI  - Low-dimensional encoding of decisions in parietal cortex reflects long-term training history
AID  - 10.1101/2021.10.07.463576
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.10.07.463576
4099  - http://biorxiv.org/content/early/2021/10/09/2021.10.07.463576.short
4100  - http://biorxiv.org/content/early/2021/10/09/2021.10.07.463576.full
AB  - Neurons in parietal cortex exhibit task-related activity during decision-making tasks. However, it remains unclear how long-term training to perform different tasks over months or even years shapes neural computations and representations. We examine lateral intraparietal area (LIP) responses during a visual motion delayed-match-to-category (DMC) task. We consider two pairs of monkeys with different training histories: one trained only on the DMC task, and another first trained to perform fine motion-direction discrimination. We introduce generalized multilinear models to quantify low-dimensional, task-relevant components in population activity. During the DMC task, we found stronger cosine-like motion-direction tuning in the pretrained monkeys than in the DMC-only monkeys, and that the pretrained monkeys’ performance depended more heavily on sample-test stimulus similarity. These results suggest that sensory representations in LIP depend on the sequence of tasks that the animals have learned, underscoring the importance of training history in studies with complex behavioral tasks.Competing Interest StatementThe authors have declared no competing interest.