Instituto de Neurobiología, UNAM, Campus Juriquilla, Queretaro, 76230, Mexico.
Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK.
Nat Commun. 2018 Mar 15;9(1):1098. doi: 10.1038/s41467-018-03482-8.
Perceptual categorization depends on the assignment of different stimuli to specific groups based, in principle, on the notion of flexible categorical boundaries. To determine the neural basis of categorical boundaries, we record the activity of pre-SMA neurons of monkeys executing an interval categorization task in which the limit between short and long categories changes between blocks of trials within a session. A large population of cells encodes this boundary by reaching a constant peak of activity close to the corresponding subjective limit. Notably, the time at which this peak is reached changes according to the categorical boundary of the current block, predicting the monkeys' categorical decision on a trial-by-trial basis. In addition, pre-SMA cells also represent the category selected by the monkeys and the outcome of the decision. These results suggest that the pre-SMA adaptively encodes subjective duration boundaries between short and long durations and contains crucial neural information to categorize intervals and evaluate the outcome of such perceptual decisions.
知觉分类取决于根据灵活的类别边界的概念，将不同的刺激分配到特定的类别中。为了确定类别边界的神经基础，我们记录了猴子执行区间分类任务时前扣带皮层神经元的活动，在一个会话的试验块之间，短和长类别之间的界限发生变化。大量细胞通过接近相应的主观极限的恒定活动峰值来编码这个边界。值得注意的是，达到这个峰值的时间根据当前块的类别边界而变化，这预测了猴子在逐次试验基础上的类别决策。此外，前扣带皮层神经元还代表了猴子选择的类别和决策的结果。这些结果表明，前扣带皮层自适应地编码了短和长持续时间之间的主观持续时间边界，并包含了对区间进行分类和评估此类知觉决策结果的关键神经信息。
