Perceptual Categorization: Connectionist Modelling and Decision Rules

Although it is currently popular to model human associative learning using connectionist networks, the mechanism by which their output activations are converted to probabilities of response has received relatively little attention. Several possible models of this decision process are considered here, including a simple ratio rule, a simple difference rule, their exponential versions, and a winner-take-all network. Two categorization experiments that attempt to dissociate these models are reported. Analogues of the experiments were presented to a single-layer, feed-forward, delta-rule network. Only the exponential ratio rule and the winner-take-all architecture, acting on the networks' output activations that corresponded to responses available on test, were capable of fully predicting the mean response results. In addition, unlike the exponential ratio rule, the winner-take-all model has the potential to predict latencies. Further studies will be required to determine whether latencies produced under more stringent conditions conform to the model's predictions.     

睡眠不足对人际交互的影响及其认知神经机制

睡眠不足会对人的认知、情感和人际交互产生诸多影响。这种影响在社会情绪层面表现为个体情绪共情和认知共情的减少,易激惹性与愤怒情绪的增加;在社会行为层面则表现为亲社会行为的减少和攻击行为的增加。在睡眠不足状态下,情绪系统和认知系统功能连接的减弱可能是这些变化的潜在机制。未来应结合生态效度较高的睡眠操作手段,系统考察睡眠不足如何导致各种高级社会情绪的改变,以及这些社会情绪的变化如何导致社会行为的变化。