Abstract: There is growing evidence that working memory, episodic/semantic memory, and procedural memory all play important roles in at least some types of category learning. Little is known, however, about the role of the perceptual representation memory system (PRS). Two experiments are reported that provide evidence that under certain conditions, the PRS, by itself,...
Abstract: A biologically detailed computational model is described of how categorization judgments become automatic in tasks that depend on procedural learning. The model assumes 2 neural pathways from sensory association cortex to the premotor area that mediates response selection. A longer and slower path projects to the premotor area via the striatum, globus pallidus,...
Abstract: Categorization is the act of responding differently to objects or events in separate classes or categories. It is a vitally important skill that allows us to approach friend and escape foe, to find food and avoid toxin. Every organism must have some categorization ability. Even bacteria categorize. For example, the bacterium e. coli...
Abstract: The target article postulates that rule-based and similaritybased categorization are best described by a unitary process. A number of recent empirical dissociations between rule-based and similarity-based categorization severely challenge this view. Collectively, these new results provide strong evidence that these two types of category learning are mediated by separate systems. This is paper...
Abstract: Many studies suggest that the sustained activation underlying working memory (WM) maintenance is mediated by a distributed network that includes the prefrontal cortex and other structures (e.g., posterior parietal cortex, thalamus, globus pallidus, and the caudate nucleus). A computational model of WM, called FROST (short for FROntal–Striatal–Thalamic), is proposed in which the representation...
Abstract: Standard techniques from pharmacology and current theories on the biochemistry of dopamine (DA) are used to derive a new model of how DA modulates cortical activation. The model assumes that DA potentiates the glutamate response through the NMDA receptor and depresses the glutamate response through non-NMDA receptors. A static version of the model...
Abstract: There is much recent interest in the question of whether people have available a single category learning system or a number of qualitatively different systems. Most proponents of multiple systems have hypothesized an explicit, rule-based system and some type of implicit system. Although there has been general agreement about the nature of the...