Cognitive Memory System

The identified brain-wide distributed network, or cognitive memory system, comprises three major subsystems: the medial temporal lobe, the temporal cortex, and the frontal cortex. Humans memory types are extended into animals as episodic-like (event) memory or semantic-like (fact) memory.

The ultimate storage sites for explicit memories (for facts and events) appear to be cortical, but the medial temporal lobe plays a critical enabling role in storage. The unique configurational association between environmental stimuli and behavioral context, which likely form the basis of episodic-like memory, relies on neural circuits in the medial temporal lobe. Memory traces representing repeated associations, whichlikely form the basis of semantic-like memory, are consolidated in the domain-specific regions in the temporal cortex.

During recall, domain-specific cortical regions in the temporal lobes are reactivated and contribute to the contents of a memory. This reactivation process is mediated by various signals, including a top-down signal from the prefrontal cortex and a signal up from the limbic cortex. The active, top-down retrieval signal runs from the frontal cortex for effortful. Automatic retrieval spreads backward from the medial temporal lobe.

Strategic attempts for retrieval and encoding are mediated by the frontal regions, which also monitor outcome. By sending the top-down signal to the temporal cortex, frontal regions manipulate and organize to-be-remembered information, devise strategies for retrieval, and also monitor the outcome, with dissociated frontal regions making functionally separate contributions. The dissociated frontal regions perform functionally separate contributions.

Adapted from here.

No comments: