Discussion Meeting: Semantic
Memory
Acute stress enhances general-knowledge semantic memory
Smith et al. (2019)
Introduction
Stress has been shown to influence retrieval via a post-stress hormonal cascade that
impairs activity in brain regions associated with retrieval. However, not all types of
memory are controlled in these brain regions.
Present research → aimed to determine how stress influences memories that do not
depend on neural pathways that are disrupted by stress.
Episodic memory: memory for events and information that are associated with the
context in which they took place
Semantic memory: general knowledge of facts, concepts, and language that is
independent of a learning context
Research has focused on the effects of stress on episodic memory, but EM and SM
have different neural substrates. Both EM and SM retrieval recruit the HPC. However,
neuropsychological studies show that the HPC is only essential for retrieving EMs.
When HPC functioning is reduced or eliminated, many SMs can still be retrieved. This
may occur because SM retrieval recruits neocortical and striatal pathways, which
provide retrieval routes that bypass the HPC.
SM retrieval may benefit from stress because the neocortical and striatal regions that
support SM also exhibit increased activity during the stress response.
It is important to consider that across studies on stress and EM retrieval, the impairment
typically observed occurs more commonly on effortful memory tests (e.g., free recall)
than on easier tests (e.g., T/F). This raises the question of whether SM is immune to
stress, or low-demand memory tests tend to be unaffected by stress.