Distinct cortisol effects on item and associative memory across memory phases.

Area of Science:

• Neuroscience
• Psychology
• Endocrinology

Background:

• Stressful situations significantly influence episodic memory formation, consolidation, and retrieval.
• Stress hormones, like cortisol, affect memory for individual items and their associations, but their interplay with memory phases and emotionality is unclear.

Purpose of the Study:

• To investigate the complex effects of cortisol on item and associative memory across different memory phases (encoding, consolidation, retrieval).
• To examine how emotionality of stimuli and cortisol administration timing interact to modulate memory performance.

Main Methods:

• Within-subject, double-blind, placebo-controlled study using exogenous cortisol (10 mg hydrocortisone) administration.
• Participants encoded neutral and emotional noun-image pairs, with cortisol administered pre-encoding, post-encoding, or pre-retrieval.
• Memory for individual items and associations was tested after a 24-hour delay, with salivary cortisol levels measured.

Main Results:

• Cortisol administration timing differentially affected item and associative memory.
• Post-encoding cortisol enhanced item memory, whereas pre-encoding and pre-retrieval administration impaired it.
• Pre-encoding cortisol impaired associative memory for neutral stimuli, with effects modulated by cortisol levels and emotionality.

Conclusions:

• Cortisol exerts complex, phase-dependent effects on both item and associative memory.
• The emotional content of memories interacts with cortisol's influence, highlighting a nuanced stress-memory relationship.
• Findings underscore the intricate modulation of memory by stress hormones across various stages and stimulus types.