Acute stress throughout the memory cycle: Diverging effects on associative and item memory

Area of Science:

• Cognitive Neuroscience
• Psychology

Background:

• Acute stress is known to affect memory, but its specific influence on memory for individual items versus associations between items is not well understood.
• Understanding these differential effects is crucial for comprehending memory's adaptability under stress.

Purpose of the Study:

• To investigate the distinct effects of acute stress on item memory and associative memory in humans.
• To examine how the timing of stress (pre-encoding, post-encoding, preretrieval) and cortisol levels influence different memory components.

Main Methods:

• A within-subjects design was employed, where participants formed associations between negative words and neutral objects.
• Subjective arousal was rated, followed by delayed recognition tasks for both items and paired associations.
• Salivary cortisol levels were measured to correlate with memory performance.

Main Results:

• Pre-encoding stress enhanced associative memory for high-arousal pairs.
• Post-encoding stress selectively improved item memory.
• Preretrieval stress impaired both item and associative memory.
• Cortisol showed a linear relationship with item memory and a quadratic relationship with associative memory.

Conclusions:

• Stress exerts differential effects on item and associative memory depending on its timing within the memory cycle.
• These findings highlight the complex interplay between acute stress, cortisol, and the distinct neural mechanisms supporting different types of memory formation and retrieval.