Hippocampal Contribution to Context Encoding across Development Is Disrupted following Early-Life Adversity

Area of Science:

• Neuroscience
• Developmental Psychology
• Cognitive Science

Background:

• Contextual processing is crucial for appropriate responses to environmental stimuli.
• Little is known about developmental changes in contextual processing or the impact of early life experiences.
• Childhood exposure to violence may alter how individuals process contextual information, particularly in threatening situations.

Purpose of the Study:

• To investigate age-related changes in context memory and neural correlates of context encoding in children and adolescents.
• To examine the influence of early life exposure to interpersonal violence on contextual processing and hippocampal function.
• To explore the relationship between hippocampal volume, functional connectivity, and memory for context-face pairings.

Main Methods:

• Sixty children and adolescents (8-19 years) completed a context encoding task during functional magnetic resonance imaging (fMRI).
• Participants encoded neutral, happy, and angry facial cues within realistic background scenes.
• A delayed match-to-sample design was used, followed by an out-of-scanner memory test for context-face pairings. Hippocampal volume was also assessed.

Main Results:

• Context memory and neural correlates of encoding did not vary significantly with age.
• Larger hippocampal volume correlated with better overall context memory.
• Children exposed to violence showed impaired memory for contexts with angry faces, reduced hippocampal volume, and atypical neural activity, including altered hippocampus-vlPFC connectivity.

Conclusions:

• The posterior hippocampus is involved in context encoding, a process that remains consistent from middle childhood to late adolescence.
• Childhood violence exposure is associated with deficits in encoding contextual information in the presence of threat.
• Atypical neural responses in violence-exposed children suggest attentional narrowing on threat cues, potentially impairing broader context processing and contributing to maladaptive fear responses.