Brain activation during human defensive behaviour: A systematic review and preliminary meta-analysis

Area of Science:

• Neuroscience
• Behavioral Science

Background:

• Understanding the neural basis of defensive behaviors is crucial for both fundamental research and clinical applications.
• Defensive behaviors encompass simple threat avoidance and complex approach-avoidance during goal conflicts.

Purpose of the Study:

• To systematically review neural responses during simple avoidance and approach-avoidance behaviors.
• To conduct an exploratory meta-analysis of whole-brain data related to defensive behaviors.

Main Methods:

• Systematic literature search of Scopus, PsychInfo, and Web of Science databases up to March 2018.
• Inclusion of 8 simple avoidance and 11 goal-conflict studies, with 5 datasets for meta-analysis.
• Exploratory meta-analysis of whole-brain imaging data.

Main Results:

• Observed a shift in neural activation from forebrain to midbrain as threat proximity increased.
• This pattern aligns with Reinforcement Sensitivity Theory and some animal studies.
• Preliminary meta-analysis findings did not consistently reflect the observed activation shift.

Conclusions:

• Significant heterogeneity exists in current defensive behavior research paradigms.
• There is a notable lack of research involving clinically relevant populations.
• Further research with standardized paradigms is needed to clarify the neural underpinnings of defensive behaviors.