Global genetic variations predict brain response to faces.

Area of Science:

• Neuroscience
• Behavioral Genetics
• Developmental Psychology

Background:

• Facial expressions convey crucial social information.
• Understanding the genetic basis of brain responses to social cues is vital.

Purpose of the Study:

• To quantify the proportion of phenotypic variance in brain responses to facial expressions attributable to common genetic factors.
• To investigate the relationship between genetic influences, brain network properties, and individual differences in neural responses to facial expressions.

Main Methods:

• Utilized genomic-relationship-matrix restricted maximum likelihood (GREML) to analyze genetic variance.
• Employed functional magnetic resonance imaging (fMRI) in a large adolescent sample (n=1,620).
• Assessed brain responses in 25 regions of a defined face network.

Main Results:

• Common genetic variance explained 40-50% of phenotypic variance in 9 face network regions for ambiguous, but not angry, facial expressions.
• Genotype-phenotype relationship strength correlated with inter-individual variability in functional connections (R(2) = 0.38).
• Variability in connections showed inverted U-shaped relationships with observed connections (R(2) = 0.48) and response magnitude (R(2) = 0.32).

Conclusions:

• Common genetic variance significantly predicts brain responses to facial expressions in specific adolescent face network regions.
• Genetic influences appear to capture variations in how adolescent brains integrate these regions into the face network, particularly those with high connection variability.