ABSTRACT
Recent theorising has emphasised motivational systems, rather than specific emotional reactions, when interpreting frontal asymmetry. We examined the predictive utility of infant electroencephalogram (EEG) frontal asymmetry during two approach-oriented tasks within 82 mother-infant dyads (infant age: M = 38.88 weeks, SD = 8.13 weeks; infant ethnicity: 86.7% Caucasian; infant sex: 51.2% female). Peek-a-boo (PAB) and toy removal (TR) were chosen as predictors of mother-reported temperament, as both elicit approach motivation via a blocked goal in a joyful and frustrating context, respectively. TR asymmetry effect on surgency/positive affectivity (SPA) was observed and driven primarily by a significant predictive relationship between TR asymmetry and smiling and laughter, f
2
= 0.31. Negative emotionality (NE) related outcomes were predicted by TR asymmetry, driven by sadness, f
2
= 0.20. Other than occasional contributions of covariates, no additional statistically significant results were noted. These findings are discussed as most consistent with the capability model of lateralization.