Are Orchids Left and Dandelions Right? Frontal Brain Activation Asymmetry and Its Sensitivity to Developmental Context

Abstract

To clarify long-standing conceptual and empirical inconsistencies in models describing the relation between frontal brain asymmetry and emotion, we tested a theory of biological sensitivity to context. We examined whether asymmetry of alpha activation in frontal brain regions, as measured by resting electroencephalography, is sensitive to early developmental contexts. Specifically, we investigated whether frontal asymmetry moderates the association between birth weight and adult outcomes. Adults with left frontal asymmetry (LFA) who were born at extremely low birth weight exhibited high levels of attention problems and withdrawn behaviors in their 30s, whereas normal-birth-weight adults with LFA had low levels of these problem behaviors. Adults with right frontal asymmetry (RFA) displayed a relatively moderate amount of problem behavior regardless of birth weight. Our findings suggest that LFA is associated with sensitivity to developmental context and may help explain why LFA is associated with both positive and negative outcomes, whereas RFA seems to be associated with a more canalized process in some contexts.

Maternal sensitivity and infant response to frustration: The moderating role of EEG asymmetry

“…In contrast, in the presence of positive environmental context, right frontal asymmetry was associated with more negativity; consistent with previous work in which right frontal asymmetry reliably characterizes negative affectivity (e.g. Schmidt, 1999; Fortier et al, in press). …”

“…An alternative explanation of our findings comes from emerging work (Fortier, Can Lieshout, Waxman, Boyle, Saigal, & Schmidt, in press) which suggests that resting frontal EEG asymmetry may be a biological factor indexing sensitivity to developmental context; essentially conceptualizing frontal asymmetry in terms of the differential susceptibility to environment theory (Belsky, Bakermans-Kranenburg, & Van IJzendoorn, 2007; Belsky & Pluess, 2009; Ellis et al, 2011). Fortier and colleagues found that adults who exhibited left frontal asymmetry and were born with extremely low birth weight (their measure of early developmental context) exhibited the highest levels of attention problems in adulthood, while adults with left frontal asymmetry who were born with a normal birth weight displayed the lowest levels of problem behaviors.…”

Longitudinal Associations Among Child Maltreatment, Resting Frontal Electroencephalogram Asymmetry, and Adolescent Shyness

“…As can be observed from Figure , levels of shyness for relative left frontal asymmetry are relatively high across all participants, and control participants with relative left asymmetry have shyness levels comparable to maltreated participants. This finding is consistent with the notion that relative left frontal asymmetry supports both positive and negative emotional experiences (see Fortier et al., ), and it is possible that among control participants in our sample, left asymmetry is associated with negative emotionality. These results extend earlier work that has suggested that individual differences in resting frontal EEG asymmetry may serve as a differential susceptibility factor (Fortier et al., ).…”

“…This finding is consistent with the notion that relative left frontal asymmetry supports both positive and negative emotional experiences (see Fortier et al., ), and it is possible that among control participants in our sample, left asymmetry is associated with negative emotionality. These results extend earlier work that has suggested that individual differences in resting frontal EEG asymmetry may serve as a differential susceptibility factor (Fortier et al., ). Future research should examine the role of relative frontal asymmetry in the link between child maltreatment and additional social‐emotional outcomes.…”

“…Thus, frontal EEG alpha asymmetry at rest may be a correlate of exposure to early adversity. However, we know relatively little about whether this neurobiological sensitivity (Fortier et al., ) plays a role in the development of behavioral phenotypes among adolescents who were exposed to maltreatment as children. Given the link between right frontal asymmetry‐ and withdrawn‐related behaviors, it is likely that this neurobiological marker may also serve as a moderator (Coan & Allen, ) between the impact of child maltreatment and the development of shyness, as well as psychopathology.…”