Neural correlates of face familiarity in institutionalised children and links to attachment disordered behaviour.

BACKGROUND
One of the most well-documented sequelae of early maltreatment and institutionalisation is attachment problems, including behaviours under the labels of reactive attachment disorder (RAD) and disinhibited social engagement disorder (DSED). Despite growing evidence of the neurobiological effects of institutionalisation, the neural correlates of these behavioural patterns are largely unknown.


METHODS
The current study examined effects of both institutionalisation in general and attachment disordered behaviour, in particular, on brain-based markers of face processing, in 100 Portuguese children (70 currently institutionalised, 30 continuously raised by their families). Children's neural processing of caregiver's and stranger's faces was assessed with Event-Related Potentials (ERPs).


RESULTS
Compared to children from the community, institutionalised children showed smaller amplitudes in the N170, to both stranger and caregiver faces. Amongst the institutionalised group, living in a setting with a higher children-to-caregivers' ratio was associated with smaller P400 amplitudes. The display of DSED symptoms was associated with a smaller P1 to both faces, as well as a reduced differentiation between faces in P400 amplitudes and smaller P400 to the stranger's face. In contrast, RAD symptoms were not associated with any ERP measures.


CONCLUSIONS
Results replicate previously reported hypoactivation in institutionalised children, in a less-globally deprived setting than past work, indicating that such a pattern is associated with lack of individualised care and increased symptoms of DSED.