Neural correlates of face familiarity in institutionalized 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 lessglobally deprived setting than past work, indicating that such a pattern is associated with lack of individualised care
and increased symptoms of DSED.
Acknowledgements The authors are grateful to Santiago Galdo-Alvarez for designing the ERP paradigm, to Alberto Crego for his assistance with EEG data pre-processing, and to Ines Fachada and Raquel Corval for their support with data collection. Special thanks go to the children, parents, and institutional staff who participated in the study. This work was supported by the Portuguese Foundation for Science and Technology [Grants PTDC/PSI-PCL/101506/008 and SFRH/BD/69840/2010]. The authors have declared that they have no competing or potential conflicts of interest.Key points Existing evidence of neural face processing in institutionalised children has previously been limited to settings of severe deprivation and the role of social/attachment behaviour scarcely investigated. We replicated findings of blunted amplitudes in a posterior component involved in face processing, in a less globally deprived setting than past work. Reduced ERP amplitudes and reduced neural differentiation between faces were associated with DSED, but not RAD, symptoms. Reduced ERP amplitudes were associated with exposure to a higher children-to-caregivers' ratio. These findings indicate that differences in neural processing of faces are associated with lack of individualised care, even in the absence of other types of deprivation, and with DSED. Interventions should address the deleterious interpersonal experience of being cared for by multiple caregivers but lacking one-to-one interactions, to which institutionalised children are exposed.