1. Objectifs

Intentions :
This study investigates «the magnitude of the LPP [late positive potential] elicited by facial displays of threat in adults who reported CM [childhood maltreatment]. To extend previous studies, [the authors] focused on young adults who reported diverse forms of abuse (e.g., physical, emotional, and sexual abuse) during childhood, and [they] examined LPP modulation by both ambiguous and nonambiguous facial expressions of anger and fear.» (p. 145)

Questions/Hypothèses :
The authors «predicted that adults who reported a history of abuse would rate faces as more threatening across all levels of emotional intensity. [They] also predicted that the gradient from neutral to 100% threatening for both self-reported ratings and neural response would be steeper for individuals who had experienced CM compared to those who reported subthreshold levels of abuse, reflecting increased sensitivity to subtle variation in threatening content […].» (p. 145)

2. Méthode

Échantillon/Matériau :
L’échantillon final est composé de 71 participants (60 femmes et 11 hommes) recrutés au sein de l’Université McGill (Montréal). Les auteurs ont étudié les expressions faciales en procédant à des électroencéphalographies.

Instruments :
Questionnaire

Type de traitement des données :
Analyse statistique

3. Résumé

The results show that «the LPP was modulated by the intensity of fearful faces in a linear fashion among maltreated individuals, and not among individuals exposed to no CM or subthreshold CM. Specifically, as faces increased in emotional intensity and approached fearful prototypes, the LPP elicited in maltreated individuals similarly increased […]. Moreover, this linear tracking of attention to progressively more intense or unambiguous fearful faces was observed in a sample of adults who endorsed low-to-moderate levels of any type of abuse. […] Among maltreated individuals, [the authors] observed enhanced LPP amplitudes as fearful faces increased in emotional intensity, suggesting ongoing processing even in the absence of threat.» (p. 149) The authors «would note, however, that these effects were specific to fear faces, though [their] study used both angry and fearful stimuli. Contrary to [their] hypotheses, the LPP to angry faces was not modulated by emotional intensity to a greater extent in adults who reported a history of CM compared to control individuals.» (p. 150) «Results from participant self-report also indicated that participants were able to differentiate ambiguous and nonambiguous face stimuli across neutral–fearful and neutral–angry continuums. However, contrary to [their] hypothesis, the maltreated and control groups did not differ in their ratings of emotion expressed.» (p. 150) «In sum, the results of this study suggest that CM is associated with increased sensitivity to subtle variation in fearful content.» (p. 151)