Affective facial expression processing in 15-month-old infants who have experienced maltreatment: an event-related potential study

Abstract

This study examined the neural correlates of facial affect processing in 15 month-old maltreated and nonmaltreated infants. Event-related potentials (ERPs) were elicited while infants passively viewed standardized pictures of female models posing angry, happy, and neutral facial expressions. Differences between maltreated (N = 25) and nonmaltreated (N = 20) infants were observed on three ERP components: P1, P260, and Nc. The results for the P260 waveform were consistent with previous ERP findings in older maltreated children, showing a hyperresponsivity to angry facial affect relative to happy in maltreated infants. However, the findings for the P1 and Nc indicated a hyperresponsivity to relative affective novelty, whereby the maltreated infants had greater amplitude in response to happy facial affect, whereas nonmaltreated infants had greater responsivity to angry faces. The results provided further support for the hypothesis that the experience of maltreatment and the predominantly negative emotional tone in maltreating families alters the functioning of neural systems associated with the processing of facial emotion. In particular, the findings suggested that at this early stage in the development of facial affect recognition, novelty of facial emotion is especially salient. These results exemplify the importance of early preventive interventions focused on emotion for children who have experienced maltreatment early in life.

Keywords: child maltreatment; emotion; event-related potentials; face processing.

Figure 1

Amplitude of P1 component across angry and happy face emotion conditions for maltreated and nonmaltreated children, illustrating Group x Emotion interaction. Error bars are standard errors of the means. ⁺p < 0.10, ^*p <0.05, ^**p < 0.01.

Figure 2

Grand averages of occipital ERP components elicited in response to the (a) angry, (b) happy, and (c) neutral face conditions. Plot is of average amplitude of 3 occipital electrodes (O1, O2, Oz). Amplitude is represented on the vertical axis in microvolts, and time (milliseconds) is on the horizontal axis.

Figure 3

Amplitude of P260 component across angry and happy face emotion conditions for maltreated and nonmaltreated children, illustrating Group x Emotion interaction. Error bars are standard errors of the means. ⁺p < 0.10, ^*p <0.05, ^**p < 0.01, ^***p < 0.001.

Figure 4

Grand averages of central ERP components elicited in response to the (a) angry, (b) happy, and (c) neutral face conditions. Plot is of average amplitude of 5 central electrodes (C3, C4, T3, T4, Cz). Amplitude is represented on the vertical axis in microvolts, and time (milliseconds) is on the horizontal axis.

Figure 5

Grand averages of central ERP components elicited in response to the (a) angry, (b) happy, and (c) neutral face conditions. Plot is of average amplitude of 5 frontal electrodes (F3, F4, F7, F8, Fz). Amplitude is represented on the vertical axis in microvolts, and time (milliseconds) is on the horizontal axis.

Figure 6

Amplitude of Nc component across angry and happy face emotion conditions for maltreated and nonmaltreated children, illustrating Group x Emotion interaction. Error bars are standard errors of the means. ⁺p < 0.10, ^*p <0.05, ^**p < 0.01, ^***p < 0.001.