In the face of a potential threat to his or her child, a parent’s caregiving system becomes activated, motivating the parent to protect and care for the child. However, the neural correlates of these responses are not yet well understood. The current study was a pilot study to investigate the processing of subliminally presented threatening primes and their effects on neural responses to familiar and unfamiliar children’s faces. In addition, we studied potential moderating effects of empathy and childhood experiences of love-withdrawal. A total of 45 students participated in an fMRI experiment in which they were shown pictures of familiar children (pictures morphed to resemble the participant like an own child would) and unfamiliar children preceded by neutral and threatening primes. Participants completed a modified version of the Children’s Report of Parental Behavior Inventory to measure parental love withdrawal, and the Empathic Concern scale of the Interpersonal Reactivity Index to measure affective empathy. Contrary to our expectations, we did not find evidence for subliminal priming effects. However, we did find enhanced activity in the right inferior frontal gyrus (IFG; involved in self-referential processing) and in face processing areas (infero-lateral occipital cortex and fusiform areas) in response to the familiar child, indicating preferential processing of these faces. Effects of familiarity in face processing areas were larger for participants reporting more love withdrawal, suggesting enhanced attention to and processing of these highly attachment relevant stimuli. Unfamiliar faces elicited enhanced activity in bilateral superior temporal gyrus (STG) and other regions associated with theory of mind (ToM), which may indicate more effortful ToM processing of these faces. We discuss the potential difference between a familiarity and a caregiving effect triggered by the morphed faces, and emphasize the need for replication in parents with pictures of their “real” own child.

Introduction Functional MRI (fMRI) is commonly used to investigate the neural mechanisms underlying psychological processes and behavioral responses. However, to draw well‐founded conclusions from fMRI studies, more research on the reliability of fMRI is needed. Methods We invited a sample of 41 female students to participate in two identical fMRI sessions, separated by 5 weeks on average. To investigate the potential effect of left‐handedness on the stability of neural activity, we oversampled left‐handed participants ( N = 20). Inside the scanner, we presented photographs of familiar and unfamiliar children's faces preceded by neutral and threatening primes to the participants. We calculated intraclass correlations (ICCs) to investigate the test–retest reliability of peak activity in areas that showed significant activity during the first session (primary visual cortex, fusiform face area, inferior frontal gyrus, and superior temporal gyrus). In addition, we examined how many trials were needed to reliably measure the effects. Results Across all participants, only fusiform face area activity in response to faces showed good test–retest reliability (ICC = 0.71). All other test–retest reliabilities were low (0.01 ≤ ICC ≤ 0.35). Reliabilities varied only slightly with increasing numbers of trials, with no consistent increase in ICCs. Test–retest reliabilities for left‐handed participants (0.28 ≤ ICC ≤0.66) were generally somewhat higher than for right‐handed participants (−0.13 ≤ ICC ≤0.75), but not statistically significant. Conclusion Our study shows good test–retest reliability for fusiform facer area activity in response to faces, but low test–retest reliability for other contrasts and areas.

Facial resemblance serves as an important kinship cue in humans and, as such, facilitates kin recognition. Mechanisms to facilitate kin recognition exist in many different species and have probably evolved to promote nepotism and avoid inbreeding. Responses to facial resemblance may however be affected by a person’s own (childhood) experiences with close relatives. In the present study, we investigated whether the degree of resemblance of children’s faces with the participant’s face was related to participants’ positive and negative appraisals of the children’s faces. We morphed pictures of an unfamiliar child’s face with the participant’s face and with the face of an unfamiliar adult, to create facial stimuli that differed in their degree of facial resemblance with the participant. We examined the effects of childhood experiences with parental love-withdrawal and participants’ neural processing of facial identity (fusiform face area activity, FFA). As hypothesized, negative appraisal of the faces decreased linearly with increasing facial resemblance. In addition, love-withdrawal and FFA activity moderated the relation between facial resemblance and negative appraisal. Participants who both reported high love-withdrawal and showed greater FFA activity showed the largest decrease in negative appraisals with increasing resemblance. Positive appraisal of the faces was not associated with resemblance of the child face to the participant’s face. Future research should address the effects of phenotypic kinship cues on actual parental behavior.