# Interactive behavior in mothers with and without borderline personality disorder: non-hostile behavior is associated with stronger neural activation of the theory of mind network in response to sad faces of the own child

## TL;DR

Mothers with borderline personality disorder show reduced ability to recognize their child's emotions, and non-hostile behavior is linked to stronger brain activity in regions related to understanding others' emotions.

## Contribution

This study links non-hostile maternal behavior to stronger theory of mind network activation in response to a child's sad face in mothers with and without BPD.

## Key findings

- Mothers with BPD showed lower performance in recognizing child facial expressions across emotions.
- Maternal non-hostility was associated with higher activation in the temporoparietal junction and dorsomedial prefrontal cortex when viewing their own child's sad face.
- Stronger theory of mind network activation in response to a child's sad face is linked to less hostile maternal behavior.

## Abstract

Borderline personality disorder (BPD) affects many facets of interpersonal functioning, including maternal caregiving. Deficits in theory of mind (ToM) may put mothers with BPD at risk of showing dysfunctional parenting behavior. The present study investigated the association between the ToM brain network activation and parental behavior using functional magnetic resonance imaging (fMRI).

In the present study conducted within the UBICA project (Understanding and Breaking the Intergenerational Cycle of Abuse), mothers with BPD (n=19) and healthy controls (HCs, n=30) completed an affect recognition task where they viewed sad, happy, and neutral faces of their own vs. unknown children during fMRI. Additionally, maternal non-hostility, the degree of maternal angry or irritable negative affect during mother-child-interactions, was assessed with the emotional availability scales.

Mothers with BPD compared to HCs showed lower performance in recognizing child facial expressions across emotions. Further, maternal non-hostility across groups was associated with higher activation of the ToM neural network including the temporoparietal junction (left TPJ; T = 4.52, pFWE = .03; right TPJ: T = 4.44, pFWE = .04) and the dorsomedial prefrontal cortex (dmPFC; T = 4.39, pFWE = .05) in response to sad faces of mother’s own vs. unknown children.

The results indicate reduced child affect recognition in mothers with BPD. Further, mothers showing stronger neural activation of the TPJ and dmPFC while seeing their own sad children were more non-hostile, pointing towards an important role of affective ToM in maternal care, which might be a viable therapeutic target in future studies.