From neural signatures of emotional modulation to social cognition: individual differences in healthy volunteers and psychiatric participants

Abstract

It is commonly assumed that early emotional signals provide relevant information for social cognition tasks. The goal of this study was to test the association between (a) cortical markers of face emotional processing and (b) social-cognitive measures, and also to build a model which can predict this association (a and b) in healthy volunteers as well as in different groups of psychiatric patients. Thus, we investigated the early cortical processing of emotional stimuli (N170, using a face and word valence task) and their relationship with the social-cognitive profiles (SCPs, indexed by measures of theory of mind, fluid intelligence, speed processing and executive functions). Group comparisons and individual differences were assessed among schizophrenia (SCZ) patients and their relatives, individuals with attention deficit hyperactivity disorder (ADHD), individuals with euthymic bipolar disorder (BD) and healthy participants (educational level, handedness, age and gender matched). Our results provide evidence of emotional N170 impairments in the affected groups (SCZ and relatives, ADHD and BD) as well as subtle group differences. Importantly, cortical processing of emotional stimuli predicted the SCP, as evidenced by a structural equation model analysis. This is the first study to report an association model of brain markers of emotional processing and SCP.

Keywords: ADHD; BD; N170; SEM; schizophrenia; social cognition.

Fig. 1

DVT. The trial begins with the presentation of a fixation cross (1000 ms), followed by the presentation of a target stimulus (100 ms) that consists of a single stimulus face, a single stimulus word, (single stimulus block) or a face and a word that are presented simultaneously (simultaneous stimuli block). A fixation cross was then presented and remained in place until the participant responded. Reproduced from PloS One (Ibanez et al., 2012b).

Fig. 2

Procedure for the N170 global scores extraction from the DVT. This figure shows data preprocessed (low-pass filtered for visualization purposes) from a single normal volunteer. (A) Scalp location of each electrode and electrode selection for each category near the T6 and T7 electrodes. (B) Butterfly montage showing the average temporal window that was selected for further analysis of the N170 signal. (C) The N170 amplitude modulation in response to the DVT categories of face, words and simultaneous stimuli regarding ST and valence. (D) DVT global scores (in µV) that were obtained via category subtraction: ST (face minus word); face valence (positive faces minus negative ones); word valence (positive words minus negative ones); simultaneous valence (positive simultaneous minus negative ones).

Fig. 3

ERP results of the DVT. Global scores for ST, face valence (Face Val), word valence (Word Val) and simultaneous valence (SIM Val) in controls, SCZ, SFDR, BD and ADHD groups. Boxes and bars are indicative of means and s.d., respectively. Asterisks (*) and number sign (#) indicate significant differences and a trend, respectively, in the scores of a particular group regarding those of the control group.

Fig. 4

SEM model. Significant SEM used to test the effects of the E-N170 and STN170 signals on the SCP scores, χ²(22, n = 100) = 28.3, RMSEA = 0.054 and CFI = 0.96. Coefficients that met significance criterion are marked in bold.; Face Val, N170 modulation of facial affect; Word Val, N170 modulation of semantic affect; SIM Val, N170 modulation of simultaneous affect; E-N170, emotional modulation of N170; ST-N170, ST modulation of N170; FI, fluid intelligence; PS, processing speed; EF, executive function; RME, reading the mind in the eyes task; FPT, faux pas test.

Fig. 5

Auxiliary analysis. Relationship between factor score (E-N170) and the SCPs of each group.