Research Article: Fluid Intelligence and Automatic Neural Processes in Facial Expression Perception: An Event-Related Potential Study

Date Published: September 16, 2015

Publisher: Public Library of Science

Author(s): Tongran Liu, Tong Xiao, Xiaoyan Li, Jiannong Shi, Piia Susanna Astikainen.


The relationship between human fluid intelligence and social-emotional abilities has been a topic of considerable interest. The current study investigated whether adolescents with different intellectual levels had different automatic neural processing of facial expressions. Two groups of adolescent males were enrolled: a high IQ group and an average IQ group. Age and parental socioeconomic status were matched between the two groups. Participants counted the numbers of the central cross changes while paired facial expressions were presented bilaterally in an oddball paradigm. There were two experimental conditions: a happy condition, in which neutral expressions were standard stimuli (p = 0.8) and happy expressions were deviant stimuli (p = 0.2), and a fearful condition, in which neutral expressions were standard stimuli (p = 0.8) and fearful expressions were deviant stimuli (p = 0.2). Participants were required to concentrate on the primary task of counting the central cross changes and to ignore the expressions to ensure that facial expression processing was automatic. Event-related potentials (ERPs) were obtained during the tasks. The visual mismatch negativity (vMMN) components were analyzed to index the automatic neural processing of facial expressions. For the early vMMN (50–130 ms), the high IQ group showed more negative vMMN amplitudes than the average IQ group in the happy condition. For the late vMMN (320–450 ms), the high IQ group had greater vMMN responses than the average IQ group over frontal and occipito-temporal areas in the fearful condition, and the average IQ group evoked larger vMMN amplitudes than the high IQ group over occipito-temporal areas in the happy condition. The present study elucidated the close relationships between fluid intelligence and pre-attentive change detection on social-emotional information.

Partial Text

The nature of human intelligence is an enduring topic in scientific research of cognition. Fluid intelligence or g factor of intelligence has been widely adopted to describe the intelligence profile that originates from an individual’s birth, and which cannot be impacted by knowledge or experience. This factor indicates how well individuals can adapt themselves to their emotional and non-emotional environment [1]. Studies on the cognitive characteristics have consistently found that those with high IQ have better memory, attention, and cognitive control abilities than individuals with average IQ [1–2]. However, there exist different theories relating intelligence and social-emotional abilities: Spearman proposed the psychometric theory of intelligence, which posited at least modest correlations between an individual’s social-emotional abilities and his or her cognitive abilities [3]. In contrast, Gardner’s multiple intelligence theory proposed complete independence of emotional abilities and cognitive abilities or academic aptitude [4].

The current study investigated the relationship between intelligence and neural activation associated with automatic facial expression processing, with the aim of adding electrophysiological evidence to the body of research. The behavioral results showed that adolescents with high IQ performed faster than their average IQ peers in reporting how many times the fixation cross changed, indicating better performance on this cognitive task [1–2]. It was also observed that participants responded more quickly in the happy condition than in the fearful condition, which might reveal that positive affect (i.e., context, or mood) facilitated their cognitive processes [41] and/or negative affect impaired the cognitive processes [42].