Personality modulates the effects of emotional arousal and valence on brain activation

Abstract

The influence of personality on the neural correlates of emotional processing is still not well characterized. We investigated the relationship between extraversion and neuroticism and emotional perception using functional magnetic resonance imaging (fMRI) in a group of 23 young, healthy women. Using a parametric modulation approach, we examined how the blood oxygenation level dependent (BOLD) signal varied with the participants' ratings of arousal and valence, and whether levels of extraversion and neuroticism were related to these modulations. In particular, we wished to test Eysenck's biological theory of personality, which links high extraversion to lower levels of reticulothalamic-cortical arousal, and neuroticism to increased reactivity of the limbic system and stronger reactions to emotional arousal. Individuals high in neuroticism demonstrated reduced sustained activation in the orbitofrontal cortex (OFC) and attenuated valence processing in the right temporal lobe while viewing emotional images, but an increased BOLD response to emotional arousal in the right medial prefrontal cortex (mPFC). These results support Eysenck's theory, as well as our hypothesis that high levels of neuroticism are associated with attenuated reward processing. Extraversion was inversely related to arousal processing in the right cerebellum, but positively associated with arousal processing in the right insula, indicating that the relationship between extraversion and arousal is not as simple as that proposed by Eysenck.

Healthy aging is associated with increased neural processing of positive valence but attenuated processing of emotional arousal: an fMRI study

“…The young cohort is the same as those described in Kehoe et al (2011); however this study additionally contains data from an older cohort and concentrates on aging differences. The groups did not differ in their educational attainment (t ϭ 1.15, p Ͼ 0.05).…”

“…Previous studies have found that neuroticism can influence the neural substrates of emotional processing (Canli et al, 2001;Haas et al, 2008;Kehoe et al, 2011), leading to sustained processing of sad stimuli for example (Haas et al, 2008), and increased activation in response to arousal in the mPFC (Kehoe et al, 2011). Therefore in order to control for the possible confounding effect of this trait it was included as a covariate of no interest in all of the fMRI analyses.…”

“…The stimuli for the fMRI paradigm consisted of 190 colored photographs as described in detail in Kehoe et al (2011), which were either positive or neutral in valence and varied in arousal level over the entire range. They were a combination of 98 images from the IAPS (Lang et al, 2008) and 92 images gathered by the experimenters from various sources.…”

“…The task was an emotional perception task (Kehoe et al, 2011), in which the participants viewed 190 colored images which varied in valence and arousal as they underwent fMRI. The task consisted of 2 experimental runs, each containing 95 trials and lasting approximately 20 minutes.…”

“…Only women were included in the study because there have been considerable differences found between genders in emotional reactivity (Bradley et al, 2001) and in the neural representation of emotion (Beck et al, 1996;Cahill et al, 2001;Wager et al, 2003;Wrase et al, 2003). Similar to several other fMRI studies of emotional processing (Heinzel et al, 2005;Kehoe et al, 2011;Lewis et al, 2007;Phan et al, 2004), we utilized a parametric modulation approach, including the participants' subjective emotional ratings as parametric modulators in the fMRI analysis. This method allowed us to isolate the brain regions where the blood oxygen-level dependent (BOLD) response varied linearly with valence and arousal, and investigate whether this differed in the aging brain.…”