Alexithymic trait and voluntary control in healthy adults

Abstract

Background: Alexithymia is a personality trait characterized by deficiency in understanding, processing, or describing emotions. Recent studies have revealed that alexithymia is associated with less activation of the anterior cingulate cortex, a brain region shown to play a role in cognitive and emotional processing. However, few studies have directly investigated the cognitive domain in relation to alexithymia to examine whether alexithymic trait is related to less efficient voluntary control.

Methodology/principal findings: We examined the relationship between alexithymic trait and voluntary control in a group of healthy volunteers. We used the 20-item Toronto Alexithymia Scale (TAS-20) to measure alexithymic trait. Additionally, we examined state and trait voluntary control using the revised Attention Network Test (ANT-R) and the Adult Temperament Questionnaire (ATQ), respectively. Alexithymic trait was positively correlated with the overall reaction time of the ANT-R, and negatively correlated with the Effortful Control factor of the ATQ.

Conclusions/significance: Our results suggest that alexithymic trait is associated with less efficient voluntary control.

Figure 1. Schematic of the revised Attention Network Test (ANT-R).

In each trial, depending on the cue condition (none, double, and valid or invalid cues), a cue box flashes for 100 ms. After a variable duration (0, 400, or 800 ms), the target (the center arrow) and two flanker arrows on the left and right side (congruent or incongruent flankers) are presented for 500 ms. The participant makes a response to the target's direction. The post-target fixation period varies between 2000 to 12000 ms.

Figure 2. Distribution curve of the overall scores of TAS-20.

Figure 3. Correlations between overall TAS-20 score and (A) response speed of ANT-R, and (B) the Effortful Control subscale of ATQ.