Gender Difference in Emotion Modulation of Attentional Resource Allocation

• Main Authors: Yu-Shiuan Yen, 顏毓萱
• Other Authors: Li-Fen Chen
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/jz3cqj

碩士 === 國立陽明大學 === 腦科學研究所 === 97 === As a form of cognitive control in emotion regulation, attentional control can transform one’s attention to a specific target and might be biased by the affective value of stimuli. Such attentional bias caused slower reaction time (RT) for negative stimuli and higher false alarm (FA) for positive stimuli, whereas the gender effects on attentional bias is still unclear. Several cross-national studies reported that the proportion of females in major depression patients was significantly larger than that of males. In this study, we hypothesized that females tend to exhibit an attentional bias towards negative stimuli more than males. Twenty healthy right-handed volunteers (10 male, aged 19-34 years) without neurological/psychiatric disorders were recruited and provided informed consent for participation. These subjects were asked to perform an emotional Go/Nogo task (Neutral-Go/Fearful-Nogo, NeutralGo-/Happy-Nogo, Fearful-Go/Neutral-Nogo, and Happy-Go/Neutral-Nogo). The magnetoencephalography were recorded with a 306-channel whole-head neuromagnetometer. The pre-processed signals underwent a source analysis procedure, Maximum Contrast Beamformer, to estimate spatiotemporal neuronal activities. We performed statistics analyses for source distribution images between genders using SPM5 and correlations between brain activation and RTs/FAs using SPSS. The behavior results of cross-gender comparison showed that females exhibited higher FAs while facing fear stimuli and males had shorter RTs for happy stimuli. For the fearful-nogo condition, females showed higher bilateral dorsal anterior cingulate cortex activation than males and the right superior temporal gyrus displayed a strong sustained activation after 120 ms, which implicated that the bottom-up reappraisal system was engaged to evaluate the fearful signal repeatedly. Besides, the higher dorsolateral prefrontal cortex activation in males indicated that males allocated major resources to inhibition control so as to display lower FAs. With regard to the happy-go condition, the higher medial prefrontal cortex activation in males showed that males allocated more cognitive resources to executive function at very early stage M130. However, the activation of right insula, inferior frontal gyrus and caudate at M170 in females were higher than males, which caused females shifted their attention to positive emotional context and resulted in delayed responses. In conclusion, the emotional response tendency towards positive signals in males enhanced the information processing style of goal-directed behavior and resulted in fast behavioral response. However, females in the present study exhibited an attentional bias towards negative signals. This tendency bias boosted the information style of context evaluation and made females be short of capacity for cognitive control to inhibit the habitual behavioral response. Besides, the neural activation patterns of hyperactive appraisal system were similar to the previous neuroimaging researches in the depressive patient. These findings suggested a possible neural mechanism about the cause of higher proportion of females among the patients with major depressive disorder.