The amygdala, imaged here, functions to process emotions such as fear and rage. The researchers found activation of the right amygdala in response to negative images, and that this activation seemed to cause activation of the dmPFC. (Source: Wikimedia Commons)
Even in the face of increasing gender equity, scientists are aware of existing differences between the genders, whether biologically or psychosocially. Previous studies have already demonstrated one such difference: that women tend to have stronger emotional responses to negative stimuli than men, which may account for their doubled likelihood of having depressive or anxiety disorder (1).
According to a recent study released by a group of scientists at the CIUSSS de l’Est-de-l’Île-de Montréal and the University of Montreal, differences in brain activity in the limbic system and prefrontal cortex, modulated by hormonal differences, may account for the increased emotional reactivity in women compared to men (1, 2).
The researchers asked 46 participants (25 female, 21 male) to rate various images on a scale from 0 to 8 based on the emotional response elicited by the image, 0 being no emotion and 8 being strongest emotion. In addition, the scientists used fMRIs to measure brain activity, assayed blood estrogen, progesterone, and testosterone levels, and asked subjects to fill out a gender questionnaire (1, 2).
As hypothesized, on average, women rated the negative images higher on the scale than men. Regardless of gender, subjects with lower testosterone and higher progesterone levels tended to rate negative images higher on the scale of emotional response. In response to the negative images, both genders exhibited brain activity in the right amygdala, linked to processing threats and emotions such as fear and rage, and the dorsomedial prefrontal cortex (dmPFC), involved in cognition, reasoning, and perception (1).
However, when the researchers analyzed the connections between these brain regions through a statistical measure called Granger causality, they found a causal link between activation of the right amygdala and activation of the dmPFC (1). Furthermore, men had greater Granger causality when responding to negative images than women; these differences were modulated by testosterone. These findings suggest that men and women may process emotions differently. Specifically, the increased activity in the dmPFC in men compared to in women may indicate that men rely more on cognitive evaluation rather than affective processing of a stimulus (1).
The researchers also found, however, that those with higher femininity as measured psychosocially by the questionnaire had lower Granger causality, suggesting that biological sex and hormonal differences are not sufficient to explain the gender differences in emotional response (1, 2). Gender learning may also play a role in these differences.
The scientist acknowledge the limitations of the study, namely that the use of IAPS images which only tests the broad category of “negative” rather than specific negative emotions like fear or anger. Moving forward, the group hopes to not only address these different negative emotions but also other hormonal fluctuations like those of estrogen and progesterone during the female menstrual cycle, known to affect emotional response (1, 2).
In other words, despite the copious research done on gender differences in emotional processing, the issue still remains a complex one, involving not only biological sex but also gender identity and cultural learning.
References:
- Lungu, O., Potvin, S., Tikàsz, A., Mendrek, A (2015, August 13). Sex differences in effective fronto-limbic connectivity during negative emotion processing. Psychoneuroendocrinology, 62, 180-188 doi:1016/j.psyneuen.2015.08.012
- Université de Montréal. (2015, September 23). Do women experience negative emotions differently than men?. ScienceDaily. Retrieved September 24, 2015 from www.sciencedaily.com/releases/2015/09/150923083417.htm