Our interactions with other people involve both verbal and non-verbal communication, with information being processed in parallel. Non-verbal communication includes body language and can be very useful in making conclusions about unspoken intentions. Although we rely on verbal communication to receive information, it seems highly important to understand body language as well. Body language informs us about feelings and intentions of other people. From the evolutionary perspective, observing and reacting to emotional conditions of others may have been critical for our survival.

Indeed, the scientific literature suggests that we are more impressed by the information received non-verbally. Maybe this is because more than 50% of communication is based on our body language. On the other hand, less than 10% comes from what we actually say, while almost 40% comes from the tone of our voice.

At first look, it might seem easy to understand someone’s body language, through the perception of their body posture, gestures, and movements. But, the process is more complex than it looks. It involves specific regions and complex neuronal networks in our brain decoding body expressions and giving them adequate meaning. While the recognition of facial expressions is well studied, processing of body posture and gestures has received less attention until recently.

How does brain read body language?

The scientific literature suggests that brain has several specialized structures that process socially relevant information. As neuroimaging studies have revealed, the processing of body expressions activates a complex network of neurons. This not only includes visual areas but also includes subcortical and cortical emotion-related regions, as well as regions involved in planning and execution of actions.

The visual representation of the human body and its emotions activates two main visual areas in the brain. These are the extrastriate body area and the face-selective fusiform body area. Using MRI scans, researchers measured the degree of activation in these brain areas in response to “normal” and “emotional” body language by showing short video clips to volunteers. These clips represented people who were performing emotionally neutral gestures and movements or expressing 5 basic emotions:  happiness, sadness, anger, disgust, or fear.

The results showed that brain areas were influenced by the emotional weight of body movements. More precisely, activation of the extrastriate body area (EBA) and the face fusiform body areas (FBA) were significantly greater in response to emotional body language than to neutral body language. Also, both of the areas reacted most strongly to happiness, anger, and disgust. While fear significantly influenced the EBA, the modulation was not significant in the case of FBA. Sadness failed to significantly activate both regions. The lack of modulation by sadness may be due to the excitement associated with sadness. Levels of excitement have a crucial role in activation of the amygdala, a part of the brain playing an important role in the processing of emotions. In addition, there is a positive correlation between amygdala activation and modulation of EBA and FBA areas.

Despite the complex non-facial gestures that people use to communicate most of the studies are based on facial expression only. To address this issue, one recent study created a set of body language patterns by taking photos of actors personifying emotional states. The photos portrayed typical emotional states (for instance “I am in love”, “I hate you” and others), i.e., they captured gestures and actions reflecting emotional body language. The results of this study have indicated that the body (including the face) mimics and gestures undergo prioritized fast procession.

In order to better measure neural processes involved in the comprehension of emotional body language, a short verbal description of the emotional state preceded the pictures. The verbal descriptions were both congruent (matching the state presented on pictures) and incongruent. The analyses showed that body language is rapidly compared with verbal information. Importantly, the results indicated that incongruent body language was revealed just 300 ms following the stimulus. Thus, the process of body language comprehension in the brain is obviously able to provide information about the sincerity of others. This is important for regulation of our social interactions.

Can we react unintentionally to body language?

There are inconsistent data on how the brain processes emotional stimuli as an important part of our body language. While some findings suggest that emotional stimuli are processed automatically, i.e., without attention, other researchers believe that attention is necessary for processing emotional expressions. Namely, behavioral studies have found that the processing of facial expression occurs not only automatically but without conscious awareness as well. It has been shown that brain regions, such as the amygdala, may be activated when emotional stimuli (such as fear) are masked and the subject seems to be unaware of them. Still, most of the studies suggesting that the processing of body postures is automatic have focused on the interpretation of fearful body language.

Are there any factors affecting the brain coding of body language?

The activation of specific brain regions by witnessing body language may vary in accordance with individual differences. Factors such as personality, genotype, and gender may affect the neuronal response to body language. For instance, in response to emotionally aversive (unpleasant) stimuli, specific brain regions are more activated in women as compared to men. On the other side, activation is greater in men when it comes to viewing emotional faces, scenes, and words. Still, empathy levels may influence these gender differences. As one study demonstrated, participants with higher self-reported empathy were characterized by higher activation in brain areas associated with the interpretation of emotions.

Despite our limited knowledge of body language processing by the brain, several conclusions can be made:

• Specific brain areas are activated in order to process body language and facial expressions. Among these, two visual areas and the amygdalas are the most important ones.
• We may react more explicitly to body language expressing happiness than sadness, due to higher activation of specific brain regions.
• There may be some gender difference in reacting to body language, due to the different activation of brain areas. Still, personality is an important cofactor.
• Sometimes, like in the case of fearful body language, we might react unintentionally.

The lack of detailed research leaves lots of question about the processing of body language, as well as about how we use this channel of communication, intentionally or not. As the neuroscience on the subject advances, we will most certainly learn much more about this fascinating topic.

References

Tipper, C.M., Signorini, G., Grafton, S.T. (2015). Body language in the brain: constructing meaning from expressive movement. Frontiers in Human Neuroscience. 9: 450. doi: 10.3389/fnhum.2015.00450.

Calbi, M., Angelini, M., Gallese, V., Umiltàm, M.A. (2017). “Embodied Body Language”: an electrical neuroimaging study with emotional faces and bodies. Scientific Reports. 7(1): 6875. doi:10.1038/s41598-017-07262-0

Peelen, M.V., Atkinson, A.P., Andersson, F., Vuilleumier, P. (2007).  Emotional modulation of body-selective visual areas. Social Cognitive and Affective Neuroscience. 2(4): 274-283. Doi: 10.1093/scan/nsm023

Proverbio, A.M., Calbi, M., Manfredi, M., Zani, A. (2014). Comprehending body language and mimics: an ERP and neuroimaging study on Italian actors and viewers. PLoS One. 9(3):e91294. Doi: 10.1371/journal.pone.0091294

Pessoa, L., McKenna, M., Gutierrez, E., Ungerleider, L.G. (2002). Neural processing of emotional faces requires attention. Proceedings of the National Academy of Sciences of the United States of America. 99(17): 11458-11463. doi:  10.1073/pnas.172403899

Kana, R.K., Travers, B.G. (2012). Neural substrates of interpreting actions and emotions from body postures. Social Cognitive and Affective Neuroscience. 7(4): 446-456. Doi: 10.1093/scan/nsr022

Image via KeithJJ/Pixabay.