Can a bump on the head make it harder for us to understand other peoples’ emotions?
You had a head trauma a few years ago but haven’t given it much thought. You notice that you are unable to socialize like you used to because you can’t understand others’ emotions properly, but you don’t know why! “Is it me?” you might ask. Well, it could be, but it could also be due to that head trauma you once had.
Generally, people don’t recognize that closed head injury could be serious and might have long-lasting consequences. Closed-head injuries can range from mild injuries to debilitating brain injuries and can lead to severe brain damage or even death. Diffuse axonal injury (or DAI) is a type of closed head injury with widespread damage to brain white matter tracts resulting from sudden physical forces that shear the connections between grey and white matter junctions. It is one of the most common and devastating types of traumatic brain injury. White matter injuries are not limited to those with head trauma only, such injuries can occur in several situations. Even shaking your baby vigorously or forcefully hitting them on the head might lead to white matter injuries (See Shaken baby syndrome). This is aside from several closed head injuries such as sports injuries affecting athletes or blast injuries affecting veterans.
Obvious symptoms such as headaches, dizziness, nausea, and vomiting aside, social interaction deficits could also result from certain head injuries like DAI. One such deficit is not being able to recognize facial emotions properly. This is important because if someone is having difficulty recognizing other people’s facial emotions, then it would be harder for them to understand a given social situation. The reason being that we depend much more on non-verbal cues than on verbal ones, especially faces, to understand others’ emotions and what they are trying to convey.
A lab at Kyoto University’s Department of Neuropsychiatry performed the first study of its kind assessing facial emotion recognition in patients with focal and diffuse axonal injury showing that white matter injury per se could lead to problems in facial emotion recognition. The study also argued that emotion recognition of faces is not localized to one part of the brain. These findings were supported by previous literature reporting that facial emotion recognition ability requires the processing of several brain regions working together, and thus such ability could be disrupted if there were problems in the regions involved in such collective processing or the white matter tracts connecting those regions.
Millions of people have different types of brain white-matter anomalies each year. Causes such as sports injuries, war injuries, car accidents, in addition to other white matter diseases affecting the brain could result in social interaction deficits that often go unnoticed at the initial clinical presentation. Many of these patients suffer from post-traumatic brain injury symptoms or other symptoms related to white matter injury that they themselves are unaware of. Knowing and understanding that social interaction impairment could result even from a milder form of brain injury is important for those who suffer from the injury, their caregivers, friends, and community. The prejudice and stigma resulting from the observed change in the behavior of these individuals might be minimized by being aware of the fact that there could be a clinical underlying cause of such change.
The results from the above study might also be of interest to those who are studying autism and other disorders involving white matter abnormalities. Since several individuals with autism, for example, have diverse white matter connectivity deficits as well as social interaction deficits. Practically, this could help improve targeted therapeutic approaches toward head injury patients as well as other patients with brain white matter aberrations.
Creating awareness about the possible effects of closed head injury could hopefully lessen the stigma and prejudice against these individuals and would also be informative for some physicians to know what to look for when their patients present with social interaction problems post brain injury.
