AUT research shows that a mild traumatic brain injury can impair social cognition - the ability to 'read' social interactions. Any impairment of social cognitive functions may lead to social-behavioural problems, poor communication skills, relationship difficulties, unemployment, stress, loneliness and reduced social participation.
A study led by Associate Professor Alice Theadom, a psychologist at the School of Public Health and Psychosocial Studies, reveals that people who have experienced a mild Traumatic Brain Injury (TBI), also known as concussion, have significantly poorer skills in interpreting what people are saying and understanding the intention of their remarks. In particular, they have difficulty identifying sarcasm, which requires the ability to understand that the literal meaning is not the intended meaning.
The study recently appeared in the American journal Neuropsychology.
Associate Professor Theadom is a Rutherford Discovery Fellow and member of the National Institute for Stroke and Applied Neurosciences (NISAN) at AUT. Her research looks at how people recover following a mild-TBI.
“Mild traumatic brain injury is a growing public health concern, due to its prevalence and the potential longer-term health effects. Now, we’re uncovering evidence that those effects may be much broader than we thought,” she says.
“Social difficulties can have a real impact on people’s lives, affecting their ability to perform well at work, maintain relationships and feel connected to society.”
About 36,000 people in New Zealand suffer a TBI each year. Most are caused by falls and people being hit by, or hitting their head against, an object. They can occur during everyday activities, ranging from sports and accidents while driving or operating machinery, to assaults. One in three people will experience at least one TBI by the age of 25.
Up to 90% of all TBIs are classified as being of mild severity.
Limited research has been conducted on social cognition following a mild-TBI, with previous studies having only looked at these skills in people with more severe brain injury.
To address this gap, researchers assessed the social cognition of 155 adults who had experienced a mild-TBI four years earlier. They were all recruited from the Brain Injury Outcomes New Zealand in Community (BIONIC) study.
The participants watched 16 video vignettes depicting everyday social interactions – half were enacted as sarcastic exchanges, while the other half represented a white lie. For each video, they were asked four questions to assess their understanding of the emotions, beliefs, meanings and intentions of the people on screen and their exchanges. The results were compared to a group of adults of the same age and gender, who had not experienced a brain injury.
The study shows that one in five people in the mild-TBI group experienced difficulties in social inference, compared to one in 10 people in the control group. The group differences remained significant even after controlling for cognitive difficulties, such as the ability to process new information, make decisions and change task quickly. This suggests that there may be a specific brain deficit.
There was no significant difference in recognition of basic emotions or detecting lies.
Associate Professor Theadom says replication of these findings may suggest a new era of screening and intervention. “More research is needed to reduce the burden of mild-TBI. We need to understand exactly how an injury affects the brain and how people function, so we can develop effective treatment.”
A recent survey of clinicians working in rehabilitation showed that two-thirds of them had never or infrequently evaluated social cognitive deficits in mild-TBI patients using a formal assessment tool. Consequently, few of these patients received treatment to address the problem.
Longitudinal studies would help determine whether social cognitive deficits that emerge following a mild-TBI improve, decline or remain stable over time. Population differences and the role of ethnicity also need to be explored.
The study was funded by the Health Research Council of New Zealand.
HRC chief executive, Professor Kathryn McPherson, says: “Increasing international literature indicates that mild-TBI, for many people, is not so mild. This study highlights that even four years after a mild-TBI, some social skills that most of us take for granted – skills that make it easier to have relationships – may be impacted. In view of the data from the BIONIC study, that New Zealand has a high rate of TBI, these results are important for funders like ACC, as well as GPs and other community health providers”.
Associate Professor Theadom heads AUT’s new TBI Network, which will see researchers, clinicians, communities and policymakers working together to achieve health and wellbeing for people with traumatic brain injuries. This starts by collectively determining what research needs to be done.
“We want to revolutionise the way that we prevent, identify and treat traumatic brain injuries. There is the potential for us to be world leaders in this space, but we need to build capacity and interest because the problem will only be solved by a village,” she says.
AUT will officially launch the TBI Network on May 21.