The research, published in the Journal of Head Trauma Rehabilitation, reveals that appropriate training can result in significant gains in "emotional perception", which is crucial for successful social communication.
The study involved 18 participants recruited from an outpatient service at the Liverpool Hospital Brain Injury Rehabilitation Unit, in Sydney, Australia. All had experienced a severe traumatic brain injury at least six months earlier and had significantly impaired ability to interpret emotions in others.
Observations by clinicians or the participants themselves had identified chronic social difficulties or isolation, an apparent disregard or a lack of awareness of social cues, or inappropriate social responding.
Someone who has suffered traumatic brain injury - commonly due to a blow to the skull - can lose the ability to accurately read other people's emotional cues, which may make their social behaviour awkward, badly timed or miscalculated, notes the study's lead author, UNSW clinical psychologist, Dr Cristina Bornhofen.
"These people find it difficult to integrate the cluster of non-verbal cues that accompany speech," says Bornhofen. "Their inability to interpret emotional expression causes significant frustration because it impairs their social competence."
They may have difficulty interpreting an emotion such as sarcasm, for example, in which a positive verbal message is paired with a voice tone and facial expression intended to convey a meaning opposite to the verbal message.
Traditional treatments have emphasised training in positive social behaviours, such as turn-taking, giving compliments, and reducing undesirable behaviours, such as excessive talking and inappropriate conversation topics, Dr Bornhofen says. However, these programs have had limited success.
"Good social communication is possible only if people can effectively use feedback, such as that provided by the emotional responses of others. Behaviourally-oriented programs have tended to neglect this critical aspect of social skills," she says.
Using photographs and videos, the participants were tested before and after the program on an array of outcomes: independent living skills, psycho-social health, and emotional discrimination tasks requiring them to identify emotions such as happiness, sadness, anger, anxiety, disgust and surprise.
Earlier research had suggested that the accurate perception of emotional cues requires a variety of cognitive skills involving several brain regions and pathways, which are yet to be clearly defined. Dr Bornhofen and her co-researcher, Professor Skye McDonald, therefore compared two broadly different treatment regimes, randomly assigning program participants to each treatment.
The first, known as "self-instruction training", taught patients to answer questions by using a set of strategic questions to guide them through emotion discrimination tasks, using questions such as: What is it am I deciding about? What do I already know about it? What do I need to look or listen for?
The second regime, called "errorless learning", began with extremely easy discriminations, providing extensive practice at each stage and strongly discouraged learners from guessing when unsure. For example, repeated practice of identifying patterns associated with basic emotions (such as wide eyes and raised eyebrows in surprise) was carried out using line drawings of basic expressions laid out on a table alongside a card with the words "not sure." Participants were encouraged to point to "not sure" rather than guess the answer, and were positively acknowledged whenever they did so. Both regimes were carefully designed to ensure that participants received comparable levels of positive feedback and therapeutic attention in each.
"The results suggested that self-instruction training was slightly better at improving program participants' ability to judge facial expressions from photographs, and deciding whether someone was speaking sarcastically, on the basis of a speaker's emotional demeanour," says Dr Bornhofen.
Informal subjective reports from treatment group members and their relatives revealed improvements in the participants' ability to understand the emotional state of others during day-to-day interactions and an increased confidence in their ability to successfully engage in social contexts.
The sister of one study participant said: "My brother is engaging better with his children and they are enjoying doing more things with him. He is enjoying a far better relationship with his parents. His anger and frustration have virtually disappeared and he is achieving well at work. His sense of humour has returned and he can laugh off things that would once trouble him deeply. The impact of the program has been life changing."
"Overall, self-instruction training appears to be the most beneficial strategy for teaching emotion perception skills to most traumatically brain injured patients, although further research is required to substantiate this finding. We are continuing research in this direction, and, in the meantime, we are preparing to publish the treatment program in manual form so that clinicians can utilise the best of the materials and techniques in their work with patients.
"As there are currently no other evidence-based treatment materials available for this kind of rehabilitation with people who have brain injuries, we believe the work will be of great assistance. We have already had numerous requests for the program, especially from the U.S., where the growing number of returning armed service personnel with head injuries is raising awareness in this area."