Social Cognition and How to Measure It in Dementia

The behavioral variant frontotemporal dementia (BvFTD) is a neurodegenerative disease that occurs as a consequence of the constant loss of cells in the frontal and temporal regions of the brain (atrophy), affecting the social cognition at the same time.

In a study conducted by F. Kumfor et al. (2017), the long and short versions (TASIT-S) of a test (TASIT – The Awareness of Social Inference Test; McDonald, Flanagan, Rollins and Kinch 2003) that measures the social cognition performance through various methods, were administered on Frontotemporal dementia and Alzheimer’s patients, and the results were compared among themselves and to those of healthy individuals. During the TASIT, the participants were shown a video clip and asked about the emotions and intentions of the people in that video clip. The first part of the test measured the emotional perception of the individuals (happiness, sorrow, anger, apprehension/fear, disgust, astonishment), while the second part measured whether they could perceive the sarcastic messages of the person. On the other hand, the MRI scans of the participants were analyzed in order to see what brain parts were impaired and to measure which brain parts the test performances were associated with.

The following results were obtained as a result of the tests:

1. The original version of the test, and its shortened version were strongly correlated. Therefore, the short version could be preferred in clinical practice, instead of the one-hour long version.
2. As per the neuroimaging results;
   • While anterior atrophy was observed in BvFTD patients (in frontal lobes, bilateral orbifrontal cortex, and temporal lobes), posterior atrophy was observed in Alzheimer’s patients (bilateral frontal lobe, bilateral hippocampus, posterior cingulate, temporoparietal regions).
   • The frontal medial cortex and the right insular region of BvFTD patients were affected more, compared to AD, while the precuneus region of AD patients suffered a higher level of loss of cells.
3. When general cognitive skills and educational backgrounds were taken into consideration in the first part of the TASIT-S (recognition of emotions), the performance of the BvFTD and AD in the diagnosed group was slower, compared to the healthy control group, and there were no differences between both patient groups in terms of performance. Nevertheless, according to the MRI results, there were differences in the regions that were associated with the test performances of both groups.
   • While the performance of BvFTD patients was associated with frontal lobes, right temporal lobe, and right insula, where anterior atrophy was observed, the performance of AD was explained with other regions, in addition to the regions that were associated with social brain.
4. In the second part of the test (discerning sarcastic words), however, BvFTD patients showed a performance that was at distinctly lower levels, compared to that of Alzheimer’s patients. Furthermore, the fact that the patients had no problems in recognizing sincere expressions in the test, and the fact that they only failed to separate sarcastic expressions from sincere ones, put forth that the low test performances they have cannot be explained with general cognitive impairment, or with the failure to comprehend the requirements of the test. As per the neuroimaging results:
   • Not a single brain region was found to be associated with the performances of healthy and AD individuals.
   • Following an overall analysis, the test performances were associated with right amygdala, right orbitofrontal cortex, left precuneus, temporal lobes, and left fusiform cortex.
5. Based on those results, the researchers concluded as follows: The low performances shown by Alzheimer’s patients in TASIT-S were associated with the overall decline in their cognitive skills, while the fact that BvFTD patients showed a much lower performance, compared to other groups, even though the education factor and other general cognitive skills were controlled, substantially explained the decline in the patients’ skills of recognizing emotions and comprehending sarcastic messages.
6. According to the results of the MRI, which was used to research the association of the test performance with social brain regions, the amygdala, temporal lobes, insula, fusiform cortex, frontal lobes, and precuneus regions were associated with the overall TASIT-S performance. While the amygdala was found to be associated with insula and temporal lobes in the “recognition of emotions” part of the test, the “perceiving sarcastic words” part was associated with the amygdala and temporal lobes, as well as with the orbitofrontal cortex, and the precuneus region that is correlated with the skills of guessing what others think. Moreover, the applicability of the short version of the test is further increased by the fact that these regions were also found to have been associated with the longer version of test in previous studies.

The study by Kumfor et al. sets forth that impairments in social cognition rarely occur in the Alzheimer’s population if the disease is not at acute levels; that the decline in overall cognitive skills is effective for AD patients in terms of low performance in social cognition tests; and that, in turn, overall cognitive skills must be controlled in social cognition research conducted on dementia population.

The study also revealed that the shorter version of the TASIT, measuring the skills of recognizing emotions and perceiving sarcastic messages, could also measure the social cognitive skills of BvFTD patients. It puts forward that tests that control this factor are more useful, as the low levels of those skills among overall cognitive skills affect the determination of the social cognition in the dementia population.  Nonetheless, the fact that tests that measure social cognition are affected by culture and social values, requires that the research should be repeated in this population as well for validity and accuracy purposes in the event that the test is adapted into Turkish.

ABBREVIATIONS:
AD: Alzheimer’s Disease
BvFTD: Behavior variant Frontotemporal Dementia
TASIT: The Awareness of Social Inference Test

REFERENCES:
– Baez, S., Manes, F., Huepe, D., Torralva, T., Fiorentino, N., Richter, F., … & Matallana, D. (2014). Primary empathy deficits in frontotemporal dementia. Frontiers in aging neuroscience, 6, 262.
– Ibañez, A., & Manes, F. (2012). Contextual social cognition and the behavioral variant of frontotemporal dementia. Neurology, 78(17), 1354-1362.
– Kumfor, F., Honan, C., McDonald, S., Hazelton, J. L., Hodges, J. R., & Piguet, O. (2017). Assessing the “social brain” in dementia: applying TASIT-S. Cortex, 93, 166-177.
– McDonald, S., Flanagan, S., Rollins, J., & Kinch, J. (2003). TASIT: A new clinical tool for assessing social perception after traumatic brain injury. The Journal of head trauma rehabilitation, 18(3), 219-238.