Laptop-based Testing of Emotion Discrimination and Interoception in Amyotrophic Lateral Sclerosis

Background: <br/>ALS shares neuropathological similarities with Frontotemporal Dementia (FTD) resulting in social cognitive dysfunction. Neuropathologically triggered cognitive deficits are not yet well explored in ALS research, and it has been argued that changes in subdomains of social cognition are part of the ALS neuropsychological profile independent of FTD symptoms.<br/> <br/>Objectives/Method: <br/>This study utilizes a computer-based setup to investigate the potential positivity-bias in ALS patients without FTD, specifically regarding facial emotion perception. We also explored the metacognitive insight of patients’ perception abilities to understand where in the emotion perception process dysfunction arises and the neuropsychological profile of ALS.<br/>The study is ongoing. Currently, 31 ALS patients (18 male, mean age = 61.74) and 9 healthy subjects (2 male, mean age = 63.33) have been included. Patients were on average 50 months after diagnosis, and all fulfilled the latest diagnostic criteria (Gold Coast criteria) for ALS. <br/>An emotion discrimination task (EDT) was administered using a standard laptop computer. Participants were presented with a total of 60 images of faces morphed between angry and happy facial expressions. <br/>Participants were given a forced-choice “happy or angry” evaluating the emotion presented after stimulus presentation. Following each stimulus a confidence rating was obtained, on a scale from “pure guess” (value = 0) to “very sure” (value = 100).<br/>Emotion intensity (EI) represents degree of digital interlacement of recognizable facial expressions of angry (EI = 0) and happy (EI = 200). The EI level where a participant is equally likely to report happy or angry represents the EI Threshold (EIT) and one would expect healthy controls to have an EIT around 100.<br/>The paradigm presented morphed faces in an adaptive way adjusting the presentation to participants answers, creating a short test (~18 minutes) with most expressions presented around the EIT.<br/><br/>Results: <br/>Preliminary data shows a tendency for a lower patient EIT (mean = 81.46, SD = 22.76) compared to control EIT (mean = 86.54, SD = 17.28, p = 0.465). Representing perception of slightly angry faces as neutral. <br/>Patients’ confidence ratings were significantly higher when perceiving happy faces (mean = 73.24, SD = 17.78) compared to when perceiving angry faces (mean = 60.84, SD = 26.69, p = 0.042) indicating higher confidence in perception of happy faces. <br/><br/>Discussion/Conclusion: <br/>This study is ongoing, and the results are preliminary. Nonetheless, these findings suggest a positivity-bias in ALS patients when interpreting ambiguous facial emotions. This points to the potential use of the brief laptop-based test for disturbances in emotional processing in ALS. Future work should compare the results to standardized tests of emotional perception to overall cognition. Insights into the neuropsychological manifestations of ALS can benefit family members and caregivers, improve treatment adherence, and reduce caregiver burden.<br/>