<p>Neurocognitive mechanisms of theory of mind impairment in neurodegeneration: a transdiagnostic approach</p>

Abstract

Much of human interaction is predicated upon our innate capacity to infer the thoughts, beliefs, emotions, and perspectives of others, in short, to possess a “theory of mind” (ToM). While the term has evolved considerably since its inception, ToM encompasses our unique ability to apprehend the mental states of others, enabling us to anticipate and predict subsequent behavior. From a developmental perspective, ToM has been a topic of keen research interest, with numerous studies seeking to explicate the origins of this fundamental capacity and its disruption in developmental disorders such as autism. The study of ToM at the opposite end of the lifespan, however, is paradoxically new born, emerging as a topic of interest in its own right comparatively recently. Here, we consider the unique insights afforded by studying ToM capacity in neurodegenerative disorders. Arguing from a novel, transdiagnostic perspective, we consider how ToM vulnerability reflects the progressive degradation of neural circuits specialized for an array of higher-order cognitive processes. This mechanistic approach enables us to consider the common and unique neurocognitive mechanisms that underpin ToM dysfunction across neurodegenerative disorders and for the first time examine its relation to behavioral disturbances across social, intimate, legal, and criminal settings. As such, we aim to provide a comprehensive overview of ToM research in neurodegeneration, the resultant challenges for family members, clinicians, and the legal profession, and future directions worthy of exploration.

Psychological and Cognitive Markers of Behavioral Variant Frontotemporal Dementia–A Clinical Neuropsychologist's View on Diagnostic Criteria and Beyond

“…Considering cases of selective impairment of theory of mind in bvFTD [e.g., (204)], and the vast evidence for theory of mind processing deficits across a wide range of different tasks (i.e., from simple first-order false belief task to more complex test requiring context and social norms processing such as in faux pas detection tasks), a primary deficit of theory of mind in bvFTD, somewhat independent of other cognitive dysfunctions becomes likely. In contrast to that, in AD, a secondary deficit (i.e., impacted by memory or executive dysfunctions) may be assumed (220, 223, 232, 234). However, the primary vs. secondary opposition needs to be refined and may lack of clinical relevancy for single case diagnoses until more reliable measures of theory of mind are available for clinical routine.…”

“…An impairment in theory of mind abilities has been extensively described in bvFTD (222, 223). Deficits have been observed using different paradigms based on false-belief (224–226), detection of sarcasm (210, 227) or insincere communication (228), agency attribution (229), as well as emotional inference or attribution (209, 230, 231), emotional movement-based inference (232) and social faux pas detection and understanding (207, 209, 212, 213).…”

Exploring the Relationship Between Social Cognition Deficits and Neurodegenerative Dementia: Protocol for a Systematic Review

“…Christidi et al (13) pointed out that some de cits in SC may represent central diagnostic criteria in bvFTD, while in others, such as Alzheimer-type dementia (AD), these de cits may arise during the course of the disease as critical aspects. Strikwerda-Brown et al (14) limited their review to the relationship between theory of mind and neurodegenerative disorders, but did not consider other aspects of SC. These and other published reviews (13)(14)(15)about the relationships between SC and neurodegenerative disorders were not performed systematically and did not describe the methodology used.…”

“…Strikwerda-Brown et al (14) limited their review to the relationship between theory of mind and neurodegenerative disorders, but did not consider other aspects of SC. These and other published reviews (13)(14)(15)about the relationships between SC and neurodegenerative disorders were not performed systematically and did not describe the methodology used. Thus, we consider that the present work, in addition to ll in the gaps of the previous reviews, will provide strength to the results obtained, since it is a systematic review.…”

The interplay of emotional and social conceptual processes during moral reasoning in frontotemporal dementia – a role for the uncinate fasciculus

“…One particularly fruitful avenue for exploring the mechanisms of moral reasoning is to study everyday examples of its breakdown. The behavioural variant of frontotemporal dementia (bvFTD) offers a unique glimpse into the degeneration of the "social brain" given its hallmark alterations in personality and behaviour, including emotional blunting, loss of empathy, and an inability to consider the thoughts and perspectives of others (Dermody et al, 2016;Strikwerda-Brown, Ramanan, & Irish, 2019;Synn et al, 2018). These symptoms arise due to early degeneration of large-scale functional brain networks specialised for socioemotional functioning, centered on medial prefrontal and frontoinsular cortices (Seeley, Zhou, & Kim, 2012).…”