Metacognitive deficits in frontotemporal dementia

Abstract

Objectives: To investigate whether metacognitive impairments in self-awareness and self-monitoring occur in patients with frontotemporal dementia (FTD), particularly among those with prominent social and dysexecutive impairments. Methods: Patients diagnosed with FTD were divided by clinical subtype (social-dysexecutive (n = 12) aphasic (n = 15), and constituent subgroups of progressive non-fluent aphasia and semantic dementia) and compared with subjects with probable Alzheimer's disease (AD, n = 11) and age-matched healthy controls (n = 11). All subjects completed comprehensive behavioural ratings scales, which were compared with caregiver ratings. Subjects also rated their test performances in verbal associative fluency, word list learning, and memory task with comparisons made between actual and judged performance levels. Results: The FTD sample as a whole showed significantly less behavioural self-awareness and selfknowledge than the AD and healthy control samples. FTD patients with prominent social and dysexecutive impairments demonstrated the most extensive loss of self-awareness and self-knowledge, significantly overrating themselves in multiple social, emotional, and cognitive domains, and failing to acknowledge that any behavioural change had occurred in most areas. The remaining clinical samples showed select and minimal discrepancies. All clinical groups were significantly unaware of their apathy levels. Most FTD patients judged episodic cognitive test performance adequately, with partial difficulties observed in the socially impaired and progressive non-fluent aphasia subgroups. Conclusions: FTD patients, particularly those with prominent social and dysexecutive impairments, exhibit profound metacognitive anosognosia that may represent a loss of self-awareness, self-monitoring, and self-knowledge, likely related to significant prefrontal pathophysiology. Other FTD clinical groups and AD patients showed less pervasive and more select metacognitive deficiencies. M etacognition refers to diverse processes of self-knowledge, self-monitoring, and self-regulation that contribute to adaptive behaviour in complex and changing environments. [1][2][3][4] Metacognition is considered a domain of information processing that comprises personal awareness and knowledge as well as adaptive strategies. These processes can be operationalised as experimental measures in certain tasks. For example, individuals can be asked to predict their expected performance in a particular task, such as learning a word list. This entails derived selfknowledge of abilities (established on the basis of various previous experiences, incorporation of feedback, and selfreflection), experiences and synthesis of that information for judgement purposes. Individuals can also be asked how hard or easy it will be to learn particular words, as in judgement of learning measures that draw upon knowledge of stimulus characteristics and previous experience with those types of items. In addition to self-predictions, metacognition can be probed by secur...

Social Cognition, Executive Functioning, and Neuroimaging Correlates of Empathic Deficits in Frontotemporal Dementia

“…On the other hand, the subgroup of patients with bvFTD have significant executive-function deficits, 42,43 and it is reasonable to propose that the social disorder in bvFTD is due in part to their executive-resource limitations. Although we demonstrated this in our previous assessments of social problem-solving and self-awareness, 12,15 such associations between social-emotional and executive-cognitive functioning may not have been seen in other work because of limited ascertainment of cognitive measures, such as assessment of a partial range of relevant measures. For example, Lough and coworkers 9,41 examined a limited range of executive measures requiring cognitive estimation, but did not assess measures of mental flexibility that may be a more pertinent cognitive component of empathy.…”

“…Such correlations have been suspected in bvFTD patients on the basis of results of clinical studies, and overlapping pathophysiology that has been identified in focal frontal lesion cases 17 and in previous assessments of social cognition in bvFTD. 12,15 For example, during a three-alternative, forced-choice, social problem-solving task, we identified a significant deficit in bvFTD. Correlational analyses revealed that performance was related to theory of mind, empathy, and cognitive flexibility measures.…”

“…Correlational analyses revealed that performance was related to theory of mind, empathy, and cognitive flexibility measures. 12 A regression analysis demonstrated that the measure of cognitive flexibility accounted for the largest portion of the variance in social judgment performance. Observations such as these and the findings of the present study provide support for the social executor model.…”

“…We related these deficits to cortical atrophy in a large-scale neural network encompassing at least orbital frontal, medial frontal, and superior temporal regions, more prominently in the right hemisphere. 12,14,15 …”

“…9 Hence, we hypothesized that analysis of a standardized behavioral inventory would confirm significant cognitive and emotional empathic deficits in a bvFTD sample, although we were uncertain about empathic changes in an FTD aphasic sample (SD and PNFA), since we have not observed such changes in previous research or in clinical care. Although limited insight into their own social deficits has been documented in previous studies of bvFTD, 11,12 few studies have specifically compared ratings of empathy in bvFTD patients with the ratings of their caregivers.…”