Comparing Moral Judgments of Patients With Frontotemporal Dementia and Frontal Stroke

Abstract

ore than a century ago, the Phineas Gage case revealed that frontal lobe lesions can cause personality and social cognition impairment. Since its description, clinical observations 1 have highlighted important similarities between the symptoms of patients with prefrontal lesions (PFL) and patients with the behavioral variant of frontotemporal dementia (bvFTD). Both conditions share symptoms such as distractibility, personality changes, social inappropriateness, and markedly impaired moral judgments. 2,3 However, to our knowledge, no studies have compared PFL and bvFTD regarding any social cognition domain. Social cognition tasks are particularly sensitive in detecting impairment in frontal patients. 4 Moral reasoning is a social cognition domain affected in both conditions. 2,3 The brain areas usually affected in bvFTD 5,6 (the ventromedial prefrontal cortex [VMPC], orbitofrontal cortex, anterior temporal lobes, amygdala, and insula) are involved in moral cognition. 7 Moreover, patients with VMPC damage show abnormal moral judgments of harmful intentions in the absence of harmful outcomes. 3 However, to our knowledge, no studies of bvFTD have previously examined the processing of intentions and outcomes in moral judgment. This work compared the moral judgments of patients with bvFTD and patients with PFL by means of a well-characterized task 3 involving scenarios that disentangle the contributions of intentions and outcomes to moral judgment. Methods Participants All participants provided written informed consent in agreement with the Helsinki declaration. The ethics committee of the Institute of Cognitive Neurology approved this study. Eight patients with unilateral chronic cerebrovascular lesions confined to frontal structures were recruited. All patients were assessed at least 6 months after the lesion and none of them had aphasia or motor difficulties. Nineteen patients fulfilled the revised criteria for probable bvFTD. 8 All patients underwent neurological, neuropsychiatric, and neuropsychological examinations and were in the early or mild stages of the disease. Patients with bvFTD and patients with PFL with psychiatric disorders, other neurological diseases, or diffuse brain damage in neuroimaging were excluded. IMPORTANCE Several clinical reports have stated that patients with prefrontal lesions or patients with the behavioral variant of frontotemporal dementia share social cognition impairments. Moral reasoning is impaired in both conditions but there have been few investigations that directly compare this domain in the 2 groups. OBSERVATIONS This work compared the moral judgments of these patient groups using a task designed to disentangle the contributions of intentions and outcomes in moral judgment. For both disorders, patients judged scenarios where the protagonists believed that they would cause harm but did not as being more permissible than the control group. Moreover, patients with frontotemporal dementia judged harmful outcomes in the absence of harmful intentions as less permissible than the co...

Integration of Intention and Outcome for Moral Judgment in Frontotemporal Dementia: Brain Structural Signatures

“…This study replicated the results of a recent report [23] showing that bvFTD patients judged attempted harm as more permissible and accidental harm as less permissible than control subjects. Unlike controls, and consistently with the VBM results (see below), bvFTD patients judged attempted harm by focusing on the neutral outcome rather than the protagonist's negative intention.…”

“…In line with the network models, a recent study [23] demonstrated similar impairments in integrating intention and outcome information for moral judgment in patients with prefrontal lesions either with or without VMPFC damage, as well as in behavioral variant frontotemporal dementia (bvFTD) patients. Although the VMPFC may be affected in bvFTD patients, their atrophy pattern extends to other frontotemporal areas.…”

“…Each case was individually reviewed in a multidisciplinary clinical meeting involving cognitive neurologists, psychiatrists, and neuropsychologists. bvFTD patients were recruited as part of a broader ongoing study on frontotemporal dementia [23,29,33,34]. Patients presented with functional impairment and prominent changes in personality and social behavior as verified by a caregiver during initial assessment.…”

“…According to a protocol reported elsewhere [21,23], we presented the participants with 24 scenarios. Four variations of each scenario followed a 2 × 2 design: (1) the protagonists either harmed another person (negative outcome) or did no harm (neutral outcome); (2) the protagonists either believed that they would cause harm (negative intention) or believed that they would cause no harm (neutral intention; fig.…”

“…This study is the first to report gray matter (GM) changes associated with moral judgments in bvFTD patients and controls. First, we compared the behavioral performance of both groups on a well-characterized task [21,23] involving scenarios that separate the contributions of intentions and outcomes to moral judgment. Then, we performed voxel-based morphometry (VBM) to measure and compare GM volumes in bvFTD patients and controls.…”