Biomedical subjects

Facundo Manes

Publications and source records attributed to Facundo Manes.

6 recordsLinked to original sources

PubMed2006

The relationship between affective decision-making and theory of mind in the frontal variant of fronto-temporal dementia.

Structural brain imaging and neuropsychological data implicate the orbital aspects of prefrontal cortex in the developing neuropathology of fvFTD. Damage to this region is associated with deficient performance on laboratory tasks assessing theory of mind (ToM) and affective decision-making (DM), but the relationship between these two capacities in patients with prefrontal cortex dysfunction is unclear. We studied a group of patients with early/mild fvFTD (n=20) and a group of matched normal controls (n=10) on the Iowa gambling task (IGT) of affective decision-making, and the "reading the mind in the eyes" (MIE) and "faux pas" (FP) tests of ToM. The fvFTD group was impaired in both ToM tasks and the IGT. While performance measures from the two ToM tasks were significantly correlated, they were not associated with IGT performance. This suggests that whilst similar prefrontal circuitry is implicated in ToM and DM tasks, these cognitive domains may be independent. In clinical settings, the IGT may be useful as a complementary tool to the frontal test battery for patients with early/mild fvFTD. Deficits in decision-making and ToM observed in this study have distinct but additive effects upon the development of social behaviour in patients with prefrontal dysfunction.

Aged↗

PubMed2004

Impaired recognition of anger following damage to the ventral striatum.

Comparative neuropsychology has identified a role for the ventral striatum (VS) in certain forms of aggression. To address whether the homologous region in humans also contributes to the emotion anger, we studied a case series of four human subjects with focal lesions affecting the VS. All four demonstrated a disproportionate impairment in recognizing human signals of aggression. By contrast, a control group of individuals with damage to more dorsal basal ganglia (BG) regions showed no evidence of an anger impairment. Our findings demonstrate that the VS makes a significant contribution to coding signals of aggression in humans, and emphasize the importance of an approach to human affective neuroscience based on cross-species homologies. The results are discussed in relation to the ventral striatal dopamine system's role in the pursuit of biological resources in general. We propose that the role of the VS in the recognition of human signals of anger may reflect a more general role in the coordination of behaviour relevant to the acquisition and protection of valued resources, including detection of signals of conspecific challenge (anger).

Adult↗

PubMed2004

Social and emotional decision-making following frontal lobe injury.

Neuropsychological, psychophysiological and functional imaging research has begun to offer insights into the everyday difficulties in decision-making experienced by some patients with frontal lobe damage. It is widely accepted that the ventral prefrontal cortex plays a pivotal role in social and emotional decision-making. This article will review experimental findings using the Iowa Gambling Task and the Cambridge Gamble Task that explore the brain mechanisms of decision-making. Convergent evidence from the two tasks confirms the importance of ventral PFC, but also highlights the relevance of lesion laterality, lesion aetiology, and the contribution of other brain regions (including the dorsal prefrontal cortex and amygdala) to decision-making abilities. The extent to which disrupted decision-making can be separated from the broader domain of executive function is discussed.

Brain Injuries↗

PubMed2003

The contributions of lesion laterality and lesion volume to decision-making impairment following frontal lobe damage.

Lesions to prefrontal cortex (PFC) in humans can severely disrupt everyday decision-making, with concomitant effects on social and occupational functioning. Forty-six patients with unilateral lesions to prefrontal cortex and 21 healthy control subjects were administered three neuropsychological measures of decision-making: the Iowa Gambling Task, the Cambridge Gamble Task, and the Risk Task. Magnetic resonance imaging (MRI) scans were acquired from 40 patients, with region of interest (ROI) mapping of prefrontal subregions. The frontal patients showed only limited damage in medial and orbital prefrontal cortex, but greater damage in lateral prefrontal regions of interest. Patients with right frontal lesions preferred the risky decks on the Iowa Gambling Task, and differed significantly from left frontal and control subjects. Within the right frontal group, the preference for the risky decks was correlated with the total lesion volume and the volume of damage outside of the ventromedial prefrontal region. Right and left frontal groups did not differ significantly on the Cambridge Gamble Task or the Risk Task, and performance was not associated with lesion volume. The results indicate a laterality effect on the Iowa Gambling Task, and the contribution of prefrontal regions outside the ventromedial region to task performance. The Cambridge Gamble Task and Risk Task were less sensitive to the effects of unilateral frontal lobe lesions, and may be more selectively associated with ventral prefrontal damage.

Adult↗

PubMed2002

Decision-making processes following damage to the prefrontal cortex.

Recent work has suggested an association between the orbitofrontal cortex in humans and practical decision making. The aim of this study was to investigate the profile of cognitive deficits, with particular emphasis on decision-making processes, following damage to different sectors of the human prefrontal cortex. Patients with discrete orbitofrontal (OBF) lesions, dorsolateral (DL) lesions, dorsomedial (DM) lesions and large frontal lesions (Large) were compared with matched controls on three different decision-making tasks: the Iowa Gambling Task and two recently developed tasks that attempt to fractionate some of the cognitive components of the Iowa task. A comprehensive battery including the assessment of recognition memory, working memory, planning ability and attentional set-shifting was also administered. Whilst combined frontal patients were impaired on several of the tasks employed, distinct profiles emerged for each patient group. In contrast to previous data, patients with focal OBF lesions performed at control levels on the three decision-making tasks (and the executive tasks), but showed some evidence of prolonged deliberation. DL patients showed pronounced impairment on working memory, planning, attentional shifting and the Iowa Gambling Task. DM patients were impaired at the Iowa Gambling Task and also at planning. The Large group displayed diffuse impairment, but were the only group to exhibit risky decision making. Methodological differences from previous studies of OBF patient groups are discussed, with particular attention to lesion laterality, lesion size and psychiatric presentation. Ventral and dorsal aspects of prefrontal cortex must interact in the maintenance of rational and 'non-risky' decision making.

Adult↗

PubMedDate not supplied

Assessing level of consciousness and cognitive changes from vegetative state to full recovery.

Although investigations addressing cognitive recovery from the vegetative state have been reported, to date there have been no detailed studies of these patients combining both neuropsychology and functional imaging to monitor and record the recovery of consciousness. This paper describes the recovery of a specific vegetative state (VS) case. The patient (OG) remained in the vegetative state for approximately two months, increasing her level of awareness to a minimally conscious state, where she continued for approximately 70 days. In the course of the ensuing 18 months, she was able to reach an acceptable level of cognitive functioning, with partial levels of independence. Throughout this two year period, she received continuous cognitive evaluation, for which several different tools were applied including coma and low functioning scales, full cognitive batteries, and structural and functional magnetic resonance imaging (MRI). We present here preliminary data on fMRI using a word presentation paradigm before and after recovery; we also discuss the difficulty of how to determine level of consciousness using the tools currently available, and the subsequent improvement in different cognitive domains. We confirm that accurate diagnosis and proper cognitive assessment are critical for the rehabilitation of patients with disorders of consciousness.

Adult↗