Abnormal patterns of regional cerebral blood flow in schizophrenia with primary negative symptoms during an effortful auditory recognition task.

OBJECTIVE: Using functional brain imaging, the authors sought to replicate their earlier finding of low metabolism in the middle frontal and inferior parietal cortices of schizophrenic patients with primary negative symptoms. METHOD: According to the presence or absence of enduring negative symptoms, patients with schizophrenia were classified as having deficit or nondeficit schizophrenia, respectively. Twelve normal volunteers and 18 drug-free schizophrenic volunteers (deficit, N=8; nondeficit, N=10) were trained in a tone discrimination task. They were trained to perform with 70%-80% accuracy and were then scanned with positron emission tomography with [(15)O]H(2)O during three conditions: rest, sensory-motor control task, and decision task. RESULTS: Levels of performance of the auditory recognition task were similar in the three groups. An initial hypothesis-driven analysis revealed that across tasks the deficit group failed to show significant activation in the middle frontal cortex. This was in contrast to both the normal volunteers and nondeficit patients. When the patient groups were contrasted, the deficit patients showed significantly less activation in the middle frontal cortex bilaterally during the control task and in the right middle frontal cortex and inferior parietal cortex during the decision task. An exploratory analysis contrasting deficit and nondeficit patients across conditions did not reveal further differences between groups. CONCLUSIONS: This study replicated the finding of low activation in the middle frontal cortex and inferior parietal cortex in deficit schizophrenia. This deficit was observed without performance confound and may provide a marker of primary negative symptoms and a target for new therapies.     

Schizophrenic Patients and Their Unaffected Siblings Share Increased Resting-State Connectivity in the Task-Negative Network but Not Its Anticorrelated Task-Positive Network

Background:

Abnormal connectivity of the anticorrelated intrinsic networks, the task-negative network (TNN), and the task-positive network (TPN) is implicated in schizophrenia. Comparisons between schizophrenic patients and their unaffected siblings enable further understanding of illness susceptibility and pathophysiology. We examined the resting-state connectivity differences in the intrinsic networks between schizophrenic patients, their unaffected siblings, and healthy controls.

Methods:

Resting-state functional magnetic resonance images were obtained from 25 individuals in each subject group. The posterior cingulate cortex/precuneus and right dorsolateral prefrontal cortex were used as seed regions to identify the TNN and TPN through functional connectivity analysis. Interregional connectivity strengths were analyzed using overlapped intrinsic networks composed of regions common to all subject groups.

Results:

Schizophrenic patients and their unaffected siblings showed increased connectivity in the TNN between the bilateral inferior temporal gyri. By contrast, schizophrenic patients alone demonstrated increased connectivity between the posterior cingulate cortex/precuneus and left inferior temporal gyrus and between the ventral medial prefrontal cortex and right lateral parietal cortex in the TNN. Schizophrenic patients exhibited increased connectivity between the left dorsolateral prefrontal cortex and right inferior frontal gyrus in the TPN relative to their unaffected siblings, though this trend only approached statistical significance in comparison to healthy controls.

Conclusion:

Resting-state hyperconnectivity of the intrinsic networks may disrupt network coordination and thereby contribute to the pathophysiology of schizophrenia. Similar, though milder, hyperconnectivity of the TNN in unaffected siblings of schizophrenic patients may contribute to the identification of schizophrenia endophenotypes and ultimately to the determination of schizophrenia risk genes.     

Reductions in phenomenological, physiological and attentional indices of depressive mood after 2 Hz rTMS over the right parietal cortex in healthy human subjects

Research into emotion and emotional disorders by repetitive transcranial magnetic stimulation (rTMS) has largely been restricted to the prefrontal regions. There is, however, also evidence for the parietal cortex being implicated in emotional (dys-)functioning. Here we used rTMS to investigate a role of the right parietal cortex in depression. In a placebo-controlled design, 2 Hz rTMS at 90% of the individual motor threshold (MT) was applied over the right parietal cortex of eight healthy subjects for 20 min continuously. Effects on mood, autonomic activity and motivated attention were investigated. Significant reductions in depressive mood were observed immediately following and 30 min after stimulation. Moreover, these findings were objectified by a concurring pattern of autonomically mediated changes in the attentional processing of angry facial expressions. These data suggest a role for the right parietal cortex in affective brain circuits regulating phenomenological, physiological and attentional aspects of depressive functioning.     

A preliminary functional magnetic resonance imaging study in offspring of schizophrenic parents

Studies of high-risk offspring (HR) of schizophrenic patients have found abnormalities in attention, working memory and executive functions, suggesting impaired integrity of the prefrontal cortex and related brain regions. The authors conducted a preliminary high-field (3 T) functional magnetic resonance imaging (fMRI) study to assess performance and activation during a memory-guided saccade (MGS) task, which measures spatial working memory. HR subjects showed significant decreases in fMRI-measured activation in the dorsolateral prefrontal cortex (Brodmann's areas 8 and 9/46) and the inferior parietal cortex (Brodmann's area 40) compared to age- and sex-matched healthy controls (HC). Abnormal functional integrity of prefrontal and parietal regions of the heteromodal association cortical (HAC) regions in subjects at genetic risk for schizophrenia is consistent with findings observed in adults with the illness [Callicott et al., Cereb. Cortex 10 (2000) 1078; Manoach et al., Biol. Psychiatry 48 (2000) 99.]. These abnormalities need to be prospectively investigated in nonpsychotic individuals at risk for schizophrenia in order to determine their predictive value for eventual emergence of schizophrenia or related disorders.     

Social brain dysfunctions in schizophrenia: a review of neuroimaging studies

Several studies have indicated that schizophrenic patients show impaired performance in various aspects of social cognition, including theory of mind, emotion processing, and agency judgments. Neuroimaging studies that have compared patients and healthy subjects during such mental activity indicate an abnormal hemodynamic response in the medial prefrontal cortex, the prefrontal cortex, the amygdala, the inferior parietal lobe, i.e., a set of regions known to be critically involved in social cognition. This paper addresses a number of issues raised by schizophrenia research into theory of mind, emotion perception and self-agency with regards to the neural systems that mediate social cognition. In healthy subjects, typical brain patterns are associated with theory of mind, emotion perception and self-agency; some activated clusters overlap, while others are distinct. For instance, activations in the paracingulate gyrus are almost systematically associated with theory of mind tasks, while the amygdala is mainly involved in emotion perception tasks. Additional foci are frequently found activated during those tasks: superior temporal sulcus, inferior frontal area. Moreover, the inferior parietal lobe is thought to contribute to agency judgments. In the light of the data on brain abnormalities and neurochemical dysfunctions in schizophrenia, we discuss the interaction of social cognitive dysfunction with the supposed information processing abnormalities caused by dopamine dysregulation.     

Social brain dysfunctions in schizophrenia: A review of neuroimaging studies

Several studies have indicated that schizophrenic patients show impaired performance in various aspects of social cognition, including theory of mind, emotion processing, and agency judgments. Neuroimaging studies that have compared patients and healthy subjects during such mental activity indicate an abnormal hemodynamic response in the medial prefrontal cortex, the prefrontal cortex, the amygdala, the inferior parietal lobe, i.e., a set of regions known to be critically involved in social cognition. This paper addresses a number of issues raised by schizophrenia research into theory of mind, emotion perception and self-agency with regards to the neural systems that mediate social cognition. In healthy subjects, typical brain patterns are associated with theory of mind, emotion perception and self-agency; some activated clusters overlap, while others are distinct. For instance, activations in the paracingulate gyrus are almost systematically associated with theory of mind tasks, while the amygdala is mainly involved in emotion perception tasks. Additional foci are frequently found activated during those tasks: superior temporal sulcus, inferior frontal area. Moreover, the inferior parietal lobe is thought to contribute to agency judgments. In the light of the data on brain abnormalities and neurochemical dysfunctions in schizophrenia, we discuss the interaction of social cognitive dysfunction with the supposed information processing abnormalities caused by dopamine dysregulation.     

Facial emotion recognition in Chinese with schizophrenia at early and chronic stages of illness

Deficits in facial emotion recognition have been recognised in Chinese patients diagnosed with schizophrenia. This study examined the relationship between chronicity of illness and performance of facial emotion recognition in Chinese with schizophrenia. There were altogether four groups of subjects matched for age and gender composition. The first and second groups comprised medically stable outpatients with first-episode schizophrenia (n=50) and their healthy controls (n=26). The third and fourth groups were patients with chronic schizophrenic illness (n=51) and their controls (n=28). The ability to recognise the six prototypical facial emotions was examined using locally validated coloured photographs from the Japanese and Caucasian Facial Expressions of Emotion. Chinese patients with schizophrenia, in both the first-episode and chronic stages, performed significantly worse than their control counterparts on overall facial emotion recognition, (P<0.001), with specific impairment in identifying surprise, fear and disgust. The level of deficit was similar at the two stages of illness. Findings suggest that impaired recognition of facial emotion did not appear to have worsened over the course of disease progression, suggesting that recognition of facial emotion is a rather stable trait of the illness. The emotion-specific deficit may have implications for understanding the social difficulties in schizophrenia.     

Parietal dysfunction is associated with increased outcome-related decision-making in schizophrenia patients.

BACKGROUND: Decision-making is a complex process and depends on a network of fronto-parietal and cingulate areas. Decision-making dysfunctions in schizophrenia patients are characterized by an alternation between stereotypic and unpredictable responses. This study tested the hypothesis that schizophrenia patients show less decision-making-related activation in the prefrontal and parietal cortex.METHODS: Fifteen schizophrenia patients were matched with fifteen normal comparison subjects. During functional magnetic resonance imaging (fMRI) scanning, subjects were tested on the two-choice prediction task (predicting the location of a randomly presented stimulus) and the two-choice response task (responding according to the location of the stimulus).RESULTS: Schizophrenia patients relative to comparison subjects generated more outcome-dependent responses. Schizophrenia patients and normal comparison subjects showed decision-making-related activation in right prefrontal cortex, insula, anterior cingulate, and bilateral precuneus. Schizophrenia patients showed less activation in inferior, medial prefrontal, and right superior temporal cortex and more activation in the postcentral and inferior parietal cortex. Decision-making-related activation in both right prefrontal and bilateral parietal cortex was higher in medicated compared to unmedicated schizophrenia patients.CONCLUSIONS: These results support the hypothesis that the interaction between prefrontal and parietal cortex during decision-making by schizophrenia patients is dysregulated, which results in an increased outcome-dependent response selection.     

Attribution of emotions to body postures: An independent component analysis study of functional connectivity in autism

The ability to interpret others' body language is a vital skill that helps us infer their thoughts and emotions. However, individuals with autism spectrum disorder (ASD) have been found to have difficulty in understanding the meaning of people's body language, perhaps leading to an overarching deficit in processing emotions. The current fMRI study investigates the functional connectivity underlying emotion and action judgment in the context of processing body language in high‐functioning adolescents and young adults with autism, using an independent components analysis (ICA) of the fMRI time series. While there were no reliable group differences in brain activity, the ICA revealed significant involvement of occipital and parietal regions in processing body actions; and inferior frontal gyrus, superior medial prefrontal cortex, and occipital cortex in body expressions of emotions. In a between‐group analysis, participants with autism, relative to typical controls, demonstrated significantly reduced temporal coherence in left ventral premotor cortex and right superior parietal lobule while processing emotions. Participants with ASD, on the other hand, showed increased temporal coherence in left fusiform gyrus while inferring emotions from body postures. Finally, a positive predictive relationship was found between empathizing ability and the brain areas underlying emotion processing in ASD participants. These results underscore the differential role of frontal and parietal brain regions in processing emotional body language in autism. Hum Brain Mapp 35:5204–5218, 2014. © 2014 Wiley Periodicals, Inc .     

Event-related fMRI of frontotemporal activity during word encoding and recognition in schizophrenia

OBJECTIVE: Neuropsychological studies have demonstrated verbal episodic memory deficits in schizophrenia during word encoding and retrieval. This study examined neural substrates of memory in an analysis that controlled for successful retrieval. METHOD: Event-related blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) was used to measure brain activation during word encoding and recognition in 14 patients with schizophrenia and 15 healthy comparison subjects. An unbiased multiple linear regression procedure was used to model the BOLD response, and task effects were detected by contrasting the signal before and after stimulus onset. RESULTS: Patients attended during encoding and had unimpaired reaction times and normal response biases during recognition, but they had lower recognition discriminability scores, compared with the healthy subjects. Analysis of contrasts was restricted to correct items. Previous findings of a deficit in bilateral prefrontal cortex activation during encoding in patients were reproduced, but patients showed greater parahippocampal activation rather than deficits in temporal lobe activation. During recognition, left dorsolateral prefrontal cortex activation was lower in the patients and right anterior prefrontal cortex activation was preserved, as in the authors' previous study using positron emission tomography. Successful retrieval was associated with greater right dorsolateral prefrontal cortex activation in the comparison subjects, whereas orbitofrontal, superior frontal, mesial temporal, middle temporal, and inferior parietal regions were more active in the patients during successful retrieval. CONCLUSIONS: The pattern of prefrontal cortex underactivation and parahippocampal overactivation in the patients suggests that functional connectivity of dorsolateral prefrontal and temporal-limbic structures is disrupted by schizophrenia. This disruption may be reflected in the memory strategies of patients with schizophrenia, which include reliance on rote rehearsal rather than associative semantic processing.     

Neural interaction of the amygdala with the prefrontal and temporal cortices in the processing of facial expressions as revealed by fMRI.

Some involvement of the human amygdala in the processing of facial expressions has been investigated in neuroimaging studies, although the neural mechanisms underlying motivated or emotional behavior in response to facial stimuli are not yet fully understood. We investigated, using functional magnetic resonance imaging (fMRI) and healthy volunteers, how the amygdala interacts with other cortical regions while subjects are judging the sex of faces with negative, positive, or neutral emotion. The data were analyzed by a subtractive method, then, to clarify possible interaction among regions within the brain, several kinds of analysis (i.e., a correlation analysis, a psychophysiological interaction analysis and a structural equation modeling) were performed. Overall, significant activation was observed in the bilateral fusiform gyrus, medial temporal lobe, prefrontal cortex, and the right parietal lobe during the task. The results of subtraction between the conditions showed that the left amygdala, right orbitofrontal cortex, and temporal cortices were predominantly involved in the processing of the negative expressions. The right angular gyrus was involved in the processing of the positive expressions when the negative condition was subtracted from the positive condition. The correlation analysis showed that activity in the left amygdala positively correlated with activity in the left prefrontal cortex under the negative minus neutral subtraction condition. The psychophysiological interaction revealed that the neural responses in the left amygdala and the right prefrontal cortex underwent the condition-specific changes between the negative and positive face conditions. The right amygdaloid activity also had an interactive effect with activity in the right hippocampus and middle temporal gyrus. These results may suggest that the left and right amygdalae play a differential role in effective processing of facial expressions in collaboration with other cortical or subcortical regions, with the left being related with the bilateral prefrontal cortex, and the right with the right temporal lobe.     

Effects of incidental and intentional feature binding on recognition: a behavioural and PET activation study.

Using Positron Emission Tomography (PET), we investigated cerebral regions associated with the episodic recognition of words alone and words bound to contextual colours. Two modes of colour encoding were tested: incidental and intentional word-to-colour binding. Word-only recognition was associated with brain activation in a lexico-semantic left middle temporal region and in the cerebellum following an incidental colour encoding, and with brain activation in the left posterior middle frontal gyrus, right anterior cingulate and right inferior frontal gyrus following an intentional encoding. Recognition of bound features was associated with activation in left prefrontal and superior parietal regions following an incidental colour encoding, and with preferential right prefrontal cortex activation following an intentional colour encoding. Our results are in line with the hypothesis of a parietal involvement in context processing, and prefrontal areas in monitoring retrieval processes. Our results also support the hypothesis of a 'cortical asymmetry for reflective activity' (CARA).     

Imitating expressions: emotion-specific neural substrates in facial mimicry

Intentionally adopting a discrete emotional facial expressioncan modulate the subjective feelings corresponding to that emotion;however, the underlying neural mechanism is poorly understood.We therefore used functional brain imaging (functional magneticresonance imaging) to examine brain activity during intentionalmimicry of emotional and non-emotional facial expressions andrelate regional responses to the magnitude of expression-inducedfacial movement. Eighteen healthy subjects were scanned whileimitating video clips depicting three emotional (sad, angry,happy), and two ‘ingestive’ (chewing and licking)facial expressions. Simultaneously, facial movement was monitoredfrom displacement of fiducial markers (highly reflective dots)on each subject's face. Imitating emotional expressions enhancedactivity within right inferior prefrontal cortex. This patternwas absent during passive viewing conditions. Moreover, themagnitude of facial movement during emotion-imitation predictedresponses within right insula and motor/premotor cortices. Enhancedactivity in ventromedial prefrontal cortex and frontal polewas observed during imitation of anger, in ventromedial prefrontaland rostral anterior cingulate during imitation of sadness andin striatal, amygdala and occipitotemporal during imitationof happiness. Our findings suggest a central role for rightinferior frontal gyrus in the intentional imitation of emotionalexpressions. Further, by entering metrics for facial muscularchange into analysis of brain imaging data, we highlight sharedand discrete neural substrates supporting affective, actionand social consequences of somatomotor emotional expression.     

Differentiating between self and others: an ALE meta-analysis of fMRI studies of self-recognition and theory of mind

The perception of self and others is a key aspect of social cognition. In order to investigate the neurobiological basis of this distinction we reviewed two classes of task that study self-awareness and awareness of others (theory of mind, ToM). A reliable task to measure self-awareness is the recognition of one’s own face in contrast to the recognition of others’ faces. False-belief tasks are widely used to identify neural correlates of ToM as a measure of awareness of others. We performed an activation likelihood estimation meta-analysis, using the fMRI literature on self-face recognition and false-belief tasks. The brain areas involved in performing false-belief tasks were the medial prefrontal cortex (MPFC), bilateral temporo-parietal junction, precuneus, and the bilateral middle temporal gyrus. Distinct self-face recognition regions were the right superior temporal gyrus, the right parahippocampal gyrus, the right inferior frontal gyrus/anterior cingulate cortex, and the left inferior parietal lobe. Overlapping brain areas were the superior temporal gyrus, and the more ventral parts of the MPFC. We confirmed that self-recognition in contrast to recognition of others’ faces, and awareness of others involves a network that consists of separate, distinct neural pathways, but also includes overlapping regions of higher order prefrontal cortex where these processes may be combined. Insights derived from the neurobiology of disorders such as autism and schizophrenia are consistent with this notion.     

Ventromedial frontal lobe plays a critical role in facial emotion recognition

The ventromedial prefrontal cortex has been implicated in a variety of emotion processes. However, findings regarding the role of this region specifically in emotion recognition have been mixed. We used a sensitive facial emotion recognition task to compare the emotion recognition performance of 7 subjects with lesions confined to ventromedial prefrontal regions, 8 subjects with lesions elsewhere in prefrontal cortex, and 16 healthy control subjects. We found that emotion recognition was impaired following ventromedial, but not dorsal or lateral, prefrontal damage. This impairment appeared to be quite general, with lower overall ratings or more confusion between all six emotions examined. We also explored the relationship between emotion recognition performance and the ability of the same patients to experience transient happiness and sadness during a laboratory mood induction. We found some support for a relationship between sadness recognition and experience. Taken together, our results indicate that the ventromedial frontal lobe plays a crucial role in facial emotion recognition, and suggest that this deficit may be related to the subjective experience of emotion.     

Comparing the brain areas supporting nondeclarative categorization and recognition memory

Brain areas associated with both nondeclarative categorization and recognition memory were identified and contrasted using functional magnetic resonance imaging (fMRI) of healthy volunteers. Activity during dot-pattern categorization and recognition were compared with a control task (counting dots) in two separate groups of participants (n=5 each). The network of areas associated with nondeclarative categorization was found to include bilateral inferior prefrontal and parietal cortical areas that have been implicated in several other studies of categorization. During recognition, increased activity was found in posterior visual areas, the precuneus, posterior cingulate and right prefrontal cortex. Using the common control condition as a reference, recognition and categorization were contrasted and recognition was found to evoke more activity in posterior early visual cortex, the precuneus, right medial temporal lobe and right dorso-lateral prefrontal cortex. Previous research has implicated changes in visual representation in learning a category of dot-pattern by comparing activity evoked by categorical and non-categorical stimuli. The current findings support those results and additionally identify brain areas active during categorization that are involved in expressing this category knowledge.     

Proton magnetic resonance spectroscopy of the medial prefrontal cortex in patients with deficit schizophrenia: preliminary report

OBJECTIVE: Proton magnetic resonance spectroscopy (1H-MRS) was used to study medial prefrontal metabolic impairments in schizophrenic patients with the deficit syndrome. METHOD: The subjects were 22 schizophrenic patients categorized as deficit (N=5) or nondeficit (N=17) and 21 healthy subjects. (1)H-MRS was performed for the right and the left medial prefrontal cortex. RESULTS: The patients with the deficit syndrome had significantly lower ratios of N-acetylaspartate to creatine plus phosphocreatine than did the healthy subjects or nondeficit patients. CONCLUSIONS: As N-acetylaspartate levels could reflect neuronal density and/or viability, this finding suggests a neuronal loss in the medial prefrontal cortex of deficit patients.     

A Tc-99m HMPAO SPECT study of regional cerebral blood flow in drug-free schizophrenic patients with deficit and non-deficit syndrome

Twenty-nine patients with DSM-IV diagnoses of schizophrenia were categorized into deficit syndrome (n=14) and non-deficit syndrome (n=15) subgroups on the basis of the Schedule for the Deficit Syndrome. The patients, who had all been free of antipsychotic medication for at least 3 weeks, and 17 sex- and age-matched normal controls were studied with single-photon emission computed tomography with Tc-99m HMPAO. Age at onset, Brief Psychiatric Rating Scale (BPRS) total scores, BPRS positive symptom subscores and duration of illness were similar between the two schizophrenic subgroups. As expected, the deficit patients had more negative symptoms than the non-deficit patients. There were no statistically significant correlations between clinical parameters and regional cerebral blood flow (rCBF) values. The deficit syndrome subgroup showed diminished rCBF in the frontal regions bilaterally, right parietal regions and right superior temporal region compared with the control groups. Deficit patients showed significantly lower rCBF perfusion ratios in the right superior and inferior frontal cortex than did the non-deficit patients. No differences were detected between the controls and the non-deficit schizophrenic patients in terms of rCBF perfusion indices. The results of the present study confirm previous reports of different patterns of rCBF in deficit vs. non-deficit schizophrenic subgroups.     

Differential brain activation during facial emotion discrimination in first-episode schizophrenia

Background

Aberrant brain activation during facial emotion discrimination has been described in chronic schizophrenia, while little is known about early stages of the illness. The aim of the current study was to investigate valence-specific brain activation of emotion discrimination in first-episode schizophrenia. These patients provide the advantage of lacking the effects of long-term medication and chronic illness course and can hence further enhance the understanding of underlying psychopathological mechanisms.

Methods

Using event-related fMRI, we investigated 18 first-episode schizophrenia patients and 18 matched healthy subjects during an explicit emotion discrimination task presenting happy, sad and neutral monochromatic facial expressions. A repeated measure analysis of variance (ANOVA) with the factors Group (patients, healthy subjects), Gender and Emotion (happy, sad, neutral) was performed on behavioural and functional data.

Results

Behavioural performance did not differ between groups. Valence-independent hypoactivations in patients were observed for the anterior cingulate and orbitofrontal cortex while hyperactivations emerged in the posterior cingulate and the precuneus. Emotion-specific group differences were revealed in inferior parietal and orbitofrontal brain areas and the hippocampus.

Conclusions

First-episode schizophrenia already affects areas involved in processing of both, emotions and primary facial information. Our study underlines the role of dysfunctional neural networks as the basis of disturbed social interactions in early schizophrenia.     

Structural correlates of facial emotion recognition deficits in Parkinson's disease patients

The ability to recognize facial emotion expressions, especially negative ones, is described to be impaired in Parkinson's disease (PD) patients. Previous neuroimaging work evaluating the neural substrate of facial emotion recognition (FER) in healthy and pathological subjects has mostly focused on functional changes. This study was designed to evaluate gray matter (GM) and white matter (WM) correlates of FER in a large sample of PD. Thirty-nine PD patients and 23 healthy controls (HC) were tested with the Ekman 60 test for FER and with magnetic resonance imaging. Effects of associated depressive symptoms were taken into account. In accordance with previous studies, PD patients performed significantly worse in recognizing sadness, anger and disgust. In PD patients, voxel-based morphometry analysis revealed areas of positive correlation between individual emotion recognition and GM volume: in the right orbitofrontal cortex, amygdala and postcentral gyrus and sadness identification; in the right occipital fusiform gyrus, ventral striatum and subgenual cortex and anger identification, and in the anterior cingulate cortex (ACC) and disgust identification. WM analysis through diffusion tensor imaging revealed significant positive correlations between fractional anisotropy levels in the frontal portion of the right inferior fronto-occipital fasciculus and the performance in the identification of sadness. These findings shed light on the structural neural bases of the deficits presented by PD patients in this skill.