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1.
Eur J Neurosci ; 59(8): 1863-1876, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37160716

RESUMO

People with schizophrenia experience difficulties with social interactions. One contributor to these social deficits is dysfunction in processing facial features and facial emotional expressions. However, it is not known whether face processing deficits are evident in those with other psychotic disorders or in those genetically at-risk for psychosis (i.e., first-degree relatives of those with psychosis). We assessed event-related potentials (ERPs) during a facial and emotion processing task in 100 people with a diagnosis of schizophrenia or another psychotic condition (PSY), 32 of their siblings (SIB) and 45 healthy comparison participants (CTL). In separate blocks, participants identified the sex (male or female) or emotion (happy, angry, neutral) of faces. In a comparison condition, participants indicated whether buildings had one or two floors. ERPs were examined in two stages. First, we compared ERPs across the emotion, sex and building identification conditions. Second, we compared ERPs among the three different facial emotions. PSY exhibited significantly lower amplitudes over parietal-occipital regions between 111 and 151 ms when viewing faces but not buildings than CTL, consistent with a face-selective N170 ERP component deficit. The SIB group was intermediate for faces, but not significantly different than PSY or CTL. During emotion identification, all three groups showed increased N170 amplitudes to angry and happy versus neutral expressions, with no group differences. In follow up analyses, we examined differences between PSY with or without affective psychosis, and differences between those with schizophrenia versus other psychotic disorders; there were no significant differences in these analyses. Face processing deficits assessed with ERPs were observed in a group of diverse psychotic disorders, though deficits were not seen to be modulated by facial emotion expression. Additionally, N170 deficits are not evident in siblings of those with PSY.


Assuntos
Reconhecimento Facial , Transtornos Psicóticos , Humanos , Masculino , Feminino , Reconhecimento Facial/fisiologia , Eletroencefalografia , Irmãos , Potenciais Evocados/fisiologia , Transtornos Psicóticos/psicologia , Emoções/fisiologia , Expressão Facial
2.
Psychol Med ; : 1-9, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38314526

RESUMO

BACKGROUND: People with schizophrenia on average are more socially isolated, lonelier, have more social cognitive impairment, and are less socially motivated than healthy individuals. People with bipolar disorder also have social isolation, though typically less than that seen in schizophrenia. We aimed to disentangle whether the social cognitive and social motivation impairments observed in schizophrenia are a specific feature of the clinical condition v. social isolation generally. METHODS: We compared four groups (clinically stable patients with schizophrenia or bipolar disorder, individuals drawn from the community with self-described social isolation, and a socially connected community control group) on loneliness, social cognition, and approach and avoidance social motivation. RESULTS: Individuals with schizophrenia (n = 72) showed intermediate levels of social isolation, loneliness, and social approach motivation between the isolated (n = 96) and connected control (n = 55) groups. However, they showed significant deficits in social cognition compared to both community groups. Individuals with bipolar disorder (n = 48) were intermediate between isolated and control groups for loneliness and social approach. They did not show deficits on social cognition tasks. Both clinical groups had higher social avoidance than both community groups. CONCLUSIONS: The results suggest that social cognitive deficits in schizophrenia, and high social avoidance motivation in both schizophrenia and bipolar disorder, are distinct features of the clinical conditions and not byproducts of social isolation. In contrast, differences between clinical and control groups on levels of loneliness and social approach motivation were congruent with the groups' degree of social isolation.

3.
Soc Psychiatry Psychiatr Epidemiol ; 59(1): 111-120, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37314492

RESUMO

PURPOSE: Mental health trajectories during the COVID-19 pandemic have been examined in Veterans with tenuous social connections, i.e., those with recent homelessness (RHV) or a psychotic disorder (PSY), and in control Veterans (CTL). We test potential moderating effects on these trajectories by psychological factors that may help individuals weather the socio-emotional challenges associated with the pandemic (i.e., 'psychological strengths'). METHODS: We assessed 81 PSY, 76 RHV, and 74 CTL over 5 periods between 05/2020 and 07/2021. Mental health outcomes (i.e., symptoms of depression, anxiety, contamination concerns, loneliness) were assessed at each period, and psychological strengths (i.e., a composite score based on tolerance of uncertainty, performance beliefs, coping style, resilience, perceived stress) were assessed at the initial assessment. Generalized models tested fixed and time-varying effects of a composite psychological strengths score on clinical trajectories across samples and within each group. RESULTS: Psychological strengths had a significant effect on trajectories for each outcome (ps < 0.05), serving to ameliorate changes in mental health symptoms. The timing of this effect varied across outcomes, with early effects for depression and anxiety, later effects for loneliness, and sustained effects for contamination concerns. A significant time-varying effect of psychological strengths on depressive symptoms was evident in RHV and CTL, anxious symptoms in RHV, contamination concerns in PSY and CTL, and loneliness in CTL (ps < 0.05). CONCLUSION: Across vulnerable and non-vulnerable Veterans, presence of psychological strengths buffered against exacerbations in clinical symptoms. The timing of the effect varied across outcomes and by group.


Assuntos
COVID-19 , Veteranos , Humanos , Saúde Mental , Pandemias , Emoções , Ansiedade/epidemiologia , Depressão/epidemiologia
4.
Cereb Cortex ; 29(1): 77-90, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29186348

RESUMO

Attending to a visual stimulus increases its detectability, even if gaze is directed elsewhere. This covert attentional selection is known to enhance spiking across many brain areas, including the primary visual cortex (V1). Here we investigate the temporal dynamics of attention-related spiking changes in V1 of macaques performing a task that separates attentional selection from the onset of visual stimulation. We found that preceding attentional enhancement there was a sharp, transient decline in spiking following presentation of an attention-guiding cue. This disruption of V1 spiking was not observed in a task-naïve subject that passively observed the same stimulus sequence, suggesting that sensory activation is insufficient to cause suppression. Following this suppression, attended stimuli evoked more spiking than unattended stimuli, matching previous reports of attention-related activity in V1. Laminar analyses revealed a distinct pattern of activation in feedback-associated layers during both the cue-induced suppression and subsequent attentional enhancement. These findings suggest that top-down modulation of V1 spiking can be bidirectional and result in either suppression or enhancement of spiking responses.


Assuntos
Potenciais de Ação/fisiologia , Atenção/fisiologia , Sinais (Psicologia) , Estimulação Luminosa/métodos , Tempo de Reação/fisiologia , Córtex Visual/fisiologia , Animais , Macaca mulatta , Macaca radiata , Masculino , Distribuição Aleatória
5.
Hum Brain Mapp ; 40(16): 4703-4715, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31322784

RESUMO

Individuals with schizophrenia and bipolar disorder show alterations in functional neural connectivity during rest. However, resting-state network (RSN) disruptions have not been systematically compared between the two disorders. Further, the impact of RSN disruptions on social cognition, a key determinant of functional outcome, has not been studied. Forty-eight individuals with schizophrenia, 46 with bipolar disorder, and 48 healthy controls completed resting-state functional magnetic resonance imaging. An atlas-based approach was used to examine functional connectivity within nine RSNs across the cortex. RSN connectivity was assessed via nonparametric permutation testing, and associations with performance on emotion perception, mentalizing, and emotion management tasks were examined. Group differences were observed in the medial and lateral visual networks and the sensorimotor network. Individuals with schizophrenia demonstrated reduced connectivity relative to healthy controls in all three networks. Individuals with bipolar disorder demonstrated reduced connectivity relative to controls in the medial visual network and connectivity within this network was significantly positively correlated with emotion management. In healthy controls, connectivity within the medial and lateral visual networks positively correlated with mentalizing. No significant correlations were found for either visual network in schizophrenia. Results highlight the role of altered early visual processing in social cognitive deficits in both schizophrenia and bipolar disorder. However, individuals with bipolar disorder appear to compensate for disrupted visual network connectivity on social cognitive tasks, whereas those with schizophrenia do not. The current study adds clarity on the neurophysiology underlying social cognitive deficits that result in impaired functioning in serious mental illness.


Assuntos
Transtorno Bipolar/diagnóstico por imagem , Transtorno Bipolar/psicologia , Cognição , Rede Nervosa/diagnóstico por imagem , Esquizofrenia/diagnóstico por imagem , Psicologia do Esquizofrênico , Comportamento Social , Adolescente , Adulto , Idoso , Mapeamento Encefálico , Transtornos Cognitivos/diagnóstico por imagem , Transtornos Cognitivos/psicologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Descanso , Adulto Jovem
6.
Hum Brain Mapp ; 40(5): 1608-1617, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30575206

RESUMO

Functional magnetic resonance imaging (fMRI) adaptation (also known as fMRI repetition suppression) has been widely used to characterize stimulus selectivity in vivo, a fundamental feature of neuronal processing in the brain. We investigated whether SZ patients and BD patients show aberrant fMRI adaptation for object perception. About 52 SZ patients, 55 BD patients, and 53 community controls completed an object discrimination task with three conditions: the same object presented twice, two exemplars from the same category, and two exemplars from different categories. We also administered two functional localizer tasks. A region of interest analysis was employed to evaluate a priori hypotheses about the lateral occipital complex (LOC) and early visual cortex (EVC). An exploratory whole brain analysis was also conducted. In the LOC and EVC, controls showed the expected reduced fMRI responses to repeated presentation of the same objects compared with different objects (i.e., fMRI adaptation for objects, p < .001). SZ patients showed an adaptation effect that was significantly smaller compared with controls. BD patients showed a lack of fMRI adaptation. The whole brain analyses showed enhanced fMRI responses to repeated presentation of the same objects only in BD patients in several brain regions including anterior cingulate cortex. This study was the first to employ fMRI adaptation for objects in SZ and BD. The current findings provide empirical evidence of aberrant fMRI adaptation in the visual cortex in SZ and BD, but in distinctly different ways.


Assuntos
Adaptação Psicológica , Transtorno Bipolar/diagnóstico por imagem , Transtorno Bipolar/psicologia , Esquizofrenia/diagnóstico por imagem , Psicologia do Esquizofrênico , Adolescente , Adulto , Idoso , Transtorno Bipolar/fisiopatologia , Mapeamento Encefálico , Discriminação Psicológica , Feminino , Giro do Cíngulo/diagnóstico por imagem , Giro do Cíngulo/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Lobo Occipital/diagnóstico por imagem , Lobo Occipital/fisiopatologia , Escalas de Graduação Psiquiátrica , Esquizofrenia/fisiopatologia , Córtex Visual/diagnóstico por imagem , Córtex Visual/fisiopatologia , Percepção Visual , Adulto Jovem
7.
Cereb Cortex ; 27(5): 2984-2993, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-27226446

RESUMO

Patients with schizophrenia show specific abnormalities in visual perception, and patients with bipolar disorder may have related perceptual deficits. During tasks that highlight perceptual dysfunction, patients with schizophrenia show abnormal activity in visual brain areas, including the lateral occipital complex (LOC) and early retinotopic cortex. It is unclear whether the anatomical structure of those visual areas is atypical in schizophrenia and bipolar disorder. In members of those two patient groups and healthy controls, we localized LOC and early retinotopic cortex individually for each participant using functional magnetic resonance imaging (MRI), then measured the thickness of those regions of interest using structural MRI scans. In both regions, patients with schizophrenia had the thinnest cortex, controls had the thickest cortex, and bipolar patients had intermediate cortical thickness. A control region, motor cortex, did not show this pattern of group differences. The thickness of each visual region of interest was significantly correlated with performance on a visual object masking task, but only in schizophrenia patients. These findings suggest an anatomical substrate for visual processing abnormalities that have been found with both neural and behavioral measures in schizophrenia and other severe mental illnesses.


Assuntos
Transtorno Bipolar/complicações , Esquizofrenia/complicações , Transtornos de Sensação/etiologia , Transtornos de Sensação/patologia , Córtex Visual/patologia , Percepção Visual/fisiologia , Adolescente , Adulto , Idoso , Transtorno Bipolar/diagnóstico por imagem , Feminino , Seguimentos , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Oxigênio/sangue , Mascaramento Perceptivo , Estimulação Luminosa , Esquizofrenia/diagnóstico por imagem , Transtornos de Sensação/diagnóstico por imagem , Córtex Visual/diagnóstico por imagem , Adulto Jovem
8.
Cereb Cortex ; 26(3): 1211-1220, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25576537

RESUMO

We report that preexisting individual differences in the cortical thickness of brain areas involved in a perceptual learning task predict the subsequent perceptual learning rate. Participants trained in a motion-discrimination task involving visual search for a "V"-shaped target motion trajectory among inverted "V"-shaped distractor trajectories. Motion-sensitive area MT+ (V5) was functionally identified as critical to the task: after 3 weeks of training, activity increased in MT+ during task performance, as measured by functional magnetic resonance imaging. We computed the cortical thickness of MT+ from anatomical magnetic resonance imaging volumes collected before training started, and found that it significantly predicted subsequent perceptual learning rates in the visual search task. Participants with thicker neocortex in MT+ before training learned faster than those with thinner neocortex in that area. A similar association between cortical thickness and training success was also found in posterior parietal cortex (PPC).


Assuntos
Aprendizagem/fisiologia , Lobo Parietal/anatomia & histologia , Lobo Parietal/fisiologia , Adulto , Circulação Cerebrovascular/fisiologia , Medições dos Movimentos Oculares , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Tamanho do Órgão , Oxigênio/sangue , Estimulação Luminosa , Testes Psicológicos , Percepção Visual/fisiologia
9.
Hum Brain Mapp ; 37(6): 2319-30, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26970441

RESUMO

Many perceptual learning experiments show that repeated exposure to a basic visual feature such as a specific orientation or spatial frequency can modify perception of that feature, and that those perceptual changes are associated with changes in neural tuning early in visual processing. Such perceptual learning effects thus exert a bottom-up influence on subsequent stimulus processing, independent of task-demands or endogenous influences (e.g., volitional attention). However, it is unclear whether such bottom-up changes in perception can occur as more complex stimuli such as conjunctions of visual features are learned. It is not known whether changes in the efficiency with which people learn to process feature conjunctions in a task (e.g., visual search) reflect true bottom-up perceptual learning versus top-down, task-related learning (e.g., learning better control of endogenous attention). Here we show that feature conjunction learning in visual search leads to bottom-up changes in stimulus processing. First, using fMRI, we demonstrate that conjunction learning in visual search has a distinct neural signature: an increase in target-evoked activity relative to distractor-evoked activity (i.e., a relative increase in target salience). Second, we demonstrate that after learning, this neural signature is still evident even when participants passively view learned stimuli while performing an unrelated, attention-demanding task. This suggests that conjunction learning results in altered bottom-up perceptual processing of the learned conjunction stimuli (i.e., a perceptual change independent of the task). We further show that the acquired change in target-evoked activity is contextually dependent on the presence of distractors, suggesting that search array Gestalts are learned. Hum Brain Mapp 37:2319-2330, 2016. © 2016 Wiley Periodicals, Inc.


Assuntos
Atenção/fisiologia , Aprendizagem/fisiologia , Percepção Visual/fisiologia , Adulto , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Testes Neuropsicológicos , Adulto Jovem
10.
Neuroimage ; 110: 171-81, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25652392

RESUMO

Useful information in the visual environment is often contained in specific conjunctions of visual features (e.g., color and shape). The ability to quickly and accurately process such conjunctions can be learned. However, the neural mechanisms responsible for such learning remain largely unknown. It has been suggested that some forms of visual learning might involve the dopaminergic neuromodulatory system (Roelfsema et al., 2010; Seitz and Watanabe, 2005), but this hypothesis has not yet been directly tested. Here we test the hypothesis that learning visual feature conjunctions involves the dopaminergic system, using functional neuroimaging, genetic assays, and behavioral testing techniques. We use a correlative approach to evaluate potential associations between individual differences in visual feature conjunction learning rate and individual differences in dopaminergic function as indexed by neuroimaging and genetic markers. We find a significant correlation between activity in the caudate nucleus (a component of the dopaminergic system connected to visual areas of the brain) and visual feature conjunction learning rate. Specifically, individuals who showed a larger difference in activity between positive and negative feedback on an unrelated cognitive task, indicative of a more reactive dopaminergic system, learned visual feature conjunctions more quickly than those who showed a smaller activity difference. This finding supports the hypothesis that the dopaminergic system is involved in visual learning, and suggests that visual feature conjunction learning could be closely related to associative learning. However, no significant, reliable correlations were found between feature conjunction learning and genotype or dopaminergic activity in any other regions of interest.


Assuntos
Núcleo Caudado/fisiologia , Aprendizagem/fisiologia , Percepção Visual/fisiologia , Mapeamento Encefálico , Dopamina/metabolismo , Dopamina/fisiologia , Feminino , Genótipo , Humanos , Imageamento por Ressonância Magnética , Masculino , Polimorfismo de Nucleotídeo Único , Desempenho Psicomotor/fisiologia , Adulto Jovem
11.
Hum Brain Mapp ; 35(4): 1201-11, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23418123

RESUMO

Most visual activities, whether reading, driving, or playing video games, require rapid detection and identification of learned patterns defined by arbitrary conjunctions of visual features. Initially, such detection is slow and inefficient, but it can become fast and efficient with training. To determine how the brain learns to process conjunctions of visual features efficiently, we trained participants over eight consecutive days to search for a target defined by an arbitrary conjunction of color and location among distractors with a different conjunction of the same features. During each training session, we measured brain activity with functional magnetic resonance imaging (fMRI). The speed of visual search for feature conjunctions improved dramatically within just a few days. These behavioral improvements were correlated with increased neural responses to the stimuli in visual cortex. This suggests that changes in neural processing in visual cortex contribute to the speeding up of visual feature conjunction search. We find evidence that this effect is driven by an increase in the signal-to-noise ratio (SNR) of the BOLD signal for search targets over distractors. In a control condition where target and distractor identities were exchanged after training, learned search efficiency was abolished, suggesting that the primary improvement was perceptual learning for the search stimuli, not task-learning. Moreover, when participants were retested on the original task after nine months without further training, the acquired changes in behavior and brain activity were still present, showing that this can be an enduring form of learning and neural reorganization.


Assuntos
Atenção/fisiologia , Aprendizagem/fisiologia , Plasticidade Neuronal/fisiologia , Lobo Occipital/fisiologia , Percepção Visual/fisiologia , Mapeamento Encefálico , Circulação Cerebrovascular , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Prática Psicológica , Análise e Desempenho de Tarefas , Fatores de Tempo , Córtex Visual/fisiologia , Adulto Jovem
12.
Schizophr Res ; 272: 112-119, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39214021

RESUMO

Impaired visual target detection is a common finding in schizophrenia that is linked to poor functional outcomes. However, the neural mechanisms that contribute to this deficit remain unclear. Recent research in healthy samples has identified relationships between the phase of pre-stimulus electroencephalographic (EEG) activity in the alpha band (8-12 Hz) or theta band (4-7 Hz) and the likelihood of visual target detection with and without attentional cueing, but these effects have not yet been explored in schizophrenia. We performed a study to investigate such effects in schizophrenia (n = 19) and healthy participants (n = 14), using a visual target detection task with attentional cues. We found significant relationships between pre-stimulus EEG phase properties and visual target detection in both groups, but also clear differences in the effects as a function of frequency, group, and attentional cueing. Alpha-band phase effects were relatively uniform across groups and conditions. By contrast, theta-band phase effects showed differences by group and attentional condition which could be consistent with attentional hyperfocusing in the schizophrenia group. Thus, our results elucidate a novel neural mechanism that may help to explain known impairments affecting both visual target detection and attention in schizophrenia.


Assuntos
Atenção , Eletroencefalografia , Esquizofrenia , Humanos , Esquizofrenia/fisiopatologia , Esquizofrenia/diagnóstico , Masculino , Feminino , Adulto , Projetos Piloto , Atenção/fisiologia , Sinais (Psicologia) , Adulto Jovem , Percepção Visual/fisiologia , Estimulação Luminosa , Ritmo Teta/fisiologia , Pessoa de Meia-Idade
13.
Artigo em Inglês | MEDLINE | ID: mdl-38909899

RESUMO

BACKGROUND: Schizophrenia (SCZ) and bipolar disorder (BD) are associated with information processing abnormalities, including visual perceptual and cognitive impairments, that impact daily functioning. Recent work with healthy samples suggests that peak alpha frequency (PAF) is an electrophysiological index of visual information processing speed that is correlated with cognitive ability. There is evidence that PAF is slowed in SCZ, but it remains unclear whether PAF is reduced in BD or whether slower PAF is associated with impaired visual perception and cognition in these clinical disorders. METHODS: We recorded resting-state brain activity (both eyes open and closed) with electroencephalography in 90 participants with SCZ, 62 participants with BD, and 69 healthy control participants. Most participants also performed a visual perception task (backward masking) and cognitive testing (MATRICS Concensus Cognitive Battery). RESULTS: We replicated previous findings of reduced PAF in patients with SCZ compared with healthy control participants. In contrast, PAF in patients with BD did not differ significantly from that in healthy control participants. Furthermore, PAF was significantly correlated with performance on the perceptual and cognitive measures in SCZ but not BD. PAF was also correlated with visual perception in the healthy control group and showed a trend-level correlation with cognition. CONCLUSIONS: Together, these results suggest that PAF deficits characterize SCZ, but not BD, and that individual differences in PAF are related to abnormalities in visual information processing and cognition in SCZ.

14.
J Psychiatr Res ; 172: 102-107, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38373371

RESUMO

The COVID-19 pandemic disproportionately impacted marginalized populations including Black Americans, people with serious mental illness, and individuals experiencing homelessness. Although the double disadvantage hypothesis would suggest that individuals with multiple minoritized statuses would experience worse psychosocial impacts from the pandemic, this may not be the case for vulnerable Black Veterans. The present study investigated the sustained mental health and functional responses to the pandemic in Black and White Veterans with psychosis or recent homelessness and in a control group of Veterans enrolled in the Department of Veterans Affairs healthcare services. Clinical interviews and questionnaires were administered remotely by telephone at five time points from May 2020 through July 2021, including a retrospective time point for March 2020 (i.e., before the pandemic started). Overall, there was a striking absence of systematic differences by race in the trajectories of psychiatric symptoms and functioning among Veterans during the study period. These findings are consistent with a report on initial responses to the pandemic that revealed only a few select differences by race among Veteran groups. The lack of racial disparities is inconsistent with the double disadvantage hypothesis. Although further investigation is needed, one possible interpretation is that the wrap-around services offered by the Veterans Health Administration may have mitigated expected differences by race among Veterans with psychosis or homelessness. Future research should continue to examine whether VA services mitigate disparities in mental health and psychosocial outcomes.


Assuntos
COVID-19 , Pessoas Mal Alojadas , Transtornos Psicóticos , Veteranos , Estados Unidos/epidemiologia , Humanos , Saúde Mental , Pandemias , Estudos Retrospectivos , Brancos , United States Department of Veterans Affairs , Transtornos Psicóticos/epidemiologia
15.
Clin EEG Neurosci ; 55(4): 395-405, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38298008

RESUMO

People with schizophrenia (SCZ) and bipolar disorder (BD) have impairments in processing social information, including faces. The neural correlates of face processing are widely studied with the N170 ERP component. However, it is unclear whether N170 deficits reflect neural abnormalities associated with these clinical conditions or differences in social environments. The goal of this study was to determine whether N170 deficits would still be present in SCZ and BD when compared with socially isolated community members. Participants included 66 people with SCZ, 37 with BD, and 125 community members (76 "Community-Isolated"; 49 "Community-Connected"). Electroencephalography was recorded during a face processing task in which participants identified the gender of a face, the emotion of a face (angry, happy, neutral), or the number of stories in a building. We examined group differences in the N170 face effect (greater amplitudes for faces vs buildings) and the N170 emotion effect (greater amplitudes for emotional vs neutral expressions). Groups significantly differed in levels of social isolation (Community-Isolated > SCZ > BD = Community-Connected). SCZ participants had significantly reduced N170 amplitudes to faces compared with both community groups, which did not differ from each other. The BD group was intermediate and did not differ from any group. There were no significant group differences in the processing of specific emotional facial expressions. The N170 is abnormal in SCZ even when compared to socially isolated community members. Hence, the N170 seems to reflect a social processing impairment in SCZ that is separate from level of social isolation.


Assuntos
Transtorno Bipolar , Eletroencefalografia , Potenciais Evocados , Expressão Facial , Esquizofrenia , Isolamento Social , Humanos , Transtorno Bipolar/fisiopatologia , Masculino , Feminino , Eletroencefalografia/métodos , Adulto , Esquizofrenia/fisiopatologia , Potenciais Evocados/fisiologia , Pessoa de Meia-Idade , Isolamento Social/psicologia , Emoções/fisiologia , Reconhecimento Facial/fisiologia
16.
Neuroimage ; 78: 249-60, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23587693

RESUMO

How quickly can information about the neural response to a visual stimulus be detected in the hemodynamic response measured using fMRI? Multi-voxel pattern analysis (MVPA) uses pattern classification to detect subtle stimulus-specific information from patterns of responses among voxels, including information that cannot be detected in the average response across a given brain region. Here we use MVPA in combination with rapid temporal sampling of the fMRI signal to investigate the temporal evolution of classification accuracy and its relationship to the average regional hemodynamic response. In primary visual cortex (V1) stimulus information can be detected in the pattern of voxel responses more than a second before the average hemodynamic response of V1 deviates from baseline, and classification accuracy peaks before the peak of the average hemodynamic response. Both of these effects are restricted to early visual cortex, with higher level areas showing no difference or, in some cases, the opposite temporal relationship. These results have methodological implications for fMRI studies using MVPA because they demonstrate that information can be decoded from hemodynamic activity more quickly than previously assumed.


Assuntos
Mapeamento Encefálico/métodos , Reconhecimento Visual de Modelos/fisiologia , Córtex Visual/fisiologia , Adulto , Feminino , Hemodinâmica , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Estimulação Luminosa
17.
Neuropsychologia ; 188: 108621, 2023 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-37321406

RESUMO

BACKGROUND: Individuals with psychosis spectrum disorders (PSD) have difficulty developing social relationships. This difficulty may reflect reduced response to social feedback involving functional alterations in brain regions that support the social motivation system: ventral striatum, orbital frontal cortex, insula, dorsal anterior cingulate cortex, and amygdala. Whether these alterations span PSD is unknown. METHODS: 71 individuals with PSD, 27 unaffected siblings, and 37 control participants completed a team-based fMRI task. After each trial, participants received performance feedback paired with the expressive face of a teammate or opponent. A 2 × 2 (win versus loss outcome x teammate versus opponent) repeated measures ANOVA by group was performed on activation in the five key regions of interest during receipt of feedback. RESULTS: Across groups, three social motivation regions, ventral striatum, orbital frontal cortex, and amygdala, showed sensitivity to feedback (significant main effect of outcome), with greater activation during win versus loss trials, regardless of whether the feedback was from a teammate or opponent. In PSD, ventral striatum and orbital frontal cortex activation to win feedback was negatively correlated with social anhedonia scores. CONCLUSIONS: Patterns of neural activation during social feedback were similar in PSD, their unaffected siblings, and healthy controls. Across the psychosis spectrum, activity in key social motivation regions during social feedback was associated with individual differences in social anhedonia.


Assuntos
Anedonia , Transtornos Psicóticos , Humanos , Anedonia/fisiologia , Motivação , Mapeamento Encefálico , Transtornos Psicóticos/diagnóstico por imagem , Neuroimagem , Imageamento por Ressonância Magnética , Recompensa
18.
Am J Psychiatry ; 180(5): 367-376, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36891649

RESUMO

OBJECTIVE: Negative symptoms are a primary cause of disability in schizophrenia for which there are no established pharmacotherapies. This study evaluated a novel psychosocial intervention that combined two evidence-based practices-motivational interviewing and cognitive-behavioral therapy (MI-CBT)-for the treatment of motivational negative symptoms. METHODS: Seventy-nine participants with schizophrenia and moderate to severe negative symptoms were included in a randomized controlled trial comparing the 12-session MI-CBT treatment with a mindfulness control condition. Participants were assessed at three time points through the study period, which included 12 weeks of active treatment and 12 weeks of follow-up. The primary outcome measures were motivational negative symptoms and community functioning; the secondary outcomes included a posited biomarker of negative symptoms: pupillometric response to cognitive effort. RESULTS: Compared with the control group, participants in the MI-CBT group showed significantly greater improvements in motivational negative symptoms over the acute treatment period. Their gains relative to baseline were maintained at follow-up, although the differential benefit relative to control subjects was attenuated. There were nonsignificant effects toward improvements in community functioning and differential change in the pupillometric markers of cognitive effort. CONCLUSIONS: The results show that combining motivational interviewing with CBT yields improvements in negative symptoms, a feature of schizophrenia generally thought of as resistant to intervention. Motivational negative symptoms not only responded to the novel treatment, but the gains were maintained over the follow-up period. Implications for future studies and for improving the generalization of the negative symptom gains to daily functioning domains are discussed.


Assuntos
Terapia Cognitivo-Comportamental , Atenção Plena , Entrevista Motivacional , Esquizofrenia , Humanos , Entrevista Motivacional/métodos , Esquizofrenia/diagnóstico , Esquizofrenia/terapia , Intervenção Psicossocial , Terapia Cognitivo-Comportamental/métodos
19.
Schizophr Res ; 248: 151-157, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36063606

RESUMO

Schizophrenia is associated with deficits in both object perception and visual attention. However, few studies in schizophrenia have investigated object-based attention, which is dissociable from other forms of visuospatial attention. Recent research in healthy populations has shown that the 'spotlight' of sustained visual attention flickers in a rhythmic, oscillatory fashion at specific frequencies in the 4-12 Hz range. In healthy samples, this oscillatory signature has been used to investigate spatiotemporal dynamics of object-based attention, showing that the attentional spotlight spreads to uncued locations within cued objects, and also periodically alternates focus between cued and uncued objects. In this study, we adapted a performance-based visual object cueing task to investigate object-based attention in individuals with a schizophrenia diagnosis and healthy controls. In controls, spatiotemporal patterns of object-based attention closely resembled those reported in previous studies of healthy individuals. In the schizophrenia group, the oscillatory signature of attention also appeared in the location of the cue and on uncued objects, similar to the effects in controls. Indeed, the oscillatory signature of attention at the spatial location of the cue was stronger in the schizophrenia group than in controls. However, attention did not spread across the cued object in schizophrenia; rather, attention appeared to remain hyperfocused at the spatial location of the cue. These findings provide the first evidence that visual attention has oscillatory characteristics in schizophrenia, as in the general population. The results also show that the fundamental process of attentional spreading which underlies object-based attention is abnormal in schizophrenia.


Assuntos
Esquizofrenia , Humanos , Sinais (Psicologia) , Percepção Visual , Tempo de Reação
20.
Psychiatry Res ; 307: 114324, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34894423

RESUMO

Representation of people who identify as members of sexual and gender minority (SGM) groups is lacking in psychiatric research. Few researchers openly identify as members of an SGM group, and those who do continue to face career obstacles. Separately, in the context of psychiatric research studies, little attention has been paid to how participants' SGM identities might intersect with other factors to influence each individual's experience of mental illness. In this brief commentary, we summarize these and related issues, then offer suggestions for how institutions, professional societies, labs, and individuals might help to improve SGM representation in psychiatric research.


Assuntos
Transtornos Mentais , Minorias Sexuais e de Gênero , Identidade de Gênero , Humanos , Grupos Minoritários , Comportamento Sexual
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