RESUMO
Individuals with body dysmorphic disorder (BDD) often experience anxiety, as well as perceptual distortions of appearance. Anxiety has previously been found to impact visual processing. This study therefore tested the relationship between anxiety and visual processing of faces in BDD. Medication-free participants with BDD (N=17) and healthy controls (N=16) viewed photographs of their face and a familiar face during functional magnetic resonance imaging. Blood-oxygen-level dependent signal changes in regions involved in anxiety (amygdala) and detailed visual processing (ventral visual stream-VVS) were regressed on anxiety scores. Significant linear relationships between activity in the amygdala and VVS were found in both healthy controls and individuals with BDD. There was a trend of a quadratic relationship between anxiety and activity in the right VVS and a linear relationship between anxiety and activity in the left VVS for the BDD sample, and this was stronger for own-face stimuli versus familiar-face. Results suggest that anxiety symptoms in BDD may be associated with activity in systems responsible for detailed visual processing. This may have clinical implications related to heightened perceptual distortions associated with anxiety.
Assuntos
Ansiedade/etiologia , Transtornos Dismórficos Corporais , Dinâmica não Linear , Reconhecimento Visual de Modelos/fisiologia , Vias Visuais/patologia , Adulto , Transtornos Dismórficos Corporais/complicações , Transtornos Dismórficos Corporais/patologia , Transtornos Dismórficos Corporais/psicologia , Feminino , Lateralidade Funcional , Humanos , Processamento de Imagem Assistida por Computador , Modelos Lineares , Imageamento por Ressonância Magnética , Masculino , Oxigênio/sangue , Estimulação Luminosa , Vias Visuais/irrigação sanguínea , Adulto JovemRESUMO
Individuals with body dysmorphic disorder (BDD) are preoccupied with perceived defects in appearance. Preliminary evidence suggests abnormalities in global and local visual information processing. The objective of this study was to compare global and local processing in BDD subjects and healthy controls by testing the face inversion effect, in which inverted (upside-down) faces are recognized more slowly and less accurately relative to upright faces. Eighteen medication-free subjects with BDD and 17 matched, healthy controls performed a recognition task with sets of upright and inverted faces on a computer screen that were either presented for short duration (500 ms) or long duration (5000 ms). Response time and accuracy rates were analyzed using linear and logistic mixed effects models, respectively. Results indicated that the inversion effect for response time was smaller in BDD subjects than controls during the long duration stimuli, but was not significantly different during the short duration stimuli. Inversion effect on accuracy rates did not differ significantly between groups during either of the two durations. Lesser inversion effect in BDD subjects may be due to greater detail-oriented and piecemeal processing for long duration stimuli. Similar results between groups for short duration stimuli suggest that they may be normally engaging configural and holistic processing for brief presentations. Abnormal visual information processing in BDD may contribute to distorted perception of appearance; this may not be limited to their own faces, but to others' faces as well.
Assuntos
Transtornos Dismórficos Corporais/diagnóstico , Transtornos Dismórficos Corporais/fisiopatologia , Face , Reconhecimento Visual de Modelos/fisiologia , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Estimulação Luminosa/métodos , Tempo de Reação/fisiologia , Fatores de Tempo , Adulto JovemRESUMO
CONTEXT: Body dysmorphic disorder (BDD) is a psychiatric disorder in which individuals are preoccupied with perceived defects in their appearance, often related to their face. Little is known about its pathophysiology, although early research provides evidence of abnormal visual processing. OBJECTIVE: To determine whether patients with BDD have abnormal patterns of brain activation when visually processing their own face with high, low, or normal spatial resolution. DESIGN: Case-control study. SETTING: A university hospital. PARTICIPANTS: Seventeen right-handed medication-free subjects with BDD and 16 matched healthy control subjects. Intervention Functional magnetic resonance imaging while viewing photographs of face stimuli. Stimuli were neutral-expression photographs of the patient's own face and a familiar face (control stimuli) that were unaltered, altered to include only high spatial frequency (fine spatial resolution), or altered to include only low spatial frequency (low spatial resolution). MAIN OUTCOME MEASURE: Blood oxygen level-dependent signal changes in the BDD and control groups during each stimulus type. RESULTS: Subjects with BDD showed relative hyperactivity in the left orbitofrontal cortex and bilateral head of the caudate for the unaltered own-face vs familiar-face condition. They showed relative hypoactivity in the left occipital cortex for the low spatial frequency faces. Differences in activity in frontostriatal systems but not visual cortex covaried with aversiveness ratings of the faces. Severity of BDD symptoms correlated with activity in frontostriatal systems and visual cortex. CONCLUSIONS: These results suggest abnormalities in visual processing and frontostriatal systems in BDD. Hypoactivation in the occipital cortex for low spatial frequency faces may indicate either primary visual system abnormalities for configural face elements or top-down modulation of visual processing. Frontostriatal hyperactivity may be associated both with aversion and with symptoms of obsessive thoughts and compulsive behaviors.
Assuntos
Transtornos Dismórficos Corporais/epidemiologia , Transtornos Dismórficos Corporais/fisiopatologia , Corpo Estriado/fisiopatologia , Lobo Frontal/fisiopatologia , Transtornos da Percepção/epidemiologia , Transtornos da Percepção/fisiopatologia , Percepção Visual/fisiologia , Adulto , Transtornos Dismórficos Corporais/diagnóstico , Estudos de Casos e Controles , Manual Diagnóstico e Estatístico de Transtornos Mentais , Feminino , Humanos , Entrevista Psicológica , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Lobo Occipital/fisiopatologia , Índice de Gravidade de Doença , Adulto JovemRESUMO
Body dysmorphic disorder (BDD) is a severe psychiatric condition in which individuals are preoccupied with perceived defects in their appearance. Little is known of the pathophysiology or neurobiology of BDD. Recent evidence from a functional MRI study examining visual processing of faces demonstrated abnormal activation patterns in regions including left-sided inferior frontal gyrus (IFG) and amygdala. To investigate morphometric abnormalities, we compared brain volumes from high-resolution T1 magnetic resonance images of 12 unmedicated subjects with BDD to images of 12 matched controls using voxel-based morphometry (VBM). In addition, we compared volumes in specific regions of interest including the IFG, amygdala, caudate, and total grey and white matter and examined correlations with symptom severity. VBM revealed no statistically significant volumetric differences, nor were there significant differences in any of the regions of interest. However, there were significant positive correlations between scores on the BDD version of the Yale-Brown Obsessive-Compulsive Disorder Scale (BDD-YBOCS) and volumes of the left IFG (r=0.69) and the right amygdala (r=0.54). These findings of correlations between BDD symptom severity and volumes of the left IFG and the right amygdala. These are in concordance with the involvement of these regions in pathological face processing, which may contribute to the primary symptomatology.