Neural basis of implicit memory for socio-emotional information in schizophrenia

Abstract

Individuals with schizophrenia are impaired in processing social signals such as facial expressions of emotion. Perceiving facial expressions is a complex process that depends on a distributed neural network of regions involved in affective, cognitive, and visual processing. We examined repetition priming, a non-conscious form of perceptual learning, to explore the visual-perceptual processes associated with perceiving facial expression in people with schizophrenia. Functional magnetic resonance imaging (fMRI) was also employed to probe the sensitivity of face-responsive regions in the ventral pathway to the repetition of stimuli. Subjects viewed blocks of novel and repeated faces displaying fear expressions and neutral expressions and identified each face as male or female. Gender decisions were faster for repeated encoding relative to initial encoding of faces, indicating significant priming for facial expressions. Priming was normal in schizophrenia patients, but, as expected, recognition memory for the expressions was impaired. Neuroimaging findings showed that priming-related activation for patients was reduced in the left fusiform gyrus, relative to controls, regardless of facial expression. The findings suggest that schizophrenia patients have altered neural sensitivity in regions of the ventral visual processing stream that underlie early perceptual learning of objects and faces.

Emotionally Neutral Stimuli Are Not Neutral in Schizophrenia: A Mini Review of Functional Neuroimaging Studies

“…Finally, the aberrant brain reactivity to irrelevant stimuli in schizophrenia may be explained by reduced neural habituation to emotionally neutral faces ( 52 ), but this possibility has been examined in only one study ( 32 ).…”

Social memory performance in schizophrenia

“…In the other hand, Walther et al (2009) found both encoding and face recognition abnormalities and those associated to a low activation of the right fusiform face area. A more recent work has shown impairment in memory for faces, despite the expression in patients with schizophrenia in a repetition priming task, and the decreasing in performance was associated to an abnormal activation of the left fusiform gyrus (Schwartz et al, 2012).…”

Estudio piloto. Memoria implícita, memoria explícita y deterioro cognitivo: evolución en el trastorno psicótico

“…Las personas con esquizofrenia presentan un deterioro en el procesamiento de señales sociales como las expresiones faciales de emoción. La percepción de expresiones faciales es un proceso complejo que depende de una red neuronal distribuida dentro de las regiones implicadas en el procesamiento visual, cognitivo y afectivo; en un estudio se examinó el priming de repetición, se exploraron los procesos perceptivos visuales asociados a la percepción de la expresión facial en personas con esquizofrenia; como resultado el priming fue normal en los pacientes con esquizofrenia, pero, como era de esperar, la memoria de reconocimiento para las expresiones faciales estaba deteriorada (18) . En otro estudio se observó que los pacientes esquizofrénicos logran un priming tan alto como el de los controles en la tarea de decisión léxica; en contraste, sólo los controles mostraron priming significativo en la tarea de verificación de la categoría.…”