The contribution of social cognition in predicting social participation following moderate and severe TBI in youth.

Youth with moderate or severe traumatic brain injury (TBI) are at risk for reduced social participation after the injury, and the contribution of social cognition to these changes in functioning has been little studied. This study aimed to examine social participation and to measure the contribution of social and non-social cognitive functions to social participation impairment in youth (ages 12-21) who sustained moderate or severe TBI. Youth with TBI (n = 23) were compared to typically developing (TD) controls on self- and parent-rated social participation questionnaires. Direct testing of social cognition (mentalising, social knowledge, emotion recognition) and higher order cognitive abilities (intellectual abilities, attention and executive functions) was also conducted. Significant differences were found between the TBI participants and TD controls on social participation measures. Mentalising and problem-solving abilities revealed to be significant correlates of social participation as reported by youth with brain-injury and their parents. Overall, these results corroborate previous findings by showing that social participation is significantly reduced after TBI, and further shows that mentalising, which is not always considered during rehabilitation, is an important contributing factor. In addition to executive function measures, social cognition should therefore be systematically included in assessment following youth TBI for intervention and prevention purposes.

Disfunción prefrontal en esquizofrenia: implicación en el reconocimiento de asociaciones / Prefrontal dysfunction in schizophrenia: implication is associative recognition

Objetivo. En este estudio empleamos la resonancia magnética funcional (RMf) para examinar los sustratos neurales del déficit de memoria para el reconocimiento de asociaciones en esquizofrenia. Métodos. Quince pacientes con diagnóstico de esquizofrenia y 18 sujetos control sanos fueron sometidos a RMf mientras realizaban una prueba de memoria (codificación y reconocimiento) de objetos visuales. Durante la codificación los sujetos estudiaron ítems y pares de ítems. Durante la recuperación los sujetos tenían que reconocer ítems (decisiones entre ítems nuevos/estudiados) o reconocer asociaciones (decisiones entre pares intactos/reacomodados). El diseño del estudio fue basado en un modelo de efecto aleatorio y el análisis de la RMf fue restringido únicamente a las respuestas correctas. Resultados. A nivel del desempeño, el rendimiento de ambos grupos fue similar durante el reconocimiento de ítems, mientras que durante el reconocimiento de asociaciones los pacientes con esquizofrenia mostraron un rendimiento inferior. A nivel cerebral el contraste entre el reconocimiento de ítems y el reconocimiento de asociaciones demostró una mayor activación predominantemente a nivel de la corteza prefrontal dorsal izquierda y prefrontal inferior derecha en el grupo control en relación al grupo de pacientes. Conclusiones. Los hallazgos de este estudio de RMf sugieren que una disfunción de la corteza prefrontal pudiera ser la responsable del déficit selectivo de memoria para el reconocimiento de asociaciones observado en pacientes con esquizofrenia

Objective. We used an event related functional magnetic resonance imaging (fMRI) method to examine the neural basis of associative recognition memory deficit in schizophrenia. Methods. Fifteen people with schizophrenia and 18 healthy control subjects were scanned with fMRI while performing a memory task (coding and recognition) of visual objects. During coding, the subjects studied items and pairs of items. During recovery, the subjects had to recognize items (old/new decisions) and recognize associations (intact/rearranged decisions). The study design was based on a random effect model and the fMRI analysis was restricted to correct items only. Results. At the behavioral level, both groups performed equally well on item recognition, whereas people with schizophrenia demonstrated poorer performance on associative recognition. At the brain level, comparison between associative and item recognition tasks revealed greater left dorsolateral prefrontal and right inferior prefrontal activations in the control group relative to the schizophrenia group. Conclusions. The findings of this fMRI study suggest the prefrontal cortex as the basis for the selective memory deficit for associative recognition obsevered in schizophrenia

[Prefrontal dysfunction in schizophrenia: implication is associative recognition]. / Disfunción prefrontal en esquizofrenia: implicación en el reconocimiento de asociaciones.

OBJECTIVE: We used an event related functional magnetic resonance imaging (fMRI) method to examine the neural basis of associative recognition memory deficit in schizophrenia. METHODS: Fifteen people with schizophrenia and 18 healthy control subjects were scanned with fMRI while performing a memory task (coding and recognition) of visual objects. During coding, the subjects studied items and pairs of items. During recovery, the subjects had to recognize items (old/new decisions) and recognize associations (intact/rearranged decisions). The study design was based on a random effect model and the fMRI analysis was restricted to correct items only. RESULTS: At the behavioral level, both groups performed equally well on item recognition, whereas people with schizophrenia demonstrated poorer performance on associative recognition. At the brain level, comparison between associative and item recognition tasks revealed greater left dorsolateral prefrontal and right inferior prefrontal activations in the control group relative to the schizophrenia group. CONCLUSIONS: The findings of this fMRI study suggest the prefrontal cortex as the basis for the selective memory deficit for associative recognition observed in schizophrenia.