RESUMO
We examined the age-related variation in one type of inter-trial effect of visual search, the distractor previewing effect (DPE), in affectively neutral and affectively charged contexts. In Experiment 1, children, adolescents, and young adults were faster to identify the shape of a color target when the color of the current distractors had already been previewed than when the target had been previewed in the preceding target-absent trial, indicative of a color-based DPE. The results revealed a greater DPE in children than in adolescents and young adults, but it can be attributed to children's slower RTs than the other two groups. In Experiment 2, children, adolescents, and young adults were instructed to respond to a schematic face that was different from the other two faces. Young adults were faster in searching for a threatening face among friendly ones when they had previewed a target-absent display consisting of friendly faces than that of threatening faces, indicating an emotional DPE. By contrast, children showed a reversed DPE under the same condition, whereas adolescents showed no DPE. Taken together, these results suggested that the three age groups were all able to create an inhibitory attentional bias on the basis of trial history in affectively neutral context, whereas children and adolescents were not able to create such an inhibitory attentional bias in affectively charged contexts in the same way as adults did. These findings implied that the development of attentional inhibition abilities in affectively charged contexts might be delayed compared to those in affectively neutral contexts.
Assuntos
Atenção/fisiologia , Inibição Psicológica , Reconhecimento Visual de Modelos/fisiologia , Estimulação Luminosa/métodos , Tempo de Reação/fisiologia , Adolescente , Adulto , Criança , Emoções/fisiologia , Feminino , Humanos , Masculino , Adulto JovemRESUMO
In this study, we examined whether luminance processing in the human visual system would exhibit any history effect (i.e., inter-trial modulation) in psychophysical and magnetoencephalographic experiments. A disk was presented against a black background at various luminance levels in a randomized order. During the MEG recording, participants were instructed to rate the brightness of the disk (magnitude estimation) and to report it aloud during inter-stimulus interval. The MEG results showed that the neuromagnetic activation around 200-220 ms after the stimulus onset in the left occipito-temporal regions at a given trial was weaker when the disk luminance in the immediately prior trial was higher. An inverse inter-trial effect was also observed in the psychophysical experiment. These findings suggest that the neuromagnetic activity reflects the inter-trial modulation of luminance processing that correlates with the subjective perception of brightness.
En este estudio, se examinó si el procesamiento de iluminación en el sistema visual humano exhibie algún efecto de historia (es decir, modulación inter-ensayo) en experimentos psicofísicos y de magnetoencefalografía (MEG). Un disco se presentó contra un fondo negro en varios niveles de iluminación en un orden aleatorio. Durante el registro de MEG, los participantes fueron instruidos para clasificar el brillo del disco (estimación de magnitud) y reportarlo durante el intervalo inter-ensayo. Los resultados de MEG mostraron que la activación neuromagnetica alrededor 200-220 ms después de la aparición de estímulo en las regiones occipito-temporal izquierda en un ensayo dade fue más débil cuando la iluminación de disco en el ensayo inmediatamente antes fue mayor. También se observó un efecto inverso inter-ensayo en el experimento psicofísico. Estos hallazgos sugieren que la actividad neuromagnética refleja la modulación inter-ensayo de procesamiento de iluminación que se correlaciona con la percepción subjetiva de brillo.
