RESUMEN
Event-related brain potentials (ERPs) were used to examine the different negative emotional contexts on involuntary attention, induced by a task-irrelevant sound, in an auditory-visual distraction paradigm. The emotional contexts comprised sad, fearful and neutral, and the irrelevant auditory stimuli consisted of repetitive standard sounds (80%) and environmental novel sounds (20%). The present results revealed that there were apparently different mismatch negativity (MMN) and Novelty-P3 components among these emotional contexts. Specifically, the amplitude of MMN showed no significant difference, indicating that the early stage of involuntary attention was not affected by the emotional context. Then, the amplitude of Novelty-P3, indicating the involuntary orienting of attention to novel sounds, attenuated greatest in the sad context. This pattern of results was more likely due to the competition for attention resources between affective processing and the novel sounds. That is to say, sad inhibit the involuntary attention to some extent, whereas perceiving fear cues facilitated novelty detection.
Asunto(s)
Atención/fisiología , Emociones , Potenciales Evocados/fisiología , Estimulación Acústica/métodos , Electroencefalografía/métodos , Cara , Femenino , Humanos , Masculino , Adulto JovenRESUMEN
Event-related brain potentials (ERPs) were used to examine the electrophysiological effect of working memory (WM) load on involuntary attention caused by a task-irrelevant sound in an auditory-visual distraction paradigm. The different WM loads were manipulated by requiring subjects to remember the order of either three digits (low-load condition) or seven digits (high-load condition), and the irrelevant auditory stimuli consisted of repetitive standard sounds (80%) and environmental novel sounds (20%). We found that the difference waves (novel-minus-standard) showed significant MMN and Novelty-P3 components in the two WM load conditions. The amplitude of MMN increased with increasing the WM load, which indicated a more engaged change detection process under high-load condition. Then, the amplitude of Novelty-P3 was attenuated under high-load condition, which indicated a much reduced involuntary orienting of attention to novel sounds when increasing the WM load. These results indicated the top-down control of involuntary attention might be mainly active at the early change detection stage and the control of the later involuntary orienting of attention might be passive.