Se presenta un modelo neurocognitivo que propone dos mecanismos cerebrales para la captura involuntaria de la atención dirigida, basado en datos de Potenciales Evocados (PEs). El modelo sostiene que los estímulos que destacan repentinamente en el entorno acústico activan un mecanismo detector de transiciones asociado al componente supratemporal de N1, que dispara una "llamada" a la atención dirigida. Cambios acústicos sutiles activan un segundo mecanismo que dispara una señal de disparidad (Potencial de Disparidad: Mismatch Negativity, MMN) como resultado de la comparación no coincidente del estímulo cambiante con una huella del entorno acústico desarrollada en la memoria ecoica. El modelo propone, finalmente, que la reorientación consumada de la atención dirigida se manifiesta electrofiológicamente en el componente P3a de los PEs.

Brain mechanisms of involuntary switching of attention: Mismatch negativity (MMN), N1, and P3a. A neurocognitive model proposing two brain mechanisms for the involuntary capture of directed attention is presented. This model is mostly based on event-related brain potential (ERP) data. The model proposes that new stimuli appearing in the acoustic environment activate a transient-detector mechanism associated with the supratemporal N1 component of the auditory ERP, triggering a "call" for directed attention. The model also proposes that subtle changes in the acoustic stream activate a second mechanism based in the process generating the Mismatch Negativity (MMN). This mechanism works on the basis of a comparison between the afferent sensory input and a neural representation of the acoustic environment developed in the echoic memory. Finally, the model proposes that the P3a component is an electrophysiological index of the actual involuntary reorientation of attention to changes in the environment.