Although recent behavior studies have provided much evidence about the process of EAB, details about the cognitive neural mechanisms of EAB are still unknown. Therefore, this research aimed to examine the cognitive neural processing mechanisms of the EAB and verify the divergences between views of the Bottleneck Theory (Martens & Wyble, 2010; Zhang & Wang, 2009) and the Overinvestment theory (as well as the Boost and Bounce Theory; Olivers & Meeter, 2008; Olivers & Nieuwenhuis, 2006).
To achieve this purpose, the present study employed a modified dual-task RSVP paradigm referred from the Study 1 of Stein et al. (2009). Moreover, the technology of event related potentials (ERPs) was used to examine the fast neural process of the EAB. In this RSVP stream, emotional faces (three conditions: fear faces, neutral faces, and face absent) were used as T1, and pictures of house scene (neutral: outdoor vs. indoor) were used as T2 stimuli. Participants were instructed to recognize T1 and T2 when the visual stream was presented. Once the visual stream disappeared, participants had to make judgment of T1 and T2 based on their categories or features. Meanwhile, EEG/ERPs from the facial recognition of T1 to the scene recognition of T2 were recorded and off-line analyzed.
The results of the final behavioral data analysis revealed that the condition of emotion T1 (fear faces) led to a significant reduction in the efficiency of T2 recognition, which was much lower than that in the conditions of neutral T1 (neutral faces) and T1 missing. These behavioral results indicated a typical EAB effect. In addition, the ERPs results provided the first evidence for the process of the EAB. In this research, we focused on the P3 components of the two processing stages of T1 and T2, respectively. Because these P3 components indexed the resource of attention in central processing. The final results showed that compared with other stimuli conditions (neutral T1 and T1 absent), the P3 amplitudes evoked by emotion T1 and T2 presentation were both enhanced. This effect should deny the resource bottleneck between the T1 and T2 competition but support the emotional/affective overinvestment in EAB. Based on these results, the neural mechanisms of EAB were discussed.