Visual verbal working memory processing may be interfered by previously seen faces Andres A. Gonzalez-Garrido a,b, ⁎ , Julieta Ramos-Loyo a , Fabiola R. Gomez-Velazquez a , Marina Alvelais Alarcón a , Juan Moises de la Serna Tuya c a Instituto de Neurociencias, Universidad de Guadalajara, México b O.P.D. Hospital Civil de Guadalajara, México c Universidad de Sevilla, España Received 22 July 2006; received in revised form 6 April 2007; accepted 16 April 2007 Available online 29 April 2007 Abstract Processing and maintenance in working memory involve active attention allocation; consequently, it is possible that a recognition process could interfere with the performance of highly demanding working memory tasks. Event-related brain potentials (ERPs) were recorded while fourteen healthy male adults performed a visual verbal dual working memory task. Three conditions were examined: A) reference (with no preceding stimuli); B) happy, angry or neutral faces presented 250 ms prior to task onset for 30 ms; and, C) visual noise control condition. Behavioral results showed that reaction times were significantly longer in the condition preceded by the presentation of faces, regardless of their emotional content. ERPs showed a predominantly right temporo-occipital negative component at around 170 ms during conditions B and C (higher amplitude in B), which probably reflects the pre-categorical structural encoding of the face. Succeeding task-onset, an early positive right temporo-parietal component (P380) appeared during condition B, probably reflecting a delayed reallocation of working memory attentional resources to carry out the task requirements. Afterwards, two other main fronto-parietal components were observed in the three conditions: a positive wave that peaked at around 410 ms, and a subsequent negative component (N585). This latter waveform reached a significantly higher amplitude during the reference condition (A) and was interpreted as mirroring the phonologic-lexical manipulation of the stimuli in working memory. These results suggest that early face detection could induce an attentional decrement that interfere a subsequent visual verbal working memory task performance. They also suggest that while face detection and facial emotional content analysis might be parallel processes, they are not onset-synchronized. © 2007 Elsevier B.V. All rights reserved. Keywords: Working memory; Face recognition; Facial emotional expression; ERP; Dual task 1. Introduction The intrinsic nature and supporting neural substrates that explain the influence of the preceding circumstances on cognitive task performance remain unclear, in spite of their ecological importance. In daily life, faces will often be encountered while the observer is either initiating some other attention-demanding visual task or is already engaged in one. Faces are a critical source of social information and it appears as though we are biologically prepared to perceive and respond to faces in a unique manner (Ekman, 1993). Given that face recognition depends on attention, faces can be very effective at capturing attention, even more than other types of changing objects (Jenkins et al., 2005; Ro et al., 2001). Visual face recognition is widely considered to be an automatic process that functionally involves mainly the middle fusiform gyrus (Kanwisher et al., 1997) and the inferior occipital cortex (Gauthier et al., 2000a), with a clear right hemisphere advantage (Rossion et al., 2000, 2003a; Sergent and Signoret, 1992). Nevertheless, the role of these areas in functional processing does not seem to be restricted to faces. The neural correlate of visual categorical information is considered to reside in the brain areas that process visual forms, such as the inferior temporal (IT) and prefrontal cortices (PFC) (see Farah, 1990, for a review), but categorization also involves the fusiform gyrus related to previous experience in identifying objects (Gauthier et al., 2000b). In fact, International Journal of Psychophysiology 65 (2007) 141 – 151 www.elsevier.com/locate/ijpsycho ⁎ Corresponding author. Instituto de Neurociencias, Universidad de Guada- lajara, Francisco de Quevedo 180. Col. Arcos Vallarta, Guadalajara, Jalisco, 44130, México. Tel.: +52 33 38 18 07 40; fax: +52 33 36 15 52 01. 0167-8760/$ - see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.ijpsycho.2007.04.005