N170 or N1? Spatiotemporal Differences between Object and Face Processing Using ERPs

Abstract

The ERP component N170 is face-sensitive, yet its specificity for faces is controversial. We recorded ERPs while subjects viewed upright and inverted faces and seven object categories. Peak, topography and segmentation analyses were performed. N170 was earlier and larger to faces than to all objects. The classic increase in amplitude and latency was found for inverted faces on N170 but also on P1. Segmentation analyses revealed an extra map found only for faces, reflecting an extra cluster of activity compared to objects. While the N1 for objects seems to reflect the return to baseline from the P1, the N170 for faces reflects a supplement activity. The electrophysiological 'specificity' of faces could lie in the involvement of extra generators for face processing compared to objects and the N170 for faces seems qualitatively different from the N1 for objects. Object and face processing also differed as early as 120 ms.

Effect of configural distortion on a face-related ERP evoked by random dots blinking

“…In previous ERP studies, the peak latency of N170 was significantly longer for configural distortions [inverted faces (Bentin et al 1996;Honda et al 2007;Itier and Taylor 2004a;Itier et al 2006;Sagiv and Bentin 2001;Watanabe et al 2003Watanabe et al , 2005, Thatcherized faces (Carbon et al 2005), and scrambled faces (George et al 1996)] than for upright faces. In addition, Latinus and Taylor (2006) found that photographic and schematic faces evoked a similar N170 when the upright face was presented, but the N170 was increased in latency when the inverted face was presented.…”

“…In previous studies using inverted faces (Bentin et al 1996;Honda et al 2007;Itier and Taylor 2004a;Itier et al 2006;Latinus and Taylor 2006;Sagiv and Bentin 2001;Watanabe et al 2003Watanabe et al , 2005, faces with scrambled features (George et al 1996;Latinus and Taylor 2006), and individual components such as the eyes and nose Taylor 2004a, Itier et al 2006;Shibata et al 2002;Watanabe et al 1999a), the N170 was longer in latency for inverted faces than for upright faces, regardless of the same low-level properties, such as luminance. These results indicate that N170 is related to differences in higher-level processing rather than changes in luminance and that its latency is affected by whether a subject easily and quickly detects a stimulus as a whole face or not.…”

“…For example, a schematic drawing consisting of a circle, two dots, and a straight line is recognized as a face, although no individual component of the drawing is part of a real face. Since Bruce and Young (1986) proposed the ''face recognition model'', there have been many studies of face perception using neuroimaging and electrophysiological methods (e.g., Bentin et al 1996;George et al 1996;Haxby et al 1996Haxby et al , 1999Honda et al 2007;Itier and Taylor 2004a;Itier et al 2006;Kanwisher et al 1998;Latinus and Taylor 2006;Miki et al 2007;Rossion and Jacques 2008;Sagiv and Bentin 2001;Shibata et al 2002;Watanabe et al 1999bWatanabe et al , 2002Watanabe et al , 2003Watanabe et al , 2005. In studies of event-related potential (ERP) using averaging electroencephalography (EEG) (e.g., Bentin et al 1996;George et al 1996), static human faces evoked a negative potential in the bilateral occipito-temporal areas peaking at around 170 ms, termed N170, which is considered to be sensitive to faces.…”

Spatio-temporal reconstruction of brain dynamics from EEG with a Markov prior

“…We further observe that cross-validation was not effective for T-MSBL. (Itier and Taylor, 2004) The solvers peaked between 150 ms and 170 ms after stimuli, however, the N170 peak was less defined for MSP, TMSBL and M-FOCUSS for subject "B". It is further noted that MarkoVG differed from the other methods by being temporally as well as spatially more sparse.…”

Visual stimuli modulate frontal oscillatory rhythms in a cortically blind patient: Evidence for top-down visual processing

“…Faces are among the most relevant stimuli for humans (Itier and Taylor, 2004). The processing of this type of stimuli has been linked to the occipito-temporal network in an fMRI study (Rossion et al, 2003) and to frontal activations in terms of face-selective responses in the macaque (Scalaidhe et al, 1997).…”