Structural Encoding of Human and Schematic Faces: Holistic and Part-Based Processes

Abstract

Abstract& The range of specificity and the response properties of the extrastriate face area were investigated by comparing the N170 event-related potential (ERP) component elicited by photographs of natural faces, realistically painted portraits, sketches of faces, schematic faces, and by nonface meaningful and meaningless visual stimuli. Results showed that the N170 distinguished between faces and nonface stimuli when the concept of a face was clearly rendered by the visual stimulus, but it did not distinguish among different face types: Even a schematic face made from simple line fragments triggered the N170. However, in a second experiment, inversion seemed to have a different effect on natural faces in which face components were available and on the pure gestalt-based schematic faces: The N170 amplitude was enhanced when natural faces were presented upside down but reduced when schematic faces were inverted. Inversion delayed the N170 peak latency for both natural and schematic faces. Together, these results suggest that early face processing in the human brain is subserved by a multiple-component neural system in which both whole-face configurations and face parts are processed. The relative involvement of the two perceptual processes is probably determined by whether the physiognomic value of the stimuli depends upon holistic configuration, or whether the individual components can be associated with faces even when presented outside the face context. &

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.…”

“…However, when the spatial relation among the individual components is distorted, a face can no longer easily be detected. Previous studies reported that the component N170 was evoked by schematic faces as well as photographs of real faces Sagiv and Bentin 2001). In the present study, we used a schematic face, which subjects detect as a face, which is easily drawn by the RDB method.…”

“…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.…”

Human face preference in gamma-frequency EEG activity

“…This suggests that during basic-level categorization tasks (such as monitoring for flowers) the mechanism eliciting the N170 is particularly sensitive to stimuli that have a global structure of a face (regardless of whether the face is human, ape face or schematic, cf. Sagiv and Bentin 2001). In fact the N170 is higher for any stimulus that includes unequivocal physiognomic information.…”