Knowledge scale effects in face recognition: An electrophysiological investigation

Abstract

Although the amount or scale of biographical knowledge held in store about a person may differ widely, little is known about whether and how these differences may affect the retrieval processes triggered by the person's face. In a learning paradigm, we manipulated the scale of biographical knowledge while controlling for a common set of minimal knowledge and perceptual experience with the faces. A few days after learning, and again after 6 months, knowledge effects were assessed in three tasks, none of which concerned the additional knowledge. Whereas the performance effects of additional knowledge were small, event-related brain potentials recorded during testing showed amplitude modulations in the time range of the N400 component-indicative of knowledge access-but also at a much earlier latency in the P100 componentreflecting early stages of visual analysis. However, no effects were found in the N170 component, which is taken to reflect structural analyses of faces. The present findings replicate knowledge scale effects in object recognition and suggest that enhanced knowledge affects both early visual processes and the later processes associated with semantic processing, even when this knowledge is not task-relevant.

Knowledge is power: How conceptual knowledge transforms visual cognition

“…One possibility is that semantic knowledge modulates electrophysiological correlates of visual processing by attracting additional attention to faces or objects that have been associated with knowledge. However, training induced increases in attention would likely increase (Hillyard & Anllo-Vento, 1998; Hopfinger, Luck, & Hillyard, 2004), as opposed to attenuate, the P100 as seen in these studies (Abdel-Rahman & Sommer, 2008; Abdel-Rahman & Sommer, 2012). Alternatively, conceptual knowledge may make the visual processes underlying the P100 component more efficient.…”

“…Taken together, these studies suggest that the earliest stages of visual analysis are penetrable to influences from higher-order conceptual knowledge. It is interesting to note that there was no influence of in-depth semantic learning on the N170 component for the faces in the Abdel-Rahman & Sommer (2012) study. This finding is consistent with the findings of Paller and colleagues (2000) and Kaughman and colleagues (2008), and support the suggestion that conceptual knowledge may only influence the processes underlying the N170 component when stimuli are presented twice in rapid succession (Heisz Shedden, 2009; Herzmann Sommer, 2010).…”

“…For example, research showing that category learning can modify perceptual representations (De Baene et al, 2008; Folstein et al, 2012; Goldstone, 1994; Goldstone et al, 2001; Notman et al, 2005); that perceptual sensitivity (d’) is influenced by language (Meteyard et al, 2007); that social-categorical knowledge can influence luminance perception (Levin & Banaji, 2006); and that semantic knowledge can bias electrophysiological markers of pre-attentive visual processing (Abdel-Rahman & Sommer, 2008; Abdel-Rahman & Sommer, 2012; Holmes et al, 2009), are all incompatible with modular views in which perception is completely encapsulated from cognition. It remains unclear whether conceptual knowledge influences perceptual processing by modifying perceptual representations within visual cortex, or through top-down feedback from higher-order to sensory areas of the brain (Bar et al, 2006).…”

“…Two recent studies have shown that conceptual knowledge can penetrate even earlier stages of visual recognition, as revealed by modulations of the P100 component (Abdel-Rahman & Sommer, 2008; Abdel-Rahman & Sommer, 2012). The P100 component typically has a post-stimulus onset of 60-90ms, with a peak between 100 and 130ms.…”

“…The in-depth stories facilitated recognition when these objects were blurred in an identification task, and this effect was associated with an attenuated P100 component. Using a similar training paradigm as that reported in the previous study, Abdel-Rahman & Sommer (2012) investigated the influence of in-depth semantic knowledge on the perception of faces. Consistent with their previous findings, faces associated with in-depth semantic knowledge elicited a reduced P100 component, relative to faces associated with only minimal semantic knowledge.…”