N250 ERP Correlates of the Acquisition of Face Representations across Different Images

Abstract

We used ERPs to investigate neural correlates of face learning. At learning, participants viewed video clips of unfamiliar people, which were presented either with or without voices providing semantic information. In a subsequent face-recognition task (four trial blocks), learned faces were repeated once per block and presented interspersed with novel faces. To disentangle face from image learning, we used different images for face repetitions. Block effects demonstrated that engaging in the face-recognition task modulated ERPs between 170 and 900 msec poststimulus onset for learned and novel faces. In addition, multiple repetitions of different exemplars of learned faces elicited an increased bilateral N250. Source localizations of this N250 for learned faces suggested activity in fusiform gyrus, similar to that found previously for N250r in repetition priming paradigms [Schweinberger, S. R., Pickering, E. C., Jentzsch, I., Burton, A. M., & Kaufmann, J. M. Event-related brain potential evidence for a response of inferior temporal cortex to familiar face repetitions. Cognitive Brain Research, 14, 398-409, 2002]. Multiple repetitions of learned faces also elicited increased central-parietal positivity between 400 and 600 msec and caused a bilateral increase of inferior-temporal negativity (>300 msec) compared with novel faces. Semantic information at learning enhanced recognition rates. Faces that had been learned with semantic information elicited somewhat less negative amplitudes between 700 and 900 msec over left inferior-temporal sites. Overall, the findings demonstrate a role of the temporal N250 ERP in the acquisition of new face representations across different images. They also suggest that, compared with visual presentation alone, additional semantic information at learning facilitates postperceptual processing in recognition but does not facilitate perceptual analysis of learned faces.

The activation of visual face memory and explicit face recognition are delayed in developmental prosopagnosia

“…This shows that the N250 reflects the activation of long-term face memory as well as the activation of a recently learned representation of a previously unfamiliar face in short-term memory. The N250 to participants' own face was already present in the first half of the experiment, while the N250 to target faces only emerged during the second half, suggesting that an episodic representation of a previously unfamiliar target face builds up gradually (see also Kaufmann, Schweinberger, & Burton, 2009). Target Faces and Own faces also elicited a sustained positivity that peaked around 500 ms post-stimulus in the study by studies of famous face recognition (Gosling & Eimer, 2011;Eimer et al, 2012).…”

Telling faces together: Learning new faces through exposure to multiple instances

“…It has been shown that seeing a face for longer (Reynolds & Pezdek, 1992) or more often (Xue, Dong, Chen, Lu, Mumford & Poldrack, 2010) can improve subsequent recognition. Furthermore, learning faces alongside semantic or personal information leads to more accurate recognition (Klatzky, Martin & Kane, 1982), and accompanying differences in neural activation (Kaufmann, Schweinberger & Burton, 2009). Faces that are successfully associated with semantic information are recognized more confidently, spanning multiple sessions (Bonner, Burton, Jenkins & McNeill, 2003).…”

Event-related potentials reveal the development of stable face representations from natural variability

“…Moreover, in this study N250 amplitude further increased with increasing 13 familiarity of the faces over different experimental blocks. Therefore, a larger N250 to 14 different-image, non-immediate repetitions of faces reflects an index of familiarity that can 15 be used to track the establishment of face representations (Kaufmann et al, 2009). At the 16 same time, increasing N250 amplitudes in the course of learning appear to reflect the 17 acquisition of a stable face representation, independent of the repetition of specific images.…”