scholarly journals The effect of scrambling upright and inverted faces on the N170

2018 ◽  
Vol 71 (11) ◽  
pp. 2464-2476 ◽  
Author(s):  
Ciro Civile ◽  
Heike Elchlepp ◽  
Rossy McLaren ◽  
Carl Michael Galang ◽  
Aureliu Lavric ◽  
...  

The face inversion effect refers to a decrement in performance when we try to recognise familiar faces turned upside down (inverted), compared with familiar faces presented in their usual (upright) orientation. Recently, we have demonstrated that the inversion effect can also be found with checkerboards drawn from prototype-defined categories when the participants have been trained with these categories, suggesting that factors such as expertise and the relationships between stimulus features may be important determinants of this effect. We also demonstrated that the typical inversion effect on the N170 seen with faces is found with checkerboards, suggesting that modulation of the N170 is a marker for disruption in the use of configural information. In the present experiment, we first demonstrate that our scrambling technique greatly reduces the inversion effect in faces. Following this, we used Event-Related Potentials ( ERPs) recorded while participants performed an Old/New recognition study on normal and scrambled faces presented in both upright and inverted orientations to investigate the impact of scrambling on the N170. We obtained the standard robust inversion effect for normal faces: The N170 was both larger and delayed for normal inverted faces as compared with normal upright faces, whereas a significantly reduced inversion effect was recorded for scrambled faces. These results show that the inversion effect on the N170 is greater for normal compared with scrambled faces, and we interpret the smaller effect for scrambled faces as being due to the reduction in expertise for those faces consequent on scrambling.

2010 ◽  
Vol 69 (3) ◽  
pp. 161-167 ◽  
Author(s):  
Jisien Yang ◽  
Adrian Schwaninger

Configural processing has been considered the major contributor to the face inversion effect (FIE) in face recognition. However, most researchers have only obtained the FIE with one specific ratio of configural alteration. It remains unclear whether the ratio of configural alteration itself can mediate the occurrence of the FIE. We aimed to clarify this issue by manipulating the configural information parametrically using six different ratios, ranging from 4% to 24%. Participants were asked to judge whether a pair of faces were entirely identical or different. The paired faces that were to be compared were presented either simultaneously (Experiment 1) or sequentially (Experiment 2). Both experiments revealed that the FIE was observed only when the ratio of configural alteration was in the intermediate range. These results indicate that even though the FIE has been frequently adopted as an index to examine the underlying mechanism of face processing, the emergence of the FIE is not robust with any configural alteration but dependent on the ratio of configural alteration.


2001 ◽  
Vol 15 (4) ◽  
pp. 275-285 ◽  
Author(s):  
Melissa S. James ◽  
Stuart J. Johnstone ◽  
William G. Hayward

Abstract The effects of manipulating configural and feature information on the face recognition process were investigated by recording event-related potentials (ERPs) from five electrode sites (Fz, Cz, Pz, T5, T6), while 17 European subjects performed an own-race and other-race face recognition task. A series of upright faces were presented in a study phase, followed by a test phase where subjects indicated whether inverted and upright faces were studied or novel via a button press response. An inversion effect, illustrating the disruption of upright configural information, was reflected in accuracy measures and in greater lateral N2 amplitude to inverted faces, suggesting that structural encoding is harder for inverted faces. An own-race advantage was found, which may reflect the use of configural encoding for the more frequently experienced own-race faces, and feature-based encoding for the less familiar other-race faces, and was reflected in accuracy measures and ERP effects. The midline N2 was larger to configurally encoded faces (i. e., own-race and upright), possibly suggesting configural encoding involves more complex processing than feature-based encoding. An N400-like component was sensitive to feature manipulations, with greater amplitude to other-race than own-race faces and to inverted than upright faces. This effect was interpreted as reflecting increased activation of incompatible representations activated by a feature-based strategy used in processing of other-race and inverted faces. The late positive complex was sensitive to configural manipulation with larger amplitude to other-race than own-race faces, and was interpreted as reflecting the updating of an own-race norm used in face recognition, to incorporate other-race information.


Author(s):  
Sam S. Rakover ◽  
Sam S. Rakover

Perception and recognition of faces presented upright are better than Perception and recognition of faces presented inverted. The difference between upright and inverted orientations is greater in face recognition than in non-face object recognition. This Face-Inversion Effect is explained by the “Configural Processing” hypothesis that inversion disrupts configural information processing and leaves the featural information intact. The present chapter discusses two important findings that cast doubt on this hypothesis: inversion impairs recognition of isolated features (hair & forehead, and eyes), and certain facial configural information is not affected by inversion. The chapter focuses mainly on the latter finding, which reveals a new type of facial configural information, the “Eye-Illusion”, which is based on certain geometrical illusions. The Eye-Illusion tended to resist inversion in experimental tasks of both perception and recognition. It resisted inversion also when its magnitude was reduced. Similar results were obtained with “Headlight-Illusion” produced on a car‘s front, and with “Form-Illusion” produced in geometrical forms. However, the Eye-Illusion was greater than the Headlight-Illusion, which in turn was greater than the Form-Illusion. These findings were explained by the “General Visual-Mechanism” hypothesis in terms of levels of visual information learning. The chapter proposes that a face is composed of various kinds of configural information that are differently impaired by inversion: from no effect (the Eye-Illusion) to a large effect (the Face-Inversion Effect).


2002 ◽  
Vol 13 (3) ◽  
pp. 250-257 ◽  
Author(s):  
B. Rossion ◽  
I. Gauthier ◽  
V. Goffaux ◽  
M.J. Tarr ◽  
M. Crommelinck

Scalp event-related potentials (ERPs) in humans indicate that face and object processing differ approximately 170 ms following stimulus presentation, at the point of the N170 occipitotemporal component. The N170 is delayed and enhanced to inverted faces but not to inverted objects. We tested whether this inversion effect reflects early mechanisms exclusive to faces or whether it generalizes to other stimuli as a function of visual expertise. ERPs to upright and inverted faces and novel objects (Greebles) were recorded in 10 participants before and after 2 weeks of expertise training with Greebles. The N170 component was observed for both faces and Greebles. The results are consistent with previous reports in that the N170 was delayed and enhanced for inverted faces at recording sites in both hemispheres. For Greebles, the same effect of inversion was observed only for experts, primarily in the left hemisphere. These results suggest that the mechanisms underlying the electrophysiological face-inversion effect extend to visually homogeneous nonface object categories, at least in the left hemisphere, but only when such mechanisms are recruited by expertise.


2020 ◽  
Vol 15 (7) ◽  
pp. 765-774 ◽  
Author(s):  
Sebastian Schindler ◽  
Maximilian Bruchmann ◽  
Anna-Lena Steinweg ◽  
Robert Moeck ◽  
Thomas Straube

Abstract The processing of fearful facial expressions is prioritized by the human brain. This priority is maintained across various information processing stages as evident in early, intermediate and late components of event-related potentials (ERPs). However, emotional modulations are inconsistently reported for these different processing stages. In this pre-registered study, we investigated how feature-based attention differentially affects ERPs to fearful and neutral faces in 40 participants. The tasks required the participants to discriminate either the orientation of lines overlaid onto the face, the sex of the face or the face’s emotional expression, increasing attention to emotion-related features. We found main effects of emotion for the N170, early posterior negativity (EPN) and late positive potential (LPP). While N170 emotional modulations were task-independent, interactions of emotion and task were observed for the EPN and LPP. While EPN emotion effects were found in the sex and emotion tasks, the LPP emotion effect was mainly driven by the emotion task. This study shows that early responses to fearful faces are task-independent (N170) and likely based on low-level and configural information while during later processing stages, attention to the face (EPN) or—more specifically—to the face’s emotional expression (LPP) is crucial for reliable amplified processing of emotional faces.


Perception ◽  
10.1068/p3012 ◽  
2000 ◽  
Vol 29 (2) ◽  
pp. 159-170 ◽  
Author(s):  
Alejo Freire ◽  
Kang Lee ◽  
Lawrence A Symons

We report four experiments leading to conclusions that: (i) the face-inversion effect is mainly due to the deficits in processing of configural information from inverted faces; and (ii) this effect occurs primarily at the encoding stage of face processing, rather than at the storage stage. In experiment 1, participants discriminated upright faces differing primarily in configuration with 81% accuracy. Participants viewing the same faces presented upside down scored only 55%. In experiment 2, the corresponding discrimination rates for faces differing mainly in featural information were 91% (upright) and 90% (inverted). In experiments 3 and 4, the same faces were used in a memory paradigm. In experiment 3, a delayed matching-to-sample task was used, in which upright-face pairs differed either in configuration or features. Recognition rates were comparable to those for the corresponding upright faces in the discrimination tasks in experiments 1 and 2. However, there was no effect of delay (1 s, 5 s, or 10 s). In experiment 4, we repeated experiment 3, this time with inverted faces. Results were comparable to those of inverted conditions in experiments 1 and 2, and again there was no effect of delay. Together these results suggest that an ‘encoding bottleneck’ for configural information may be responsible for the face-inversion effect in particular, and memory for faces in general.


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