Right perceptual bias and self-face recognition in individuals with congenital prosopagnosia

Abstract

The existence of a drift to base judgments more on the right half-part of facial stimuli, which falls in the observer's left visual field (left perceptual bias (LPB)), in normal individuals has been demonstrated. However, less is known about the existence of this phenomenon in people affected by face impairment from birth, namely congenital prosopagnosics. In the current study, we aimed to investigate the presence of the LPB under face impairment conditions using chimeric stimuli and the most familiar face of all: the self-face. For this purpose we tested 10 participants with congenital prosopagnosia and 21 healthy controls with a face matching task using facial stimuli, involving a spatial manipulation of the left and the right hemi-faces of self-photos and photos of others. Even though congenital prosopagnosics performance was significantly lower than that of controls, both groups showed a consistent self-face advantage. Moreover, congenital prosopagnosics showed optimal performance when the right side of their face was presented, that is, right perceptual bias, suggesting a differential strategy for self-recognition in those subjects. A possible explanation for this result is discussed.

Holistic but with reduced right-hemisphere involvement: The case of dyslexia in Chinese character recognition

“…All stimuli were displayed until the participant responded, by pressing corresponding buttons on a response box, to judge which of the two chimeric characters looked more similar to the original one The inclusion of non-linguistic stimuli such as faces will also help us understand whether the observed LSB and HP effects are related to impaired linguistic processing. In contrast to Chinese readers with dyslexia, people with prosopagnosia were reported to have reduced LSB (Malaspina et al, 2016) and HP (Avidan et al, 2011) in face perception. These findings suggest that the deficits may be related to difficulties in forming appropriate configural representations in the RH.…”

Diagnosing developmental prosopagnosia: repeat assessment using the Cambridge Face Memory Test

“…To some extent this is offset by diagnostic approaches that require impaired performance on multiple tests within the same session (e.g. [69][70][71]), although the most popular tasks (CFMT, CFPT and famous faces) arguably tap different sub-processes of face recognition that can be selectively impaired in some individuals. Thus, the issue of repeat assessment on different versions of the same test is particularly pertinent in such cases.…”

Mapping self-face recognition strategies in congenital prosopagnosia.

“…Thus, previous findings seem to support the idea that, along with the inability to recognize familiar and unfamiliar faces and the presence of an anomalous scan path behavior, individuals with CP explore every face in the same way, independently of whether the face is familiar (or famous) to them or not. However, recent findings have demonstrated that despite their face recognition impairment, congenital prosopagnosics (Malaspina, Albonico & Daini, 2016) achieve considerable accuracy when they have to recognize their own face. Similarly, one study on an acquired prosopagnosic patient showed preserved trait inferencing from the self-face but not from familiar faces (Klein, Gabriel, Gangi, & Robertson, 2008).…”