Holistic crowding of Mooney faces

Abstract

An object or feature is generally more difficult to identify when other objects are presented nearby, an effect referred to as crowding. Here, we used Mooney faces to examine whether crowding can also occur within and between holistic face representations (C. M. Mooney, 1957). Mooney faces are ideal stimuli for this test because no cues exist to distinguish facial features in a Mooney face; to find any facial feature, such as an eye or a nose, one must first holistically perceive the image as a face. Through a series of six experiments we tested the effect of crowding on Mooney face recognition. Our results demonstrate crowding between and within Mooney faces and fulfill the diagnostic criteria for crowding, including eccentricity dependence and lack of crowding in the fovea, critical flanker spacing consistent with less than half the eccentricity of the target, and inner-outer flanker asymmetry. Further, our results show that recognition of an upright Mooney face is more strongly impaired by upright Mooney face flankers than inverted ones. Taken together, these results suggest crowding can occur selectively between high-level representations of faces and that crowding must occur at multiple levels in the visual system.

Object-level visual information gets through the bottleneck of crowding

“…2; all subjects, P Ͻ 0.001). This reduction in discrimination of the target faces with the addition of flankers is due to crowding and has been demonstrated to result from interactions at the level of holistic face information (Farzin et al 2009;Louie et al 2007). Crowding resulted in a drop to chance-level performance in one subject (NS) and slightly above-chance performance in the other three subjects.…”

Attentional priming releases crowding

“…Flankers typically induce larger crowding when they are more eccentric than the targets (Banks, Bachrach, & Larson, 1977;Bouma, 1970;Farzin, Rivera, & Whitney, 2009;Petrov, Popple, & McKee, 2007). In Experiments 1 and 2, the flankers appeared closer to fixation than did the search items, which may not be maximally sensitive to crowding.…”

Developmental changes during childhood in single-letter acuity and its crowding by surrounding contours

“…Moreover, reciprocal crowding occurs between targets defined by luminance and distracters defined by contrast or vice versa (Chung, Li, & Levi, 2007), two visual characteristics that single cell recordings in monkeys indicate activate the same neurons in area V4 but not in lower levels of the visual system (Ferrera, Nealey, & Maunsell, 1994). Similarly, the demonstration that holistic face processing can be affected by crowding (Farzin et al, 2009) suggests that crowding can occcur at higher cortical levels involved in face processing. Thus, the greater crowding in children than in adults may reflect immaturities in the cortical structures beyond V1 that are involved in the integration of local information.…”