Conceptual size representation in ventral visual cortex. (29th January 2016)

• Record Type: Journal Article
• Authors: Gabay, Shai; Kalanthroff, Eyal; Henik, Avishai; Gronau, Nurit
• Is Part Of: Neuropsychologia. Volume 81(2016)
• Page Start: 198
• Page End: 206
• Publication Date: 2016-01-29
• Subjects: Conceptual size -- Parahippocampal place area -- Occipital place area -- Size-preference -- Numerical processing; Neuropsychology -- Periodicals; Neurology -- Periodicals; Psychophysiology -- Periodicals; Neuropsychologie -- Périodiques; Neuropsychology; Periodicals; Electronic journals; 616.8
• DOI: 10.1016/j.neuropsychologia.2015.12.029
• Languages: English
• ISSNs: 0028-3932

Abstract

Abstract: Recent findings suggest that visual objects may be mapped along the ventral occipitotemporal cortex according to their real-world size (Konkle and Oliva, 2012 ). It has been argued that such mapping does not reflect an abstract, conceptual size representation, but rather the visual or functional properties associated with small versus big real-world objects. To determine whether a more abstract conceptual size representation may affect visual cortical activation we used meaningless geometrical shapes, devoid of semantic or functional associations, which were associated with specific size representations by virtue of extensive training. Following training, participants underwent functional magnetic resonance imaging (fMRI) scanning while performing a conceptual size comparison task on the geometrical shapes. In addition, a size comparison task was conducted for numeral digits denoting small and big numbers. A region-of-interest analysis revealed larger blood oxygenation level dependent (BOLD) responses for conceptually 'big' than for conceptually 'small' shapes, as well as for big versus small numbers, within medial (parahippocampal place area, PPA) and lateral (occipital place area, OPA) place-selective regions. Processing of the 'big' visual shapes further elicited enhanced activation in early visual cortex, possibly reflecting top-down projections from PPA. By using arbitrary shapes and numbers we minimized visual, categorical, or functional influences on fMRI measurement, providing evidence for a possible neural mechanism underlying the representation of abstract conceptual size within the ventral visual stream. Highlights: Meaningless shapes were linked with various conceptual sizes via extensive training. fMRI scanning was performed during shape and number conceptual size tasks. Scene-selective areas (PPA, OPA) were activated by big conceptual sizes and numbers. Sensitivity for big sizes in early visual cortex may reflect a top-down effect. A shared neural substrate for conceptual size and numerosity is suggested.