eprintid: 3746
rev_number: 5
eprint_status: archive
userid: 69
dir: disk0/00/00/37/46
datestamp: 2017-08-04 10:23:17
lastmod: 2017-08-04 10:23:17
status_changed: 2017-08-04 10:23:17
type: article
metadata_visibility: show
creators_name: Handjaras, Giacomo
creators_name: Leo, Andrea
creators_name: Cecchetti, Luca
creators_name: Papale, Paolo
creators_name: Lenci, Alessandro
creators_name: Marotta, Giovanna
creators_name: Pietrini, Pietro
creators_name: Ricciardi, Emiliano
creators_id: 
creators_id: 
creators_id: luca.cecchetti@imtlucca.it
creators_id: 
creators_id: 
creators_id: 
creators_id: pietro.pietrini@imtlucca.it
creators_id: emiliano.ricciardi@imtlucca.it
title: Modality-independent encoding of individual concepts in the left parietal cortex
ispublished: inpress
subjects: RC0321
divisions: CSA
full_text_status: none
keywords: Semantic representation; Blindness; Representational similarity encoding analysis; FMRI; GIST; Shock-graph
abstract: Abstract The organization of semantic information in the brain has been mainly explored through category-based models, on the assumption that categories broadly reflect the organization of conceptual knowledge. However, the analysis of concepts as individual entities, rather than as items belonging to distinct superordinate categories, may represent a significant advancement in the comprehension of how conceptual knowledge is encoded in the human brain. Here, we studied the individual representation of thirty concrete nouns from six different categories, across different sensory modalities (i.e., auditory and visual) and groups (i.e., sighted and congenitally blind individuals) in a core hub of the semantic network, the left angular gyrus, and in its neighboring regions within the lateral parietal cortex. Four models based on either perceptual or semantic features at different levels of complexity (i.e., low- or high-level) were used to predict fMRI brain activity using representational similarity encoding analysis. When controlling for the superordinate component, high-level models based on semantic and shape information led to significant encoding accuracies in the intraparietal sulcus only. This region is involved in feature binding and combination of concepts across multiple sensory modalities, suggesting its role in high-level representation of conceptual knowledge. Moreover, when the information regarding superordinate categories is retained, a large extent of parietal cortex is engaged. This result indicates the need to control for the coarse-level categorial organization when performing studies on higher-level processes related to the retrieval of semantic information.
date: 2017
date_type: published
publication: Neuropsychologia
publisher: Elsevier
id_number: 10.1016/j.neuropsychologia.2017.05.001
refereed: TRUE
issn: 0028-3932
official_url: http://www.sciencedirect.com/science/article/pii/S0028393217301677
citation:   Handjaras, Giacomo and Leo, Andrea and Cecchetti, Luca and Papale, Paolo and Lenci, Alessandro and Marotta, Giovanna and Pietrini, Pietro and Ricciardi, Emiliano  Modality-independent encoding of individual concepts in the left parietal cortex.  Neuropsychologia.   ISSN 0028-3932    (In Press)   (2017)