Spatial imagery in haptic shape perception

• Type of Material: Article
• Authors: Simon Lacey, Emory University; Randall Stilla, Emory University; Karthik Sreenivasan, Auburn University; Gopikrishna Deshpande, Auburn University; Krishnankutty Sathian, Emory University
• Language: English
• Date: 2014-07-01
• Publisher: Elsevier
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2014 Elsevier Ltd.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.neuropsychologia.2014.05.008
• Title of Journal or Parent Work: Neuropsychologia
• ISSN: 0028-3932
• Volume: 60
• Issue: 1
• Start Page: 144
• End Page: 158
• Grant/Funding Information: Support to KS from the National Institutes of Health (RO1 EY012440) and the Veterans Administration is gratefully acknowledged.
• Keywords: TASK; Psychology, Experimental; Psychology; FMRI; MENTAL-IMAGERY; Object familiarity; Neurosciences & Neurology; Neurosciences; TACTILE PERCEPTION; Effective connectivity; PARIETAL CORTEX; GRANGER CAUSALITY ANALYSIS; Life Sciences & Biomedicine; REPRESENTATION; Multisensory; Social Sciences; Behavioral Sciences; Science & Technology; Granger causality; BASAL GANGLIA; fMRI; OBJECT; AREAS
• Research Categories: Psychology, Experimental; Biology, Neuroscience; Health Sciences, Rehabilitation and Therapy

Abstract

We have proposed that haptic activation of the shape-selective lateral occipital complex (LOC) reflects a model of multisensory object representation in which the role of visual imagery is modulated by object familiarity. Supporting this, a previous functional magnetic resonance imaging (fMRI) study from our laboratory used inter-task correlations of blood oxygenation level-dependent (BOLD) signal magnitude and effective connectivity (EC) patterns based on the BOLD signals to show that the neural processes underlying visual object imagery (objIMG) are more similar to those mediating haptic perception of familiar (fHS) than unfamiliar (uHS) shapes. Here we employed fMRI to test a further hypothesis derived from our model, that spatial imagery (spIMG) would evoke activation and effective connectivity patterns more related to uHS than fHS. We found that few of the regions conjointly activated by spIMG and either fHS or uHS showed inter-task correlations of BOLD signal magnitudes, with parietal foci featuring in both sets of correlations. This may indicate some involvement of spIMG in HS regardless of object familiarity, contrary to our hypothesis, although we cannot rule out alternative explanations for the commonalities between the networks, such as generic imagery or spatial processes. EC analyses, based on inferred neuronal time series obtained by deconvolution of the hemodynamic response function from the measured BOLD time series, showed that spIMG shared more common paths with uHS than fHS. Re-analysis of our previous data, using the same EC methods as those used here, showed that, by contrast, objIMG shared more common paths with fHS than uHS. Thus, although our model requires some refinement, its basic architecture is supported: a stronger relationship between spIMG and uHS compared to fHS, and a stronger relationship between objIMG and fHS compared to uHS.