title: fMRI Activity in Posterior Parietal Cortex Relates to the Perceptual Use of Binocular Disparity for Both Signal-In-Noise and Feature Difference Tasks.
abstract: Visually guided action and interaction depends on the brain's ability to (a) extract and (b) discriminate meaningful targets from complex retinal inputs. Binocular disparity is known to facilitate this process, and it is an open question how activity in different parts of the visual cortex relates to these fundamental visual abilities. Here we examined fMRI responses related to performance on two different tasks (signal-in-noise "coarse" and feature difference "fine" tasks) that have been widely used in previous work, and are believed to differentially target the visual processes of signal extraction and feature discrimination. We used multi-voxel pattern analysis to decode depth positions (near vs. far) from the fMRI activity evoked while participants were engaged in these tasks. To look for similarities between perceptual judgments and brain activity, we constructed 'fMR-metric' functions that described decoding performance as a function of signal magnitude. Thereafter we compared fMR-metric and psychometric functions, and report an association between judged depth and fMRI responses in the posterior parietal cortex during performance on both tasks. This highlights common stages of processing during perceptual performance on these tasks.
authors.affiliation: School of Psychology, University of Birmingham, Edgbaston, United Kingdom, B15 2TT; School of Psychology, UNSW Australia, Sydney, NSW, Australia.
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Patten
authors.affiliation: School of Psychology, University of Birmingham, Edgbaston, United Kingdom, B15 2TT; Department of Psychology, University of Cambridge, Cambridge, United Kingdom, CB2 3EB.
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Welchman
mesh_terms: D000328:Adult; D001931:Brain Mapping; D003867:Depth Perception / Q000502:physiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D010296:Parietal Lobe / Q000000981:diagnostic imaging*; D010775:Photic Stimulation; D011859:Radiography; D059629:Signal-To-Noise Ratio; D015357:Vision Disparity / Q000502:physiology*; D055815:Young Adult