Crossmodal enhancement in the LOC for visuohaptic object recognition over development

• Published in: Neuropsychologia 2015-10, Vol.77, p.76-89
• Main Authors: Jao, R. Joanne, James, Thomas W., James, Karin Harman
• Format: Article
• Language: English
• Subjects: Adult; Brain - growth & development; Brain - physiology; Brain Mapping; Cerebrovascular Circulation - physiology; Child; Child Development - physiology; Crossmodal; Development; Female; fMRI; Haptics; Humans; Magnetic Resonance Imaging; Male; Multisensory; Neuropsychological Tests; Object recognition; Oxygen - blood; Pattern Recognition, Visual - physiology; Photic Stimulation; Recognition (Psychology) - physiology; Vision
• ISSN: 0028-3932; 1873-3514
• DOI: 10.1016/j.neuropsychologia.2015.08.008

Research has provided strong evidence of multisensory convergence of visual and haptic information within the visual cortex. These studies implement crossmodal matching paradigms to examine how systems use information from different sensory modalities for object recognition. Developmentally, behavioral evidence of visuohaptic crossmodal processing has suggested that communication within sensory systems develops earlier than across systems; nonetheless, it is unknown how the neural mechanisms driving these behavioral effects develop. To address this gap in knowledge, BOLD functional Magnetic Resonance Imaging (fMRI) was measured during delayed match-to-sample tasks that examined intramodal (visual-to-visual, haptic-to-haptic) and crossmodal (visual-to-haptic, haptic-to-visual) novel object recognition in children aged 7–8.5 years and adults. Tasks were further divided into sample encoding and test matching phases to dissociate the relative contributions of each. Results of crossmodal and intramodal object recognition revealed the network of known visuohaptic multisensory substrates, including the lateral occipital complex (LOC) and the intraparietal sulcus (IPS). Critically, both adults and children showed crossmodal enhancement within the LOC, suggesting a sensitivity to changes in sensory modality during recognition. These groups showed similar regions of activation, although children generally exhibited more widespread activity during sample encoding and weaker BOLD signal change during test matching than adults. Results further provided evidence of a bilateral region in the occipitotemporal cortex that was haptic-preferring in both age groups. This region abutted the bimodal LOtv, and was consistent with a medial to lateral organization that transitioned from a visual to haptic bias within the LOC. These findings converge with existing evidence of visuohaptic processing in the LOC in adults, and extend our knowledge of crossmodal processing in adults and children. •Functional MRI was used to measure the development of multisensory object recognition.•Intramodal and crossmodal processes were examined in delayed match-to-sample tasks.•The neural substrates of crossmodal matching were present, but not yet adult-like by age 7.•The LOC showed increased sensitivity to changes in sensory modality.•A medial to lateral transition from a visual to haptic bias was found in the LOC.