Dissociable identity- and modality-specific neural representations as revealed by cross-modal nonspatial inhibition of return.
There are ongoing debates on whether object concepts are coded as supramodal identity-based or modality-specific representations in the human brain. In this fMRI study, we adopted a cross-modal "prime-neutral cue-target" semantic priming paradigm, in which the prime-target relationship was manipulated along both the identity and the modality dimensions. The prime and the target could refer to either the same or different semantic identities, and could be delivered via either the same or different sensory modalities. By calculating the main effects and interactions of this 2 (identity cue validity: "Identity_Cued" vs. "Identity_Uncued") × 2 (modality cue validity: "Modality_Cued" vs. "Modality_Uncued") factorial design, we aimed at dissociating three neural networks involved in creating novel identity-specific representations independent of sensory modality, in creating modality-specific representations independent of semantic identity, and in evaluating changes of an object along both the identity and the modality dimensions, respectively. Our results suggested that bilateral lateral occipital cortex was involved in creating a new supramodal semantic representation irrespective of the input modality, left dorsal premotor cortex, and left intraparietal sulcus were involved in creating a new modality-specific representation irrespective of its semantic identity, and bilateral superior temporal sulcus was involved in creating a representation when the identity and modality properties were both cued or both uncued. In addition, right inferior frontal gyrus showed enhanced neural activity only when both the identity and the modality of the target were new, indicating its functional role in novelty detection.
Center for Studies of Psychological Application and School of Psychology, South China Normal University, Guangzhou, China.
Yukai
Y
Chi
Zhenzhu
Z
Yue
Yupin
Y
Liu
Lei
L
Mo
Qi
Q
Chen
D000161:Acoustic Stimulation; D001307:Auditory Perception / Q000502:physiology; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D003463:Cues; D004192:Discrimination, Psychological / Q000502:physiology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008606:Mental Processes / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D010775:Photic Stimulation; D012660:Semantics; D014796:Visual Perception / Q000502:physiology; D055815:Young Adult
cross-modal priming paradigm; cue validity; fMRI; identity-based; modality-based