scholarly journals Representation of Semantic Similarity in the Left Intraparietal Sulcus: Functional Magnetic Resonance Imaging Evidence

2017 ◽  
Vol 11 ◽  
Author(s):  
Veerle Neyens ◽  
Rose Bruffaerts ◽  
Antonietta G. Liuzzi ◽  
Ioannis Kalfas ◽  
Ronald Peeters ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Semantic Similarity ◽  
Intraparietal Sulcus ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Evidence

Functional Magnetic Resonance Imaging Evidence for a Hierarchical Organization of the Prefrontal Cortex

2007 ◽  
Vol 19 (12) ◽  
pp. 2082-2099 ◽  
Author(s):  
David Badre ◽  
Mark D'Esposito
Keyword(s):  
Magnetic Resonance Imaging ◽  
Prefrontal Cortex ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Hierarchical Organization ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Evidence ◽  
Organized Action ◽  
Selection Of

The prefrontal cortex (PFC) is central to flexible and organized action. Recent theoretical and empirical results suggest that the rostro-caudal axis of the frontal lobes may reflect a hierarchical organization of control. Here, we test whether the rostro-caudal axis of the PFC is organized hierarchically, based on the level of abstraction at which multiple representations compete to guide selection of action. Four functional magnetic resonance imaging (fMRI) experiments parametrically manipulated the set of task-relevant (a) responses, (b) features, (c) dimensions, and (d) overlapping cue-to-dimension mappings. A systematic posterior to anterior gradient was evident within the PFC depending on the manipulated level of representation. Furthermore, across four fMRI experiments, activation in PFC subregions was consistent with the sub- and superordinate relationships that define an abstract representational hierarchy. In addition to providing further support for a representational hierarchy account of the rostro-caudal gradient in the PFC, these data provide important empirical constraints on current theorizing about control hierarchies and the PFC.

Dissociable Roles of the Superior Temporal Sulcus and the Intraparietal Sulcus in Joint Attention: A Functional Magnetic Resonance Imaging Study

2008 ◽  
Vol 20 (1) ◽  
pp. 108-119 ◽  
Author(s):  
Simone Materna ◽  
Peter W. Dicke ◽  
Peter Thier
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Joint Attention ◽  
Eye Gaze ◽  
Superior Temporal Sulcus ◽  
Brain Regions ◽  
Intraparietal Sulcus ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging

Previous imaging work has shown that the superior temporal sulcus (STS) region and the intraparietal sulcus (IPS) are specifically activated during the passive observation of shifts in eye gaze [Pelphrey, K. A., Singerman, J. D., Allison, T., & McCarthy, G. Brain activation evoked by perception of gaze shifts: The influence of context. Neuropsychologia, 41, 156–170, 2003; Hoffman, E. A., & Haxby, J. V. Distinct representations of eye gaze and identity in the distributed human neural system for face perception. Nature Neuroscience, 3, 80–84, 2000; Puce, A., Allison, T., Bentin, S., Gore, J. C., & McCarthy, G. Temporal cortex activation in humans viewing eye and mouth movements. Journal of Neuroscience, 18, 2188–2199, 1998; Wicker, B., Michel, F., Henaff, M. A., & Decety, J. Brain regions involved in the perception of gaze: A PET study. Neuroimage, 8, 221–227, 1998]. Are the same brain regions also involved in extracting gaze direction in order to establish joint attention? In an event-related functional magnetic resonance imaging experiment, healthy human subjects actively followed the directional cue provided by the eyes of another person toward an object in space or, in the control condition, used a nondirectional symbolic cue to make an eye movement toward an object in space. Our results show that the posterior part of the STS region and the cuneus are specifically involved in extracting and using detailed directional information from the eyes of another person to redirect one's own gaze and establish joint attention. The IPS, on the other hand, seems to be involved in encoding spatial direction and mediating shifts of spatial attention independent of the type of cue that triggers this process.

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