Medizin - Open Access LMU - Teil 19/22

Ventral and dorsal streams processing visual motion perception (FDG-PET study)


Listen Later

Background: Earlier functional imaging studies on visually induced self-motion perception (vection) disclosed a bilateral network of activations within primary and secondary visual cortex areas which was combined with signal decreases, i.e., deactivations, in multisensory vestibular cortex areas. This finding led to the concept of a reciprocal inhibitory interaction between the visual and vestibular systems. In order to define areas involved in special aspects of self-motion perception such as intensity and duration of the perceived circular vection (CV) or the amount of head tilt, correlation analyses of the regional cerebral glucose metabolism, rCGM (measured by fluorodeoxyglucose positron-emission tomography, FDG-PET) and these perceptual covariates were performed in 14 healthy volunteers. For analyses of the visual-vestibular interaction, the CV data were compared to a random dot motion stimulation condition (not inducing vection) and a control group at rest (no stimulation at all). Results: Group subtraction analyses showed that the visual-vestibular interaction was modified during CV, i.e., the activations within the cerebellar vermis and parieto-occipital areas were enhanced. The correlation analysis between the rCGM and the intensity of visually induced vection, experienced as body tilt, showed a relationship for areas of the multisensory vestibular cortical network (inferior parietal lobule bilaterally, anterior cingulate gyrus), the medial parieto-occipital cortex, the frontal eye fields and the cerebellar vermis. The "earlier" multisensory vestibular areas like the parieto-insular vestibular cortex and the superior temporal gyrus did not appear in the latter analysis. The duration of perceived vection after stimulus stop was positively correlated with rCGM in medial temporal lobe areas bilaterally, which included the (para-) hippocampus, known to be involved in various aspects of memory processing. The amount of head tilt was found to be positively correlated with the rCGM of bilateral basal ganglia regions responsible for the control of motor function of the head. Conclusions: Our data gave further insights into subfunctions within the complex cortical network involved in the processing of visual-vestibular interaction during CV. Specific areas of this cortical network could be attributed to the ventral stream ("what" pathway) responsible for the duration after stimulus stop and to the dorsal stream ("where/how" pathway) responsible for intensity aspects.
...more
View all episodesView all episodes
Download on the App Store

Medizin - Open Access LMU - Teil 19/22By Ludwig-Maximilians-Universität München


More shows like Medizin - Open Access LMU - Teil 19/22

View all
In search of dark matter by Prof. Dr. Andreas Burkert

In search of dark matter

0 Listeners

Theoretical Physics Schools (ASC) by The Arnold Sommerfeld Center for Theoretical Physics (ASC)

Theoretical Physics Schools (ASC)

2 Listeners

MCMP – Mathematical Philosophy (Archive 2011/12) by MCMP Team

MCMP – Mathematical Philosophy (Archive 2011/12)

6 Listeners

Hegel lectures by Robert Brandom, LMU Munich by Robert Brandom, Axel Hutter

Hegel lectures by Robert Brandom, LMU Munich

6 Listeners

MCMP – Philosophy of Science by MCMP Team

MCMP – Philosophy of Science

1 Listeners

MCMP – Logic by MCMP Team

MCMP – Logic

3 Listeners

Epistemology and Philosophy of Science: Prof. Dr. Stephan Hartmann – HD by Ludwig-Maximilians-Universität München

Epistemology and Philosophy of Science: Prof. Dr. Stephan Hartmann – HD

1 Listeners

ISCB34 - 34th Annual Conference of the International Society for Clinical Biostatistics - Munich, 25-29 August 2013 by Prof. Dr. rer. nat. Ulrich Mansmann

ISCB34 - 34th Annual Conference of the International Society for Clinical Biostatistics - Munich, 25-29 August 2013

0 Listeners

MCMP – Philosophy of Physics by MCMP Team

MCMP – Philosophy of Physics

3 Listeners

LMU An introduction to Bohmian Mechanics by Florian Hoffmann und Nicola Vona

LMU An introduction to Bohmian Mechanics

2 Listeners