INSTITUT FÜR PSYCHOLOGIE

Termin 

 23.04.2024

17.15

 G22a-362

16.11.2024

17:15

 G22a-362

 Herr Dr. Ralph Weidner,

Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Center Jülich, Germany.

Visual information processing in the human brain: The role of lateral occipital cortex in visual context integration

 Visual perception is not a passive projection of external information onto an internal representational medium. Rather, our brain actively interprets sensory signals to come up with an interpretation that constitutes a consistent and useful model of the external world. This is nicely illustrated by many visual illusions where changes of an object’s context alter our brain’s interpretation of an object and hence its visual percept. Context-induced changes of an object’s perceived size have been demonstrated to go along with activation changes within a network of brain areas involving early visual and lateral occipital cortex (Murray et al. 2006, Weidner & Fink, 2007, Plewan et al. 2012). Investigating the role of these brain regions using transcranial magnetic stimulation (TMS) (Zeng et al. 2020) showed that TMS over both early visual and lateral occipital cortex LOC impairs illusory size perception. Interestingly, the strongest effects of TMS applied over early visual cortex occurred later than those of observed following lateral occipital cortex stimulation, supporting a functionally relevant feedback modulation from LOC to EVC for scaling size information. These results suggest that context integration and the concomitant change of perceived size require LOC and result in modulating representations in EVC via recurrent processing

References

Murray, S. O., Boyaci, H., & Kersten, D. (2006). The representation of perceived angular size in human primary visual cortex. Nature neuroscience, 9(3), 429-434.

Plewan, T., Weidner, R., Eickhoff, S. B., & Fink, G. R. (2012). Ventral and dorsal stream interactions during the perception of the Müller-Lyer illusion: evidence derived from fMRI and dynamic causal modeling. Journal of Cognitive Neuroscience, 24(10), 2015-2029.

Weidner, R., & Fink, G. R. (2007). The neural mechanisms underlying the Müller-Lyer illusion and its interaction with visuospatial judgments. Cerebral Cortex, 17(4), 878-884.

Zeng, H., Fink, G. R., & Weidner, R. (2020). Visual size processing in early visual cortex follows lateral occipital cortex involvement. Journal of Neuroscience, 40(22), 4410-4417.

Dr. Artjom Zinchenko

 Titel TBA