Research Group “Visual attention and perceptual learning” Institute for Neurobiology, Magdeburg
Prof. Dr. med. Jens-Max Hopf
Dipl. neurobiol. Hendrik Strumpf
Dr. rer. nat. Mandy Bartsch
Dipl.-Psych. Anja Rautzenberg
MSc. Haydee Guadalupe Garcia-Lazaro
- Dr. rer. nat. Carsten Nicolas Boehler (Department of Experimental Psychology, Ghent University, Belgium)
- Prof. John K. Tsotsos (Centre for Vision Science, York University, Toronto)
- Prof. Steven Hillyard (UCSD, LaJolla, USA)
- Prof. Steven J. Luck (UC Davis, Davis, USA)
- Prof. George R. Mangun (UC Davis, Davis, USA)
- Prof. Mircea A. Schoenfeld (Section Experimental Neurology, University Magdeburg)
- Prof. Emrah Düzel (Institute for Cognitive Neuroscience, University College London)
- Prof. Jochen Braun (Institute for Biology, University Magdeburg)
The long-term goal of this group is to gain a deeper understanding of the brain mechanisms that enable humans to attend to elementary properties of objects (e.g. its location, color, orientation) in a selective way. To assess the involved cortical and subcortical processes, we combine high-resolution noninvasive brain imaging technologies including Electroencephalography (EEG), Magnetoencephalography (MEG), and functional Magnetresonance Imaging (fMRI).
Topic 1 - Solving cortical architecture-bound problems of visual selection:
1.1 The problem of spatial sampling and resolution: Neural mechanisms of surround attenuation and distractor competition in visual search
Our research into mechanisms that solve architecture-bound problems of attentional selection we focused on two problems more intensively: (a) the problem of spatial sampling and resolution, and (b) the problem of feature correspondence.
1.2 The problem of feature correspondence: Neural mechanisms of object-based feature integration in visual search
A recent investigation of the mechanisms underlying object-based attention revealed another architecture-bound problem – the problem of feature correspondence. The stunning observation was that attention, commonly assumed to solve this problem via feature integration, actually caused the problem to arise (Boehler et al., 2011a).
Topic 2 - Neural mechanisms of surround attenuation and distractor competition: Subcortical structures
Continuing our research into the neural mechanisms of spatial selectivity and distractor competition, we targeted the role of the (subcortical) pulvinar nucleus of the thalamus (the red structure in Figure 2) during attentional selection in visual search (Strumpf et al., 2013). This research was exclusively based on functional brain imaging (fMRI), because electromagnetic responses cannot be obtained from the pulvinar.
Topic 3 - Mechanisms of global feature-based attentional selection in human visual cortex.
One notable property of feature-based attention, previously documented by us (Boehler et al., 2011a; Stoppel et al., 2012b) and by many others, is that it operates in a spatially global way. That is, attending to a feature of an object biases the selection of that feature outside the attended object at any place in the visual field the feature happens to be present.
Topic 4 - Mechanisms of reward-dependent feature selection and its relation to attention
The research reported under Topic 3 shows that feature attention involves multiple steps of gain modulations in ventral extrastriate visual cortex, with early modulations reflecting the selection based on the mere task relevance of a feature.
Hopf JM, Schoenfeld MA, Buschschulte A, Rautzenberg A, Krebs RM, Boehler CN (2015) The modulatory impact of reward and attention on global feature selection in human visual cortex. Visual Cognition 23:229-248.
Krebs RM, Hopf JM, Boehler CN (2015) Within-trial effects of stimulus-reward associations. In: Motivation and Cognitive Control (Braver T, ed). New York: Psychology Press. (in press)
Becke A, Muller N, Vellage A, Schoenfeld MA, Hopf JM (2015) Neural sources of visual working memory maintenance in human parietal and ventral extrastriate visual cortex. Neuroimage 110:78-86.