n my dissertation, I investigated the neuronal mechanisms underlying object recognition and categorization in the human visual system. In particular, I focused on three main aspects: Sampling, Invariance and Plasticity. I first investigated how the cortical systems for overt visual attention and object recognition interact. Combining eye-tracking with ambiguous visual displays, we were able to demonstrate a bi-directional influence. Furthermore, I investigated potential mechanisms and features underlying viewpoint invariant object- and face-recognition. Using multivariate analyses on fMRI and MEG/EEG data, as well as TMS, we focused on a peculiar cortical shortcut: the joint selectivity for mirror-symmetric viewpoints. Finally, I asked how the visual system, despite highly reliable and efficient performance, is capable of maintaining considerable plasticity, allowing it to almost immediately learn and integrate novel categories. Here, we performed a longitudinal study in which we combined extensive category training with multiple MEG measurements to unravel the temporal and spatial aspects of cortical category-learning. The project was funded by a PhD position in the Neurobiopsychology lab of Professor König and by a Fulbright scholarship during my time in Professor Frank Tong’s lab.
urrently, we investigate (a)
how long-term visual experience shapes visual representations and perception. In addition to the effects of extended category training, we ask how visual invariances might be extracted from the statistics of the natural input to the system. (b)
We furthermore investigate at what stages and latency invariant face recognition is reached in the visual system in order to better understand the underlying mechanisms. To better understand the complex structure of the recorded high-dimensional data, we apply machine-learning techniques and computational models to the empirical data. (c)
Finally, we investigate object-based reference frames asking how different parts of a face are bound into a coherent perceptual experience.
Current and Past Collaborators include: Niko Kriegeskorte
, Olaf Hauk
, Peter König
, Frank Tong
, Andreas Engel
, Randolph Blake
, Sam Ling
, Niklas Wilming
, Jose Ossandon
, Torsten Betz
’The human eye is utterly passive.’ she said, obviously quoting some professor or textbook, ’Only the brain can see.’