My research in cognitive neuroscience focuses on issues of social relationships, empathy, self, action perception and creativity. I use functional neuroimaging combined with behavioral studies of normal and clinical populations to examine the neural mechanisms that underlie our experience of resonating with other people and being aware of our selves.
I am currently Research Assistant Professor at the University of Southern California, in the Brain and Creativity Institute and the Department of Psychology.
In the 1980's Antonio Damasio proposed a neural architecture in which neurons in high level association cortex serve as "converge-divergence zones", or CDZs. These neurons receive bottom-up inputs from multiple sensory modalities (convergence), and can therefore be activated by both the sight and sound of an object. However, they also send reciprocal projections back to lower level sensory cortices (divergence). Through these top-down connections CDZs are able to re-instantiate representations in early sensory cortices.
One prediction of this framework is that bottom-up activation triggered by a sensory stimulus in one modality will always be accompanied by associated top-down activation of other sensory modalities. For example, the sight of a bell would ultimately lead to activation of associated representations in auditory cortex as we hear the bell in our "mind's ear". Using multi-variate pattern analysis (MVPA), we found evidence that this is indeed the case (Meyer et al., 2010). In this first study, subjects watched a series of video clips that were silent, but implied sounds (e.g. a rooster crowing). Using voxels anatomically restricted to auditory cortex, we found that a support vector machine (SVM) could predict which video clip the subject was watching significantly better than chance. Thus the videos in our experiment evoked content-specific activation patterns in auditory cortex.
We next extended this finding into the somatosensory domain (Meyer et al., 2011). In that study subjects watched five videos that showed a hand touching one of several textured objects. Our SVM was able to predict which touch-implying video the subject saw using only voxels from somatosensory cortex. Furthermore, we found that these patterns in somatosensory cortex were similar enough across individuals that we could predict which stimulus someone was viewing using a classifier trained on data from different individuals (Kaplan et al., 2012).
Our current work seeks to extend these findings by directly examining interactions between stimuli presented through multiple sensory modalities.
Description coming soon.
More information about this project can be found here.
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