Research

I’m a cognitive neuroscientist who studies on attention and working memory. My central area of investigation is how our sensory input constrains and shapes higher-level cognition. A second line of work tests the role of predictability and expectation.

As co-director of CMU’s Laboratory in Multisensory Neuroscience, I work on a wide variety of research questions and methodological approaches. Our skills span from basic psychophysics to complex neuroimaging work.

Below are recent posters from our group, as well as brief descriptions of my current research areas. Publications are listed under Publications

Recent LiMN posters

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Cortical networks for visual and auditory short-term memory

I established a robust, reliable method of using fMRI to map sensory-biased cortical networks, using auditory and visual working memory activation in individual subjects. I have characterized the resulting networks’ cognition, exploring their extent, behavior, and connectivity. These results have shown that discrete sub-regions of prefrontal cortex have strong preferences for specific sensory modalities. Auditory-biased networks are slightly left-lateralized, and are extremely selective for auditory cognition; visual-biased networks are slightly right-lateralized, and are more general in their activation.

Distinguishing auditory attention states

I have shown when and where in the brain auditory attention is represented, using fMRI and EEG neuroimaging data in cojunction with representational analysis tecniques. While many aspects of attention are similar regardless of what is being attended to, the underlying brain states carry critical information about the cue or feature that is being used. Our results have demonstrated that the target of auditory attention is briefly represented in evoked neural responses, but sustained in oscillatory activity. We have also identified key regions in sensory, parietal, and prefrontal cortex that encode attentional state.

Perceptual organization in working memory

By exploring the relationships among perceptual organiztion, inter-stimulus similarity, and working memory task demands, I have shown that the perceptual grouping of sound objects into memory items critically impacts their accessibility at memory retrieval. This work builds on my doctoral exploration of the learning processes by which arbitrary visuospatial trajectories become familiar paths.

Information domains associated with sensory modality.

Vision’s innate affinity for spatial information an audition’s innate affinity for temporal information affect people’s ability to encode information into workin memory. Further, spatial attention and working memory activate brain activity that is characteristic of visual processing, regardless of sensory modality. I have developed appropriately-matched visual and auditory tasks probing these processes, and find that when task demands require auditory spatial processing, or visual temporal processing, people recruit cognitive machinery usually associated with the “other” sensory modality.

Prediction and familiarity of distractors in attention

Most studies of attention have disregarded the non-target distractors; my work explores how predictability of the distractors supports focused attention. Across these projects, we tested the probability of various distractor configurations, as well as testing the role of predictable timing. Across the board, we find that predictable distractors are easier to ignore, leading to better attention performance.