Elise A. Piazza
Investigating Real-Life Communication Using fNIRS
Our current understanding of the neural underpinnings of human communication is primarily limited to the processing of isolated components of language (e.g., word lists) by individual subjects lying flat in an fMRI scanner. Using functional near-infrared spectroscopy (fNIRS), I am beginning to investigate communication during live, naturalistic interactions between multiple people. In particular, I am interested in how neural coupling, or synchrony, between children and their caregivers underlies successful language learning and social development early in life.
Measuring speaker-listener neural coupling with functional near infrared spectroscopy.
Liu, Piazza, Simony, Shewokis, Onaral, Hasson, & Ayaz. Scientific Reports, 2017.
Press: WIRED | Huffington Post | ScienceAlert | Schmidt Transformative Technology Award press release
Statistical Summary in Auditory Perception
I am interested in how humans use summary statistics to efficiently perceive complex sounds. In a recent study, we found that listeners encode the average pitch of a tone sequence and that this summary statistical representation is stronger than their representation of information about the individual tones in the sequence (e.g., their pitches or temporal positions).
In ongoing work, I am studying how caregivers shift the summary statistics of their voices to engage babies in language learning and help them quickly identify familiar sounds.
Humans use summary statistics to perceive auditory sequences.
Piazza, Sweeny, Wessel, Silver, & Whitney. Psychological Science, 2013.
Press: UC Berkeley press release | Science Today interview
Perception of Musical Pitch and Timbre
In another line of research, I am investigating perception of the pitch and timbre of musical (and other complex) sounds. For example, in one study, we find that timbre may represent a high-level, configural property of natural sounds, processed similarly to faces in vision.
(Photo of my chamber trio in 2013).
Resolving Ambiguity in Visual Perception
How does the brain select what we consciously perceive when the world is ambiguous? In my dissertation, I used binocular rivalry (a bistable phenomenon that occurs when two conflicting images are presented separately to the two eyes, resulting in perceptual alternation between the images) as a model of visual ambiguity to study the effects of various factors on conscious awareness.
In one study, we found that asymmetry between the two cerebral hemispheres impacts our conscious perception during binocular rivalry. Our results indicate that conscious representations differ across the visual field and that these differences persist for a long time (at least 30 seconds) after the onset of a stimulus. In a follow-up study, we found that this hemispheric filtering is based on a relative comparison of the SFs available in the current environment.
In another set of studies, we investigated the impact of predictive information on perception. First, we showed that people are more likely to perceive a given image during binocular rivalry when that image matches the prediction of a recently-viewed stream of rotating gratings. In ongoing work, we have found that arbitrary associations between sounds and images (established during a brief statistical learning period) impact perceptual selection during rivalry.
Persistent hemispheric differences in the perceptual selection of spatial frequencies.
Piazza, & Silver. Journal of Cognitive Neuroscience, 2014.
Relative spatial frequency processing drives hemispheric asymmetry in conscious awareness.
Piazza, & Silver. Frontiers in Psychology, 2017.
Predictive context influences perceptual selection during binocular rivalry.
Denison, Piazza, & Silver. Frontiers in Human Neuroscience, 2011.
Rapid crossmodal learning influences perceptual selection during binocular rivalry.
Piazza, Denison, & Silver, in prep.