About Our Research
What tools do we use?
Psychophysics is the branch of psychology that examines how physical changes in stimuli,
such as intensity or duration, affect behavioral and neural responses. Our experiments use
finely controlled auditory, visual, and somatosensory (touch) stimuli to assess how information
from these three sensory modalities is integrated across time.
Electroencephalography (EEG) is the way we measure electrical activity in the brain during psychophysics experiments. We do this by placing non-invasive electrodes on the scalp and repeatedly presenting stimuli to produce a voltage difference on the scalp called an Event Related Potential (ERP). Obtaining ERPs does not affect your brain in any way. The raw EEG data is time-locked and averaged across many trials. Different ERP components are indicative of different cognitive mechanisms, such as semantic processing or detection of a unique stimulus.
For more information about ERP's, click here.
NIH Grant: The Neurophysiology of Sensory Processing and Multisensory Integration in Autism Spectrum Disorder (ASD)
Sensory symptoms of ASD vary broadly between individuals. Some people experience oversensitivity to sound, touch, or visual stimuli, while others have decreased responses to pain, hypersensitivity to certain textures, or hyposensitivity to touch. In our NIH-funded line of research, we seek to identify and classify sensory subtypes in ASD that may have clinical and phenotypic implications. We are able to do this by presenting auditory, visual, and/or somatosensory stimuli and measuring behavioral responses and electroencephalography (EEG) signals from the brain. This novel research can be translated into concrete recommendations for the testing and efficacy of clinical interventions and provide important information regarding the mechanisms that produce behaviors characteristic of ASD. Future studies will examine how the brain responds to dynamically changing stimuli.
Hill Grant: Temporal Visual Search in ASD
Attention allows individuals to selectively extract salient information from our ever-changing environment. Individuals with autism demonstrate strengths in the ability to find target stimuli among distractors. Generally this is studied when all of the information is simultaneously presented. Here we assess whether this enhanced detection ability extends to the time domain. That is, when participants with autism are asked to find targets in time instead of space, will they also be better than typically developing children? In addition, how do their brains respond to these targets?
Multisensory Integration with Visual and Auditory Stimuli
Among typically developing individuals, response times (RT) to multisensory stimuli are much faster when sounds and pictures match (e.g., meow and cat picture) than when they do not (e.g., dog bark and cat picture). This phenomenon is called semantic multisensory integration. Research indicates that persons with ASD have difficulties integrating sensory information. This project aimed to extend previous work on semantic processing to the spatial domain and to shed light on these processes. Typically developing participants were asked to detect whether sounds and pictures emanate from the same or different spatial locations. In addition, they were asked to fill out a self-report questionnaire, Autism Spectrum Quotient (AQ). In that way, we could see if participants with autistic traits had lower accuracy rates in detecting the stimuli.