Project 1: Attending to complex rhythms: An fMRI study

This project is aimed at investigating neural activation related to rhythmic auditory attending. A rhythm reproduction task was used to investigate the role of attending in perceiving, remembering and reproducing complex rhythmic patterns. Subjects were asked to attend to a repeated rhythmic pattern, mentally rehearse the pattern, and reproduce the pattern by tapping on a midi drum pad. In an attend visual/ignore auditory condition, participants were instructed to perform a verbal memory task and ignore the auditory stimulus. Compared with rest, rhythmic attending recruited activity in right basal ganglia and SMA, areas known to play a role in motor behavior. Attending compared to ignoring the rhythms resulted in increased activity in bilateral anterior cingulate (BA 24 and 32), and medial frontal gyrus (BA 9). Anterior cingulate and prefrontal areas have been previously implicated in expectancy and attention, and appear here to be related specifically to rhythmic attending.

Project 2: Limbic and paralimbic responses to music performance

Project: Upper Motor Rehabilitation in Stroke Patients Using Music Therapy and Occupational Therapy

The objective of this study is to assess the improvement of stroke patients undergoing various levels of occupational therapy and music therapy. Patients are randomly assigned to treatment conditions lasting 4 weeks. The treatment conditions include varying amounts of occupational therapy, individual music therapy, and rhythmic auditory stimulation. Assessments are administered pre- & post-treatment that allow us to quantitatively measure improvement in motor skills, entrainment, cognitive skills, and activities of daily living (i.e. dressing, bathing, grooming). These outcome measures will be used to gain knowledge about the role of entrainment and music therapy in motor rehabilitation and it's impact when used in addition to, or concurrent with, occupational therapy. This research will improve therapy prescriptions for stroke and other brain damaged patients, as well as improve our understanding of neural recovery and the role of entrainment.

This study is being conducted in collaboration with Dr. Concetta M. Tomaino and the Institute for Music and Neurologic Function in the Bronx, NY.

Project: Dynamical Modeling of Auditory Perception and Attention

Conventional linear resonator models are computationally and analytically tractable, however tractability is achieved at the expense of capturing many significant features of attention and perception. Allocation of attention to complex event sequences displays significant nonlinearities, including phase transitions and higher-order resonances. The perception of acoustic events also shows significant nonlinearities including extreme perceptual sensitivity, high frequency resolution, and higher-order resonances. Modern theoretical models of attentional and perceptual phenomena have one thing in common: they are all nonlinear oscillators or networks of nonlinear oscillators responding to perceptual input. We are developing a computer toolbox for signal analysis by gradient frequency nonlinear resonator networ

Dissertation:

Neural Correlates of Meter Perception in High-Frequency Brain Activity

This dissertation applies electroencephalography (EEG) toward understanding the neural basis of meter perception, the extraction of a periodic accent pattern that is central to rhythm perception in music and speech. EEG provides the necessary temporal resolution to describe brain dynamics involved in the processing of events in complex metrical patterns. The first experiment examined auditory responses to tones presented at a range of tempos found in music, 150–3125 ms inter-onset interval (IOI). Early responses showed constant amplitude across tempos, while later responses showed smaller amplitude at faster tempos. Early and late responses were explainable by phase dynamics of the ongoing EEG. A second experiment presented metrical patterns of alternating strong and weak accents defined by loud and soft tones, with occasional tone omissions. Synchronous with expected tone onset time, induced high-frequency gamma-band activity (GBA) showed larger responses for strongly accented positions, regardless of whether tones were presented or omitted. A third experiment defined meter by the temporal distribution of tone onsets and found evoked GBA that was larger for stronger metrical positions. The findings of this dissertation suggest that high-frequency brain activity occurring around tone onset times shows correlates of metrical expectancy and metrical accent.

Project: Perceiving emotion in expressive piano performance

We aimed to identify brain areas involved in responding to affect communicated by expressive piano performance. Our subjects listened to two versions of Chopin’s Etude in E major, Opus 10, No. 3. The first version was an expressive performance, recorded by a highly trained musician on a computer-monitored piano. Our control was a computer-generated, mechanical performance of the same composition. Data analysis revealed differential brain activation in the two listening conditions. The expressive performance elicited greater activation in anterior cingulate, right temporal pole, right inferior frontal gyri, inferior parietal lobe and superior temporal gyri, areas that have been associated with emotion, attention, speech perception. The mechanical performance elicited greater activation in cerebellum, parahippocampal gyrus, supplementary motor area and dorsolateral prefrontal cortex, areas primarily involved in motor and sequencing tasks. Our results confirm that expressive music performance communicates affect beyond the melody, harmony, tonality, and rhythm of the notated composition. Our observations also suggest that the perception of emotion in music shares neural resources with the perception of emotion in speech, and that these pathways may be different from those recruited during other types of emotional experience.

Dissertation: Neural correlates of auditory perception, attention and expectation

This dissertation examined the neural correlates of auditory perception, attention and expectation in three experiments. Experiment 1 analyzed neural correlates of auditory perception and expectation in an electroencephalography (EEG) experiment using a temporally perturbed metronome to establish an expectation for auditory events, then violate and reestablish that expectation. High frequency evoked (phase-locked) gamma band activity (GBA) was observed to follow the onset of tones whereas induced (non-phase-locked) GBA reached maximum power simultaneously with the occurrence of tone onset. Moreover, the latency of induced GBA was perturbed after an expectancy violation and relaxed back into synchrony as the expectation was reestablished. Experiment 2 investigated sparse sampling, a functional magnetic resonance imaging (fMRI) scanning technique designed to minimize MR noise interference. Experiment 3 was conducted to study auditory expectancy and attention. First, subjects were tested behaviorally to determine their ability to tap the beat of ten highly syncopated patterns. Subjects were asked to return for one EEG and one fMRI session. In these sessions, they were instructed to attend to a syncopated pattern, mentally rehearse the pattern, and then reproduce the pattern. During the control condition, subjects heard the auditory patterns, however, they were instructed to study a list of words, remember the words during the retention interval, and then report all words remembered. Brain activity was localized to frontal and auditory regions when attending to the patterns and occipital-auditory areas when attending to the words. Evoked activity was shown to reflect the subject’s anticipation of the beat and was attenuated when ignoring the auditory stimulus. Taken together, these results suggest that GBA indexes auditory perception, attention and expectation. The current results suggest that attention and task engagement may elicit stronger neural phase locking.