NCT04989309

Left and Right Hemisphere Contributions to Speech Perception

The Role of Frontal and Temporal Brain Areas in the Perception of Phonetic Category Structure

• Status: Enrolling By Invitation
• Phase: N/A
• Study type: Interventional
• Enrollment: 26 (estimated)
• Sponsor: University of Connecticut · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Accepted

Summary

Left and right temporal brain areas are thought to contribute to speech perception, but the division of labor between left and right hemisphere regions is still unclear. Here we use transcranial magnetic stimulation (TMS) to stimulate left and right temporal foci and a vertex control site to temporarily disrupt activation at the stimulation site, using a "virtual lesion" approach to test the effect of stimulation site on a series of speech perception tasks. This portion of the project is basic research. However, since TMS is viewed as an intervention, studies involving TMS in this grant are considered clinical trials.

Detailed description

This study uses TMS to temporarily disrupt neural activity in the left and right temporal cortex and examine the effect of this disruption on speech perception tasks. Vertex stimulation is included as a control condition against which left and right superior temporal stimulation effects are compared. Adult participants first undergo structural MRI and a speech localizer using functional MRI to identify speech-sensitive voxels in the left and right temporal cortex. These regions are set by-participant as the foci for stimulation. Stimulation site is blocked, and typically distributed across sessions. 10 Hz pulse trains of 2.5 sec each are delivered to the stimulation site, with an auditory stimulus arriving either immediately after the last pulse (Exps 2 and 6) or, for longer sentence level stimuli (Exp 3), during the pulse train. Behavioral measures include accuracy and reaction times to rate phonetic stimuli (Exp 2), detect the presence of a probe word in the preceding sentence (Exp 3), or categorize stimuli by phonetic contrast and talker (Exp 6).

Conditions

• Neural Bases of Speech Perception

Interventions

Type	Name	Description
DEVICE	Transcranial Magnetic Stimulation	TMS will be delivered in 10 Hz pulses for 2.5 seconds, with behavioral measures of speech perception and object categorization immediately following each pulse. TMS at this schedule is thought to temporarily disrupt activity at the stimulation site.

Timeline

• Start date: 2024-12-19
• Primary completion: 2025-12-31
• Completion: 2026-06-30
• First posted: 2021-08-04
• Last updated: 2025-06-15

Locations

1 site across 1 country: United States