Novel Optical Parallelized Diffuse Correlation Spectroscopy Distinguishes Subtle Task-Specific Prefrontal Cortical Activity

Poster Session F - Tuesday, April 1, 2025, 8:00 – 10:00 am EDT, Back Bay Ballroom/Republic Ballroom

Akhilesh Chegu¹ (akhilesh.chegu@duke.edu), Lucas Kreiss¹, Paul McKee¹, Melissa Wu¹, Roarke Horstmeyer¹, Scott Huettel¹; ¹Duke University

Non-invasive optical imaging measures physiological markers of brain activity at high temporal resolution, with fewer restrictions, and at a lower cost than traditional neuroimaging techniques. Here we explore the potential of a new technique, Parallelized Diffuse Correlation Spectroscopy (PDCS), which measures the scattering of near-infrared light using a single-photon avalanche diode (SPAD) array. Fluctuations in the resulting speckle patterns create a calculated blood flow index (BFI) that provides insights into capillary perfusion, often underestimated by traditional absorbance-based techniques. Building on prior work distinguishing prefrontal cortex (PFC) blood flow in resting vs. task-activated states, this study evaluates PDCS’ ability to differentiate PFC activation across executive functioning tasks. Participants completed a Go-No-Go task (targeting the right inferior frontal cortex [RIFC]) and a Verbal Fluency Task (VFT; targeting the left inferior frontal cortex [LIFC]) while PDCS measured regional blood flow. Results were compared to functional near-infrared spectroscopy (fNIRS), a well-established technique that tracks cortical blood oxygenation via light absorption. PDCS data revealed distinct task-specific activation: Go-No-Go increased RIFC activation relative to LIFC and VFT, while VFT increased LIFC activation relative to RIFC and Go-No-Go. These findings demonstrate PDCS’ sensitivity to subtle, region-specific neural activity, supporting its potential as an effective tool for optical blood-flow neuroimaging.

Topic Area: METHODS: Neuroimaging