Exploring the predictive role of GABA and Glutamate on temporal binding window in audiovisual perception

Poster Session D - Monday, April 15, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC

Viquar Unnisa Begum¹ (unnisa.opt@gmail.com), Remy Cohan², Dania Abuleil¹, Jennifer Steeves², Ben Thompson¹, Michael Barnett-Cowan¹; ¹University of Waterloo, ²York University

Introduction: This study explores age-related differences in audiovisual integration (AV) by examining the temporal binding window width (TBW) and differences in brain neurotransmitters in young and older adults. Behavioral studies have suggested a broader TBW in older adults, possibly tied to variations in brain excitation and chemistry (Bedard & Barnett-Cowan, 2016; Setti et al., 2011; Basharat et al., 2018). This research correlates AV integration tasks with gamma amino-butyric acid (GABA) and glutamate (GLU) concentrations in the visual cortex. Methods: Participants, comprising 14 young and 11 older adults, underwent behavioral simultaneity (SJ) and temporal order judgement (TOJ) tasks to measure AV integration and magnetic resonance spectroscopy (MRS) with a voxel of interest centered in the occipital lobe to measure neurotransmitter concentrations. Results: Preliminary results suggest MRS_GABA (df=1, f=55.48) and MRS_GLU (df=1, f=4.56) significantly different between younger and older adults, (p<0.05). Linear regression analysis revealed yO significant for MRS_GABA and TBW_SJ (yO =256, t=3.27, p=0.004) and TBW_TOJ (yO =128, t=3.67, p=0.002). Additionally, yO was also significant for MRS_ GLU and TBW_SJ (yO =139.6, t=32.1, p=0.04) and TBW_TOJ (yO =175.7, t=3.3, p=0.004) Conclusion: The study evaluates the potential of neurotransmitter concentrations in predicting AV integration. However, expanding the sample size is imperative for a more comprehensive understanding, particularly in elucidating mechanisms behind age-related declines in multisensory processing.

Topic Area: PERCEPTION & ACTION: Multisensory