Schedule of Events | Symposia

Adaptive inhibitory feedback mechanisms for perceptual learning

Poster Session F - Tuesday, April 1, 2025, 8:00 – 10:00 am EDT, Back Bay Ballroom/Republic Ballroom
Also presenting in Data Blitz Session 3 - Saturday, March 29, 2025, 10:30 am – 12:00 pm EDT, Constitution A.

Zsofia Zavecz¹ (zz501@cam.ac.uk), Ye Gu¹, Joseph Ziminski², Diana Rotaru³, Yuan Gao⁴, Chie Takahashi¹, Uzay Emir⁵, Zoe Kourtzi¹; ¹University of Cambridge, ²Sainsbury Wellcome Centre, ³Columbia University, ⁴Zhejiang University, ⁵University of North Carolina at Chapell Hill

Detecting relevant information in cluttered environments is key for successful recognition and interactions. Yet, our understanding of the brain mechanisms that underlie our ability to improve in perceptual tasks with training—a skill known as perceptual learning—remains limited. Here, we investigate the neurochemical and electrophysiological processes that support perceptual learning. We trained healthy young adults to detect radial vs. concentric patterns embedded in noise (i.e., Glass patterns) and measured neurochemical and electrophysiological signals before and after training. Using magnetic resonance spectroscopy (MRS), we measured neurotransmitters—glutamate and GABA—in the early visual cortex. Using electroencephalography (EEG), we assessed brain synchronization in the alpha frequency proposed as a feedback mechanism between higher- and lower-order visual areas. First, we demonstrate that training improved participants’ perceptual judgments. Second, training altered the excitatory-inhibitory balance in the early visual cortex, with glutamatergic excitation increasing while GABAergic inhibition decreasing. Decreased inhibition was associated with faster rates of perceptual learning. Third, alpha synchronization in occipital areas changed with training; that is, alpha power following stimulus presentation increased. This increase in alpha synchronization was linked to faster learning rates, suggesting that inhibitory feedback mechanisms contribute to perceptual learning. Finally, these learning-dependent changes in alpha synchronization were positively correlated with increased glutamate levels in the early visual cortex, suggesting that inhibitory feedback may drive excitation in the visual cortex to boost perceptual decisions with training. Our findings reveal a strong link between adaptive neurochemical and electrophysiological inhibitory mechanisms for optimized perceptual decisions in the adult human brain.

Topic Area: PERCEPTION & ACTION: Vision