Schedule of Events | Symposia

Modeling target search in blind echolocators using a Kalman Filter with realistic exploratory behavior simulations

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

Sofia Krasovskaya¹ (skrasovskaya@ski.org), James M. Coughlan¹, Aarshil Patel¹, Santani Teng¹; ¹The Smith-Kettlewell Eye Research Institute

Some blind persons aid their mobility with echolocation, a technique in which auditory feedback from a sequence of self-generated tongue clicks guides perception and action. To investigate echoacoustically guided sensorimotor dynamics, we present a model for estimating azimuthal head movements based on target location and a series of noisy click-based measurements. The model simulates realistic head movements using an exploratory behavior phase, adjusting head azimuth towards the target over time, with larger adjustments at the start and progressively smaller ones with more feedback. We simulate echoacoustic feedback using Gaussian noise to reflect uncertainty. A Kalman Filter (KF) then tracks changes in head azimuth by combining prior estimates with new noisy measurements. The system assumes a constant angular head velocity and updates estimates using process and measurement noise covariance. Initially, it makes large adjustments, but with each measurement it estimates target location more precisely. We test the model across multiple simulations of trials and participants per trial against a control condition model simulating a zero-feedback scenario, where system updates are based solely on the prior and process noise. We assess the performance of both models using metrics such as Mean Absolute Error (MAE), Root Mean Squared Error (RMSE), Mean Error and normalized accuracy. Results demonstrate that KF performance improves with feedback but deteriorates without feedback. This resembles the observed behavior of real-life expert echolocators in click and no-click conditions. The proposed model provides a quantitative framework for understanding ecologically relevant behavior in a poorly understood perceptual mode.

Topic Area: PERCEPTION & ACTION: Audition