Towards the detection of Alzheimer’s disease through eye movement changes using a hearable

Hearables are wearable devices with in-ear microphones that utilize the occlusion effect to detect amplified low-frequency signals propagated by tissue and bone conduction, such as eardrum oscillations caused by eye movements [Greuters et al., 2018, PNAS, 115(6)]. Saccades, which are rapid and simultaneous movements of both eyes, provide valuable insight into a person's motor abilities and can be used to assess cognitive dysfunction. Research indicates that individuals with Alzheimer’s disease exhibit delayed, slow, and hypometric (i.e., undershooting) saccades, along with less fixation stability [Fletcher & Sharpe, 1986. An. Neuro. 20(4)]. In this project, 35 patients with Alzheimer’s disease or mild cognitive impairment, along with 35 matched control participants, will undergo various experiments, such as a picture description task, while wearing an eye tracking device and a hearable. The objective is to correlate recorded eardrum oscillations from the hearable and the amplitude and trajectory of horizontal and vertical saccades from the glasses. In addition, we aim to predict AD group inclusion based on data collected from the hearable. The long-term goal of this project is to develop a wearable, non-intrusive, and easy-to-use device capable of identifying Alzheimer’s disease and potentially predicting it earlier than the standard diagnosis timeframe.