Cognitive Impairment Detection Based on Frontal Camera Scene While Performing Handwriting Tasks

Abstract

Diagnosing cognitive impairment is an ongoing field of research especially in the elderly. Assessing the health status of the elderly can be a complex process that requires both subjective and objective measures. Subjective measures, such as self-reported responses to questions, can provide valuable information about a person’s experiences, feelings, and beliefs. However, from a scientific point of view, objective measures, based on quantifiable data that can be used to assess a person’s physical and cognitive functioning, are more appropriate and rigorous. The proposed system is based on the use of non-invasive instrumentation, which includes video images acquired with a frontal camera while the user performs different handwriting tasks on a Wacom tablet. We have acquired a new multimodal database of 191 elder subjects, which has been classified by human experts into healthy and cognitive impairment users by means of the standard pentagon copying test. The automatic classification was carried out using a video segmentation algorithm through the technique of shot boundary detection, in conjunction with a Transformer neural network. We obtain a multiclass classification accuracy of 77% and two-class accuracy of 83% based on frontal camera images, which basically detects head movements during handwriting tasks. Our automatic system can replicate human classification of handwritten pentagon copying test, opening a new method for cognitive impairment detection based on head movements. We also demonstrate the possibility to identifying the handwritten task performed by the user, based on frontal camera images and a Transformer neural network.