Visual scanpath training to emotional faces following severe traumatic brain injury: A single case design

Abstract

The visual scanpath to emotional facial expressions was recorded in BR, a 35-year-old male with chronic severe traumatic brain injury (TBI), both before and after he underwent intervention. The novel intervention paradigm combined visual scanpath training with verbal feedback and was implemented over a 3-month period using a single case design (AB) with one follow up session. At baseline BR’s scanpath was restricted, characterised by gaze allocation primarily to salient facial features on the right side of the face stimulus. Following intervention his visual scanpath became more lateralised, although he continued to demonstrate an attentional bias to the right side of the face stimulus. This study is the first to demonstrate change in both the pattern and the position of the visual scanpath to emotional faces following intervention in a person with chronic severe TBI. In addition, these findings extend upon our previous work to suggest that modification of the visual scanpath through targeted facial feature training can support improved facial recognition performance in a person with severe TBI.

Baseline Variability Affects N-of-1 Intervention Effect: Simulation and Field Studies

“…Our study had several limitations. First, the number of trials in the baseline and intervention phases was set to 5 and 10, respectively, based on the number of sessions in previous N-of-1 research [2,3,7,10,15]. Our simulation results could not be applied to much longer or shorter trial periods, although a small number of trials (i.e., 5 to 10) in the baseline and intervention phases could be applied to broad rehabilitation interventions.…”

“…An N-of-1 research design can be used to examine the effectiveness of rehabilitation interventions for a single patient. This research design involves multiple measurements over time in one patient and is advantageous for assessing behavioral and functional changes in individual patients in various rehabilitation settings [1][2][3]. Two major types of N-of-1 research designs are reversal design (Figure 1A) and multiple-baseline design (Figure 1B) [4][5][6][7].…”

“…𝛽 of the baseline phase was 0.1, whereas 𝛽 of the intervention phase multiplied the slope of the baseline phase by 1.0 to 2.2 (0.2 steps), reflecting the change in slope. 𝑡 was set from 0 to 4 in the baseline phase and from 5 to 14 in the intervention phase in accordance with the number of trials in previous N-of-1 research[2,3,7,10,15]. Equations were constructed using the Python 3.9.7 (Python Software Foundation, Wilmington, DE, USA).…”

SARS-CoV-2 infection impairs oculomotor functions: A longitudinal eye-tracking study

“…However, these tests require highly qualified individuals to administer and may fail to detect mild cognitive or neurological impairments that do not reveal themselves in observable symptoms or magnetic resonance imaging (MRI) scans, such as mild traumatic brain injuries (Hunt et al, 2016). While researchers and medical practitioners continue to search for alternative diagnostic methods, there has been a recent surge in the utilization of eye-tracking technologies for detecting neurological impairments (Levantini et al, 2020;McDonald et al, 2022;Tao et al, 2020), assessing cognitive deficits (Caldani et al, 2020;Panagiotidi et al, 2017), and evaluating treatment responses (Fletcher-Watson & Hampton, 2018;Mihara et al, 2023;Stafford et al, 2019;Vassallo & Douglas, 2021). Eye-tracking allows quick acquisition of objective and real-time analytics (Benson et al, 2012), and various eye-tracking tasks have been designed to capture eye movement metrics that help to reveal the neurological or psychological profile of an individual.…”