Devising a modified Flanker Task for the assessment of attention after stroke

Background: Two-thirds of stroke survivors have cognitive impairment of which attention deficits are the most prominent. The growth in research focused on developing rehabilitation programs to improve attention after stroke (i.e., brain training), has made it critical to have effective tools for the assessment of attention. Attention can be assessed behaviourally or electrophysiologically (i.e., recording brain activity). Purpose: To test a novel tool for the assessment of behaviour and brain activity associated with attention, and to compare it to a more commonly used tool. It is anticipated that the novel tool (modified Flanker task) will produce more distinct electrophysiological indices of attention than the commonly used tool (oddball task), with similar behavioural performance observed across tools. Methods: Forty non-disabled adult participants (18-28 years) will be recruited. In a single experimental session, participants will perform the three-stimulus oddball task, and two modifications of the Flanker task [mixed (visual and auditory) and single (visual) modality] in a randomized order. Electrophysiological data will be obtained using high-density electroencephalography (EEG) and behavioural performance (reaction time and accuracy) collected throughout. Event-related analysis of EEG data will be performed to obtain the P300 and its sub-components P3a and P3b. Two-way ANOVA (p < 0.05) will be used to analyze reaction time and accuracy, as well as to compare amplitude and latency of the P3a and P3b waveforms. Impact: The outcome of this study will be a novel tool that provides a more sensitive measure for assessing both behavioural and electrophysiological aspects of attention. Importantly, the project will yield normative data that will be used to compare the results from a sample of people who have post-stroke attention deficit, and who are currently undergoing cognitive rehabilitation. Data collection for this project is underway.