Dynamic Difficulty Adjustment in a P300 Speller Task for Attention Training

National University of Ireland, Maynooth

Status: Completed

Conditions: Attention

Treatments: Other: Task difficulty adaptation according to Arvaneh et al. (2019); Other: Task difficulty adaptation according to iterative learning controller; Other: Random task difficulty

Study type: Interventional

Funder types: Other

Identifiers

NCT05576649

BSRESC-2022-2474456

Details and patient eligibility

About

This study compares different adaptation approaches in a P300-based BCI neurofeedback training to improve short-term attention. Participants will spell several words on a computer by focusing on a letter on the screen while their brain activity is recorded (P300 speller). The difficulty of this task will be adapted to train their attention. Their cognitive abilities will be evaluated using a random dot kinematogram, where they are asked to indicate the direction a fraction of moving dots on the computer screen is going in, before and after the training to analyse any improvements. Questionnaires will be used to compare the perceived task load of the different adaptation approaches.

Full description

Healthy participants will complete several runs in a P300-speller task, where the number of flashes per row and column is progressively adapted to their performance (in control group 1 and experimental group) or chosen randomly (in control group 2). Decreasing the number of flashes per row and column makes it harder for the computer to identify the letter the participant is focusing on, which encourages them to improve their focus to maintain their performance. The number of flashes can therefore be interpreted as the task difficulty of the P300 speller task.

The participants will complete a continuous version of the random dot kinematogram, where a fraction of incoherently moving dots will start moving coherently. The participants are asked to indicate which direction these dots are moving in. This task is completed before and after the P300 speller training, so that response times in the task can be compared.

To evaluate the perceived task load of the different adaptation approaches, the participants will complete a questionnaire about fatigue and boredom before and after the training session, as well as the NASA Task Load Index at the end of the experiment.

Enrollment: 51 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• 18 years and older
• able to consent
• normal or corrected-to-normal vision

Exclusion criteria

• history of neurological or cognitive illnesses
• negative reaction to electroconductive gel used in the study (an allergy patch test will be carried out before the experiment starts)
• illiteracy

Trial design

Primary purpose: Other

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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51 participants in 3 patient groups

Control Group 1

Active Comparator group

Description:

In this group, the number of flashes per row and column during the P300 speller training will be adapted based on the participants' previous performance according to the approach used by Arvaneh et al. (2019).

Treatment:

Other: Task difficulty adaptation according to Arvaneh et al. (2019)

Control Group 2

Sham Comparator group

Description:

In this group, the number of flashes per row and column during the P300 speller training will be chosen randomly. It is independent of the participants' performance.

Treatment:

Other: Random task difficulty

Experimental Group

Experimental group

Description:

In this group, the number of flashes per row and column during the P300 speller training will be adapted according to an iterative learning control law that was developed by the principal investigator of this study. The control law uses the previous number of flashes, as well as the participants' previous performance.

Treatment:

Other: Task difficulty adaptation according to iterative learning controller