Clinical Trial Details
— Status: Active, not recruiting
Administrative data
| NCT number |
NCT05694377 |
| Other study ID # |
01/2019 |
| Secondary ID |
|
| Status |
Active, not recruiting |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
February 1, 2019 |
| Est. completion date |
April 30, 2023 |
Study information
| Verified date |
January 2023 |
| Source |
University School of Physical Education in Wroclaw |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
Executive function play a key role in boosting human behavioural performance. Based on
scientific literature, it is still controversial whether electroencephalography-based
neurofeedback (EEG-NFB) represents an effective technique for enhancing healthy adults'
executive function. This study evaluates generalized effects of 3-week EEG-NFB training,
using self-regulation of the theta to beta wave ratio (TBR), on executive function in healthy
adults. The subjects are an uniform group of healthy young right-handed males divided into
two equal groups. The trained group (TR) performs 3-week EEG-NFB training (three sessions per
week) focused on a cognitive self-regulation of TBR (to achieve the lower TBR values as
beneficial cognitive effect), while the control group (CO) does not participate in the
EEG-NFB training. Cognitive function are rated before and after 3-week EEG-NFB training by
psychological tests: Trail Making Test (TMT, parts A and B) and the Stroop Test (ST, parts I
and II). This project is important for the future development of effective EEG-NFB protocols
to be used by healthy people to improve their behavioural performance.
Description:
2. MATERIALS AND METHODS
2.1. Subjects A total of 50 healthy male students will be randomly assigned to one of two
groups of 25 subjects each using a computerized randomization method. The trained group will
undergo 3 weeks of EEG-NFB training, whereas the control group will not undergo training.
Inclusion criteria for study participation will be lack of any neurological disorders and
motor or cognitive deficits, lack of neurological incident in the past, age between 20 to 25
years, male sex, and right-handedness (this inclusion criteria will be to avoid an influence
of lateralization and gender on psychological tests outcomes). The study was approved by the
ethic committee of the University School of Physical Education in Wroclaw and will be carried
out in accordance with the principles outlined in the Declaration of Helsinki.
2.2. Experimental procedure TR and CO groups will be each tested twice in the same time
periods, i.e., before 3 weeks period of EEG-NFB training (PRE) and after the training period
(POST). During the PRE and POST experimental sessions, all subjects will undergo
psychological testing to evaluate executive function. PRE testing in the both groups will be
performed 1 to 4 days before the first day of EEG-NFB training period, whereas POST testing
will be performed 1 to 4 days after the last day of EEG-NFB training period to ensure that
the measurements will be not due to the effects of the last single training session in the TR
group.
2.3. Psychological assessment All subjects will undergo cognitive testing (TMT and ST), which
will be performed by an experienced researcher. There will be two parts to the TMT: TMT-A, in
which a subject connects numbers in sequential order; and TMT-B, in which the subject
alternates between numbers and letters (1, A, 2, B, etc.). The former is used to examine
cognitive processing speed, while the latter assesses executive function. The ST also
consists of two parts: ST-I, in which a subject reads a list of 40 words, which are names of
colours printed in the colour itself; and ST-II, where colour names are printed in an
incongruent colour and the subject is required to ignore the word and correctly name the ink
colour. The former is used as a measure of processing speed and the latter to test selective
attention and inhibition. The subjects will be provided with instructions prior to starting
the TMT and ST. In both ST tests parts subjects will have the same instruction as "name the
colour of ink", and will not be informed in ST-I that all name/ink are matched. All tests
(both parts of TMT and ST) will be preceded by preparatory/training trials, a similar but
shorter version of main tests. Before starting each test, subjects will be instructed to
concentrate and to make use their maximal attention skills during testing session. In both
tests (TMT and ST), the time taken to complete the test will be used as the performance
measure, with a shorter time reflecting a better performance. The tests will be administered
in a quiet room with only one and always the same investigator present.
2.4. EEG-NFB training procedure The EEG-NFB training program will involve nine training
sessions (three times a week over a 3-week period) each lasting 30 min. EEG-NFB training will
be conducted with ProComp Infiniti Encoder and BioGraph Infiniti Software v.5.1.3. The
training protocol will be set to decrease the EEG TBR value. For the 12 training sessions,
all participants will be subjected the same EEG-NFB protocol at C3 (according to the 10-20
system), which is related to Brodmann area 4. This location is selected because the TMT and
ST used to quantify the EEG-NFB effect are also related to activity in this brain region. The
EEG-NFB training sessions consists of a 20-s baseline period (i.e., with no feedback), 30-min
feedback presentation, and another 20-s baseline period. Subjects will be seated in front of
a computer screen and animations will be used as feedback; the animation starts when the
subject is sufficiently focused for 20 s. Three 10-min animations (flying duck, roller
coaster ride, and moving ball) will be shown to the subject during each EEG-NFB training
session. The raw EEG signal, TBR value over time, EEG signal noise, and EEG theta and beta
wave amplitudes will be recorded.
TBR values will be recorded and calculated for each training session for the TR group and
will be compared between the beginning of the first and beginning of the last EEG-NFB
training sessions, to determine whether the 3-week training lead to decrease of the TBR
value.
2.5. Statistical analysis The Shapiro-Wilk test will be used to estimate the distribution of
psychological parameters. The Wilcoxon signed-rank test or Student's t-test will be used to
assess the statistical significance of differences for paired sample comparisons (i.e.,
between PRE and POST testing sessions). The Mann-Whitney test or Student's t-test will be
used for unpaired sample comparisons (i.e., between TR and CO groups). Magnitude/importance
of differences will be calculated using the Cohen effect size d value for results of the
psychological tests; a value of 0 indicates no effect, whereas values > 0.2, >0.6, and > 0.8
indicates small, moderate, and large effects, respectively. P value ≤ 0.05 will be taken as
statistically significant for all analyses. All statistical analyses will be performed using
SPSS Statistics 22.0 software (IBM, Armonk, NY, USA).
