Table 4.

Reported effects on level of functioning

Study	Number of patients (n)	Withdrawal or dropout	Results		Comments	Directness a	Limitations a	Precision a
			EEG-based neurofeedback	No intervention
Noohi, 2017 [35]	30	0	Wisconsin Card Sorting Test  Number of errors   Baseline: 75.7 (SD 22.7)   After 45 days: 19.2 (SD 15.3)   Δ −56.5	Wisconsin Card Sorting Test  Number of errors   Baseline: 73.7 (SD 21.4)   After 45 days: 46.6 (SD 25.0)   Δ −27.1 Between-group difference in pre-to-post change: Δ −29.4, p < 0.001	Both measures are well established cognitive performance tests that assess executive functioning. • Number of errors in WCST indicates rate of success in identifying a pattern. A lower score indicates a better result. • Perseveration response indicates how well an individual adjusts to a changed situation. A lower score indicates a better result. • Number of categories is a measure of how many tests an individual makes in the given time frame. In TOL a higher score indicates a better result. Both tests measure the actual number, which theoretically can be between 0 and infinity.	+	−	?
			Perseveration response   Baseline: 49.8 (SD 18.0)   After 45 days: 9.7 (SD 9.0)   Δ −40.1	Perseveration response   Baseline: 50.4 (SD 17.9)   After 45 days: 26.5 (SD 18.5)   Δ −23.9 Between-group difference in pre-to-post change: Δ −16.2, p < 0.001
			Numbers of categories   Baseline: 2.5 (SD 1.8)   After 45 days: 5.6 (SD 0.7)   Δ +3.1	Numbers of categories   Baseline: 3.2 (SD 1.7)   After 45 days: 4.2 (SD 1.7)   Δ +1.0 Between-group difference in pre-to-post change: Δ +2.1, p < 0.001
			Tower of London  Score   Baseline: 22.0 (SD 5.0)   After 45 days:  28.1 (SD 3.2)   Δ +6.1	Tower of London  Score   Baseline: 23.3 (SD 5.1)   After 45 days: 23.3 (SD 3.1)   Δ 0 Between-group difference in pre-to-post change: Δ +6.1, p < 0.001

Abbreviations: TOL, Tower of London; WCST, Wisconsin Card Sorting Test.

^a + indicates no or minor problems; ? indicates some problems; and − indicates major problems.