As known from several studies about the two-tone Oddball task, the P300-complex
of event-related potential (ERP), is usually reported as having a maximum
expression at parietal areas. Due to the simplicity of this task, the cognitive
effort for participants was supposed as low. The goal in that study was
to compare the impact of tasks on the modulation of the slow positive wave
(SPW) in relation to working memory capacity. Three 50:50 tasks (one visual-counting,
one auditive-counting and one reaction time task) as well as 1, 3, 5 digit
Sternberg tasks and Oddball task were compared. A design of repeated analysis
of variances were used consisting of the factors: Group: high vs. low working
memory capacity, Task/Stimulus: acoustic or visual relevant or relevant
and not relevant, Recording Location: F3, Fz, F4, C3, Cz, C4, P3, Pz and
P4. The 50:50 visual tasks and the Oddball task showed the largest individual
differences of parietal locations related to working memory capacity, while
the Sternberg tasks did not reach significance. However only the visual
50:50 counting task had group differences and also found an indication
at F3 for an additional aspect of working memory as reflected by SPW.