Some biological and behavioral elements which could explain differences between high and low academic attainment (HA/LA) students were identified. The qEEG of subjects under the 10-20 derivation system was recorded at rest and while completing a 3-back working memory (WM) task. While completing the task LA students showed more theta and total absolute potency at rest, and HA individuals showed more energy in delta and theta frequencies in frontal regions; LA students made a higher number of mistakes while executing the WM task with no differences in reaction time between groups. We conclude that a diminished WM capacity is present in LA students.