In everyday life relevant and distracting information often coincide and we rely on selective attention to efficiently discriminate between the pertinent information and the irrelevant noise. Existing research relates selective attention to neural oscillations in alpha frequency predominantly using spatial paradigms with one or no distractors, presented simultaneously with the target. In the current thesis the role of pre-stimulus alpha oscillations was investigated in the context of a visual search. First, the effect of visual stimulation on alpha oscillations and behavioural performance was investigated. No effects of stimulation were found and alpha oscillations were not successfully entrained. The relationship of spontaneous pre-stimulus alpha oscillations with performance was then explored. We demonstrated a negative correlation between the power of alpha oscillations and performance, indicating that high power is related to fast reaction times. Lastly, the effect of pre-stimulus alpha oscillations in the context of varying task demands was investigated. The results indicated that high alpha power is beneficial for performance when the target is presented simultaneously with multiple distractors, but not when presented with a singleton distractor. Moreover, the predictability of task demands resulted in modulation of pre-stimulus alpha oscillations, with higher power in anticipation of high task demands, as compared to low task demands.