Working memory is a fundamental function that allows one to perform everyday actions, being involved in academics, professional and social lives. It is negatively influenced by aging. But despite large number of studies, less is know about the visuo-spatial store. In order to better understand this change three studies were carried out, two with healthy participants and one with Parkinson’s disease patients. The participants performed a visuo-spatial n back task with low and high cognitive load conditions as well as a control one. In the first one the behavioural data of participants aged from 20 to 80 years was collected in order to better understand the aging process, in particular to see when it starts to become visible and to observe if the cognitive reserve had a positive influence on it. In the second one behavioural, hemodynamic and electrophysiological data was collected from adult and elderly participants, with the same educational level and cognitive reserve. In the last one, behavioural data from a Parkinson’s group on medication was collected and they were paired with control participants; the groups had high educational level and cognitive reserve in order to see if these prevent cognitive decline. The results of the first study showed that reaction time started to decrease before accuracy (34 vs 57) and that ageing has a negative effect on both; in reaction time ageing showed an interaction with the high cognitive load condition. Cognitive reserve due to educational level had positive effects on both and the total cognitive reserve score was a positive factor on accuracy results. In the second study, healthy aging impaired both the selection of response and the working memory processes: inhibition, updating and maintenance. On the other hand, in the elderly group compensation was found in the attention process. Those changes were visible in behavioural, hemodynamic and electrophysiological correlates. In the last one, the patients showed no difference in behavioural results from the control group, showing that total cognitive reserve and cognitive reserve due to work had a positive effect on this. Visuo-spatial working memory is negatively affected by aging, but cognitive reserve and educational level can prevent this effect.