Neural correlates of prospective memory: an EEG and ICA approach

Have you ever entered a room and wondered ‘What am I supposed to do here?’ or have you ever forgotten to turn off the oven, hang your clothes to dry or make a phone call. These examples illustrate the relevance of ‘prospective memory’ or ‘delayed intentions’ in our daily life activities. Prospective memory is the ability to remember to do something after a delay. This thesis addresses three questions relevant to understand maintenance and execution of intentions: Is attention required to retrieve delayed intentions? What does monitoring mean in the context of prospective memory? Is prospective memory a discrete memory system or it is based on already known attentional and memory mechanisms? To answer these questions, we used electroencephalography (EEG), in (traditional) non-movement and free-movement experimental paradigms. We explored the neural substrate of prospective memory across its different stages: (1) holding intentions during a delay, (2) detecting the right context to perform the delayed intention, and (3) retrieving the content of the intention (the action to be performed). Two types of prospective memory tasks were used: Event-based prospective memory (performing a delayed intention in response to an external cue) and time-based prospective memory (performing the intention at a particular time). Results indicate that: prospective memory always requires attention, at least in experimental contexts; monitoring involves different mechanisms depending on the particular features of the prospective memory task and; prospective memory is not a discrete memory system, but relies on well-established mechanisms for attention and executive control.