Uncovering mechanisms of attentional control by tracking preparatory states in real time

Project overview

Our perception of the outside world is not just determined by incoming sensory information, but also by our expectations and intentions. We are not merely passive recipients of perceptual signals - very often, we are already prepared for what to expect and for what will be relevant in a given situation. Being prepared allows us to deal with our environment more effectively, by focussing our attention on what is important, and filtering out other information that can be safely ignored.

Preparation is one of the most important aspects of human cognition - it shapes our conscious experience and guides our interactions with the world. However, we still know very little about how we prepare for upcoming tasks. Because the activation of preparatory states is an internal mental phenomenon that usually takes place in the absence of any directly observable behaviour, it is difficult to assess with the conventional performance-based measures of experimental psychology.

The Birkbeck project lead for this project is Professor Martin Eimer and it has been funded by the Economic and Social Research Council (ESRC).

Research aim

In this project, we will measure preparatory states directly, while they occur, by recording brain activity (EEG) from observers when they prepare for upcoming visual search tasks. In these tasks, they have to search for a specific known target object among multiple irrelevant objects (distractors). They can prepare for search by activating a mental representation of this target object, which will then help to guide their attention to the target when it appears.

Outputs and outcomes

We have recently developed new methods to measure such preparatory 'images in the mind' directly, at the moment when they are activated, and to track these activation states in real time. We can therefore now directly observe when preparation starts and how it changes across time.

We can also determine the content of such preparatory states. For example, when we prepare to search for our mobile phone on our cluttered desk, do we activate a mental image of the whole object, or just a specific attribute of this object, such as its colour or shape? Do we prepare more effectively for task goals that are motivationally relevant, because they are associated with a higher reward? How quickly can we change preparatory states affected when task goals suddenly change?

Importantly, we will also investigate links between preparation and failures of selective attention. By comparing preparatory states measured on an occasion where subsequent attentional selection operates efficiently and on an occasion where it does not, we can find out how fluctuations in preparedness produce different behavioural outcomes.