Attention may not be a prerequisite for the conscious processing of information in our brains, according to Annelinde Vandenbroucke. Our memory stores – and may even consciously process – objects we fail to notice due to a lack of attention during visual observation. Apparently, our brains process these unattended objects just as effectively as those we consciously focus on. Vandenbroucke will defend her doctoral thesis at the University of Amsterdam (UvA) on Wednesday, 30 October.
Where does our rich visual experience come from? As previous studies have shown, we only remember a few objects from our visual surroundings if we can no longer see anything (when we close our eyes, for example). Do we unconsciously process all the unattended aspects of our environment, or can our brains consciously process elements we do not notice? These questions are central to Vandenbroucke’s research.
Vandenbroucke applied neuro-imaging techniques to determine how our brain processes unattended – and thus unnamed – objects. As it turns out, participants who are highly distracted by a primary visual behavioural task are often unable to describe secondary objects displayed during the task. Vandenbroucke instructed participants in her study to carry out such tasks and measured the brain activity associated with the unnamed objects. Apparently, the participants who had been distracted – and were thus unable to identify the secondary object – processed these objects in a similar manner compared to when they were not distracted. This finding suggests that our brain is capable of effectively processing unattended objects.
Vandenbroucke also studied the perceptual qualities (such as perception of contrast, colour and depth) of unattended objects by using the change detection paradigm. The results justify a distinction between various stages of consciousness in our visual memory storage capacity. In accordance with the results of the neuro-imaging study, they also suggest that attention does not necessarily play a role in the storage of information and confirm that the quality of unattended information equals that of attended information.
Vandenbroucke’s study suggests we may have to broaden our rigid definition of consciousness. ‘However, I don’t expect to see an end to the debate on our definition of consciousness anytime soon', Vandenbroucke explains. ‘At the very least, my research results prove that our brains are capable of accurately processing unattended objects rather than simply filling in the missing information.’
A.R.E. Vandenbroucke, The Quality of Perception without Attention. PhD supervisor: Prof. V.A.F. Lamme. Co-supervisors: Dr J.J. Fahrenfort and Dr I.G. Sligte.
The graduation ceremony will take place on Wednesday, 30 October at 12:00.
Location: Agnietenkapel, Oudezijds Voorburgwal 231, Amsterdam.