Task requirements affect the neural correlates of consciousness.

The neural correlates of consciousness may not be fixed within a single brain region; instead, they can shift depending on the task a person performs. Using magnetoencephalography, researchers compared a perceptual task and a conceptual task that used identical visual stimuli. The perceptual task recruited more occipital brain activity than the conceptual task, while frontal activity varied between the two tasks in partly unexpected ways depending on the level of perceptual awareness. These results suggest that what a person is doing—the task at hand—influences which brain areas support conscious perception, challenging the idea that consciousness can be localized to a consistent set of regions.

Study at a glance

Abstract

In the search for the neural correlates of consciousness, it is often assumed that there is a stable set within the relevant sensory modality. Within the visual modality, the debate has centred upon whether frontal or occipital activations are the best predictors of perceptual awareness. Although not accepted by all as definitive evidence, no-report and decoding studies have indicated that occipital activity is the most consistently correlated with perceptual awareness whereas frontal activity might be closely related to aspects of cognition typically related to reports. However, perception is rarely just passive perception of something, but more or less always perception for something. That is, the task at hand for the perceiver may influence what is being perceived. This suggests an alternative view: that consciousness is not one specific 'function' that can be localized consistently to one area or event-related component and that the specific attributes of the neural correlates of consciousness depend on the task at hand. To investigate whether and how tasks may influence the neural correlates of consciousness, we here contrasted two tasks, a perceptual task and a conceptual task, using identical stimuli in both tasks. Using magnetoencephalography, we found that the perceptual task recruited more occipital resources than the conceptual task. Furthermore, we found that between the two conditions, the amount of frontal resources recruited differed between different gradations of perceptual awareness partly in an unexpected manner. These findings support a view of task affecting the neural correlates of consciousness.