The Functional Impact of Mental Imagery on Conscious Perception

DOI: 10.1016/j.cub.2008.05.048

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Pearson, J., Clifford, C. W., & Tong, F. (2008). The functional impact of mental imagery on conscious perception. Current Biology, 18(13), 982–986. doi:10.1016/j.cub.2008.05.048

Abstract

Mental imagery has been proposed to contribute to a variety of high-level cognitive functions, including memory encoding and retrieval, navigation, spatial planning, and even social communication and language comprehension 1, 2, 3, 4, 5. However, it is debated whether mental imagery relies on the same sensory representations as perception 1, 6, 7, 8, 9, 10, and if so, what functional consequences such an overlap might have on perception itself. We report novel evidence that single instances of imagery can have a pronounced facilitatory influence on subsequent conscious perception. Either seeing or imagining a specific pattern could strongly bias which of two competing stimuli reach awareness during binocular rivalry. Effects of imagery and perception were location and orientation specific, accumulated in strength over time, and survived an intervening visual task lasting several seconds prior to presentation of the rivalry display. Interestingly, effects of imagery differed from those of feature-based attention. The results demonstrate that imagery, in the absence of any incoming visual signals, leads to the formation of a short-term sensory trace that can bias future perception, suggesting a means by which high-level processes that support imagination and memory retrieval may shape low-level sensory representations.

Authors

Joel Pearson35
Colin W.G. Clifford1
Frank Tong2

What This Study Is About

This study explores whether the act of imagining a picture in your mind can change how you see the physical world. Researchers wanted to know if mental imagery—the ability to "see" with the mind's eye—uses the same parts of the brain as actual vision and if it leaves a lasting trace that influences future perception.

How They Studied It

Researchers used a phenomenon called "binocular rivalry." This happens when one image (like green vertical stripes) is shown to your left eye and a different image (like red horizontal stripes) is shown to your right eye. Instead of seeing a mix, your brain usually flips back and forth between the two.

In several experiments, a small group of participants was asked to either imagine one of those patterns or look at a faint version of it before the actual rivalry test began. The researchers then measured which image the participants saw first. They also tested how factors like background brightness, the timing of the imagery, and the specific angle of the stripes affected the results.

What They Found

The study found that simply imagining a pattern made participants significantly more likely to see that same pattern when the real images appeared. This "priming" effect was very specific: it only worked if the imagined image was at the same location and the same angle as the real one.

The researchers also discovered that the strength of this effect increased the longer someone spent imagining the image. Interestingly, while looking at a real faint image and imagining one had similar effects, they reacted differently to light; a bright background made mental imagery less effective at influencing vision, but it didn't stop the effect of actual physical sight.

What This Might Mean

These findings suggest that mental imagery isn't just a "thought"—it creates a real, short-term sensory trace in the brain's visual system. This suggests that imagination and seeing use much of the same neural "hardware." For the study of aphantasia (the inability to visualize), this research provides a potential way to measure imagery objectively: if someone cannot form a mental image, their imagination shouldn't be able to "prime" their vision in this specific way.

One Interesting Detail

The "memory trace" created by imagination was surprisingly durable; it could survive for several seconds even if the participant was interrupted by a different visual task before the rivalry test began.

The Functional Impact of Mental Imagery on Conscious Perception

Abstract

Authors

The Functional Impact of Mental Imagery on Conscious Perception

Abstract

Authors

The Functional Impact of Mental Imagery on Conscious Perception

Abstract

Authors

The Functional Impact of Mental Imagery on Conscious Perception

Abstract

Authors

What This Study Is About

How They Studied It

What They Found

What This Might Mean

One Interesting Detail

What This Study Is About

How They Studied It

What They Found

What This Might Mean

One Interesting Detail

Joel Pearson

Merlin Monzel

Adam Zeman

Rebecca Keogh

Martin Reuter

Juha Silvanto

Paolo Bartolomeo

Carla Dance

Jianghao Liu

Fraser Milton