Neural activity in the brain is harder to disrupt when we are aware of it

October 22, 2013

We consciously perceive just a small part of the information processed in the brain – but which information in the brain remains unconscious and which reaches our consciousness remains a mystery. However, neuroscientists Natalia Zaretskaya and Andreas Bartels from the Centre for Integrative Neuroscience (CIN) at the University of Tübingen have now come one step closer to answering this question.

Their research, published in Current Biology, used a well-known visual illusion known as 'binocular rivalry' as a technique to make visual images invisible. Eyes usually both see the same image – binocular rivalry happens when each eye is shown an entirely different image. Our brains cannot then decide between the alternatives, and our perception switches back and forth between the images in a matter of seconds. The two images are 'rivals' for our attention, and every few seconds they take turns to enter our consciousness.

Using this approach the two scientists used a moving and a static picture to cause perceptual alternations in their test subjects' minds. Simultaneously they applied magnetic pulses to disturb brain processing in a ' area' that specifically processes . The effect was unexpected: 'zapping' activity in the motion area did not have any effect on how long the moving image was perceived – instead, the amount of time the static image was perceived grew longer.

So 'zapping' the motion area while the mind was unconsciously processing motion meant that it took longer for it to become conscious of the moving image. When the moving image was being perceived, however, zapping had no effect.

This result suggests that there is a substantial difference between conscious and unconscious motion representation in the . Whenever motion is unconscious, its neural representation can easily be disturbed, making it difficult for it to gain the upper hand in the rivalry. However, once it becomes conscious it apparently becomes more resistant to disturbance, so that introducing noise has no effect. Therefore, one correlate of conscious neural codes may be a more stable and noise-resistant representation of the outside world, which raises the question of how this neural stability is achieved.

Explore further: Setting blurred images in motion improves perception

More information: Natalia Zaretskaya and Andreas Bartels: Perceptual effects of stimulating V5/hMT+ during binocular rivalry are state-specific. Current Biology, 21 October 2013.

Related Stories

Setting blurred images in motion improves perception

September 27, 2013
Blurred images that are unidentifiable as still pictures become understandable once the images are set in motion. That's because of a phenomenon called "optic flow"—which may be especially relevant as a source of visual ...

Barrow researchers unravel illusion

May 1, 2012
Barrow Neurological Institute researchers Jorge Otero-Millan, Stephen Macknik, and Susana Martinez-Conde share the recent cover of the Journal of Neuroscience in a compelling study into why illusions trick our brains. Barrow ...

Neuroscientists find greater complexity in how we perceive motion

December 5, 2011
How we perceive motion is a significantly more complex process than previously thought, researchers at New York University's Center for Neural Science, Stanford University and the University of Washington have found. Their ...

Babies show visual consciousness at five months

April 19, 2013
(Medical Xpress)—A new study by scientists in France and Denmark has identified a neurological marker in the brain of babies as young as five months that is associated with visual consciousness, or the ability to process ...

Recommended for you

The neural codes for body movements

July 21, 2017
A small patch of neurons in the brain can encode the movements of many body parts, according to researchers in the laboratory of Caltech's Richard Andersen, James G. Boswell Professor of Neuroscience, Tianqiao and Chrissy ...

Faulty support cells disrupt communication in brains of people with schizophrenia

July 20, 2017
New research has identified the culprit behind the wiring problems in the brains of people with schizophrenia. When researchers transplanted human brain cells generated from individuals diagnosed with childhood-onset schizophrenia ...

Scientists discover combined sensory map for heat, humidity in fly brain

July 20, 2017
Northwestern University neuroscientists now can visualize how fruit flies sense and process humidity and temperature together through a "sensory map" within their brains, according to new research.

Scientists reveal how patterns of brain activity direct specific body movements

July 20, 2017
New research by Columbia scientists offers fresh insight into how the brain tells the body to move, from simple behaviors like walking, to trained movements that may take years to master. The discovery in mice advances knowledge ...

Team traces masculinization in mice to estrogen receptor in inhibitory neurons

July 20, 2017
Researchers at Cold Spring Harbor Laboratory (CSHL) have opened a black box in the brain whose contents explain one of the remarkable yet mysterious facts of life.

Speech language therapy delivered through the Internet leads to similar improvements as in-person treatment

July 20, 2017
Telerehabilitation helps healthcare professionals reach more patients in need, but some worry it doesn't offer the same quality of care as in-person treatment. This isn't the case, according to recent research by Baycrest.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.