Perceptual changes - a key to our consciousness

Nov 19, 2010
The test participants had a house projected on one eye and a face on the other eye. This triggered an alternating perception, since the brain could not reconcile the two pictures with each other. Image: Max Planck Institute for Biological Cybernetics

(PhysOrg.com) -- With his coat billowing behind him and his right eye tightly closed, Captain Blackbeard watches the endless sea with his telescope. Suddenly the sea disappears as the pirate opens his right eye. The only thing he sees is his hand holding the telescope. Then, a moment later, the sea is back again. What happened was a change in perception. Our brain usually combines the two slightly divergent images of our eyes into a single consistent perception.

However, if the does not match, only one image is seen at a time. This phenomenon is called "binocular rivalry". Researchers around Andreas Bartels at the Werner Reichardt Centre for Integrative Neurosciences (CIN) and the Max Planck Institute for in Tubingen, Germany used this phenomenon to decipher a key mechanism of the brain functions that contributes to conscious visual . ( , November 18th, 2010)

We do not consciously perceive everything around us, even if it falls into our field of vision. The overwhelming abundance of information forces our brain to focus on a few important things; our perception is an ongoing process of selecting, grouping and interpreting visual information. Even though we have two eyes, our brain combines the two impressions. Experts call this . Yet, if conflicting information is presented to the eyes, only the input to one eye is perceived at a time, while the other is suppressed. Our perception changes at specific intervals between the two images - a phenomenon called "binocular rivalry". This process occurs automatically without voluntary control.

The scientists, Natalia Zaretskaya, Axel Thielscher, Nikos Logothetis and Andreas Bartels demonstrated that the frequency at which alternations between the visual information occurred could be experimentally reduced: Two different stimuli, a house and a face, were projected into the right and left eyes, respectively, of 15 experimental subjects. Since the brain could not match the pictures, alternations in perception occurred. When the scientists temporarily applied an alternating magnetic field to the subjects’ posterior parietal cortex, a higher-order area of the brain, the perception of each individual image was prolonged.

"Our findings suggest that the parietal cortex is causally involved in selecting the information that is consciously perceived," explains Natalia Zaretskaya, a Ph.D. student involved in the project. "It also demonstrates the important role of this area in visual awareness."

"Understanding the neural circuits underlying the percepts and their switches might give us some insight into how consciousness is implemented in the , or at least into the dynamic processes underlying it", explains Andreas Bartels, scientist at the CIN.

Explore further: Mental rest and reflection boost learning, study suggests

More information: Natalia Zaretskaya, et al. Disrupting parietal function prolongs dominance durations in binocular rivalry. Current Biology (2010); doi: 10.1016/j.cub.2010.10.046

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JamesThomas
3.5 / 5 (6) Nov 19, 2010
Nice intro.

Is consciousness a thing that we can study and or find in the brain? And if we can, what is studying? What is doing the finding? What sees and is aware of consciousness? Should we be looking outwards, or inwards, or both, for the core and roots of consciousness?

Damned if I know.
TabulaMentis
1.6 / 5 (7) Nov 19, 2010
@JamesThomas

The consciousness is in the soul in a different dimension that has clung onto our atomic body like an alein form outer space!

An artifical brain maybe in a biochip could have two or more perception gates that could record events/images simultaneously all at the same time.

Advantages man and machine will fight over in the future.
ormondotvos
1 / 5 (1) Nov 19, 2010
Add noise, slow down the modem. Gee, what an insight.
otto1932
1.5 / 5 (19) Nov 19, 2010
Consciousness is an illusion to convince us that the instinct for self-preservation would be worth the effort.
tigger
3.7 / 5 (6) Nov 19, 2010
OMG some of you still think there is a magical part of the human body that has special properties that are not related to the rest of the physical world?

You probably think you have free will as well... lol, what an arrogant self centred out dated view of reality. Good luck with holding onto that view over the next twenty years as the scientific method peels the layers away.
DamienS
2.2 / 5 (5) Nov 19, 2010
You probably think you have free will as well... lol

A philosophical question that cannot ever be answered.
DamienS
3.7 / 5 (3) Nov 20, 2010
For those that think my above comment was full of crap, how exactly would you go about proving that we have free will? Because you feel yourself to have the freedom to chose between two outcomes? There's far more to this question then most people realise on a philosophical level.
rgwalther
not rated yet Nov 20, 2010
Consciousness is an illusion to convince us that the instinct for self-preservation would be worth the effort.

Illusion is consciousness convincing us that self-preservation is an instinct of effortless worth.
knikiy
not rated yet Nov 20, 2010
Maybe consciousness is a big unifying name for a lot of smaller constituent phenomena? A convenient illusion or placeholder until we are able to discern the finer details. Humans have done this in the past. Witness the four elements: earth, fire, air, water.
Yogaman
5 / 5 (3) Nov 20, 2010
As my good friend, Anjali, likes to say,

"I used to think that the brain was the most wonderful organ in my body. Then I realized who was telling me this.”
Walter_Mrak
1 / 5 (1) Nov 20, 2010
Tiger: I was expressing that notion (yours) when I was 17, in 1971. It took the Church a few hundred years to accommodate Copernicus' revelations. Even within the past few decades people believed animals had no emotions, and a hooked fish felt no pain! Anthropomorphism got me thinking consciousness may be a mobius strip-like, universally pervasive, and "no big deal" indiginous quality yet to be comprehended, but most likely resident in all our cells with the most probable actuator in our brains. I fractured my skull and had subarachnoid brain heamorrhages, a usually fatal condition, but because I knew that the white light and euphoria was induced by brain swelling and iminent death due to lack of oxyegen to the brain, I survived, where otherwise I may have accepted the preferred path to "extacy."