Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Watching the brain switch off ’self’

20.04.2006
Everybody has experienced a sense of "losing oneself" in an activity--whether a movie, sport, sex, or meditation. Now, researchers have caught the brain in the act of losing "self" as it shuts down introspection during a demanding sensory task.

The researchers--led by Rafael Malach and Ilan Goldberg of the Weizmann Institute of Science reporting in the April 20, 2006, issue of Neuron--say their findings show that self-related function actually shuts down during such intense sensory tasks. Thus, an "observer" function in the brain does not appear to play an active part of in the production of our vivid sensory experiences. These findings go against common models of sensory experience that assume that there is some kind of "homunculus", or observer function in the brain that "looks at" sensory brain areas. Thus the finding, they said, has significance for understanding the basic nature of consciousness and perception.

The experimental challenge that the researchers faced was to design one task that could be used to activate specifically either sensory processing or introspection brain areas. Their solution was to ask subjects to look at the same pictures or listen to the same musical phrases, but to perform two different kinds of processing on them. To explore sensory processing, the researchers asked the subjects to use buttons to classify the images as animal/non-animal, or the musical passages as trumpet/non-trumpet. And to study introspection, the researchers asked the subjects to indicate whether emotionally they felt strongly or neutrally about the image or musical passage.

During the tests, the researchers scanned the volunteers’ brains using functional magnetic resonance imaging. In this widely used technique, harmless magnetic fields and radio waves are used to scan blood flow in brain regions, which indicates activity.

The researchers found that regions of the brain activated during sensory processing or self-reflective introspection were quite distinct and segregated. Sensory processing activated the sensory cortex and related structures, while introspection activated the prefrontal cortex, they found.

Importantly, the researchers found that activity in the self-related prefrontal cortex was silenced during intense sensory processing.

As a result, wrote the researchers, "We propose that the role of self-related cortex is not in enabling perceptual awareness, but rather in allowing the individual to reflect upon sensory experiences, to judge their possible significance to the self, and, not less importantly for consciousness research, to allow the individual to report about the occurrence of his or her sensory experience to the outside world.

"To conclude, the picture that emerges from the present results is that, during intense perceptual engagement, all neuronal resources are focused on sensory cortex, and the distracting self-related cortex is inactive. Thus, the term "losing yourself" receives here a clear neuronal correlate. This theme has a tantalizing echoing in Eastern philosophies such as Zen teachings, which emphasize the need to enter into a ’mindless,’ selfless mental state to achieve a true sense of reality," they wrote.

Heidi Hardman | EurekAlert!
Further information:
http://www.neuron.org
http://www.cell.com

More articles from Life Sciences:

nachricht Molecular Force Sensors
20.09.2017 | Max-Planck-Institut für Biochemie

nachricht Foster tadpoles trigger parental instinct in poison frogs
20.09.2017 | Veterinärmedizinische Universität Wien

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

Im Focus: Silencing bacteria

HZI researchers pave the way for new agents that render hospital pathogens mute

Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Molecular Force Sensors

20.09.2017 | Life Sciences

Producing electricity during flight

20.09.2017 | Power and Electrical Engineering

Tiny lasers from a gallery of whispers

20.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>