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 Seeing on the Quick: New Insights into Active Vision in the Brain
15.08.2018 | Eberhard Karls Universität Tübingen

nachricht New Approach to Treating Chronic Itch
15.08.2018 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

Unraveling the nature of 'whistlers' from space in the lab

15.08.2018 | Physics and Astronomy

Diving robots find Antarctic winter seas exhale surprising amounts of carbon dioxide

15.08.2018 | Earth Sciences

Early opaque universe linked to galaxy scarcity

15.08.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>