Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The Dual Functions of Sight – Perception and Action – Demonstrated for First Time

07.03.2006


The dissociation in the visual system between two separate functions – one that enables us to identify objects and the other to interact with them – has been clearly demonstrated for the first time in healthy humans by researchers at the Hebrew University of Jerusalem.


illustration of eye



These separate vision-related actions have been documented from the beginning of the 20th century in patients who suffered damage to the visual system as a result of illness or injuries in which one or the other function – identification or action – was damaged.

For example, persons suffering from ataxia are able to verbally identify an object presented to them but have difficulty in grasping it, while those who have agnosia can grasp an object if handed to them but are unable to name or indicate the position, size or texture of the object.


This dissociation between action and perception suggests the existence of two separate visual streams However, despite the wide research triggered by this theoretical concept, it had not been proved in subjects in whom both streams are functioning normally.

Now, through the use of functional magnetic resonance imaging (fMRI), Prof. Ehud Zohary and his graduate student Lior Shmuelof of the Department of Neurobiology at the Alexander Silberman Institute of Life Sciences at the Hebrew University have been able to demonstrate dissociation between perception of objects and actions in the brains of healthy persons. An article detailing their findings was published as the cover story in the journal Neuron.

In the article, the researchers described how they were able to observe dissociation between dorsal and ventral activation patterns in the brains of participants who were shown video scenes of objects and actions directed towards those objects.

What Shmuelof and Zohary saw in the fMRI images were that a complex in the occipito-temporal cortex area of the brain responded to the identity of an object presented on the screen, while a different complex in the parietal lobe region reacted when the subjects were shown actions directed at those objects.

The researchers point out that the areas of the brain responsible for motor action were activated when the experimental subjects were shown scenes of action, even though the subjects were in a passive state, viewing only video clips presenting actions by others, and were not involved in any way with the activities being screened.

What this suggests is that there is an interrelationship between guiding of our own actions and understanding actions taken by others – a kind of “stepping into another’s shoes” that may be one of the bases underlying social communication.

Jerry Barach | alfa
Further information:
http://www.huji.ac.il

More articles from Health and Medicine:

nachricht Study suggests possible new target for treating and preventing Alzheimer's
02.12.2016 | Oregon Health & Science University

nachricht The first analysis of Ewing's sarcoma methyloma opens doors to new treatments
01.12.2016 | IDIBELL-Bellvitge Biomedical Research Institute

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>