Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Moving the mind’s eye depends upon an intact eye movement system

04.05.2004


An important aspect of human vision is the ability to attend to objects or events appearing in our peripheral vision without shifting our gaze. This way of effectively looking out of the corner of the mind’s eye is thought to be particularly important for alerting us to danger. Researchers have made the seemingly paradoxical discovery that even though eye movement itself is actually dispensable for such an attention shift, eye muscle function is nevertheless required for this ability to reflexively redirect one’s attention. The new finding tests an important theory about brain function, and represents a remarkable example of the brain’s complex relationship with movement.



The ability to attend to objects or events that are not at the current centre of gaze (e.g., rapid movements which might signal danger) is referred to as the covert orienting of attention. This mechanism can be contrasted with the overt orienting of attention which typically involves the execution of an eye movement (saccade) intended to bring the object of interest into central vision.

In their new work, researchers Daniel Smith, Chris Rorden and Stephen Jackson of the University of Nottingham, UK, address an important question concerning the precise relationship between eye movements and the covert orienting of attention. While some have argued that covert orienting of attention and eye movements are independent of one another, other researchers have supported the so-called "premotor theory" of attention, which holds that covert attention is mediated by the same system that controls saccadic eye movements, and that a covert shift of attention is simply an unexecuted eye movement.


In a novel test of the premotor hypothesis, Smith and colleagues investigated the covert orienting of attention by a woman (AI) who, because of a congenital impairment in the development of her eye muscles (opthalmoplegia), had never been able to make an eye movement, but could read and scan the visual world by making saccadic head movements.

The researchers found that in contrast to individuals who possessed the ability to move their eyes, AI could not reflexively orient her attention in response to the appearance of a salient peripheral cue. Nevertheless she had no problem orienting her attention voluntarily in response to centrally presented direction cues (i.e., an arrow pointing left or right).

The results demonstrate that intact eye movements are necessary for the normal development of reflexive attention. They also show that, contrary to what one might expect, intact brain regions alone are not sufficient for the normal development of attention. Together the new findings provide strong support for the premotor theory of attention.


Daniel T. Smith, Chris Rorden, and Stephen R. Jackson : "Exogenous Orienting of Attention Depends upon the Ability to Execute Eye Movements"

Publishing in Current Biology, Volume 14, Number 9, May 4, 2004.

Heidi Hardman | EurekAlert!

More articles from Life Sciences:

nachricht Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University

nachricht How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>