Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Attention and Awareness Uncoupled

25.11.2011
Brain imaging experiments uncouple two apparently intimately connected mental processes

In everyday life, attention and awareness appear tightly interwoven. Attending to the scissors on the right side of your desk, you become aware of their attributes, for example the red handles. Vice versa, the red handles could attract your attention to the scissors.

However, a number of behavioural observations have recently led scientists to postulate that attention and awareness are fundamentally different processes and not necessarily connected. In the study now published in the journal Science, scientists of the Max Planck Institute for Biological Cybernetics in cooperation with Japanese colleagues provide the first experimental evidence that the primary visual cortex, the entrance stage to cortical visual processing, is modulated only by attention and not by awareness. This finding supports the hypothesis that attention and awareness differentially affect nerve cells.

Functional magnetic resonance imaging measures the neural activity of the brain based on the blood oxygen level dependent (BOLD) signal. Masataka Watanabe, a visiting scholar from University of Tokyo, and Yusuke Murayama in the department of Nikos Logothetis at the Max Planck Institute for Biological Cybernetics in Tübingen, Germany in cooperation with Kang Cheng, Keiji Tanaka and others of RIKEN Brain Science Institute had a closer look at the BOLD signal from the primary visual cortex. “We knew from previous experiments that visual awareness can occur without attention, and attention without awareness,” says Masataka Watanabe. “But it was a real challenge to design experiments that can reliably record BOLD activity while reproducing the rather unnatural two laboratory conditions.”

The scientists managed this by experiments with participants in a two-by-two factorial design: The visual target “visible” versus “invisible” and attention “to” versus “away” from the target. Cleverly designed composite images shown at high frequency intervals to one eye allowed a target presented in the same or the other eye to be either visible or invisible, respectively, whether or not the subject directed their attention to it. “It was important not to depend on the participant to report the visibility of the target,” explains Masataka Watanabe, since the task of reporting would itself direct attention towards the target.

The results of the experiments astonished even the scientists. “I, myself, was surprised by the finding, it shifted my mind a little,” says Masataka Watanabe. Paying attention to the target almost doubled the BOLD activity in the visual cortex, while sheer visibility of the target had almost no effect. “Here the BOLD signal is not modulated by awareness,” the scientist summarizes the results.

The outcome of these experiments may even hold implications for philosophy and psychology: So far, many scientists hold a holistic view about awareness being part of all other areas of the brain and being inseparably interwoven with other mental processes. That is because previous studies without independently controlling attention have shown robust awareness modulation in the BOLD signal of the primary visual cortex. According to the new results, these findings have to be put into question. But Masataka Watanabe cautions: “The experiment is one of a kind, showing differences in modulation between awareness and attention in the primary visual cortex, hence supporting the idea that neural activity corresponding to attention and awareness are, if not more, partially dissociated. The results need to be followed up by other types of stimuli, measurement methods, species, etc., with independent manipulation of attention and awareness.” In further experiments he wants to explore at exactly which level the hierarchical visual system starts to be modulated by awareness.

gro-pr | Research asia research news
Further information:
http://www.riken.jp
http://www.researchsea.com

More articles from Life Sciences:

nachricht BigH1 -- The key histone for male fertility
14.12.2017 | Institute for Research in Biomedicine (IRB Barcelona)

nachricht Guardians of the Gate
14.12.2017 | Max-Planck-Institut für Biochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Plasmonic biosensors enable development of new easy-to-use health tests

14.12.2017 | Health and Medicine

New type of smart windows use liquid to switch from clear to reflective

14.12.2017 | Physics and Astronomy

BigH1 -- The key histone for male fertility

14.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>