Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Great (taste) expectations: Study shows brain anticipates taste, shifts gears

23.02.2006


As the prism of our senses, the human brain has ways of refracting sensory input in defiance of reality.



This is seen, for example, in the placebo effect, when simple sugar pills or inert salves taken by unwitting subjects are seen to ease pain or have some other beneficial physiological effect. How the brain processes this faked input and prompts the body to respond is largely a mystery of neuroscience.

Now, however, scientists have begun to peel back some of the neurological secrets of this remarkable phenomenon and show how the brain can be rewired in anticipation of sensory input to respond in prescribed ways. Writing in the current issue (March 1, 2006) of the journal Brain, Behavior, and Immunity, a team of University of Wisconsin-Madison scientists reports the results of experiments that portray the brain in action as it is duped.


The new work, conducted by a team led by UW-Madison assistant professor of psychology and psychiatry Jack B. Nitschke, tested the ability of the human brain to mitigate foul taste through a ruse of anticipation. The work, conducted at the UW-Madison Waisman Center using state-of-the-art brain imaging techniques and distasteful concoctions of quinine on a cohort of college students, reveals in detail how the brain responds to a manipulation intended to mitigate an unpleasant experience.

"There is a potent impact to expectancy," says Nitschke, who, with his colleagues, exposed 43 undergraduate subjects to potions of quinine, sugar water or distilled water while undergoing magnetic resonance imaging (MRI).

The subjects, Nitschke explains, were asked beforehand to associate a prescribed set of cues with a taste. A "minus sign" flashed through fiber optic goggles to subjects undergoing MRI, for instance, was to be an anticipatory signal that a liquid subsequently dripped into the mouth would have a very bitter taste. A "zero "cue corresponded with a neutral taste, and a "plus sign" with a pleasant, sugary taste.

The cues, according to Nitschke, were flashed to subjects just prior to the administration of a few drops of liquid. But in the study, the cues would not always match the taste they were said to presage.

His group observed that when subjects were given a cue that suggested the taste they were about to experience would be less bitter, the taste was perceived as such, and the regions of the brain that code tastes were activated less.

"When the subject sees the warning signal, portions of the brain activated by the misleading cue predict the decreased brain response to the awful taste," Nitschke says. What’s more, "the (brain’s) response to the misleading cue will predict the subject’s perception of what the taste is going to be. The subject anticipates that the taste won’t be that bad, and indeed that’s what they report."

In short, the new study shows how expectancy affects how humans perceive sensory input, and how events in the brain are directly related to those perceptions.

Importantly, by mapping how the brain anticipates an event and kicks in a placebo effect, Nitschke argues, scientists can begin to think about ways that knowledge could be used in clinical settings.

For Nitschke, who also practices as a clinical psychologist specializing in the treatment of depression and anxiety disorders, the new detailed insights into the power of anticipation could lead to better treatments for such conditions.

"The placebo operates through expectancy. In this study, we’ve taken the pill out of the picture. We’re just manipulating expectancies," he says. "The results beg the question of what can we do to target anticipatory processes in our patients that might lead to better outcomes."

Jack B. Nitschke | EurekAlert!
Further information:
http://www.wisc.edu

More articles from Studies and Analyses:

nachricht Win-win strategies for climate and food security
02.10.2017 | International Institute for Applied Systems Analysis (IIASA)

nachricht The personality factor: How to foster the sharing of research data
06.09.2017 | ZBW – Leibniz-Informationszentrum Wirtschaft

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>