(Press-News.org) MADISON, Wis. — It is natural to imagine that the sense of sight takes in the world as it is — simply passing on what the eyes collect from light reflected by the objects around us.
But the eyes do not work alone. What we see is a function not only of incoming visual information, but also how that information is interpreted in light of other visual experiences, and may even be influenced by language.
Words can play a powerful role in what we see, according to a study published this month by University of Wisconsin–Madison cognitive scientist and psychology professor Gary Lupyan, and Emily Ward, a Yale University graduate student, in the journal Proceedings of the National Academy of Sciences.
"Perceptual systems do the best they can with inherently ambiguous inputs by putting them in context of what we know, what we expect," Lupyan says. "Studies like this are helping us show that language is a powerful tool for shaping perceptual systems, acting as a top-down signal to perceptual processes. In the case of vision, what we consciously perceive seems to be deeply shaped by our knowledge and expectations."
And those expectations can be altered with a single word.
To show how deeply words can influence perception, Lupyan and Ward used a technique called continuous flash suppression to render a series of objects invisible for a group of volunteers.
Each person was shown a picture of a familiar object — such as a chair, a pumpkin or a kangaroo — in one eye. At the same time, their other eye saw a series of flashing, "squiggly" lines.
"Essentially, it's visual noise," Lupyan says. "Because the noise patterns are high-contrast and constantly moving, they dominate, and the input from the other eye is suppressed."
Immediately before looking at the combination of the flashing lines and suppressed object, the study participants heard one of three things: the word for the suppressed object ("pumpkin," when the object was a pumpkin), the word for a different object ("kangaroo," when the object was actually a pumpkin), or just static.
Then researchers asked the participants to indicate whether they saw something or not. When the word they heard matched the object that was being wiped out by the visual noise, the subjects were more likely to report that they did indeed see something than in cases where the wrong word or no word at all was paired with the image.
"Hearing the word for the object that was being suppressed boosted that object into their vision," Lupyan says.
And hearing an unmatched word actually hurt study subjects' chances of seeing an object.
"With the label, you're expecting pumpkin-shaped things," Lupyan says. "When you get a visual input consistent with that expectation, it boosts it into perception. When you get an incorrect label, it further suppresses that."
Experiments have shown that continuous flash suppression interrupts sight so thoroughly that there are no signals in the brain to suggest the invisible objects are perceived, even implicitly.
"Unless they can tell us they saw it, there's nothing to suggest the brain was taking it in at all," Lupyan says. "If language affects performance on a test like this, it indicates that language is influencing vision at a pretty early stage. It's getting really deep into the visual system."
The study demonstrates a deeper connection between language and simple sensory perception than previously thought, and one that makes Lupyan wonder about the extent of language's power. The influence of language may extend to other senses as well.
"A lot of previous work has focused on vision, and we have neglected to examine the role of knowledge and expectations on other modalities, especially smell and taste," Lupyan says. "What I want to see is whether we can really alter threshold abilities," he says. "Does expecting a particular taste for example, allow you to detect a substance at a lower concentration?"
If you're drinking a glass of milk, but thinking about orange juice, he says, that may change the way you experience the milk.
"There's no point in figuring out what some objective taste is," Lupyan says. "What's important is whether the milk is spoiled or not. If you expect it to be orange juice, and it tastes like orange juice, it's fine. But if you expected it to be milk, you'd think something was wrong."
###
—Chris Barncard, 608-890-0465, barncard@wisc.edu
END
Tree growth is measured to understand tree health, fluxes in carbon sequestration, and other forest ecosystem functions. It is one of the most essential and widely collected woody plant traits. Yet, the traditional method to measure tree growth is awkward and time consuming. Scientists have developed a new, resourceful way to take repeated tree growth measurements safely and accurately.
Dendrometer bands are metal straps that wrap around a tree trunk to measure its growth. Bands are fashioned by bending banding material into a "collar" and passing the metal strap through ...
Dartmouth researchers have developed a molecular switch that changes a liquid crystal's readout color based on a chemical input. This new development may open the way for using liquid crystals in detecting harmful gases, pathogens, explosives and other chemical substances.
The findings appear in the journal Angewandte Chemie. A PDF of the study is available on request.
One of the challenges in the field of molecular switches and machines is the translation of molecular level motion into macroscopic level events by harnessing light or chemical energy -- think of a molecular-sized ...
Human activities are changing the water chemistry of many streams and rivers in the Eastern U.S., with consequences for water supplies and aquatic life, so reports a new study in the journal Environmental Science and Technology.
In the first survey of its kind, researchers looked at long-term alkalinity trends in 97 streams and rivers from Florida to New Hampshire. Sites ranged from small headwater streams to some of the nation's largest rivers. Over the past 25 to 60 years, two-thirds have become significantly more alkaline.
Alkalinity is a measure of water's ability ...
New York, NY – Researchers at Columbia University, in collaboration with biologists in Baylor College of Medicine, have made a significant step in understanding and imaging protein synthesis, pinpointing exactly where and when cells produce new proteins. Assistant Professor Wei Min's team developed a new technique to produce high-resolution imaging of newly synthesized proteins inside living cells. The findings were published in the July 9th issue of The Proceedings of the National Academy of Sciences (Volume 110; Issue 28).
Proteins carry out almost every crucial biological ...
LA JOLLA, CA—August 26, 2013—Scientists at The Scripps Research Institute (TSRI) have found a way to apply a powerful new DNA-editing technology more broadly than ever before.
"This is one of the hottest tools in biology, and we've now found a way to target it to any DNA sequence," said Carlos F. Barbas III, the Janet and Keith Kellogg II Chair in Molecular Biology and Professor in the Department of Chemistry at TSRI.
The breakthrough concerns a set of designer DNA-binding proteins called TALEs, which biologists increasingly use to turn on, turn off, delete, insert ...
SASKATOON -- When Francis Crick and James Watson discovered the double helical structure of deoxyribonucleic acid (DNA) in 1953, it began a genetic revolution to map, study, and sequence the building blocks of living organisms.
DNA encodes the genetic material passed on from generation to generation. For the information encoded in the DNA to be made into the proteins and enzymes necessary for life, ribonucleic acid (RNA), single-stranded genetic material found in the ribosomes of cells, serve as intermediary. Although usually single-stranded, some RNA sequences were ...
Each year, millions of people in the United States get a tuberculosis skin test to see if they have the infection that still affects one third of the world's population. But the standard diagnostic test is difficult to give, because a hypodermic needle must be inserted at a precise angle and depth in the arm to successfully check for tuberculosis.
Now, a team led by University of Washington engineers has created a patch with tiny, biodegradable needles that can penetrate the skin and precisely deliver a tuberculosis test. The researchers published their results online ...
This news release is available in French. The nature of the teenage brain makes users of cannabis amongst this population particularly at risk of developing addictive behaviors and suffering other long-term negative effects, according to researchers at the University of Montreal and New York's Icahn School of Medicine at Mount Sinai.
"Of the illicit drugs, cannabis is most used by teenagers since it is perceived by many to be of little harm. This perception has led to a growing number of states approving its legalization and increased accessibility. Most of the debates ...
HIV-infected people who carry a gene for a specific protein face a 20-fold greater risk of contracting cryptococcal disease, according to a study published in mBio®, the online open-access journal of the American Society for Microbiology.
Cryptococcus neoformans is the most common cause of fungal meningitis among HIV-infected individuals. While the disease is a risk for everyone with HIV who has a very low level of CD4+ T cells, researchers have discovered that those with the gene for the protein FCGR3A 158V have an immune cell receptor that binds tightly to antibody-bound ...
August 27, 2013
Nyon, Switzerland
An influential report published in the journal 'Osteoporosis International', recommends 13 best practice standards in the implementation of coordinator-based fracture liaison services (FLS). The report, 'Capture the Fracture: A Best Practice Framework and Global Campaign to Break the Fragility Fracture Cycle' (1), has been been shaped by input from leaders of established Fracture Liaison Services throughout the world and endorsed by the International Osteoporosis Foundation.
Coordinator-based FLS centre around a coordinator, often ...
