Eye Movements Reveal Reading Impairments in Schizophrenia

A study of eye movements in schizophrenia patients provides new evidence of impaired reading fluency in individuals with the mental illness.

The findings, by researchers at McGill University in Montreal, could open avenues to earlier detection and intervention for people with the illness.

While schizophrenia patients are known to have abnormalities in language and in eye movements, until recently reading ability was believed to be unaffected. That is because most previous studies examined reading in schizophrenia using single-word reading tests, the McGill researchers conclude. Such tests aren't sensitive to problems in reading fluency, which is affected by the context in which words appear and by eye movements that shift attention from one word to the next.

The McGill study, led by Ph.D. candidate Veronica Whitford and psychology professors Debra Titone and Gillian A. O'Driscoll, monitored how people move their eyes as they read simple sentences. The results, which were first published online last year, appear in the February issue of the Journal of Experimental Psychology: General.

eye movement measures provide clear and objective indicators of how hard people are working as they read. For example, when struggling with a difficult sentence, people generally make smaller eye movements, spend more time looking at each word, and spend more time re-reading words. They also have more difficulty attending to upcoming words, so they plan their eye movements less efficiently.

The McGill study, which involved 20 schizophrenia outpatients and 16 non-psychiatric participants, showed that reading patterns in people with schizophrenia differed in several important ways from healthy participants matched for gender, age, and family social status. People with schizophrenia read more slowly, generated smaller eye movements, spent more time processing individual words, and spent more time re-reading. In addition, people with schizophrenia were less efficient at processing upcoming words to facilitate reading.

The researchers evaluated factors that could contribute to the problems in reading fluency among the schizophrenia outpatients -- specifically, their ability to parse words into sound components and their ability to skillfully control eye movements in non-reading contexts. Both factors were found to contribute to the reading deficits.

"Our findings suggest that measures of reading difficulty, combined with other information such as family history, may help detect people in the early stages of schizophrenia -- and thereby enable earlier intervention," Whitford says.

Moreover, fluent reading is a crucial life skill, and in people with schizophrenia, there is a strong relationship between reading skill and the extent to which they can function independently, the researchers note. "Improving reading through intervention in people with schizophrenia may be important to improving their ability to function in society," Titone adds.


Article republished from http://www.sciencedaily.com/releases/2013/02/130219121451.htm

DHA, prevented age-related vision loss

An omega-3 fatty acid found in fish, known as DHA, prevented age-related vision loss in lab tests, according to recent medical research from the University of Alberta.

Yves Sauvé, a researcher in the Faculty of Medicine & Dentistry, and his team discovered that lab models fed DHA did not accumulate a toxic molecule at the back of the eyes. The toxin normally builds up in the retina with age and causes vision loss.

"This discovery could result in a very broad therapeutic use," says Sauvé, whose work was recently published in the peer-reviewed journalInvestigative Ophthalmology & Visual Science.

"In normal aging, this toxin increases twofold as we age. But in lab tests, there was no increase in this toxin whatsoever. This has never been demonstrated before -- that supplementing the diet with DHA could make this kind of difference."

The team recently started another study, looking at people who have age-related macular degeneration, a condition that results in loss of central vision and is the main cause of blindness in people over the age of 50. The researchers will look for DNA markers in the blood of study participants. The team wants to determine whether participants with certain genetic markers will respond better to increasing amounts of DHA in their diet, and if so, why.

Sauvé is a researcher in the departments of ophthalmology and physiology at the U of A.

Various organizations funded the research; the primary funder was the Canadian Institutes of Health Research.

ScienceDaily (May 30, 2012) — 

Story Source:

The above story is reprinted from materials provided byUniversity of Alberta Faculty of Medicine & Dentistry. The original article was written by Raquel Maurier.