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Tuesday, May 28, 2013

Visual Processing, "Noise," and Attention in CFS/ME - What We Do and Do Not Notice

It is always gratifying when researchers use simple and quantifiable tests to confirm a "subjective" symptom of ME/CFS. (Use whichever part of that acronym you prefer.) In this case, Dr. Claire V. Hutchison, a much published researcher at the University of Leicester (GB), and Dr. Stephen Badham, a research fellow at the University of Warwick (GB), combined their interests in visual processing and cognition to come up with an elegant study designed to measure the degree to which people with CFS/ME (we'll reverse it this time) can filter visual "noise." The ability to filter environmental "noise," that is simultaneous audial or visual input from a variety of sources, is one of the most frequently mentioned symptoms of ME and CFS, and one which impairs the ability to process information. These two researchers were able to document that deficit. (See the abstract below.)

Take this test and see how well you do. (I failed. Miserably.)




Patterns of abnormal visual attention in myalgic encephalomyelitis

By C.V. Hutchinson and S.P. Badham

Abstract

Purpose: To experimentally assess visual attention difficulties commonly reported by those with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Methods:Twenty-nine ME/CFS patients and 29 controls took part in the study. Performance was assessed using the Useful Field of View (UFOV), a spatial cueing task and visual search.

Results:Patients and controls performed similarly on the processing speed subtest of the UFOV. However, patients exhibited marginally worse performance compared with controls on the divided attention subtest and significantly worse performance on the selective attention subtest. In the spatial cueing task, they were slower than controls to respond to the presence of the target, particularly when cues were invalid. They were also impaired, relative to controls, on visual search tasks.

Conclusions:We have provided experimental evidence for ME/CFS-related difficulties in directing visual attention. These findings support the subjective reports of those with ME/CFS and could represent a potential means to improve diagnosis.

Source: Optom Vis Sci. 2013 Jun;90(6):607-14. doi: 10.1097/OPX.0b013e318294c232. Hutchinson CV, Badham SP. College of Medicine, Biological Sciences and Psychology, University of Leicester, Leicester, Leicestershire; and School of Psychology, University of Warwick, Coventry, United Kingdom.