Visual search in migraine and visual discomfort groups

Abstract

Two experiments that investigate automatic and conscious attention among migraine and visual discomfort groups are reported. The prediction of a heightened sensory sensitivity producing a processing speed advantage in migraine was tested. In Experiment 1, an automatic attention task was conducted. There was no effect of migraine group, but the high visual discomfort group responded significantly more slowly than the low visual discomfort group when 16 distractors were presented. In Experiment 2, a conscious visual attention task was conducted. No processing-speed advantage was found for migraine groups. In all conditions, the high visual discomfort group performed significantly more slowly than other groups. It was concluded that heightened sensory sensitivity could not explain the processing speed advantage found previously in migraine but may explain the processing speed disadvantage found for the high visual discomfort group. Results are discussed in terms of disordered sustained attention in the high visual discomfort group.

Use of Visual Search in the Assessment of Pattern-Related Visual Stress (PRVS) and Its Alleviation by Colored Filters

“…Wright et al 55 and Tyrrell et al 54 both used a task involving multiple targets (or, more precisely, multiple instances of the same target). This is of interest because, as we shall see, they resemble the task used in the present study, which is distinctly different from the single-target task structure used by Conlon et al [45][46][47] and Singleton and Henderson. 52,53 Singleton and Henderson 52 found that visual search performance in high-VS participants was impaired only when a high-IOVS, September 2008, Vol.…”

“…53 Singleton and Henderson 52 required their subjects to locate a random three-letter target word in a matrix of three-letter distractor words in one of two configurations: visually nonstressful (10-point Arial normal font surrounded by a gray background) or stressful (10-point Arial bold font surrounded by a background of alternating horizontal black and white stripes). Singleton and Henderson, 52 in contrast to Conlon and Humphreys,47 found no difference in mean visual search response time between groups of subjects with low and high visual stress (VS) in the nonpatterned (nonstressful) task configuration. They did, however, find that introduction of the patterned (stressful) background produced a significant difference in response times between low-and high-VS groups, with the high-stress group taking longer to respond, supporting a conclusion that measurement of visual search performance provided a promising diagnostic method for identifying susceptibility to visual stress.…”

“…Here, use of the terms parallel and serial follows the widely accepted assumption that search for targets with high visual salience (that is, targets that are easily discriminated from their distractors) is performed using parallel neural processing, whereas search for low-salience targets requires focused attention to determine whether each item is a target or a distractor, and therefore it involves serial processing of search items. 50,51 Conlon and Humphreys 47 found that the high-discomfort group was significantly slower than the low-discomfort group on serial search in every set-size condition (4, 8, or 16 distractors) and also on parallel search in which there were many distractors. Performance of the two groups on parallel search was no different when there were few distractors.…”

“…Although most studies of visual performance during visual stress have concentrated on rate of reading, there is also evidence that visual search performance may be impaired in some individuals with migraine and symptoms of visual stress, [45][46][47] as well as in individuals who are slow readers. 48,49 Conlon and Humphreys 47 divided a sample of individuals into low-and high-discomfort groups, according to their results on the Visual Discomfort Scale 12 and administered two different visual search tasks; parallel search involving identification of a vertical line target in a set of tilted line distractors and serial search involving identification of a target circle with a gap in a particular orientation in a set of distractor circles having gaps in a variety of different orientations.…”

Migraine and motion sickness independently contribute to visual discomfort

“…Previous studies described a link between visual aversion and performance in visual tasks. High visual aversion, in either migraine patients or HV, is associated with worse performance on visual tasks, such as those requiring discrimination among distractors in a visual array (35,36). Overload in the magnocellular system due to increased sensitivity to pattern and light, in the high visual discomfort group, may decrease efficiency in sustained attention to the target.…”