Page 149 - Migraine, the heart and the brain

The post-ictal impact of a migraine attack on cognition
Neuropsychological testing
The tasks were constructed with E-prime software. The three following computerized different tests were administered during a 60-minute session at three different time points.
Perceptual organization (global-local) task
Perceptual organization capabilities were assessed by means of a global-local task (14). Participants were presented with hierarchically organized visual gures, in which a larger (global) letter was composed of smaller (local) letters. Letters used were H, S, and O. Stimuli could be congruent (if the local letters were identical to the global letter), incongruent (if the local letter and the global letter were different), or neutral (if a large or small O was presented).
Before the presentation of each stimulus, the participant was instructed to identify the global letter or the local letter, which always was an H or an S, and to press the respective response key on the keyboard. The letter at the to-be-ignored level could be an H, S, or O. This resulted in a total of 12 different letter combinations, which could be categorized in terms of global vs. local level (of the relevant stimulus) and congruent vs. incongruent vs. neutral relationship between the stimulus at the relevant level, and the stimulus at the irrelevant level.
One session consisted of 10 mini-blocks of 12 stimuli, presented in random order
each. The visual instruction to respond to the local or global letter was presented for
2000 ms, followed by a 1000 ms blank screen and the stimulus, which was presented
for 8000 ms or until a response was being made. Each stimulus measured 2 x 4 cm
and was seen from a distance of about 60 cm. Each global letter consisted of 44 local
letters. Reaction time and the accuracy of responses were recorded, with reaction 8 times for correct responses being the main dependent variable.
Attention task (ANT)
The Attentional Network Task developed by Fan and colleagues (15) assesses three separable attentional functions (and, presumably, the underlying neural networks): alertness, orienting, and executive control of attention. The task is a combination of a flanker task (16) and a spatial cueing task (17). In each trial, participants are facing a visual cue followed by a visual target stimulus, which they respond to by pressing a left or right keyboard button.
The target stimulus consists of a horizontal row of ve symbols, and participants are to respond to the central symbol, which is an arrowhead pointing to the left or
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