Hi all,
Trying to decide between block vs. event-related design. Any opinion welcome.
I am looking at ability to perform inner speech on rhyming tasks in chronic aphasia.
Each subject will be asked to determine whether the two presented words rhymed, by indicating 'YES' or 'NO' on a designated button, pushed by their left hand.
In each list of rhyming words, there are 4 with similar orthography (look the same), 16 with dissimilar orthography (rhyme but aren't spelled the same), plus 10 non-rhyming stimuli of similar and dissimilar orthography.
Expected n of study = 12-15 people
The question I have is whether to do
1. block design: 6 trials with 10 tasks/stimuli within each trial (thus, 60 total stimuli). Thus, 3 trials of baseline and 3 trials of rhyme judgement. 4 second duration for each task, 1.5 second fixation cross between tasks.
2. event-related design: 2 trials (or one trial?) with 30 (60?) tasks within the trial. Thus, the baseline and the rhyme judgment tasks would be intermingled as separate events, occurring randomly.
I'm worried with the event-related design that intermingling the baseline and the rhyme task will muddle the judgement or RT of my chronic aphasic population, as they'll have to do a lot of "switching" between the tasks.
Thoughts?
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