Oddball paradigm
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The oddball paradigm is an experimental design used within psychology research. Presentations of sequences of repetitive stimuli are infrequently interrupted by a deviant stimulus. The reaction of the participant to this "oddball" stimulus is recorded.
Use in ERP research
The oddball method was first used in event-related potential (ERP) research by Nancy Squires, Kenneth Squires and Steven Hillyard at the UC San Diego.[1]
In ERP research it has been found that an event-related potential across the parieto-central area of the skull that usually occurs around 300 ms after stimuli presentation called P300 is larger after the target stimulus. The P300 wave only occurs if the subject is actively engaged in the task of detecting the targets. Its amplitude varies with the improbability of the targets. Its latency varies with the difficulty of discriminating the target stimulus from the standard stimuli.[2]
Other uses
The oddball paradigm has been extended to use outside of ERP research.
The oddball paradigm has robust effects on pupil dilation, although scientists are unsure of the reason underlying this effect.[3]
The perception of time seems to be modulated by our recent experiences. Humans typically overestimate the perceived duration of the initial event in a stream of identical events. Initial studies suggested that this oddball-induced “subjective time dilation” expanded the perceived duration of oddball stimuli by 30–50% but subsequent research has reported more modest expansion of around 10% or less, and the direction of the effect, whether the viewer perceives an increase or a decrease in duration, also seems to be dependent upon the stimulus used.[4]
References
- ^ Squires NK, Squires KC, Hillyard SA. (1975) Two varieties of long-latency positive waves evoked by unpredictable auditory stimuli in man. Electroencephalogr Clin Neurophysiol. 38(4):387-401. PMID 46819
- ^ Picton, W. T. (1992). The P300 wave of the human event-related potential. Journal of Clinical Neurophysiology , 456-479. doi: 1464675
- ^ G.A. Book, M.C. Stevens, G. Pearlson, K.A. Kiehl - Fusion of fMRI and the Pupil Response During an Auditory Oddball Task - Accepted to the 2008 Conference of the Cognitive Neuroscience Society.
- ^ Aaen-Stockdale C, Hotchkiss J, Heron J, Whitaker D (June 2011). "Perceived time is spatial frequency dependent". Vision Research. 51 (11): 1232–8. doi:10.1016/j.visres.2011.03.019. PMC 3121949. PMID 21477613.