Model
Digital Document
Publisher
Florida Atlantic University
Description
Sokolov's (1963) hypothesis of selective extinction of the
orienting response accounts for the phenomenon of dishabituation by a
discrepancy between immediate sensory input and a stored template of a
habituated stimulus. The "oddball" stimulus procedure often used to
elicit the P300 evoked potential waveform bears resemblance to a
habituation-dishabituation paradigm. In the present experiment
subjects were habituated to a 70 dB tone burst which was then occasionally
replaced by 50, 60, 80 or 90 dB stimuli. According to a selective
extinction model of the P300, equal absolute amounts of stimulus change
should evoke equal amplitude waveforms. While the decreased intensity
stimuli did evoke a P300, the largest P300s were associated with an
intensity increase. The N200 component was seen to be largest with
intensity decrease. It is suggested that the N200 is the evoked
potential correlate of discrepancy detection which can be obscured by
an intensity-driven P300.
orienting response accounts for the phenomenon of dishabituation by a
discrepancy between immediate sensory input and a stored template of a
habituated stimulus. The "oddball" stimulus procedure often used to
elicit the P300 evoked potential waveform bears resemblance to a
habituation-dishabituation paradigm. In the present experiment
subjects were habituated to a 70 dB tone burst which was then occasionally
replaced by 50, 60, 80 or 90 dB stimuli. According to a selective
extinction model of the P300, equal absolute amounts of stimulus change
should evoke equal amplitude waveforms. While the decreased intensity
stimuli did evoke a P300, the largest P300s were associated with an
intensity increase. The N200 component was seen to be largest with
intensity decrease. It is suggested that the N200 is the evoked
potential correlate of discrepancy detection which can be obscured by
an intensity-driven P300.
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