Single trial analysis of event related potentials: A comparison between schizophrenics and depressives

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      The aim of the present paper was to perform a single-trial analysis of event-related potentials in order to elucidate the mechanisms behind a reduced P300 amplitude occurring in unmedicated depressives (n = 11) and schizophrenics (n = 18). For this purpose, tools from linear system theory were applied to single trials in an oddball paradigm. This analysis provides estimates of the magnitude of the positive deflection occurring around the latency of P300, following target and nontarget simuli. According to the density functions of these amplitude distributions, we operationally defined “false-negative” (P300 amplitude lower than an individual threshold under target conditions) as well as “false-positive” responses (P300 amplitude higher than the threshold following nontarget stimuli). Our investigations revealed a reduction of the single-trial P300 amplitude in depression and a combination of amplitude reduction along with fewer elicited single-trial P300 waves in schizophrenics.

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        • Banks WP
        Signal detection theory and human memory.
        Psychol Bull. 1970; 74: 81-99
        • Basar E
        EEG Brain Dynamics Relation between EEG and Brain Evoked Potentials.
        Elsevier, New York1980
        • Basar E
        • Stampfer HC
        Important associations among EEG-dynamics, event-related potentials, short-term memory and learning.
        Int J Neurosci. 1985; 26: 161-180
        • Basar-Eroglu C
        • Basar C
        • Demiralp T
        • Schürmann M
        P300 response: Possible psychophysiological correlations in delta and theta frequency channels. A review.
        Int J Psychophysiol. 1992; 13: 161-179
        • Blackwood DHR
        • Whalley IJ
        • Christine JE
        • Blackburn I
        • Stclair DM
        • McInnes A
        Changes in auditory P3 event-related potential in schizophrenia and depression.
        Br J Psychiatry. 1987; 150: 154-160
        • Brecher M
        • Begleiter H
        Event-related potentials to high-incentive stimuli in unmediated schizophrenic patients.
        Biol Psychiatary. 1983; 18: 661-674
        • Diner BC
        • Holcomb PJ
        • Dykman RA
        P300 in Major Depressive Disorder.
        Psychiatry Res. 1985; 15: 175-184
        • Donchin E
        Surprise! … Surprise!.
        Psychophysiology. 1981; 18: 493-513
        • Donchin E
        • Coles MGH
        Is the P300 component a manifestation of content updating?.
        Beh Brain Sci. 1988; 11: 357-374
        • Duncan-Johnson CC
        • Donchin E
        On quantifying surprise: the variations of event-related potentials with subjective probability.
        Psychophysiology. 1977; 14: 456-467
        • Duncan-Johnson CC
        • Donchin E
        The P300 component of the event-related brain potentials as an index of information processing.
        Biol Psychol. 1982; 14: 1-52
        • Fabiani M
        • Gratton G
        • Karis D
        • Donchin E
        The definition, identification, and reliability of measurement of the P300 component of the event-related brain potential.
        in: Ackles PK Jennings JR Coles MGH Advances in Psychophysiology. Vol 2. JAI Press, Amsterdam1987: 1-78
        • Fabiani M
        • Karis D
        • Donchin E
        P300 and recall in an incidental memory paradigm.
        Psychophysiology. 1986; 23: 298-314
        • Ford JM
        • White P
        • Lim KO
        • Pfefferbaum A
        Schizophrenics have fewer, and smaller P300s: A single-trial analysis.
        Biol Psychiatry. 1994; 35: 96-103
        • Gangadhar BN
        • Ancy J
        • Janakiramaiah N
        • Umapathy C
        P300 amplitude in non-bipolar, melancholic depression.
        J Affect Disord. 1993; 28: 57-60
        • Giedke H
        • Thier P
        • Bolz J
        The relationship between P3 latency and reaction time in depression.
        Biol Psychol. 1981; 13: 31
        • Grillon C
        • Courchesne E
        • Ameli R
        • Geyer MA
        • Braff DL
        Increased distractibility in schizophrenic patients—electrophysiologic and behavioral evidence.
        Arch Gen Psychiatry. 1990; 47: 171-179
        • Johnson R
        A triarchic model of P300 amplitude.
        Psychophysiology. 1986; 23: 367-384
        • Karis D
        • Fabiani M
        • Donchin E
        P300 and memory: Individual differences in the von Restorff effect.
        Cognitive Psychol. 1984; 16: 177-216
        • Neville HJ
        • Kutas M
        • Chesney G
        • Schmidt AL
        Eventrelated brain potentials during initial encoding and recognition memory of congrous and incongrous words.
        J Mem Language. 1986; 25: 75-92
        • Pfefferbaum A
        • Wennegat BG
        • Ford JM
        • Roth WT
        • Kopell BS
        Clinical application of the P3 component of eventrelated potentials. II. Dementia, depression and schizophrenia.
        Electroencephalogr Clin Neurophysiol. 1984; 59: 104-124
        • Picton TW
        The P300 wave of the human event-related potential.
        J Clin Neurophysiol. 1992; 9: 456-479
        • Polich J
        P300, Probability, and Interstimulus Interval.
        Psychophysiology. 1990; 27: 396-403
        • Röschke J
        • Aldenhoff A
        Excitability and susceptibility of the brain's electrical activity during sleep: An analysis of late components of AEPs and VEPs.
        Int J Neurosci. 1991; 56: 255-272
        • Röschke J
        • Mann K
        • Wagner P
        • Grözinger M
        • Fell J
        • Frank C
        An approach to single trial analysis of event-related potentials based on signal detection theory.
        Int J Psychophysiol. 1996; (in press)
        • Roth WT
        • Horvath TB
        • Pfefferbaum A
        • Kopell BS
        Event-related potentials in schizophrenics.
        Electroencephalogr Clin Neurophysiol. 1980; 48: 127-139
        • Roth WT
        • Pfefferbaum A
        • Horvath TB
        • Barger PA
        • Kopell BS
        P3 reduction in auditory evoked potentials in schizophrenics.
        Electroencephalogr Clin Neurophysiol. 1980; 49: 497-505
        • Roth WT
        • Pfefferbaum A
        • Kelly AF
        • Berger PA
        • Kopell BS
        Auditory event-related potentials in schizophrenia and depression.
        Psychiatry Res. 1981; 4: 199-212