Brain Indicators of Altered Attention and Information Processing in Schizophrenic Patients

Barrett, Ken; McCallum, W.C.; Pocock, P.V.

doi:10.1192/bjp.148.4.414

Cited by 60 publications

(21 citation statements)

References 18 publications

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“…There was a strong variation on its values; this could be also due to the overlapping slow wave which was not separately con sidered when integrating the P300 curve. We did not observe an influence of neuroleptics on P300 latency, a finding consistent with other studies [16,19,40] and on its duration and area. No relationship was observed between clinical ratings and P300 parameters.…”

Section: Discussionsupporting

confidence: 81%

“…We could not reproduce the findings of Blackwood et al [19] in relation to the BPRS and of Pfefferbaum et al [17] in relation to the MMS. A relationship between negative symptoms and P300, as proposed by Barrett et al [40], could also not be observed.…”

Section: Discussionmentioning

confidence: 60%

“…It does not seem to be a drug effect as it has been shown that medication does not influence P300 ampli tude [16,19,[39][40][41]. It has been proposed that the reduc tion of the P300 amplitude in schizophrenics could reflect limbic and/or frontal pathology in this disease [42].…”

Section: Discussionmentioning

confidence: 99%

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Differences between Paranoid and Nonparanoid Schizophrenic Patients on the Somatosensory P300 Event-Related Potential

Louzã

Maurer

1989

Neuropsychobiology

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Event-related potentials were recorded from schizophrenic patients (n = 30) and healthy controls (n = 30) using a somatosensory-reaction-time version of the oddball paradigm, by stimulating the right and the left median nerve. Latency, amplitude, duration and area of the P3OO were measured. The patient group was subdivided into a paranoid (n = 16) and a nonparanoid (n = 14) subgroup and each was compared to controls. After stimulation of the right median nerve the nonparanoid group had a significantly prolonged P3OO latency and a normal amplitude. The paranoid subgroup had a trend toward reduction of the P3OO amplitude; its P3OO latency was normal. After stimulation of the left median nerve, a prolongation of the P3OO latency was observed in the paranoid subgroup. This subgroup had also a reduced P3OO amplitude, while the nonparanoid patients had both values comparable to those of the controls. Duration and area were not significantly different between the two subgroups of patients and controls. Paranoid and nonparanoid patients showed a different behavior on reaction time parameters. No relationship was observed between P3OO parameters and clinical ratings, neuroleptic dose and demographic data. The P3OO parameters did not correlate with the reaction time measures. These results are discussed in terms of a disturbance of CNS inhibitory mechanisms in cognitive processes of paranoid schizophrenic patients and could be a further indication that different subtypes of schizophrenia may have different biological substrates.

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Section: Discussionsupporting

confidence: 81%

Section: Discussionmentioning

confidence: 60%

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Differences between Paranoid and Nonparanoid Schizophrenic Patients on the Somatosensory P300 Event-Related Potential

Louzã

Maurer

1989

Neuropsychobiology

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“…The notion of smaller event-related potential (ERP) amplitudes in schizophrenics compared to controls has a long tradition (Barrett, McCallum, & Pocock, 1986;Blackwood et al, 1987;McCarley et al, 1993;Roth & Cannon, 1972; see also review by Cohen, 1991). The smaller amplitudes of negative components (such as the auditory N1, the visual N1 and N2 (e. g., Bruder et al, 1999), the mismatch negativity, MMN, or the contingent negative variation, CNV) and of the P300 have been interpreted as indicating dysfunction of the cognitive processes associated with them.…”

Section: Introductionmentioning

confidence: 99%

Event-Related Potential Correlates of Acquisition and Retrieval of Verbal Associations in Schizophrenics and Controls

Baving

Rockstroh

Rössner

et al. 2000

Journal of Psychophysiology

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Reduced amplitudes of event-related potentials (ERP) have often been reported for schizophrenic patients. Positive ERPs were examined in 16 schizophrenic patients and 16 controls in a visual paired-associate learning task, in which successful learning of word pairs was evidenced by recognition of "old" versus "new" word pairs. Patients performed significantly poorer than controls. During acquisition the to-be-associated word pairs evoked a P2 and positive Slow Wave (SW) of similar amplitude in both groups. Although the recognition of items as "old" induced larger positive ERPs in controls, ERPs did not vary with recognition in patients. The presentation of the word pairs (50% old, 50% new combinations) evoked a pronounced posterior positive SW in patients but an anterior negative SW in controls. This pattern is identical to the one obtained from a previous paired-associate learning task with cue-recall and suggests that schizophrenic patients are capable of producing large amplitude positive waves under conditions different from those typical for P300 evocation in normals. The larger positive SW may indicate increased effort to compensate for deficient acquisition or association formation.

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“…P300 variability among normal subjects can be categorized in the interindividual or intraindividual variability. For the interindividual variability, the most studied and distinguished factor is the age factor [6][7][8], where the greatest variability appeared in subjects younger than 50 years of age and older than 55, but it was much smaller in subjects between 30 and 40 years of age. While the most familiar example is the intraindividual variability, the fact is that the given probability of the target stimulus manifestation can change the amplitude and latency of the P300 complex, because in the repeated recordings, the changes in the probability of the target stimulus manifestation changed the amplitude and also the latency of the P300 wave complex [5,9,10].…”

Section: Discussionmentioning

confidence: 99%

the variability in P300 cognitive evoked potential amplitude in the auditory oddball paradigm

Biševac¹,

Popović²,

Milanovic³

et al. 2015

Praxis Med

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SUMMARYOne of the best-studied responses of cognitive evoked potentials is a so-called "P300", the late positive wave complex that occurs about 300-500 ms after the stimulus. It is obtained when the subject's attention is focused on a signal that is rare, especially if the signal has a motivational or emotional meaning. In the study of P300 potential, we followed the variations of potential amplitude and latency, so the objective was to examine whether there is a difference in Fz and Cz amplitudes of auditory induced cognitive evoked P300 potential depending on the performance of oddball tasks, both in male and female subjects. The study included 60 subjects (30 female respondents and 30 male respondents). P300 potential is induced by the auditory "oddball" paradigm with 80% of non-target and 20% of target stimuli that are presented to the patient through headphones. The target tones are high tones of 2000 Hz. The standard, 1000 Hz tones the respondent should ignore but when he hears the target tones the respondent should press the button on the special handle. The value of Fz and Cz amplitudes both in male and female subjects obtained in the classical "oddball" paradigm when the subject reacted to the signal by pressing the key with the dominant (right) arm were statistically significantly lower (p>0,05) than the values of Fz and Cz amplitudes obtained when the key was pressed by the non-dominant hand. Based on this experiment it can be concluded that both in male and female subjects the performance of oddball tasks does not affect the amplitude of P300 cognitive evoked potentials.

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Brain Indicators of Altered Attention and Information Processing in Schizophrenic Patients

Cited by 60 publications

References 18 publications

Differences between Paranoid and Nonparanoid Schizophrenic Patients on the Somatosensory P300 Event-Related Potential

Differences between Paranoid and Nonparanoid Schizophrenic Patients on the Somatosensory P300 Event-Related Potential

Event-Related Potential Correlates of Acquisition and Retrieval of Verbal Associations in Schizophrenics and Controls

the variability in P300 cognitive evoked potential amplitude in the auditory oddball paradigm

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