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A comparative study on long-term evoked auditory and visual potential responses between Schizophrenic patients and normal subjects.

Huang MW, Chou FH, Lo PY, Cheng KS - BMC Psychiatry (2011)

Bottom Line: The cognitive processing reflected by the auditory and the visual P300 latency to rare target stimuli was probably an indicator of the cognitive function in schizophrenic patients.This study shows the methodology of application of auditory and visual oddball paradigm identifies task-relevant sources of activity and allows separation of regions that have different response properties.The activation changes of visual evoked potentials are more regionally specific than auditory evoked potentials.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Biomedical Engineering, National Cheng Kung University, Tainan 701, Taiwan.

ABSTRACT

Background: The electrical signals measuring method is recommended to examine the relationship between neuronal activities and measure with the event related potentials (ERPs) during an auditory and a visual oddball paradigm between schizophrenic patients and normal subjects. The aim of this study is to discriminate the activation changes of different stimulations evoked by auditory and visual ERPs between schizophrenic patients and normal subjects.

Methods: Forty-three schizophrenic patients were selected as experimental group patients, and 40 healthy subjects with no medical history of any kind of psychiatric diseases, neurological diseases, or drug abuse, were recruited as a control group. Auditory and visual ERPs were studied with an oddball paradigm. All the data were analyzed by SPSS statistical software version 10.0.

Results: In the comparative study of auditory and visual ERPs between the schizophrenic and healthy patients, P300 amplitude at Fz, Cz, and Pz and N100, N200, and P200 latencies at Fz, Cz, and Pz were shown significantly different. The cognitive processing reflected by the auditory and the visual P300 latency to rare target stimuli was probably an indicator of the cognitive function in schizophrenic patients.

Conclusions: This study shows the methodology of application of auditory and visual oddball paradigm identifies task-relevant sources of activity and allows separation of regions that have different response properties. Our study indicates that there may be slowness of automatic cognitive processing and controlled cognitive processing of visual ERPs compared to auditory ERPs in schizophrenic patients. The activation changes of visual evoked potentials are more regionally specific than auditory evoked potentials.

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Signal processing of evoked potential responses in control and schizophrenic groups.(a) The EEG signals of behavioral performance at a task in which subjects had to identify and temporally order rapidly successive brief stimuli that in some trials. (b) Examples of evoked potential responses recorded in The Brain Atlas III Computer of the Biologic System Company. The system's versatility allows the user to record up to 4 sets of stimulus-evoked activity (including auditory ERP, visual ERP etc) and display and analyze the data in a variety of ways. The amplifier was used as follows: high filter, 30; low filter; 1.0; and gain, 20,000. (c)&(d) Averages were computed for the brain responses to target tones. Peak P300 amplitude, which accounts for individual variations in P300 latency, was measured as the most positive point from 250 to 400. Peak P400 amplitude, which accounts for individual variations in P400 latency, was measured as the most positive point from 400 to 500. The components of ERPs were identified as follows, P100, N100, P200, N200, P300, and P400. The figure 1c showed the averaged signals of evoked potentials from one normal control. The figure 1d showed the averaged signals of evoked potentials from one schizophrenic patient.
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Figure 1: Signal processing of evoked potential responses in control and schizophrenic groups.(a) The EEG signals of behavioral performance at a task in which subjects had to identify and temporally order rapidly successive brief stimuli that in some trials. (b) Examples of evoked potential responses recorded in The Brain Atlas III Computer of the Biologic System Company. The system's versatility allows the user to record up to 4 sets of stimulus-evoked activity (including auditory ERP, visual ERP etc) and display and analyze the data in a variety of ways. The amplifier was used as follows: high filter, 30; low filter; 1.0; and gain, 20,000. (c)&(d) Averages were computed for the brain responses to target tones. Peak P300 amplitude, which accounts for individual variations in P300 latency, was measured as the most positive point from 250 to 400. Peak P400 amplitude, which accounts for individual variations in P400 latency, was measured as the most positive point from 400 to 500. The components of ERPs were identified as follows, P100, N100, P200, N200, P300, and P400. The figure 1c showed the averaged signals of evoked potentials from one normal control. The figure 1d showed the averaged signals of evoked potentials from one schizophrenic patient.

Mentions: The subjects were seated comfortably in a dimly lit chamber with a portable eye-trek device (Olympus, FMD-20P) that was approximately 2 cm in front of their eyes. The visual oddball paradigm has a full-field, 1 × 1, square, black and white flashes, stimuli rate of1.3/s, bandpass of 30 and 1 Hz. The analysis time of 512 ms and sensitivity of 122.5 mV were used in visual EP testing. The latencies and the amplitudes of N100, N200, P100, P200, P300, and P400 waves were determined [19,20]. All the subjects were tested for four tasks; each task lasted approximately 5 minutes. The four tasks were labeled for auditory ERPs with counting, auditory ERPs without counting, visual ERPs with counting, and visual ERPs without counting respectively. An example showed that EEG signals of behavioral performance in a task in which subjects had to identify and temporally order rapid successive brief stimuli in some trials (Figure 1a &1b). The Figure 1c shows the average signals of evoked potentials from one normal control. The Figure 1d shows the average signals of evoked potentials from one schizophrenic patient.


A comparative study on long-term evoked auditory and visual potential responses between Schizophrenic patients and normal subjects.

Huang MW, Chou FH, Lo PY, Cheng KS - BMC Psychiatry (2011)

Signal processing of evoked potential responses in control and schizophrenic groups.(a) The EEG signals of behavioral performance at a task in which subjects had to identify and temporally order rapidly successive brief stimuli that in some trials. (b) Examples of evoked potential responses recorded in The Brain Atlas III Computer of the Biologic System Company. The system's versatility allows the user to record up to 4 sets of stimulus-evoked activity (including auditory ERP, visual ERP etc) and display and analyze the data in a variety of ways. The amplifier was used as follows: high filter, 30; low filter; 1.0; and gain, 20,000. (c)&(d) Averages were computed for the brain responses to target tones. Peak P300 amplitude, which accounts for individual variations in P300 latency, was measured as the most positive point from 250 to 400. Peak P400 amplitude, which accounts for individual variations in P400 latency, was measured as the most positive point from 400 to 500. The components of ERPs were identified as follows, P100, N100, P200, N200, P300, and P400. The figure 1c showed the averaged signals of evoked potentials from one normal control. The figure 1d showed the averaged signals of evoked potentials from one schizophrenic patient.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3113739&req=5

Figure 1: Signal processing of evoked potential responses in control and schizophrenic groups.(a) The EEG signals of behavioral performance at a task in which subjects had to identify and temporally order rapidly successive brief stimuli that in some trials. (b) Examples of evoked potential responses recorded in The Brain Atlas III Computer of the Biologic System Company. The system's versatility allows the user to record up to 4 sets of stimulus-evoked activity (including auditory ERP, visual ERP etc) and display and analyze the data in a variety of ways. The amplifier was used as follows: high filter, 30; low filter; 1.0; and gain, 20,000. (c)&(d) Averages were computed for the brain responses to target tones. Peak P300 amplitude, which accounts for individual variations in P300 latency, was measured as the most positive point from 250 to 400. Peak P400 amplitude, which accounts for individual variations in P400 latency, was measured as the most positive point from 400 to 500. The components of ERPs were identified as follows, P100, N100, P200, N200, P300, and P400. The figure 1c showed the averaged signals of evoked potentials from one normal control. The figure 1d showed the averaged signals of evoked potentials from one schizophrenic patient.
Mentions: The subjects were seated comfortably in a dimly lit chamber with a portable eye-trek device (Olympus, FMD-20P) that was approximately 2 cm in front of their eyes. The visual oddball paradigm has a full-field, 1 × 1, square, black and white flashes, stimuli rate of1.3/s, bandpass of 30 and 1 Hz. The analysis time of 512 ms and sensitivity of 122.5 mV were used in visual EP testing. The latencies and the amplitudes of N100, N200, P100, P200, P300, and P400 waves were determined [19,20]. All the subjects were tested for four tasks; each task lasted approximately 5 minutes. The four tasks were labeled for auditory ERPs with counting, auditory ERPs without counting, visual ERPs with counting, and visual ERPs without counting respectively. An example showed that EEG signals of behavioral performance in a task in which subjects had to identify and temporally order rapid successive brief stimuli in some trials (Figure 1a &1b). The Figure 1c shows the average signals of evoked potentials from one normal control. The Figure 1d shows the average signals of evoked potentials from one schizophrenic patient.

Bottom Line: The cognitive processing reflected by the auditory and the visual P300 latency to rare target stimuli was probably an indicator of the cognitive function in schizophrenic patients.This study shows the methodology of application of auditory and visual oddball paradigm identifies task-relevant sources of activity and allows separation of regions that have different response properties.The activation changes of visual evoked potentials are more regionally specific than auditory evoked potentials.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Biomedical Engineering, National Cheng Kung University, Tainan 701, Taiwan.

ABSTRACT

Background: The electrical signals measuring method is recommended to examine the relationship between neuronal activities and measure with the event related potentials (ERPs) during an auditory and a visual oddball paradigm between schizophrenic patients and normal subjects. The aim of this study is to discriminate the activation changes of different stimulations evoked by auditory and visual ERPs between schizophrenic patients and normal subjects.

Methods: Forty-three schizophrenic patients were selected as experimental group patients, and 40 healthy subjects with no medical history of any kind of psychiatric diseases, neurological diseases, or drug abuse, were recruited as a control group. Auditory and visual ERPs were studied with an oddball paradigm. All the data were analyzed by SPSS statistical software version 10.0.

Results: In the comparative study of auditory and visual ERPs between the schizophrenic and healthy patients, P300 amplitude at Fz, Cz, and Pz and N100, N200, and P200 latencies at Fz, Cz, and Pz were shown significantly different. The cognitive processing reflected by the auditory and the visual P300 latency to rare target stimuli was probably an indicator of the cognitive function in schizophrenic patients.

Conclusions: This study shows the methodology of application of auditory and visual oddball paradigm identifies task-relevant sources of activity and allows separation of regions that have different response properties. Our study indicates that there may be slowness of automatic cognitive processing and controlled cognitive processing of visual ERPs compared to auditory ERPs in schizophrenic patients. The activation changes of visual evoked potentials are more regionally specific than auditory evoked potentials.

Show MeSH
Related in: MedlinePlus