p300 potentials
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2021 ◽  
Author(s):  
Julianne Blignaut ◽  
Dawie van den Heever

This study investigated the hypothesis that neural markers associated with arbitrary decision-making are present in higher order, deliberate decisions. Furthermore, the study aimed to investigate the effect of higher order decision content on neurophysiological markers such as the readiness potential and the P300 potential. An experiment was designed to measure, evaluate, and compare these electroencephalographic potentials under both arbitrary and deliberate choice conditions. Participants were presented with legal cases and had to convict and acquit criminal offenders. Distinct readiness potentials and P300 potentials were observed for both arbitrary and deliberate decisions across all participants. These findings support the hypothesis that the readiness potential and the P300 potential are present in the neurophysiological data for higher order deliberate decisions. The study also showed initial findings of how the readiness potential may inherently relate to decision content. Increased readiness potential amplitudes were observed for participants with previous exposure to violent crime when they had to acquit or convict criminals accused of violent crimes.


Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Xin Wei ◽  
Xiaoli Ni ◽  
Junye Liu ◽  
Haiyang Lang ◽  
Rui Zhao ◽  
...  

The integration of event-related potential (ERP) and functional magnetic resonance imaging (fMRI) helps to obtain and study neural networks with high temporal and spatial resolution. EEG/fMRI data proves that in the visual tristimulus oddball paradigm, two P300 potentials (P3a and P3b) induced by target stimulation and novel stimulation are detected at the frontal-middle (Fz), center (Cz), and mid-apical (Pz) electrodes. Previous studies have shown that P3a and P3b have different spatial distributions of brain activation, but it is unclear whether they have the same neural mechanism. The purpose of this study is to determine the neuropsychological mechanisms of P3a and P3b, as well as the spatiotemporal differences in neurodynamics between the two ERP subcomponents. In a group of 25 subjects, P300 ERP induced by target stimulation and novel stimulation can be detected at the Fz, Cz, and Pz electrodes. At Cz and Fz, compared with P3b related to the target stimulus, the P3a related to the novel stimulus has a higher amplitude and the waveform declines more slowly. But at Pz, P3b has a higher amplitude than P3a. P3a appeared earlier than P3b at Cz and Fz, but the opposite phenomenon was observed at the Pz electrode. The activated brain regions of P3a included the left frontal-parietal lobe region, left anterior wedge lobe region, and right insula, while the target-driven P3b was significantly associated with BOLD changes in the bilateral fusiform gyrus, the left frontal region, and the bilateral insula. The results showed that the integration of the spatial and temporal information of the two imaging modes, namely, ERP and fMRI, proves the existence of the different brain function processes of the two P300 subcomponents. Through the analysis of the composition of P300, the results further proved that the top-down and bottom-up processing processes have played a role in the occurrence of attention capture. It is just that the modulation effects of the two processing mechanisms are different in different tasks. Therefore, it should be noted that the captured neural mechanism is not a single top-down or bottom-up processing process but should be the result of the interaction between the two.


2020 ◽  
Author(s):  
Slawomir Kroczka ◽  
Konrad Stepien ◽  
Szymon Skoczen

Abstract Background: Modern treatment protocols in childhood acute lymphoblastic leukemia (ALL) resulted in high cure rate and improved long-term survival. However, due to their high intensity, they are also associated with many side effects, including central nervous system toxicity. The aim of our study was to evaluate the use of screening of subclinical P300 event-related potentials changes in childhood ALL survivors. Methods: A group of 136 patients, 66 males (48.5%), aged 4.9 to 27.9 years who have completed ALL therapy, were screened for subclinical P300 potentials changes. ALL therapy was conducted according to modified New York (NY) (30 patients) and subsequent revisions of modified Berlin-Frankfurt-Münster (BFM): previous BFM protocols (pBFM) (32 patients) and BFM95 (74 patients). The control group consisted of 58 patients, 34 males (58.6%), aged 6 to 17 years after a syncope episode (n=29) as well as healthy subjects (n=29). Results: The total group of ALL survivors had significantly prolonged the mean latency of P300 (331.31±28.71 vs 298.14±38.76 ms, P<0.001) and reaction time (439.51±119.86 vs 380.11±79.94 ms, P=0.002) compared to the control group. Abnormalities in endogenous evoked potentials were observed in 10 (33.33%) NY, 5 (15.63%) pBFM and 21 (28.38%) BFM95 patients. The mean latency time was significantly longer compared to the control group in all analyzed protocols and the highest values were observed in pBFM patients (NY: 329.13±28.07 ms, P=0.001; pBFM: 332.97±23.97 ms, P<0.001; BFM95: 331.47±31.05 ms, P<0.001). The reaction time was similarly prolonged compared to the control group. The largest and also significant prolongation was recorded in the NY group (461.8±140.3 vs 380.1±78.04 ms, P=0.039). Analyzing the effect of radiotherapy on P300 potentials, a significantly higher frequency of prolonged reaction time in non-irradiated BFM95 patients was found (21.62 vs 15.85%, P=0.007). Radiotherapy methods used in NY and pBFM protocols have also significantly reduced the P300 wave amplitude (mean values: 10.395±5.727 vs 12.739±6.508 ms, P=0.027). Conclusions: Endogenous P300 event-related potentials may be useful in screening assessment of late subclinical cognitive changes in ALL survivors. The type of treatment protocol significantly modulates the individual parameters of the registered P300 potentials.


2020 ◽  
Author(s):  
Slawomir Kroczka ◽  
Konrad Stepien ◽  
Szymon Skoczen

Abstract BackgroundModern treatment protocols in childhood acute lymphoblastic leukemia (ALL) resulted in high cure rate and improved long-term survival. However, due to their high intensity, they are also associated with many side effects, including central nervous system toxicity. The aim of our study was to evaluate the use of P300 event-related potentials in screening of cognitive impairment in childhood ALL survivors.MethodsA group of 136 patients, 66 males (48.5%), aged 4.9 to 27.9 years who have completed ALL therapy, were screened for cognitive impairment with endogenous P300 potentials. ALL therapy was conducted according to modified New York (NY) (30 patients) and subsequent revisions of modified Berlin-Frankfurt-Münster (BFM): previous BFM protocols (pBFM) (32 patients) and BFM95 (74 patients). The control group consisted of 58 patients, 34 males (58.6%), aged 6 to 17 years after a syncope episode (n = 29) as well as healthy subjects (n = 29).ResultsThe total group of ALL survivors had significantly prolonged the mean latency of P300 (331.31 vs 298.14 ms, P < 0.001) and reaction time (439.51 vs 380.11 ms, P = 0.002) compared to the control group. Abnormalities in endogenous evoked potentials were observed in 10 (33.33%) NY, 5 (15.63%) pBFM and 21 (28.38%) BFM95 patients. The mean latency time was significantly longer compared to the control group (298.14 ms) in all analyzed protocols and the highest values were observed in pBFM patients (NY: 329.13 ms, P = 0.001; pBFM: 332.97 ms, P < 0.001; BFM95: 331.47 ms, P < 0.001). The reaction time was similarly prolonged compared to the control group. The largest and also significant prolongation was recorded in the NY group (461.8 vs 380.1 ms, P = 0.039).Analyzing the effect of radiotherapy on P300 potentials, a significantly higher frequency of prolonged reaction time in non-irradiated BFM95 patients was found (21.62 vs 15.85%, P=0.007). Radiotherapy methods used in NY and pBFM protocols have also significantly reduced the P300 wave amplitude (mean values: 10.395 vs 12.739 ms, P=0.027).ConclusionsEndogenous P300 event-related potentials may be useful in screening assessment of late cognitive impairment in ALL survivors. The type of treatment protocol significantly modulates the individual parameters of the registered P300 potentials.


2016 ◽  
Vol 26 (01) ◽  
pp. 1550039 ◽  
Author(s):  
Mengfan Li ◽  
Wei Li ◽  
Huihui Zhou

Achieving recognizable visual event-related potentials plays an important role in improving the success rate in telepresence control of a humanoid robot via N200 or P300 potentials. The aim of this research is to intensively investigate ways to induce N200 potentials with obvious features by flashing robot images (images with meaningful information) and by flashing pictures containing only solid color squares (pictures with incomprehensible information). Comparative studies have shown that robot images evoke N200 potentials with recognizable negative peaks at approximately 260[Formula: see text]ms in the frontal and central areas. The negative peak amplitudes increase, on average, from [Formula: see text]V, induced by flashing the squares, to [Formula: see text]V, induced by flashing the robot images. The data analyses support that the N200 potentials induced by the robot image stimuli exhibit recognizable features. Compared with the square stimuli, the robot image stimuli increase the average accuracy rate by 9.92%, from 83.33% to 93.25%, and the average information transfer rate by 24.56[Formula: see text]bits/min, from 72.18[Formula: see text]bits/min to 96.74 bits/min, in a single repetition. This finding implies that the robot images might provide the subjects with more information to understand the visual stimuli meanings and help them more effectively concentrate on their mental activities.


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