P300-like potential recorded from the rat frontal cortex

European Archives of Psychiatry and Clinical Neurosciences, 2004

■ Abstract The locations and time-courses of the neural generators of the event-related P300 potential have been well described using intracranial recordings. However, this invasive method is not adequate for usage in healthy volunteers or psychiatric patients and not all brain regions can be covered well with this approach. With functional MRI, a non-invasive method with high spatial resolution, most of these locations could be found again. However, the time-course of these activations can only be roughly determined with this method, even if an event-related fMRI design has been chosen. Therefore, we have now tried to analyse the time-course of the activations using EEG data providing a better time resolution. We have used Low Resolution Electromagnetic Tomography (LORETA) in the analysis of P300 data (27 electrodes) of healthy volunteers (n = 50) in the time frame 230-480 ms and found mainly the same activations that have been described using intracranial recordings or fMRI, i. e. the inferior patrietal lobe/temporo-parietal junction (TPJ), the supplementary motor cortex (SMA) and the anterior cingulate cortex (ACC), the superior temporal gyrus (STG), the insula and the dorsolateral prefrontal cortex. In these selected regions, an analysis of the activation time-courses has been performed.

Electroencephalography and Clinical Neurophysiology, 1986

Bipolar and referential responses correlated to the surface P300 auditory potential complex (components N2, P3 and N4) were studied in different subcortical structures of parkinsonian and epileptic patients with implanted electrodes used as an electrophysiological procedure for surgical treatment.

Neuroscience Letters, 1998

Effects of the spontaneous slow cortical potential (SCP) shifts of the electroencephalogram (EEG) on the P300 response were investigated on ten healthy volunteers. P300 responses were recorded using an auditory oddball paradigm, where target stimuli were presented regularly after every four standard stimuli. Single event-related potential (ERP) sweeps exhibiting negative or positive SCP shifts were averaged separately. The P300 amplitude was significantly larger during negative SCP shifts. Furthermore, the topographies of P200 and P300 waves obtained during negative and positive SCP shifts showed significant differences. The results indicate that the SCP shifts in single ERP sweeps, which are considered to be correlated with the arousal or basic activity level of the cortex, explain at least part of the inter-trial variability of P300 response.

Annals of the New York Academy of Sciences, 1984

The present paper combines a review of event-related potentials (ERPs) with empirical data concerning the question: what are the differences between auditory evoked potentials (EPs) and two types of ERPs with respect to the ir frequency components? In this study auditory EPs were elicited by 1500 Hz tones. The first type of ERPs was responses to 3rd attended ton es in an omitted stimulus paradigm where every 4th stimulus was omitted. The second type of ERPs was resporıses to ra re 1600 Hz tones in an oddball paradigrn. The amplitudes of delta and theta components of EPs and ERPs showed significant differences: in responses to 3rd attended tones there was a significant increase in the theta frequency barıd (frorıtal and parietal locations; 0-250 rns), In the delta frequency band there was no significant change. In contrast a diffuse delta increase occurred in oddball responses and an additional prolongatiorı of theta oscillatİons was observed (Iate theta response: 250-500 rns). These results are discussed in the context of ERPs as İnduced rhythmicities. The intracranial sources of ERPs, their psychological correlates and the role of theta rhythms in the cortico-hippocampal interaction are reviewed. From these results and from the literature a working hypothesis is derived assuming that delta responses are mainly involved in signal matching, decision making and surprise, whereas theta responses are more related to focused attention and signal detection. The P300 response obtained by means of the oddball paradigm has been use d successfully for psychological research and elinical diagnostics. 'Since the earlier app!ications the re have been several excellent reviews concerning methodological, psychological and elinical aspects of this paradigm (see HilIyard and Picton, 1979; John-\

Schizophrenia Research, 2005

One of the strongest correlations found between clinical symptoms and a biological index is that between the severity of positive symptoms of schizophrenia and the amplitude of the event-related potential (ERP) in the time window of the P300 deflection at left temporal scalp sites. The functional significance of the ERP component at stake is yet unknown. The present study aims at addressing this issue by testing whether or not the correlation a) is found in both the auditory and the visual modality, b) is restricted to the time window of the P300 deflection, and c) is stable over time. 12 patients suffering from schizophrenia were recorded 6 times at two month intervals in two oddball protocols, an auditory and a visual one. The correlation between the scores for the thought disturbance cluster of the PANSS (a cluster including most positive symptoms, i.e., conceptual disorganization, unusual thought content, grandiosity and hallucinations) and the P300 amplitude at left temporal sites was found 1) to occur only in the auditory modality, which, together with the late timing of the component, constrains its functional significance, 2) to appear in a time window adjacent to that of the P300 including at additional electrode sites, which would have to be confirmed by further studies, 3) to vanish along with the repetition of the recording sessions, which suggests that it is related to a processing difficulty that disappears with training. D

academia , 2023

Roh Kudus (RK) bukan hanya konsep abstrak atau kekuatan yang jauh. RK adalah pribadi Tritunggal Mahakudus yang hidup dan aktif, bekerja di dalam dan melalui kita untuk mencapai hal yang mustahil. Hari ini, kita akan menelusuri bagaimana Roh Kudus membuat segalanya menjadi mungkin dalam hidup kita.

International Conference of Design Research Society (DRS)

Ideally, designers move past existing ideas to create novel designs. But designers often experience “fixation,” where new ideas are similar to existing designs. An example concept in a brief, or early attachment to one’s initial ideas, can limit the range of designs considered. This research study explored the use of “Design Heuristics,” to overcome fixation in a design education setting. Design Heuristics are a set of prompts intended to point designers toward different types of concepts. The 77 prompts are derived from empirical studies of designers, and have been shown to be effective in developing design capability. In the study, novice engineering design students first used brainstorming, and continued to generate more ideas using Design Heuristics. The results showed that ideas created during brainstorming were more similar to initial ideas. Concepts created with Design Heuristics were judged less similar and more creative. This suggests fixation on initial examples can be mitigated by using tools like Design Heuristics during design, which contributes to how educators can help students develop ideation skills.