Event-Related Potentials: Cognition in Brain-Computer Interfaces
May 14, 2017
Organizer: João Luís Garcia Rosa
Department of Computer Science
Institute of Mathematics and Computer Sciences, University of São Paulo at São Carlos, Brazil
Abstract: In many scientific fields, a very useful way to learn about a system is to study its reaction to disturbances. In brain research, it is also a common strategy in order to see how individual neurons or large populations of neurons, as measured by electroencephalography (EEG), react to different types of stimuli. Event-related potential (ERP) is an electrical potential generated by the brain that is related to an event (usually a stimulus or a response). ERPs were originally called evoked potentials (EPs) because they were electrical potentials that were evoked by stimuli (as opposed to the spontaneous EEG rhythms). ERPs can be very useful in elucidating cognitive mechanisms and their neural substrates. Cognition depends on the functioning of the cerebral cortex. Therefore, understanding the neural basis of cognition will likely require knowledge of cortical operations at all organizational levels. The cooperative activity of the network influence the effects that are relevant for cognition. ERP components are typically identified according to their polarity (positive or negative) and their time latency following stimulus onset. ERPs can provide information about the spatial distribution of large-scale network activity underlying a cognitive function. An important ERP example is the P3 (or P300) signal observed in EEG recordings, so called because it is the third positive deflection in the EEG signal, which occurs approximately 300 ms after the stimulus. P3 is evoked by the occurrence of an unusual or unexpected stimulus. Many researchers use the P3 to study cognitive processes, such as signal comparison, recognition, decision-making, attention, and memory upgrade. Brain-computer interfaces (BCI) researchers often use ERP-based P300 spellers as an alternative channel of communication for people with severe neuro-muscular diseases. Abnormal P3 responses may reflect conditions in which cognition is impaired, as has been shown in depression, schizophrenia, dementia, and others.
Outline of the tutorial: BCI: Communication without muscles; EEG: A non-invasive procedure, Recordings, Artifacts; Stimulus-evoked activity: Response to stimuli, ERP, Analysis, ERP and cognition; Applications: P300 speller, Lie detection.
Tutorial Topic: Computational Neuroscience
Rationale: A non-invasive tool to understand brain reactions to stimuli in order to build useful computational models, like brain-computer interfaces.
Relevance for IJCNN: Brain-Computer Interfaces, brain models, and biologically inspired neural networks are subjects of interest to IJCNN audience
Disclaimer: The opinions expressed in this web page and the presentation slides are that of the organizer, not of the IJCNN conference or IEEE, or INNS, or any other entity.
Last update: March 2, 2017.