Wednesday Night Special Session
Emanuel Donchin, PhD
Distinguished University Professor
Dept of Psychology, University of South Florida
The P300BCI design invented by Farwell and Donchin (1988) is based on the Oddball Paradigm. Yet, an examination of the literature indicates that many attempts to implement a P300-based BCI tend to ignore important properties of the Oddball Paradigm.
Farwell and Donchin (1988) in the publication reporting the invention of the P300BCI emphasized the role of the Oddball Paradigm in the operation of the BCI. Specifically they asserted that “when subjects are assigned a task that requires them to determine to which of 2 possible categories each item in a series belongs, and one of the categories occurs rarely, these rare items will elicit an event-related brain potential (ERP) with an enhanced positive-going component with a latency of about 300 msec, labeled the P300. This experimental arrangement has come to be called the ‘oddball’ paradigm.” Thus, the operating principle of this BCI is the relative rarity of critical events. This, and other properties of the Oddball Paradigm, are critical to the operation of a P300 BCI as a communication device.
In this tutorial presentation I intend to review in detail the critical aspects of the Oddball Paradigm and review the data that are sometimes overlooked in recent attempted modifications of the P300 BCI design yet are critical to implementation of the Oddball Paradigm on which the P300 BCI design is based.
“Recent applications of closed-loop brain-computer interfaces”
Eberhard Fetz, PhD
Eberhard Fetz received his B.S. in physics from the Rensselaer Polytechnic Institute in 1961, and his Ph.D. in physics from the Massachusetts Institute of Technology in 1967. He came to the
University of Washington for postdoctoral work in neuroscience and has been on the faculty ever since. He is currently Professor in the Department of Physiology & Biophysics, Adjunct Professor in Bioengineering, Affiliate Professor in DXARTS and Core Staff in the Washington National Primate Research Center.
His overall research has concerned the neural control of limb movement in primates. Most recently, his lab has developed a head-fixed recurrent brain-computer interface that can record
activity of cortical cells during free behavior and convert this activity in real time to stimulationof cortex, spinal cord or muscles. This so-called “neurochip” creates a continuously operatingartificial feedback loop that the brain can learn to incorporate into behavior. A second application of the neurochip is to produce changes in the strength of synaptic connections through activity-dependent stimulation. A third application is to deliver intracranial reinforcement contingent on neural or muscular activity. The closed-loop brain-computerinterface has promise for many basic research and clinical applications.
|The BCI Meeting is organized by the BCI Society|
|Diamond Level Sponsors|
NIH Grant Award Number: R13DC015188
|NSF Award Id : 1636691|