Brainloop
 
8. Direct Brain–Computer Communication
  8.3. Components of graz BCI
  8.3.1. Parameter Estimation and Classification
    8.3.1.2. Adaptive Autoregressive Model

A classical approach for estimating time-varying AR parameter is the segmentation based approach.
In this case, the data is divided into short segments and the AR parameters are estimated from each segment. The result is a time course of the AR parameters that describes the time-varying characteristics of the process.
The segment length determines the accuracy of the estimated parameters and defines the resolution in time. The shorter the segment length, the higher is the time resolution but this has the disadvantage of an increasing error of the AR estimates.

Alternatively, the adaptive autoregressive(AAR) algorithms can perform calculation concurrent to the data acquisition, where no buffering is required.

 
8. Direct Brain–Computer Communication
  8.1. A short overview of EEG-based BCI systems
8.2. Neurophysiological considerations
  8.2.1. Dynamics of Brain Oscillations
8.2.2. Motor Imagery
8.3. Components of graz BCI
  8.3.1. Parameter Estimation and Classification
  8.3.1.1. Band Power Estimates
8.3.1.2. Adaptive Autoregressive Model
8.3.1.3. Common Spatial Patterns
8.3.1.4. Hidden Markov Model
8.3.2. Hardware–Software Requirements
  8.4. Man–Machine Learning Dilemma (MMLD)
  8.5. Visual target stimulus modifying the EEG
   

Source: Motor Imagery and Direct Brain–Computer Communication, Gert Pfurtscheller and Christa Neuper
 
 
  <back | aksioma