Cognitive Science 160

Brain Computer Interface Systems

Summer I 2003 Midterm

Practice Questions

Note: The midterm will cover all material presented in lecture through Friday, July 18, as well as all readings through week 3.

Thus, mental state BCIs and eye tracking/EMG BCIs will not be covered on the midterm.

Compared to conventional interfaces, BCIs are slow and inaccurate. Why, then, would anyone use a BCI? Provide at least

three reasons.

What was the purpose of the Suppes article in the week 1 reading? That is, what sort of mental activity did the authors try to

detect?

Briefly describe four different interfaces used in mu BCIs. You should discuss the operating environment (what the user saw

on the screen) as well as the possible outputs (what signals that the mu activity was translated to).

The BCI described in Sutter (1992) and Sutter and Tran (1992) utilized which of the following?

A. user programmable interface

B. dry electrodes

C. IR (wireless) telemetry

D. a menu based system

E. SSVER activity

F. P300s

G. A large vocabulary (relative to other BCIs)

Which of the following EEG frequencies typically falls in the range of about 8-14 Hz?

A. delta

B. theta

C. alpha

D. mu

E. beta

Wolpaw et al. (2002) lists five components of all BCIs. Name them.

A _____________ ________________ filter would remove all EEG activity above a certain frequency.

Name four factors that can affect the P300.

Below are four different types of EEG activity used in BCIs. For each, state where on the scalp this signal is typically maximum

(either with electrode site or a general description of the brain area underneath it):

Mu

P300

SSVEP

SCP

_____________ _________________ is a pattern classification approach used in Farwell and Donchin (1988). The computer

finds the most positive point in a certain range, and categorizes the ERP as attended or ignored based on the amplitude and

latency of this point.

The first study of Allison’s thesis compared the conventional single flash approach to a new means of grouping flashed characters

called the ______________ flash approach.

Three different types of noise may contaminate EEG signals of interest in a BCI: EEG noise, EXG noise,

and _________________ noise.