Physiology Lessons
for use with the
Biopac Student Lab
Richard Pflanzer, Ph.D.
Associate Professor Emeritus
Indiana University School of Medicine
Purdue University School of Science
J.C. Uyehara, Ph.D.
Biologist
BIOPAC Systems, Inc.
William McMullen
Vice President
BIOPAC Systems, Inc.
BIOPAC® Systems, Inc.
42 Aero Camino, Goleta, CA 93117
(805) 685-0066, Fax (805) 685-0067
info@biopac.com
www.biopac.com
Manual Revision 3.7.6
09092009
 BIOPAC Systems, Inc.
Lesson 3
ELECTROENCEPHALOGRAPHY I
EEG I
Relaxation and Brain Rhythms
Alpha, beta, delta, and theta rhythms
Page 4
II.
Biopac Student Lab 3.7.6
EXPERIMENTAL OBJECTIVES
1) To record an EEG from an awake, resting subject with eyes open and eyes closed.
2) To identify and examine alpha, beta, delta, and theta components of the EEG complex.
III.
MATERIALS

BIOPAC electrode lead set (SS2LA/L)

BIOPAC disposable vinyl electrodes (EL503), 3 electrodes per subject

BIOPAC electrode gel (GEL1) and abrasive pad (ELPAD) or Skin cleanser or alcohol prep

Lycra® swim cap (such as Speedo® brand) or supportive wrap (such as 3M Coban™ Self-adhering Support Wrap)
to press electrodes against head for improved contact

Cot or lab table and pillow

Biopac Student Lab System: software BSL 3.7.5 or above
data acquisition unit MP36, MP35, MP30 (Windows only), or MP45
Computer system

IV.
Experimental Methods

A.
For further explanation, use the online support options under the Help Menu.
SETUP
FAST TRACK
DETAILED EXPLANATION
1.
Turn the computer ON.
 The desktop should appear on the monitor. If it does not appear, ask the
2.
Make sure the BIOPAC MP3X unit is
turned OFF.
laboratory instructor for assistance.
3.
Plug the equipment in as follows:
Plugs into Channel 1
Electrode lead (SS2LA/L)—CH 1
4.
Turn ON the BIOPAC MP3X unit.
SS2LA/L Electrode Lead Set
Fig. 3.2 MP3X (top) and MP45 (bottom)0 equipment connections
Setup continues….
Lesson 3: EEG I
5.
Page 5
Position electrodes on the scalp.
Fig. 3.3 shows a sample configuration.
RED Lead
IMPORTANT
Electrode adhesion to the scalp
is crucial for obtaining a
meaningful EEG recording.
 If it is easier, you can
attach the BLACK lead
(ground) to the neck
instead of to the ear
lobe.
WHITE Lead
BLACK Lead
(Ground)
Fig. 3.3
 Guidelines for electrode placement:
a)
The placement of the scalp electrodes can vary (within limits)
depending on your instructor’s or Subject’s preference.
b) Keep the electrodes on one side (right or left) of the head.
c) The third electrode is the ground electrode and is connected to the
earlobe or neck. The adhesive collar is larger than the earlobe but it can
be folded under the ear.
Hints for obtaining optimal data:
a) As much as possible, move the hair away from the electrode adhesion
area. Otherwise the hair will pull the electrodes up, away from the scalp.
b) Apply pressure to the electrodes for about 1 minute after the initial
placement.
c) Subject should remain still. Blinking and other movement will affect
the recording of all four rhythms.
d) Despite your best efforts, electrode adhesion may not be strong enough
to record data; try another Subject or different electrode placement.
6.
Attach the electrode leads to the
electrodes, following the color code in
Fig. 3.3.
The pinch connectors work like a small clothespin, but only latch onto the
nipple of the electrode from one side of the connector. Drape the electrode
cables over the head so that they are not pulling on the electrodes.
7.
Place supportive cap/wrap on Subject’s
head to press electrodes against the scalp
with constant pressure.
Place a Lycra® swim cap or supportive wrap on Subject’s head to press the
electrodes against the scalp with a constant pressure. Subject should not hold
electrodes against scalp.
8.
Ask Subject to lie down and relax with
eyes closed for approximately 5 minutes
before recording.
A supine position with the head resting comfortably but tilted to one side is
recommended. Ideally, the room should be reasonably quiet to help Subject
mentally relax. This 5-minute period is also important to give the electrodes
time to establish contact with the surface of the skin.
9.
Start the Biopac Student Lab Program.

10. Choose “L03” and click OK.
Lesson L03 is Electroencephalography (EEG) I.
11. Type in your filename and click OK.
Use a unique identifier.
12. Optional: Set Preferences.
 Choose File > Preferences.
 Select an option.
 Select the desired setting and click
OK.
END OF SETUP
This ends the default setup.
This lesson has optional Preferences for data and display while recording. Per
your Lab Instructor’s guidelines, you may set:
Grids: show or hide gridlines
Journal Text: show minimum guiding text vs. detailed text
Recording Length: allow from 30 seconds to 30 minutes of data
Page 6
B.
Biopac Student Lab 3.7.6
CALIBRATION
Calibration establishes the hardware’s internal parameters (such as gain, offset, and scaling) and is critical for optimum
performance. Pay close attention to Calibration.
FAST TRACK Calibration
DETAILED EXPLANATION OF CALIBRATION STEPS
1.
Ensure that electrodes and electrode
Subject remains relaxed with eyes closed during Calibration. The best
leads are properly placed and that Subject recordings occur when Subject is relaxed for the entire recording.
is supine and relaxed.
2.
Click Calibrate.
The Calibrate button is in the upper left corner of the program screen.
3.
Check connections and click OK.
A prompt will be generated, requesting that you check the electrode
attachments one last time. Click OK to begin Calibration. The Biopac Student
Lab will begin recording data and use it to calculate optimal settings for the
Subject. Calibration will stop automatically after 8 seconds.
Calibration continues….
4.
Check the calibration data.
 If similar, proceed to the Data
Recording section.
 If different, click Redo Calibration.
At the end of the 8sec calibration
recording, the screen
should resemble Fig.
3.4.
Figure 3.4
There should be zero baseline (a relatively flat line) as in Fig. 3.4.
END OF CALIBRATION
C.
RECORDING DATA
FAST TRACK
1.
If the data shows any large spikes, click Redo Calibration and repeat the
entire calibration sequence.
Prepare for the recording.
DETAILED EXPLANATION
You will record the “raw EEG” while Subject is relaxed with eyes closed, eyes
opened, and eyes closed again. After recording the EEG signal, the software will
extract four brain rhythms: alpha, beta, delta, and theta.
In order to work efficiently, read this entire section before starting to record.
Hints for obtaining optimal data:
a) Good electrode contact is essential to minimize “noise” and increase signal
amplitude.
b) Subject should be supine and keep muscles still, especially facial muscles.
c) During the “eyes open” segment, Subject should not blink.
d) Subject should try relaxation techniques, such as concentrating on
breathing slowly or relaxing muscles.
2.
Click Record.
When you click Record, the recording will
begin and an append marker labeled “EEG
with changing eye conditions” will
automatically be inserted. You may edit the
marker label after acquisition.
TIP In this lesson, Display > Autoscale
Waveforms and Autoscale Horizontal
are enabled DURING recording.
Recording continues…
Lesson 3: EEG I
3.
Page 7
Director should instruct Subject to
remain relaxed but change eye condition,
and Recorder should insert event
markers when condition changes.
Director and Subject:
Time
Seconds 0-20
Seconds 21-40
Seconds 41-60
Recorder
Eye Condition
eyes closed
eyes open
eyes closed
 “eyes open” 21 secs. — press F4
 “eyes closed” at 41 secs. — press F5
The EEG will be recorded on CH 1. The recording should last about 60 seconds.
The Director should tell Subject to change the eye condition for 20-second
intervals, and the Recorder should insert an event marker at each change.
Recorder should press F4 when eyes are opened and F5 when eyes are closed to
insert pre-labeled markers.
First 20 seconds (secs. 0-20)
Subject should be relaxed, with eyes closed for the first 20 seconds.
Next 20 seconds (secs. 21-40)
Director should tell Subject to open the eyes and try not to blink for the
next 20 seconds.
Recorder presses F4 to insert a marker labeled “eyes open.”
After another 20 seconds (secs. 41-60)
Director should tell Subject to close his/her eyes for the next 20 seconds.
Recorder presses F5 to insert a marker labeled “eyes closed.”
 Labels can also be entered manually (F9 on Windows, Esc on Mac) or
edited after data is recorded.
4.
Click Suspend.
5.
Review the data on the screen

If similar to Fig.3.5, go to
Step 6.

If different click Redo.
 CH 1 EEG
CH 40 alpha
CH 41 beta
CH 42 delta
CH 43 theta
(Frequency band channels
are hidden during
Fig. 3.5
recording.)
Data should show a decrease in amplitude during the “eyes open” segment.
Amplitude change may be more obvious in the alpha band (CH 40) than in the
unfiltered EEG band (CH 1); to show/hide channels to review specific bands,
Windows: Ctrl-click the channel box, Mac: Option-click the channel box.
If data looks similar to Fig. 3.5, proceed to Step 6.
You should consider redoing the recording if data shows
 large drifts in baseline (poor electrode adhesion)
 large spikes (indicating Subject may have blinked or moved)
 no change (indicating electrodes may not have been properly attached to
the skin or the recording procedure may not have been properly
followed)
To redo the recording and record the “raw EEG” again, click Redo and then
click Yes, then click Resume and repeat Steps 3-5; the data you have previously
recorded will be erased.
6.
Click Done.
7.
Click Yes.
8.
Remove electrodes.
END OF RECORDING
When you click Yes, the program will compute and display the specific
frequency bands behind the dialog with close options. Make your choice, and
continue as directed (you will review the bands in the Analysis section).
If choosing the “Record from another Subject” option:
a) Attach electrodes per Setup Steps 5-8 and continue the entire lesson
from Setup Step 11.
b) Each person will need to use a unique file name.
Remove the electrode cable pinch connectors. Peel off and discard the
electrodes; BIOPAC electrodes are not reusable. Wash the electrode gel residue
from the skin, using soap and water. The electrodes may leave a slight ring on
the skin for a few hours, which is quite normal.
Page 8
IV.
Biopac Student Lab 3.7.6
DATA ANALYSIS
FAST TRACK
1.
DETAILED EXPLANATION
Enter the Review Saved Data mode.
Enter the Review Saved Data mode from the Lessons menu. 
 Note Channel Number (CH)
designations.
Channel Displays
CH 1
EEG (unfiltered, hidden)
CH 40
alpha
CH 41
beta
CH 42
delta
CH 43
theta
The data window should be similar to Fig. 3.6 (in the Recording section).
 Note measurement box settings:
Channel Measurement
CH 40
Stddev
CH 41
Stddev
CH 42
Stddev
CH 43
Stddev
SC
Freq
Rhythm
Alpha
Beta
Delta
Theta
Frequency (Hz)
8-13
13-30
1-5
4-8
Amplitude (µV)
~20-200
~5-10
~20-200
~10
The measurement boxes are above the marker region in the data window. Each
measurement has three sections: channel number, measurement type, and result.
The first two sections are pull-down menus that are activated when you click
them.

Stddev: standard deviation is a measure of the variability of data points. The
data represent amplitudes of the brain rhythms. The advantage of the stddev
measurement is that extreme values or artifacts do not unduly influence the
measurement.
Freq: converts the time segment of the selected area to frequency in
cycles/sec. It will not calculate the correct frequency if the selected area
contains more than one cycle.
Note The Freq measurement applies to all channels since it is
calculated from the horizontal time scale.
The “selected area” is the area selected by the I-Beam tool (including endpoints).
2.
Set up your display window for optimal
viewing of channels 40-43.
To hide a channel, click the channel box while holding down the “Ctrl” (control)
key on Windows or the “Option” key on Mac. This will toggle between hiding
and showing the channel’s data.
The following tools help you adjust the data window: 
Display menu: Autoscale horizontal Autoscale waveforms, Zoom Previous
Scroll Bars: Time (Horizontal); Amplitude (Vertical)
Cursor Tools: Zoom Tool
Buttons: Overlap, Split, Show Grid, Hide Grid
Data Analysis continues…
Lesson 3: EEG I
3.
Use the I-Beam cursor to select the area
of “eyes closed” data from Time 0 to the
first event marker.
Page 9
This is the data from the append marker at Time 0 to the first event marker when
Subject’s eyes were first closed. (See Fig. 3.7.)
A
Fig. 3.7
4.
Repeat Step 3 using “eyes open” data.
A
5.
Repeat Step 3 using “eyes re-closed”
data.
This is the data between the first and second event markers, when the eyes were
open.
This is the data between the second event marker and the end of the file, and
represents the time when the eyes were re-closed.
A
6.
Zoom in on a 3-4 second section of the
“eyes closed” data from Time 0 to the
first event marker.
This is the data (from the append marker at Time 0 to the first event marker)
when Subject’s eyes were first closed. Zoom in to display 3-4 seconds of data.
7.
Use the I-beam cursor to select an area
that represents one cycle in the alpha
wave (Fig. 3.8).
Accurate Frequency calculation requires a selected area of only one cycle.
B
Fig. 3.8 Selected area shows one cycle in the alpha wave.
8.
Repeat Step 9 for two other alpha wave
cycles.
Make sure you stay in the first recorded data (from the append marker at Time 0
to the first event marker) when Subject’s eyes were first closed.
B
9.
Repeat Steps 8-9 using the beta wave.
B
Data Analysis continues…
Click in the beta wave to make it the selected channel for “SC” measurements.
Page 10
Biopac Student Lab 3.7.6
10. Repeat Steps 8-9 using the delta wave.
Click in the delta wave to make it the selected channel for “SC” measurements.
B
11. Repeat Step 8-9 using the theta wave.
B
Click in the theta wave to make it the selected channel for “SC” measurements.
 You may save the data to another location, save notes that are in the
journal, or print the data file.
12. Save or print the data file.
13. Quit the program.
END OF DATA ANALYSIS
END OF LESSON 3
Complete the Lesson 3 Data Report that follows.
Lesson 3: EEG I
Page 11
ELECTROENCEPHALOGRAPHY I
EEG I
DATA REPORT
Student’s Name:
Lab Section:
Date:
I.
Data and Calculations
Subject Profile
Name
Height
Gender:
Age
A.
Male / Female
Weight
EEG Amplitude Measurements
Complete Table 3.2 with Standard Deviation measurements:
Table 3.2 Standard Deviation [Stddev]
Rhythm
CH Measurement
Eyes Closed
Eyes Open
Eyes Re-closed
Alpha
Beta
Delta
Theta
B.
EEG Frequency Measurements
Complete Table 3.3 with the frequencies for each rhythm and calculate the mean frequency. Freq measurement applies
to all channels since it is calculated from the horizontal time scale, but you must select the correct area in each band.
Table 3.3 Frequency (Hz)
Rhythm
CH Measurement
Cycle 1
Cycle 2
Alpha
Beta
Delta
Theta
II.
Questions
C. List and define two characteristics of regular, periodic waveforms.
D. Compare and contrast synchrony and alpha block.
Cycle 3
Mean
Page 12
Biopac Student Lab 3.7.6
E. Examine the alpha and beta waveforms for change between the “eyes closed” state and the “eyes open” state.
i. Does desynchronization of the alpha rhythm occur when the eyes are open?
ii. Does the beta rhythm become more pronounced in the “eyes open” state?
F. The amplitude measurements (Stddev) are indicative of how much alpha activity is occurring in Subject. But, the
amplitude values for beta do not truly reflect the amount of mental activity occurring with the eyes open. Explain.
G. Examine the delta and theta rhythm. Is there an increase in delta and theta activity when the eyes are open?
Explain your observation.
H. Define the following terms:
i.
Alpha rhythm
ii. Beta rhythm
iii. Delta rhythm
iv. Theta rhythm
End of Lesson 3 Data Report