Experience has shown that beginning physiology students are more engaged when acquiring and viewing signals from their own (or a lab partner’s) bodies in real time, particularly signals that are noninvasive to capture and easy to acquire. Watching a waveform trace across the screen and respond immediately to physical input is a sure-fire way to spark wonder and curiosity in a student. The following is a list (in no particular order) of the most common signals gathered in a beginning lab environment using the Biopac Student Lab System.
EMG is probably the top signal as far as simplicity, as the EMG signal can be consciously and directly controlled by the student, whether it be by simply making a fist to contract the forearm muscle or squeezing a hand dynamometer to measure grip strength. In addition to a raw EMG signal, a second channel showing integrated EMG can be simultaneously displayed. (Biopac Student Lab Lesson 1 and Lesson 2.)
EEG is another easy-to-acquire signal. Although not consciously controllable as EMG, the student can observe differences in the four simple periodic rhythms present in brain activity (alpha = 8-13 Hz, beta = 13-30 Hz, delta = 1-5 Hz, and theta = 4-8 Hz) while engaged in activities such as opening/closing eyes, solving simple mental math problems, or hyperventilating. (Biopac Student Lab Lesson 3 and Lesson 4.)
The ECG represents electrical events of the cardiac cycle whereas Ventricular Systole and Ventricular Diastole represent mechanical events (contraction and relaxation of cardiac muscle, passive opening and closing of intracardiac valves, etc.). Because the ECG reflects electrical activity, it is a useful “picture” of heart activity and presents several interesting components under various conditions, such as while sitting, standing, lying down, and after deep breathing or exercise. Various lead configurations highlight observable differences in the QRS complex which become apparent in analysis. (Biopac Student Lab Lessons 5, 6, and 7.)
Respiration (RSP) cycle and pulmonary function
As easy as breathing, measuring RSP signals under a variety of circumstances is another common study. Using a respiratory transducer (SS5LB) and an airflow transducer (SS11LB), we can record and analyze chest expansion and contraction during the breathing cycle, as well as pulmonary volumes/capacities and the effects of aerobic exercise. (Biopac Student Lab Lessons 8, 12, 13, and 15.)
Large and small movements of the eye can be tracked and studied under various conditions by attaching simple adhesive electrodes to the forehead and temples in conjunction with the same SS2L electrode lead set used for recording EMG and ECG signals. (Biopac Student Lab Lesson 10.)
Possibly the most fun signal to record. The participant holds a hand switch (SS10L) and pushes the button when an aural (click sound) or visual (light flash) stimulus is presented. The reaction time interval between the presentation of the stimulus and the participant’s voluntary reaction (button push) are recorded and analyzed. A variety of stimuli are presented, such as reaction to a fixed stimulus (e.g., every four seconds) opposed to a random stimulus (one to 10 seconds). Reactions are recorded holding the hand switch alternately in both the right and the left hand. It’s interesting to compare the difference in reaction time elicited from the dominant vs. non-dominant hand in response to the aural or visual stimulus. (BSL Lessons 11 and 11A.)
Other signals and studies commonly acquired in Biopac Student Lab are:
- EDA and Polygraph (Lesson 9)
- Biofeedback (Lesson 14)
- Blood Pressure (Lesson 16)
- Heart Sounds (Lesson 17)
- Spinal Cord Reflexes (Lesson 20)
We also invite you to watch a free on-demand webinar detailing Biopac Student Lab Lessons.
BIOPAC offers a wide array of wired and wireless equipment that can be used in your research. To find more information on solutions for recording and analyzing signals such as ECG, heart rate, respiration and more using any platforms mentioned in this blog post, you can visit the individual application pages on the BIOPAC website.