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Oneself as a Biological Entity. I. The Heart and Its Control

Paul Grobstein's picture

This week we're beginning a set of labs on humans as biological entities ... and a set of labs in which you should use the skills and insights you've developed as a researcher in past labs to develop and carry out your own lines of investigation. We will introduce you to some techniques for observing the pulse, and make a few observations on it together. It is then your task, in groups of three, to develop an interesting inquiry using those techniques to explore the regulation of the pulse ("who's in control?" - "the difference between animate and conscious"?), carry it out, and report your study (motivation, observations, interpretations) here in the lab forum area.


LuisanaT's picture


I think the discussion about the mental and physical interpretation of emotions at the end of lab is definitely worth thinking more about. There’s an interesting oxymoron in the idea of something being mental because it is associated with the brain, a physical part of the body. To try and understand exactly what part of the body is acting upon what in order to express emotions is like figuring out who came first, the chicken or the egg. The answer seems to be indefinite and its why  I’m glad to know that there’s a future lecture/lab that is going to further explore this.

cmcgowan's picture

Wake me up! Before you go go! BEATS PER MINUTE.

We didn't have one hypothesis overall, but instead introduced different variables and created hypotheses for each.

(We did not get to do as many trials as we would have liked to, but our thumb pressure reader thing was malfunctioning. We did fix this, however.)

Rachel's regular BPM was 75.

VARIABLE ONE: Holding breath. We did two parts for each trial: one while holding breath, and one immediately after, each for 30 s. We hypothesized that while Rachel held her breath, her BPM would slow down to "ration" the oxygen she had, and immediately after exhaling her BPM would speed up to compensate.

Trial One, part one: 37 BPM

Part two: 48 BPM

This was done with the first, malfunctioning thumb pressure reader. We essentially discarded this data, but have informally reported it here.

Trial 2.1: 70 BPM

Part 2.2: Immediately after stopping holding her breath, Rachel's BPM dropped to 40, then jumped to 100 BPM, leveled off to 80

Trial 3.1: 70 BPM

Part 3.2: Initial drop to 30, then rose to 95, and leveled off at 80.

Therefore, our hypothesis was correct. We did not anticipate, however, the initial drop in BPM in part two of each trial. We believe this may be because once Rachel exhaled, she had less oxygen than even before. So, before her BPM could regularize itself, it had to "readjust."

SECOND VARIABLE: Hilarious you-tube videos.

Hypothesis: Rachel's BPM would raise while watching the videos because excitement and BPM have a positive correlation.

Rachel's BPM rose about 5 to 80 BPM. The you-tube videos did not have as much of an effect as we anticipated (we thought her laughter and the anticipation of seeing something reliably amusing would raise it further). But perhaps, because she was too familiar with them (and the pretense of the experimental setting) affected the data.


Hypothesis: Rachel's BPM would raise substantially due to the rockin' sounds of punk-rock goddess Patti Smith.

Rachel's BPM, again, rose about 5 to 80 BPM. While it did raise a bit more (about 85) during particularly loud or quick segments, this result was, like our youtube variable, not as high as we had anticipated.

FOURTH VARIABLE: Rachel's reaction to University of Florida/John Kerry tasing video.

Hypothesis: Rachel's BPM would raise a lot because this video is disturbing, sad, and troubling.

In this case, Rachel's BPM did raise substantially: off the charts, to above 100. It had small spurts, perhaps related to Rachel knowing what would happen in the video (she was familiar with the story), but still being unable to anticipate the full volatility of her reaction.

We would have liked to perform more experiments (and perhaps with more participants) if we'd had more time. It would be interesting to see differing reactions to some of these variables as, for example, Andy had never heard of Patti Smith, and perhaps other participants would not have been so upset (or more upset) by the tasing video.


Andy, Caitlin, and Rachel

Shanika's picture

Shanika, Sharhea, LaKesha

IN this lab we look at different factors that affected our heart rate. We did exercises, we watched funny shows, and we listened to soft music.


Initial Heart Rate (BPM)

After Exercising












Initial (Finger) Pressure (mV)

After Exercising












Initial Heart Rate (BPM)

While Watching Comedy Shows/ Listening to Music*












Initial (Finger) Pressure (mV)

While Watching Comedy Shows/ Listening to Music*











In conclusion we found that when performing exercises our heart rates increased. This can be because when our heart beats were at rest our blood was flowing at a steady pace, when we did the exercises our heart pumped faster causing the blood to go through our body faster. Even though the heart beat increased only one of our blood pressure increased. We thought that whenever the heart beat increases the pressure would two.

LuisanaT's picture

Back to the heart! (part 2)

Luisana, Eri, Katie


Everyday activities have different effects on the heart. Things that woud be enjoyed would lead to a slower heart rate. Things that would cause discomfort or need additional energy to perofrm would cause the heart to undergo a faster heart rate.


Watching something that causes tension or experiencing physical exertion definitely shows signs of accelerated heart rates. Something that evokes endearment makes one more relaxed and allows them to function with a slower heart rate.


LuisanaT's picture

Back to the Heart (PART I)

Luisana, Katie, and Eri

Observation: (PART I)

- Luisana: Avg. 75 BPM with range of mV: -20 to 40 mV (Resting Rate)

Avg. 96 BPM with range of mV: -15 to 20 mV (Jogging in Place 1 min.)

Avg. 60 BPM with range of mV: -10 to 25 mV (Relaxing on Table 1 min.)

Avg. 72 BPM with range of mV: 0 to 15 mV (Watching video of kittens for 1 min.)

Avg. 65 BPM with range of mV: 0 to 20 mV (Staring at the wall for 1 min.)

- Katie: Avg. 92 BPM with range of mV: -3 to 7 mV (Resting Rate)

First 20 seconds: avg. 120 PM with 0 to 10 mV; after 20 sec. to 1 min.: decreases to range of 85 to 108 BPM with range of mV: 0 to 10 mV (Jogging in Place for 1 min.)

Holding Breath (15 sec.) --> Observation after that time:

While holding breath for 15 seconds: Heart rate gradually dropped (87-112 BPM) with mV rate of 40 to 20 mV (The longer the breath was held, the more it went down) ; After holding breath from 15 sec. to 1 min: Spiked to 120 and dropped to resting rate (92 BPM) with -10 to 40 mV

Avg. 85 BPM with range of mV: -10 to 25 mV (Relaxing on table for 1 min.)

- Eri: avg. 75 BPM with range of mV: -1 to 5 mV (Resting Rate)

Avg. 108 BPM with range of mV: 50 to 60 mV (There were many drops from 130 mV down to gradual resting rate of 75 BPM.) (Jogging in Place for 1 min.)

Avg. 90 BPM with range of mV: -15 to 50 mV (Relaxing on Table for 1 min.)

Avg. 70 BPM (sudden depressions for some periods of time to 20 BPM) with range of mV: -5 to 20 mV (Watching Coverage of Hurricane Katrina for 1 min. )

Avg. 70 BPM (range of 40 to 75 BPM) with range of mV: 0 to 15 mV (Watching Video of Kittens for 1 min.)

kcough's picture

The effect of different activites on Heart Rate

Kaitlin Cough, Elizabeth Harnett

We first thought of different activities that would effect our heart rate, and we came up with: Jumping Jacks, Sitting down, Lying down on the table, talking, listening to classical music, holding our breath and watching something funny on Youtube. We decided that each of us would do one minute trial for each type of actitivity. First we measured our resting heart rate so that we could compare it to the other activities.

Kaitlin's resting heart rate: between 68 and 75 (heart rate), 0-25 (pressure)

Elizabeth' resting heart rate: around 80 (heart rate), 0-20 (pressure)

We had some ideas about heart rate before we started the lab. First, we believed that the fluctuation of the alititude was directly correlated to the heart rate: the higher the heart rate, the higher the altitude of the wave. We thought that every pump of the heart made the graph go up (the dialostic pressure). We also noticed with the resting heart rate that when you take a deep breath your heart rate shoots up as does the pressure because of the influx of oxygen.

Here are some of our trials:

Lying on table for one minute:

Kaitlin: 60-70 (heart rate), 0-15 (pressure)

Elizabeth: 70 (heart rate) 0-5 (pressure)

Talking to each other for one minute:

Kaitlin: When talking normally between 70-80 heart rate, 0-20 pressure

Elizabeth: 70-80 for the steady heart rate, but was also erratic; heart rate directly correlated to subject, Pressure: average between 0-25; dips from -50-25


Found that depending on subjects we were talking about (crew! devils!) heart rate drops dramatically (20 beats)

Directly correlated between pressure and heart rate

Perhaps related to diastolic/systolic pressure buildup/release?

Listening to Classical Music for one minute:

Kaitlin: 65 heart rate, with really low periods and some jumps, 0-5 pressure

Elizabeth: 80 heart rate, pretty balanced, 0-25 pressure

Holding Breath for one minute (or tried to):

Kaitlin: heart rate fluctuates from 0 to 400, on average around, pressure went up to around 200 when heart rate was high, went heart rate was 0 pressure was -10 to 25

Elizabeth: heart rate was very steady, around 100BPM, while pressure was also steady: around 11.4

RETRY: Kaitlin, still erratic but balanced a little more around 100, pressure -5-20

Watching something funny on Youtube for one minute:

Elizabeth: very erratic, no real average, up with laughs? Pressure -50 to 25

Kaitlin: when not laughing very low, 20 BPM, but when laughing goes all the way up to 1000?

Jumping Jacks (Jumping Jacks for a minute, record for a minute):

Elizabeth: in spurts of very high and very low, from 20-140BPM, starts to level off a bit toward the end; Pressure very high at first, begins to level off to -20-15

Kaitlin: spurts as well, 20-150 BPM, pressure very erratic -50-100

We found out that your heart rate directly effects your pressure, physical and stressful activities make your heart rate and pressure go up, whereas more relaxing things such as sitting and resting keep your heart rate down.

Our idea: We think that each wave is a beat, so when you take a breath your heart beat is faster and that's what makes the wave fluctuate.

ekim's picture

on heart rate.

Vivian Cruz, Saskia Guerrier, Eurie Kim

For this lab, we explored what affected heart rate. We first got the resting heart rate and compared that to the effects of eating candy and listening to music or watching scary movie trailers.

Resting. 70-80 BPM
Scary movie + Candy. 63-90 BPM

Resting. 60-70 BPM
Candy. 69-92 BPM
Music (Foreign). 57-81 BPM
Music (English). 64-100 BPM
Scary movie. 37-100(+) BPM

Resting. 80-90 BPM
Candy. 90s BPM
Music. 76-89 BPM

Our Story
From looking at the different observations, our resting heart rates had a wavy pattern that could have corresponded to our breathing patterns. These patterns were affected by chemical, physical, and emotional stimulation. For instance, the physical process of eating generally steadied the wavy pattern, but the sugar in the candy highered the heart rate. Music also generally heightened the heart rate as well; maybe because our senses were at work and we were feeling the beat. The scary movie clips drastically made the heart rate fluctuate probably because of the shock factor and of breath-holding from anticipation and fright.

kharmon's picture

Effects of Stimulation on Pulse

We hypothesized that audio stimulation would cause the least increase in heart rate, mental stimulaton would cause more, and physical stimulation would cause the most. While testing each, we intensified the stimulation, getting gradually louder, or more difficult, or more demanding. We tested this hypothesis on 2 subjects. Subject 1's results are in pink. Subject 2's results are in purple.


Soft Music 73 +/- 2 57 +/- 2

Medium Music 73 +/- 2 63 +/- 4

Loud Music 73 +/- 2 70 +/- 2

Easy Math 71 +/- 3 60 +/- 3

Medium Math 72 +/- 1 64 +/- 3

Hard Math 72 +/- 1 70 +/- 5

Sitting Still 73 +/- 3 57 +/- 4

Bouncing 75 +/- 2 71 +/- 1

Criss Crossing 85 +/- 2 85 +/- 3


Summarizing our observations for subject 2, we can see that different levels of stimulation do affect heart rate. In concordance with our hypothesis, there was an increase in heart rate the most for physical and the least for audio (at least for subject 2). In the case of subject 1, there was a similar pattern, however we believe that the presence of a heart murmor may have affected her heart rate readings. Though she did increase heart rate with intensity for most of the trials, she had incredibly varying numbers and great fluctuation that was obviously impacting her average.

These findings cause us to believe that there is a connection between your pulse and your brain. We would like to do more tests to stimulate the brain and record pulse findings such as "thinking about your heart rate", visual stimulation, and stimulation of the taste buds.

Kendra's picture

The Beating Heart

In today's lab, we had to utilize different outside variables to observe what affect they had on the heart, more specifically, the heart rate. We didn't have a set hypothesis, but we did have a number of variables that we wanted to test to see if they affected heart rate. The variables that Ashley and I used were different types of music such as rap, reggaeton, classical and rock. We also used other variable like clenching the fist, holding of the breath, listening to a baby cry and being startled by clapping. Here are the results we gathered:

Kendra's Results
  Resting Reggaeton
Rock Music
Holding Breath
Chan. 1 Mean(mV)
Chan. 2 Mean (BPM)
Chan 2. Stan. Deviation (BPM)

Ashley's Results

  Resting Holding Breath
Baby Crying
Chan. 1 Mean(mV)
Chan 2. Mean (BPM)
Chan 2. Stan. Deviation (BPM)


The outside variables definitely motivated our observations. We observed that Ashley's BPM were pretty constant throughout the reaction to the variables while Kendra's changed in some manner with each variable. We wonder if these changes have anything to do with personality? or how easily frightened someone gets? Would the results vary if we tested a larger group of people. We conclude that outside variables definitely affect ones heart rate, and the question is, why??

Ruth Goodlaxson's picture

This lab was an

This lab was an investigation of the human pulse. Who or what controls this pulse, and why does it fluctuate? To answer these questions, we measured the beats per minute of our own pulse under different conditions and in response to different stimuli.

We selected list of test conditions based on elements we thought might influence fluctuation, such as stress or thought. We compared these to our resting heart rates, which are as follows:

Samar the Beautiful: 73.96 BPM

Ruth the Not Lame: 71 BPM

Catrina the Supuhstar: 83.48 BPM


This is what we observed........

Embarassing Questions (Ruth): 99.14 BPM

Pushing on a Vein (Catrina): 59 BPM

Breath Holding (Samar): 89.67 BPM

Heavy Breathing (Ruth): 80.98 BPM

Arithmetic (Ruth): 78.67 BPM

Puzzle (Samar): 78 BPM

Tickling (Ruth): off the charts, couldn't register


Our observations suggest that outside stimuli definitely effect heart rate and pulse. Embarassing questions caused a huge leap in heart rate, probably due to a combination of embarassment and laughter. Working on a puzzle, however, did not seem to have a noticable effect on the rate of pulse. Strong emotions and physical responses seem to warrant a higher rate of pulse, but thinking hard like in arithmetic and puzzles didn't.

One new question raised was what makes certain stimuli more "upsetting" than others. There must be something internally that determines what effects pulse, and we need to make observations about the human body to determine what this is. For example, why were the questions asked embarassing? Also, we know laughter effects pulse, so we have to figure out what makes someone laugh.

PS2007's picture

Heart Rate Lab

Our motivation for this lab was trying to figure out what factors influence heart rate. We chose to test factors that we knew had a phyical or emotional affect.

To try to control our heart rate we tried many different things. These included talking about things that stress us, listening to beautiful and angry music, singing, laying down.

Marie's resting heart rate was 70.19. When she talked about what stressed her this increased her heart rate to 83.01. When she listened to beautiful music her heart rate decreased to 70 and when she listened to "angry" music it went up to 76.9. When she laid down it decreased again to 65 and when she sang it increased to 89.

Jen's resting heart rate was 88.06. When she talked about what stressed her out her heart rate increased to 238.25, but this measure was obviously flawed. When she listened to the beautiful music her heart rate decreased to 72 and when she listened to "angry" music it increased to 82. When she sang her heart rate increased to 90.

In conclusion, you can't predict or control what your heart rate is going to do. We did come up with some theories about the mechanism that controls heart rate. We believe that this mechanism is influenced by emotion (as evidenced by the music listening, singing and stress). Body position did not seem to influence heart rate as much, but it definitely had some influence.

It will be interesting to compare our findings with those of the other groups.