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Using the Human Dive Reflex to Promote Emotion Regulation and Fear Counter-Conditioning
Milton Brown, Megan Thompson, and Abigail Burt
Alliant International University
Subject 1006:
26 year-old female
Cold water = 45º F
Warm water = 95º F
Duration of immersion (M = 35 sec.)
Snake phobia
There is strong evidence for a human dive reflex.
1) Holding the breath and immersing the face in cold water leads to
bradycardia, a reduction in heart rate below resting heart rate.
2) Bradycardia is the result of increased parasympathetic activation.
Mean heart rate mean per interval
Hypotheses:
1) Eliciting the dive reflex will effectively regulate emotional arousal.
Following cold-water immersion:
1a) Heart rate will decrease
1b) Parasympathetic activity will increase
1c) Self-reported arousal will decrease
2) Eliciting the dive reflex will accelerate fear reduction during in vivo
exposure therapy.
Following cold-water immersion:
2a) Heart rate will decrease more quickly
2b) Self-reported arousal will decrease more quickly
Subject 1010:
27 year-old female
Cold water = 50º F
Warm water = 80º F
Duration of immersion (M = 24 sec.)
Spider phobia
Subject # 1006
Mean heart rate mean per interval
Participants:
■ 2 graduate student volunteers
■ Excluded if:
1) heart arrhythmia disorder
2) current psychotropic medication use
3) recent use of tobacco, caffeine, or other stimulants
Measures:
• Subjective Units of Distress Scale (SUDS) ratings were reported
before and after each water immersion
• Diagnostic Symptom Questionnaire (DSQ) was used as a self-report
method of anxiety and panic symptoms
• Heart rate (HR) and other heart data was measured continuously.
• Normalized High Frequency (100 x HF/HF+LF). Higher values
indicate increased parasympathetic influence on HR.
• Heart Rate Variability (HRV). We measured HRV during 5 minute
intervals of exposure to snake/spider (between water immersions).
• Standard Deviation of the Normal to Normal Inter-beat
Intervals (SDNN).
• Standard Deviation of Heart Rate (SDHR in beats per min).
Mean Heart Rate During Water Immersion
130
Mean Heart Rate During Water Immersion
Start of first dunk
120
110
70
100
90
• For Subject 1006, heart rate got as low as 60 bmp
• For Subject 1010, heart rate got as low as 45 bmp
60
stimulus
80
50
cold water
70
Subject 1006
Subject 1010
Start of 2nd dunk
60
19
21
23
25
27
29
31
33
35
37
39
41
43
45
47
49
40
36 38 40 42 44 46
warm water
48 50 52 54 56 58 60 62 64
10 second intervals
10 second intervals
The dunks begin at 230 and 330 seconds
The dunks begin at 460 and 560 seconds
Mean Heart Rate after Water Immersion
Mean Heart Rate after Water Immersion
130
● There was no difference in the rate of decrease of
subjective fear in the 5 minutes of exposure to the snake or
spider following cold vs. warm water immersion.
• DSQ scores were not lower following cold water.
• SUDS ratings were not lower following cold water.
● There was no difference in heart rate during the 5 minute
intervals of exposure to the snake or spider following cold
vs. warm water immersion.
90
120
80
110
70
100
90
60
stimulus
80
50
70
Subject 1010
40
60
0
4
2
8
6
12
10
16
14
20
18
24
22
28
26
32
30
34
warm water
0
36
4
2
38
8
12
6
10
16
14
20
18
24
22
28
26
32
30
36
34
40
38
42
10 second intervals
10 second intervals
The post-water period (after the second dunk) begins at 40 seconds
The post-water period (after the second dunk) begins at 30 seconds
%
30
30
The following sequence of events occurred:
20
• Heart rate variability (SDNN) was higher following cold
water immersion than following warm water.
• Normalized high frequency values were higher following
cold water immersion than following warm water.
Mean Parasympathetic Response after Water
%
● Parasympathetic responses were stronger following cold
water immersion than following warm water (during the 5
minutes intervals of exposure to the snake or spider).
cold water
Subject 1006
40
Mean Normalized High Frequency
Start of 2nd dunk
80
40
WW = face immersed in Warm Water
CW = face immersed in Cold Water
Exposure 1 = least-feared stimulus (e.g., seeing snake/spider 10 ft away)
Exposure 5 = most-feared stimulus (e.g., holding snake or spider)
• Heart rate reduced by an extra 10 beats per minute
during cold water immersion (compared to warm water).
Start of first dunk
Procedures:
The procedures comprised a ABABAB design.
Participants alternated between in vivo exposure periods and pairs of
cold water or warm water dunks.
Participants remained seated throughout the trials.
Wherein:
• Breath holding and immersion in water (cold or warm) led
to a 10-30 beats per min reduction in heart rate.
90
Mean Parasympathetic Response after Water
1. Exposure 1 (2 min), WW, WW, Exposure 1 (5 min)
2. Exposure 2 (2 min), WW, WW, Exposure 2 (5 min), CW, CW, Exposure 2 (5 min)
3. Exposure 3 (2 min), CW, CW, Exposure 3 (5 min), WW, WW, Exposure 3 (5 min)
4. Exposure 4 (2 min), WW, WW, Exposure 4 (5 min), CW, CW, Exposure 4 (5 min)
5. Exposure 5 (2 min), CW, CW, Exposure 5 (5 min)
● The dive response occurred for both participants as
evidenced by the greater decrease in heart rate during cold
water immersion.
Subject # 1010
This current study uses a ABABAB single-subject design
Method
Results
• Parasympathetic response was 50-100% stronger
following cold water immersion than following warm water
Conclusions
stimulus
20
cold water
Subject 1010
Subject 1006
10
10
0
4
2
8
6
12
10
16
14
20
18
24
22
28
26
32
30
0
36
34
warm water
38
4
2
8
6
12
10
16
14
20
18
24
22
28
26
32
30
36
34
40
38
42
10 second intervals
10 second intervals
The post-water period (after the second dunk) begins at 40 seconds
The post-water period (after the second dunk) begins at 30 seconds
Heart Rate Variability Following Immersion for Four 5-minute Exposure Periods
Subject: 1006
SdNN (ms)
Subject: 1010
SdNN (ms)
Warm Water
54
52
60
72
Warm Water
70
145
109
153
Cold Water
99
88
139
137
Cold Water
138
142
168
155
Subject 1006
SdHR (beats per minute)
Subject: 1010
SdHR (beats per minute)
Warm Water
11
10
10
11
Warm water
5
15
7
12
Cold Water
14
13
18
15
Cold water
8
19
16
15
● The human dive response is a robust finding; there is a
reliable and large decrease in heart rate when the face is
immersed in cold water.
● There are enduring increases in parasympathetic activity
following immersion of face in cold water during therapeutic
exposure to feared stimuli
• The dive response is a promising method to promote
emotion regulation.
● Further studies need to test the dive response with
psychiatric patients
Using the Human Dive Reflex to Promote Emotion Regulation Via Conditioned Bradycardia
Milton Brown, Abigail Burt, and Megan Thompson
Alliant International University
There is strong evidence for a human dive reflex.
1) Holding the breath and immersing the face in cold water leads to
bradycardia, a reduction in heart rate below resting heart rate.
2) Bradycardia is the result of increased parasympathetic activation.
This current study uses an ABABAB single-subject design with several
participants to determine if conditioned stimuli can be paired with
cold water facial immersion to later elicit (without water immersion)
conditioned bradycardia and the subjective experience of
relaxation versus an opposite rebound effect. This study has
implications for use of cue controlled bradycardia and relaxation
(based on the human dive response) as a portable emotion
regulation skill.
Method
Participants:
■ 2 graduate student volunteers
■ Excluded if:
1) heart arrhythmia disorder
2) current psychotropic medication use
3) recent use of tobacco, caffeine, or other stimulants
Assessment Instruments:
• Subjective Units of Distress Scale (SUDS) ratings were reported
before and after each water immersion
• Heart rate (HR) and heart rate variability (HRV) was measured
continuously throughout. HRV will be measured as the standard
deviation of the normal to normal inter-beat intervals (SDNN).
• Skin conductance (SC) was continuously measured throughout
participation.
Results
Subject 1003: Female, 24 years old
Cold water = 45º F
Warm water = 70º F
The sequence of blocks was:
CTB, CTB, CTB, CTB, CTB, CB, CB, CB, CB, CB, CB, CTB, CTB, CTB, CTB, CTB
Wherein blocks were:
CTB = CS-C (15 sec), 45 sec, CS-W (15 sec), 45 sec
CB = (CS-C)+(UCS-C), (CS-C)+(UCS-C), 2 min, (CS-W)+(UCS-W), (CS-W)+(UCS-W), 2 min
● Conditioned responses (CR) were observed after the
temporal pairing of cold water (UCS) and conditioned
stimuli (CS)
Subject 1009: Female, 26 years old
Cold water = 52º F
Warm water = 98º F
● Opposite anticipatory responses (heart rate increases) occurred
immediately prior to cold water immersion
In summary, the sequence of blocks was:
● Opposite parasympathetic responses (decreased
occurred when cold water CS (CS-C) were presented.
CTB, CTB, CTB, CB, CB, CB, CB, CTB, CTB, CTB
Wherein blocks were:
CTB = CS-C (30 sec), 30 sec, CS-OC (30 sec), 30sec, CC-W (30 sec), 30 sec
CB = (CS-C)+(UCS-C), CS-OC, (CS-C)+(UCS-C), CS-OC, 2 min, (CS-W)+(UCS-W), (CS-W)+(UCS-W), 2 min
Start of first dunk
Subject #1003
Subject #1009
Conditioning Phases
Conditioning Phases
Start of first dunk
Start of 2nd dunk
SSDN)
● Interoceptive, auditory, and tactile stimuli that were paired with
cold water immersion did not elicit consistent conditioned
responses.
• conditioned stimuli increased heart rate for subject #1003
• conditioned stimuli decreased heart rate for subject #1009
● Conditioned stimuli that were paired with termination of cold
water immersion did alter heart rate.
Start of 2nd dunk
Conclusions
The procedures comprised a single-subject ABABAB design.
1. Pre-Conditioning Test Phase
 Repeated conditioning test blocks (CTB), which test the
response to the conditioned stimuli (CS)
2. Conditioning Phase
 Repeated conditioning blocks (CB), with CS (CS-C) paired with
cold water (UCS-C), other CS (CS-OC) paired with termination
of cold water, and (for comparison) other CS (CS-W) paired with
“warm” water (UCS-W)
3. Post-Conditioning Test Phase
 Repeated conditioning test blocks (CTB), which test the
response to the conditioned stimuli (CS)
CS were:
● The dive response occurred for both participants as
evidenced by the greater decrease in heart rate during cold
water immersion (unconditioned response).
Subject #2003
Subject #2009
Conditioning Phase
Conditioning Phase
Subject #1003
Subject #1009
Conditioning Test Phases
Conditioning Test Phases
Before Conditioning
● The human dive response is a robust finding; there is a
reliable and large decrease in heart rate when the face is
immersed in cold water.
● Conditioning of the dive response holds promise as a
method to improve psychophysiological responses even
when no cold water is available.
• Cue controlled bradycardia and relaxation (based on the
human dive response) may be able to develop as a
portable emotion regulation skill.
Before Conditioning
● Further studies are needed to clarify the variables that
moderate the direction and magnitude of conditioning
effects.
1) imagining putting one’s face in cold water, in
warm water, or taking one’s face out of cold water
2) recorded water sounds
3) silently repeated the words “so cold,” “so warm,” or “no
more cold”
no CS
Participants remained seated throughout the trials.
CS
no CS
no CS
After Conditioning
CS
no CS
After Conditioning
● Conditioning effects may be a function of:
• The water temperature
• The nature of the conditioned stimuli
•
•
sensory modality
internal versus external
• The response channel measured
•
•
•
sympathetic responses
parasympathetic responses
subjective states of arousal
• The frequency of conditioning trials
• Sensitivity to cold or pain
no CS
CS
no CS
no CS
CS
no CS
•
•
participant #1003 reported a strong aversion to cold temperatures
Many individuals report that water below 50 degrees causes facial pain
during immersion
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