Researching synchrony of heart rate in the therapeutic relationship in the treatment of early childhood trauma, en de possibility of improved emotion regulation through feedback of heart rate.

The heart rate of patients with (early childhood) trauma changes when they
relive their trauma's (heart rate goes up) and when they dissociate (heart rate
goes down) (Perry & Szalavitz, 2017; LeDoux, 2002; Ogden, Minton & Pain, 2006;
Porges, 2003; Van der Kolk, 1996a, 1996b). In these instances the patient can
go outside his window of tolerance, and when that happens continuing the usual
therapy session is not useful because the patient can't think, learn of process
as well as usual (Ogden et al., 2006; Ogden & Fischer, 2014, Siegel,
1999/2015). The therapist will have to switch to emotion regulation, in order
to get the patient back into his window of tolerance. Only then the usual
therapy can continue.

Another phenomenon is that the therapist 'resonates' with the patient through
his mirror neurons and his mentalizing abilities (Schippers, Roebroeck, Renken,
Nanetti & Keysers, 2010). This way, there is a synchrony between patient and
therapist. Research (see for an overview Koole & Tschacher, 2016) shows there
is more synchrony when there is a better relationship between patient and
therapist. Patient and therapist will, for example, move the same way more
often, speak at the same tone more often, and use the same vocabulary more
often, when they get along better.

Hypothetically, there is also a synchrony between patient and therapist in
terms of heart rate. When we apply this hypothesis to the treatment of early
childhood trauma, we expect that the heart rate of the therapist rises when the
patient is reliving his trauma, and the therapists heart rate drops when the
patient dissociates. This hypothesis would fit the clinical observation that
therapists sometimes get anxious when their patients relive their trauma's, en
get sleepy of emotionally absent when their patients dissociates (see for
example McWilliams, 2011).

Heart rate variability (HRV) can ben used as a measure for stress (Porges,
2011). Given the above, we expect to also find synchrony between the HRV of the
patient and the HRV of the therapist.

Synchrony in heart rate has previously been found in romantic relationships
(Helm, Sbarra en Ferrer, 2012; Ferrer en Helm, 2013; Hubler, 2013; en
McAssey,Helm, Hsieh, Sbarra en Ferrer, 2013; Weissman-Fogel en Shamay-Tsoory,
2017). Also, synchrony in HRV was found in romantic couples (Helm, Sbarra en
Ferrer, 2014). Synchrony of heart rate was also found in mother-infant
relationships (Field, 2012).

In the therapeutic relationship, no such research has been done. We expect to
find synchrony of heart rate and HRV here because both the patient and the
therapist want to form and maintain a working relationship, and the task of the
therapist is explicitly to facilitate this relationship, and to tune into the
patient. The skill to make contact with the patient, and to fix ruptures in the
relationship, is very central to the work of a therapist. One could argue that
the therapeutic relationship both has features of a romantic relationship and
of a mother-infant relationship. It has been established before that the better
someone is in empathizing with the other, and tuning in in the other (which is
the task of a therapist), the more there is synchrony (Goldstein,
Weissman-Fogel & Shamay-Tsoory, 2017; Levenson en Ruef, 1992). This brings us
to the hypothesis that there is also synchrony of heart rate and HRV in the
therapeutic relationship.

Therapists who treat patients with early childhood trauma try to keep their
patient within their window of tolerance (Ogden et. al. 2006; Siegel,
1999/2015). They have several instruments for this, like their mentalizing
abilities, their observations during the session (looking for signs of stress),
analysing the content of what their patients say, and their
counter-transference (e.g. the tension they feel as a result of working with
the patient). Oftentimes we see that patients with early childhood trauma have
difficulty registering their tension: they don't realize they are tensed, or
realize it too late, perhaps because they have limited contact with their
bodily sensations (Ogden & Fischer, 2014). Also we see that it can be difficult
for a therapist to realize the patient is tensed: sometimes the patient looks
relaxed when his heart rate is actually very high. And also, the therapist can
be too focused on the content of the session to be able to focus on signs of
tension. In other words: these instruments are limited and it might take a
while for the therapist to realize his patient is not fit to continue the
therapy session and should actually do some emotion regulation. As long as the
therapist continues therapy while his patient is above or below the window of
tolerance, the therapy probably won't do any good: the patient will not benefit
from the session because he is too stressed to process the content. Continuing
the session in the normal fashion could even be counter-productive: the patient
might associate therapy with being stressed out, and might begin to hate
therapy. This might trigger avoidance responses, like dropping out, stop
discussing important subjects, or cause crises (so the therapist will have to
discuss the crisis, instead of the trauma). So it's crucial that the patient
remains in the window of tolerance.

The current research is focussing on a potentially new instrument to monitor
the tension of patients, which is feedback of heart rate. Monitoring heart rate
during therapy sessions could make it easier to detect tension early. Early
detection of a heart rate running high or low, makes it possible to intervene
earlier, and that would keep the patient in his window of tolerance longer.

One way would be through direct feedback: the patient wears a heart rate meter,
and he (and the therapist) would be alarmed when heart rate would pass a
threshold. But given the hypothesis about synchrony, we can possibly also use
indirect feedback: the therapist would wear the heart rate meter, and we take
an elevation of his heart rate as a sign that the heart rate of the patient is
also elevated. The therapist could focus of regulating his own tension to
indirectly lower this patient*s heart rate. The same goes for a lowering of
heart rate.


A side effect of therapists monitoring their heart rate, and keeping themselves
within their window of tolerance, could also be a better self care for
therapists. Keeping patients within their window of tolerance would keep their
therapists healthier, since both high and low heart rates might be contagious.

The research questions:
1. Is there synchrony of heart rate and/or HRV between therapist and patient?
2. Will the patient remain in his window of tolerance longer when he receives
direct feedback of his heart rate?
3. Will the patient remain in his window of tolerance longer when his therapist
receives feedback of his heart rate?
4. Will the therapist remain in his window of tolerance longer when we receive
direct feedback of his heart rate?
5. Will the therapist remain in his window of tolerance longer when his patient
receives feedback of his heart rate?

Hypotheses per question:
1. Yes, there is synchrony of heart rate and HRV between patient and therapist,
and this synchrony is stronger when the therapeutic alliance is stronger.
2. Yes, the patient will remain in his window of tolerance longer when he gets
real-time feedback of his heart rate (because it makes early intervention
possible)
3. Yes, the patient will remain in his window of tolerance longer when the
therapist gets real-time feedback of his heart rate (because a better regulated
therapist will lead to a better regulated patient)
4. Yes, the therapist will remain in his window of tolerance longer when he
gets real-time feedback of his heart rate (because it makes early intervention
possible)
5. Yes, the therapist will remain in his window of tolerance longer when the
patients gets real-time feedback of this heartrate (because a better regulated
patient will also lead to a better regulated therapist)

36 patient/therapist couples will be measured one session of 30 minutes. The
session consists of three conditions, each lasting 10 minutes. During the 30
minutes the couples just do their normal therapy session. They are instructed
(even thought this is standard in therapy sessions) to do emotion regulation
exercises (like a breathing exercise, or orientation exercise) when tension is
getting too high, of too low.

Both patient and therapist are wearing a heart rate monitor during the 30
minutes. It is connected through Bluetooth with an IPad, that gives real-time
feedback of the heart rate. It also gives a little audio signal when the heart
rate exceeds a threshold value.

The three conditions (each 10 minutes):
A: Both patient and therapist don't get feedback of their heart rate.
B. Patient gets real-time feedback of his heart rate, which the therapist can
see as well. The therapist will not get feedback of his own heart rate.
C. Therapist gets real-time feedback of his heart rate, which the patient can
see as well. The patient will not get feedback of his own heart rate.

The couples will be asked to turn the IPad away from them in the conditions
where they are not supposed to receive feedback. They will be helped with a
whiteboard reminding them of the three conditions, and a bell that will ring
after 10 and 20 minutes.

Afterwards, they will fill in the Session Rating Scale (SRS), which measures
the quality of the therapeutic relationship. We expect this to be a moderator
in the synchrony between patient and therapist.

Instructions
Both therapist and patient will get to hear the theory of synchrony and the
window of tolerance before they start, and they will be told that heart rate is
a measure (albeit an imperfect measure) of tension or stress, so they can use
the feedback of their heart rate to regulate themselves. Furthermore, they are
instructed to just have their regular therapy session.

Pre-research
In order to determine the thresholds for a too high or too low heart rate, we
will do a pre-research with five therapist/patient couples. We will measure
them for 30 minutes, without giving them feedback of their heart rate. We will
use their mean heart rate and the standard deviation to determine cut-off
points.

Before a session
We will ask the participants to sit down quietly for two minutes before we
start measuring (to eliminate the effect of walking or stress on heart rate,
just before the session). In these minutes we answer questions participants
might have.
We ask the participants to not use any 'when necessary' medication, drink
coffee, smoke cigarettes, or sport intensively in the hour before the session
(because these things influence heart rate.

Instruments
Participants will wear a Polar H10 chest strap to measure heart rate and
interbeat intervals. This sensor is connected to the IPad, which registers the
data and gives real-time feedback.
Software: we use Heart Graph to provide real-time feedback, and Elite HRV to
register interbeat intervals.
After the session, we ask the participants to fill in the Session Rating Scale
(SRS), which measures the quality of the therapeutic relationship.

Analyses
We divide the techniques into the basics and the optional techniques. The
optional techniques are very time consuming and might not be possible within
the time available (but our aim is to use all of these techniques).

Basics
Research question 1:
The correlation between the heart rate of the patient and the therapist will be
calculated. We will then do a cross-validation analysis (see Liu, Shou, Palumbo
& Wang, 2016). Furthermore, we will do a regression analyses to determine if
the therapeutic relationship has a moderating effect on the correlation between
both heart rates.

Research questions 2, 3, 4 and 5:
Post-hoc we will compare (with a two tailed t-test) the mean heart rate and
standard deviation between the three conditions. If the hypotheses are correct,
we will find a lower mean heart rate, and a smaller standard deviation in
condition B en C comparing to condition A.

Optional techniques
Research question 1:
The same correlation will be calculated, but now for HRV. Again, we will do a
cross-validation analysis after. As a measure for HRV we will use the RMSSD for
blocks of 30 seconds.
We also want to use statistical techniques that can say something about
causation (the analyses above is only correlation). We want to use a
cross-lagged panel model for this (see for example Helm, Ferrer & Sbarra, 2014
en Hubler, 2013). It can provide further knowledge about the direction of the
synchrony (do couple influence each other, or is it mainly one who is dominant?)

Questions 2, 3, 4 and 5:
We will determine the HRV over conditions A, B and C. If the hypotheses are
correct, we will find a higher HRV in condition B and C, compared to condition
A.

Feedback of heart rate.

Participants will invest 45 minutes of time (30 minutes for the session, and 15
minutes for preparing and filling in the SRS). There are no big risks involved.