INNER-active Journal

MAS630- Final Project

Shaundra Bryant  <bryant@media.mit.edu>

Abstract

Emotions have a large impact on our physiology.  Often we are unaware of how emotions aroused during everyday events can affect our health.  Expressive writing is a technique used by psychologists that has been found to have profound effects on health for those involved.  However, the patient only receives information from the doctor rather than actively being involved in his or her own process of healing.  The intent in designing this system is to enable users to gain a better understanding of how emotions affect their bodies, expressive writing can improve their emotional and physical health.

Background

James Pennebaker and colleagues (1986) found that written emotional disclosure, writing about extremely upsetting experiences in one's life, has profound effects on physical and psychological health. The standard experimental design is to assign one group the task of written emotional disclosure and the other group the task of writing about superficial events such as the steps to brushing teeth.  Each group is instructed to write about the assigned topic for 15-20 minutes each day for 3-5 days. 

At the follow-up interviews, participants show fewer doctor visits, improved immune functioning, increased mood, and higher grade point averages.  The conclusion drawn is that writing about significant life events allows participants the opportunity to find meaning and increased understanding of their emotional reactions to the event. This can also result in reduced distress.  This technique has been shown to work in a variety of populations, from teenagers to grandparents.  An interesting question is why the act of writing emotions would be any better than verbalizing them.  Researchers have shown that emotional expression is not enough to produce a cognitive reappraisal that is necessary for improvements in mood and well being.  This means that individuals must have the opportunity to reappraise their cognitions related to the event and express emotions related to the event (Murray et al., 1989).  Another benefit of writing is that it is a safe space to disclose things that may produce discomfort if spoken about to others. In his book, Opening Up: the healing power of expressing emotions, Pennebaker states: 

    "When disclosing deeply personal experiences, there are immediate changes in brainwave patterns, skin conductance levels ... after confessions, significant drops in blood pressure and heart rate, as well as improvements in immune function, occur. In the weeks and months afterward, people's physical and psychological health is improved." (pg. 56)

For the purposes of the research, the skin conductivity, heart rate variability, and heart stress entropy will be the focus.  The galvanic skin response, or skin conductivity, is a change in the electrical properties of the skin.  The magnitude of the electrical resistance in the skin is affected not only by one's general mood, but also by immediate emotional reactions. Higher arousal (such as occurs with increased involvement) will almost instantaneously (0.2 - 0.5 sec) cause a fall in skin resistance; reduced arousal (such as occurs with withdrawal) will cause a rise in skin resistance. Thus a rise or fall relates directly to reactive arousal, due to re-stimulation of repressed mental conflict ("Tools," n.d.)  Research from HeartMath has shown that emotions are reflected in the heart rate variability.  The heart-brain interactions and the autonomic nervous system dynamics are sensitive to changes in emotional states ("Learning," n.d.).  Although there is no definitive, non-invasive method of directly measuring stress, heart rate variability (HRV), which is calculated from the EKG, can be used as an indicator.  HRV is a form of sinus arrhythmia that directly reflects bodily functions, and is typically measured from the power spectrum of the inter-beat intervals (IBIs).  This usually involves windowing the ECG, detecting the beats and computing the IBIs.  From this, the spectrogram of the time series of the IBI's is computed and divided into low-, mid-, and high-frequency bands, which separates the relative influences of the baroreflex as well as the parasympathetic and sympathetic nervous system activation (McCraty, Atkinson et al. 1995).  This measure for stress uses a new algorithm (Qi, Minka et al. 2002), developed by Yuan Qi at the MIT Media Lab, which computes spectral analysis for non-stationary, unevenly sampled data by using a Kalman filter to jointly estimate all spectral coefficients instantaneously.   After obtaining the spectral coefficients, the entropy of the result is used as a measure for stress.    

By enabling people to view their own signals, they can see for themselves the effect that their emotions have on their bodies.  This makes them active rather than passive receptors of this knowledge, which can also make them active about expressing and learning about their own emotions.

The Application 

The system, shown in figure X is programmed in Python2.3.3 and Matlab6.5.The system uses a Fitsense Heart Rate Monitor to gather the heart rate data, along with a Bluetooth galvactivator, created by Carson Reynolds to collect the galvanic skin response data. Once the application is stopped, the data will be fed into the Matlab application. All data is sent to the laptop via Bluetooth and stored in text files for access by the application.

Figure 1: Entire InnerActive system

The INNER-active Journal gives users a chance to view their heart rate variability, stress level, and galvanic skin response.  By gaining an understanding of how emotions affect the body, users can begin to take an active role in managing their emotional health.  The application begins with the user taking part in an expressive writing task.  Once the entry is finished, users can view the data collected through the interface shown below.  The drop down menu has the choice of 'Skin Conductivity', 'Instantaneous Heart Rate', and 'Heart Spectral Entropy'. Once the decision is made, the "Update" button is pressed and the new graph is displayed.  If there are any interesting peaks in the skin conductivity or heart rate graphs, the user can select the spot on the graph and then click the "Press to View Sentence" button and see what sentence corresponds to the point on the graph. The following graphic is from a session the designer set up to demonstrate how the system functions.

Figure 2: Screenshot of Graph viewing portion of inner active Journal

Confirming Results

In order to get a better idea of whether the results obtained from the expressive writing session, two short experiments were conducted.  In Experiment 1, shown in figure 3,  quick short breaths, which is known to increase skin conductivity, was followed by relaxation.  This was repeated twice.  Next, running in place to increase the heart rate followed by listening to a favorite song were explored.  As shown in figures 4 and 5, there is a noticeable difference when the subject is in motion, and at rest.  There is also an interesting result that the heart rate increases when the subject's favorite song is played. Similar results were found in the stress measures.

Figure 3: Skin Conductivity Graph Experiment 1- 

Short quick breaths followed by relaxation, repeated twice

Figure 4: Heart Rate Variability Graph Experiment 2 - 

Running in place, followed by relaxation then listening to a favorite song.

Figure 5: Heart Stres Entropy graph for Experiment 2- 

Running in place, followed by relaxation then listening to a favorite song.

There are a few things that should be considered, however, when using the system:

• Thinking of an event before writing it may cause it to show up in body signals, so writing would not correspond exactly

• Typing speed effects quality of data correlation

• Heat from computer may affect GSR data