Life Science Hardware and Software

The negative effects of stress on the body have been widely studied. Stress can be defined as a situation that is causing the current state, or homeostasis, under pressure to change. The human body’s nervous system reacts to stress by changing the amount produced of certain biomarkers. For example, when heart rate elevates, blood pressure rises and the human body reacts and secretes hormones (epinephrine, cortisol, etc.). Experimenters tested the change in the production of specific biomarkers of people with different training backgrounds to understand how acute psychological stress affects their physiological responses. The three group classifications were sedentary subjects, endurance athletes, and strength athletes.
 
EDA (skin conductance), ECG (EKG), and breathing frequency were measured continuously; BP and cortisol were measured after each experiment segment. EDA, ECG, and breathing frequency were measured during the acute psychological stress test using the BIOPAC MP150 data acquisition unit connected to wireless biopotential amplifiers and recorded on BIOPAC’s AcqKnowledge software.

Psychological stress was induced in participants using a Stroop color-word test and math problems. These problems were presented in a slide show where the subjects had a limited amount of time to solve for the correct answers. The researchers found numerous differences in changes in the biomarkers measured in response to the acute psychological stress activities between the three groups. On average, athletes’ cortisol levels changed differently when compared to the sedentary group. Also, skin conductance was shown to have higher levels in the sedentary group than in the athletes. The athletes also had a higher recovery level for systolic blood pressure, which was observed to decrease over the test for the sedentary group.
 
The participants reported to have experienced psychological stress over the course of the activities and this was reinforced by the change in values of the biomarkers measured. This experiment showed that people with different training backgrounds had different responses to psychological stress for related biomarkers. The experimenters concluded that people with different training backgrounds react differently in their changes of certain biomarkers to psychological stress.

Very little is known about the origins of cardiovascular risk factors like obesity and altered glucose metabolism and their development during childhood. Adolescence is a time when individuals develop their own health behaviors while gaining increasing autonomy from their parents and this development has an effect on their cardiovascular health later in life. The RIGHT Track Health Study is a longitudinal study that followed participants from age two through young adulthood in an effort to understand how self-regulatory behavior throughout childhood alters the trajectory of various cardiovascular risk factors during late adolescence via health behaviors. For this study, individuals in the RIGHT Track program were re-contacted and invited to participate in adolescent data collection in an effort to gain insight into the origins of behavior that could contribute to an increase in cardiovascular risk factors later in life. This information could be valuable to helping researchers and public health policy administrators target intervention efforts in early childhood, when preventing chronic diseases is most cost-effective and behavior is more malleable.

The researchers used an orthostatic challenge to assess autonomic function, via changes in participant’s heart rate variability (HRV), to a mild physiological stressor. This physical stressor was used as a way of comparing the autonomic function to the physiological stressor paradigms that participants underwent during their early developmental years as part of the RIGHT Track program. HRV measurements provided complementary information regarding the role of autonomic nervous system as a regulator of cardiac control. ECG and respiration recorded using a BioNomadix wireless amplifier set with wearable transmitter to collect HRV at rest. Physiological signals were sent to a BIOPAC MP150 Research System with AcqKnowledge software for collecting and exporting the data in real time.

Data from the RIGHT Track Health Study will provide valuable information for youth healthcare about how health behaviors developed during an individual’s adolescence—such as diet, physical activity, sleep and substance abuse—can later affect cardiovascular health and potentially indicate critical times for reducing certain cardiovascular risk factors by assessing their trajectories.

Psychophysiological Monitoring of Fear Extinction

An estimated 10% of the general population experiences fear of flying (FOF) and 25% of the population that flies experiences distress during the flight. The most effective psychological technique for the treatment of phobias is in vivo exposure. Using planes in real flights, however, takes a large amount of time and money that is not easily accessible. Virtual Reality Exposure Treatment (VRET) of FOF is now well established but generalization of such treatment in clinical settings is still rare.
Researchers from INSERM Centre of Psychiatry and Neurosciences presented a case report of a 31-year-old woman who was chosen for treatment because of her FOF. She attended a demonstration of the new VR equipment and disclosed her FOF. Researcher’s proposed a VRET as she had to fly in a few months and anticipated high anxiety during the scheduled flight. The woman received six sessions of VRET, delivered with standard BIOPAC VR setup, using the included Virtual Environment (VE) of an aircraft with minor adaptations. The woman was seated in an aircraft chair that vibrated during takeoff and turbulences. Researchers used a standard BIOPAC VR Ultimate system, a high-resolution stereoscopic head-mounted display providing a monocular field of view of 60°, a tracking device in order to adapt the field of view to head movements, connected to a MP150 physiological responses amplifier. Skin Conductance Level and Heart Rate were recorded with BIOPAC’s BioNomadix wireless transmitter-receiver modules connected to electrodes. Results showed evidence of a progressive reduction of the subject’s anxiety in the reactivity to takeoffs and turbulences. A Flight Anxiety Situations questionnaire showed a reduction of anticipation anxiety. The woman succeeded in flying alone three months after completion of VRET. Physiological monitoring may provide indexes predictive of outcome; further research is required. Full immersion rather than the graphical quality of VE is the main driver of the sense of reality experiences by the subject.

A flow state typically occurs when a person’s abilities match the level of difficulty for the current task they are completing. During this state, researchers have found that most people who exhibit flow experience changes in blood pressure, muscle activation, and mental focus, among other responses. They also lose self-awareness and subjectively evaluate time as passing more quickly than usual. All of these factors relate to both the sympathetic and parasympathetic nervous systems, suggesting that flow may involve a non-reciprocal coactivation of both systems. Neuroscience and Psychology researchers in Stockholm, Sweden hypothesize that these effects suggest a potential physiological component that differentiates flow from other states of increased mental effort. This indication may provide accurate measurement of deep concentration in a flow state during various activities, including, but not limited to, music, video games, and writing. To test this hypothesis, the researchers had a total of 77 participants play a modified version of the video game Tetris and then complete a questionnaire about their experience. Participants were instructed to play three game difficulties: Easy, Optimal, and Difficult. In the Optimal setting, researchers adjusted the speed of the game to match the participants’ ability, based on initial performance. Speed was then decreased and increased by three stages for Easy and Difficult modes, respectively. Wireless ECG and Respiration data was recorded using the wearable BioNomadix amplifier (BN-RSPEC); surface electrodes were placed on the left and right chest. In addition, mental activity was measured in 35 participants—this was determined by frontal lobe oxygenation, which was recorded by placing the BIOPAC fNIR100 optical brain imaging sensor on the forehead of each participant. After completing all three video game difficulties, subjects were given a questionnaire to indicate their subjective experience with each game level. The results found that while larger respiratory depth was associated with deeper flow, there was no significant correlation between frontal cortex activity and flow.