Archive for May 2014
Virtual Reality & Neuromarketing
Immersive
virtual reality environments can unlock physical boundaries and budget limits.
Applications
for VR protocols are varied and include Psychology, Ergonomics, Neuromarketing
& Neuroeconomics (Consumer Research), Biomechanics & Kinesiology,
Healthcare, Computer Modeling/Simulation, Education, and Training: hazard,
medical, etc.
Researchers
can immerse subjects in a VR world and record physiological data as the virtual
environment influences the subject. A feedback loop can be included for greater
control and automation of the VR world. This allows the world to change in real
time, based on the subject’s responses. Timing events are used for analysis of
the physiological data. Eye tracking can be added to the headmounted VR display
to track the subjects’ eyes as they view the immersive environment during the
experiment, and position tracking can also be included.
Wireless
transmitters, EEG caps, and eyetrackers have been used to capture data from
mobile subjects in actual environments, but virtual reality expands the research
potential by allowing participants to be immersed in variable, simulated
environments with an incredible degree of realism. For instance, neuromarketers
can allow subjects to smell and feel multiple products and move through
different display configurations, or psychologists can choose appropriate
environments to study phobias such as flying or public
speaking.
At the
first Neuromarketing World Forum
(2012, Amsterdam), the
challenge and potential of enhancing market research with neuromarketing tools
was discussed, and virtual reality immersive techniques were recognized as
valuable tools for measuring affective states while modifying product
presentation. The value of capturing
synchronized physiological data
(heart rate, HR, ECG, EDA), brain
response (EEG,
fMRI, fNIR), and behavior metrics
(eye tracking, position tracking) was also discussed.
Turnkey
VR/ Immersive systems from BIOPAC are easily combined with wireless physiology
data to synchronize VR events with physiological response data. Neuromarketers
and other researchers can record any combination of signals (ECG, EEG, EOG, EMG,
EGG, EDA, temperature, respiration, pulse, etc.) and include multimodal
stimulation with visual, auditory, olfactory, haptic, or electric stimulus.
Remote Monitoring options provide subjects with a greater degree of freedom and
allow them to move around within the virtual world.
Muscular Biofeedback | Surface EMG
Biofeedback
is
a form of self-regulation in which an individual is provided information in the
form of sensory feedback about a biological condition or function in order to
gain control over that biological function. Biofeedback is often used as a
therapeutic tool by which sports medicine/rehabilitation professionals,
neurophysiologists, psychophysiologists, and therapists can use
electrophysiological instrumentation to measure, process, and “feedback” the
recorded information to the participating athlete or subject. The feedback is
usually provided through auditory and/or visual means.
There
are many types of biofeedback modalities available. One of the most popular and
widely accepted modalities is surface
EMG biofeedback. EMG (electromyography) bioinstrumentation measures
muscle activity by recording electrochemical activity of a muscle occurring
during depolarization and recruitment of a skeletal muscle motor unit. This
modality is used for muscle
reeducation and control when
orthopedic injuries or surgeries have taken place, or when the peripheral
nervous system has been impaired. It is also used to promote muscle relaxation
to decrease muscle guarding, pain, stress, and anxiety.
A
simple muscular biofeedback experiment design might use surface EMG electrodes
placed over the Vastus Medialis and Vastus Lateralis muscles. Surface EMG
electrodes should be placed vertically (parallel to the muscle fibers), over the
muscle belly, or largest part of the muscle, and a ground electrode should also
be used. Surface EMG should be recorded in several trials, including a Baseline
without biofeedback (where the participant is asked to maximally relax, e.g.,
not contract), Maximal Contraction
without Biofeedback, and a variety of Maximal Contraction with Biofeedback, such as
visual stimulus or auditory stimulus. After recording, compare the
surface EMG recordings and use peak-peak and mean measurements to determine if
any significant change was detected between any of the variables.
Biofeedback
is considered advantageous, as it provides participants a chance to use their
visual and auditory senses to become more aware of how they are performing
during therapy or training, attempt to improve upon it, and immediately see the
improvement as it is occurring. Because participants can immediately note
improvements, they are “rewarded.” This reward will hopefully lead to larger
improvements and accomplishments.
The Body Electric | Surface EMG
Electricity
is part of everything the body does.
Surface EMG electrodes noninvasively record the electrical activity of skeletal
muscles. The unit of measure for the electrical activity is the volt, which is named after Count
Alessandro Volta (who also invented the battery). The detection, amplification,
and recording of changes in skin voltage produced by underlying skeletal muscle
contraction is called electromyography;
the recording thus obtained is called an electromyogram (EMG).
Electricity
is always flowing in the body; it flows from negatively charged parts of the
body to positively charged parts. As this electricity flows, surface EMG (sEMG)
electrodes can detect and monitor the electrical activity.
Surface EMG electrodes noninvasively record the electrical activity of skeletal
muscles. The unit of measure for the electrical activity is the volt, which is named after Count
Alessandro Volta (who also invented the battery). The detection, amplification,
and recording of changes in skin voltage produced by underlying skeletal muscle
contraction is called electromyography;
the recording thus obtained is called an electromyogram (EMG).
Skeletal
muscles are stimulated to contract by somatic motor nerves that carry signals
in the form of nerve impulses from the brain or spinal cord to the skeletal
muscles. Although a single motor neuron can innervate several muscle fibers,
each muscle fiber is innervated by only one motor neuron. The combination of a
single motor neuron and all of the muscle fibers it controls is called a motor
unit. When a somatic motor neuron is activated, all of the muscle fibers it
innervates respond to the neuron’s impulses by generating their own electrical
signals that lead to contraction of the activated muscle fibers.
Integrated EMG “averages out” noise spikes in the raw EMG
data to provide a more accurate indication of the EMG output level
Muscle activation,
strength, fatigue, or twitch can be
monitored with surface EMG electrodes from a variety of body locations
to study Gait, Range of Motion, Isometric and Isotonic Contraction, Ergonomics,
startle response, etc. sEMG data can be
combined with other data to display muscle response simultaneously with other
physiological events.