fMRI-VR: Gateway to Complex Brain Processes

➣ By Mark D. Wiederhold & Brenda K. Wiederhold

Over the last decade the use of functional magnetic resonance imaging, or fMRI, has become an increasingly popular tool among researchers, who continue to be amazed at findings reinforcing the brain’s neuroplasticity, its ability to adapt by forming new pathways and synapses. For psychologists, it has yielded new insight into the investigation of navigation, pain, anxiety, and cue exposure, and in suggesting ways to improve rehabilitation after brain injury.

What is fMRI?

MRI uses a powerful magnetic field, radio frequency pulses, and a computer to produce detailed pictures of organs, soft tissues, bone, and virtually all other internal body structures. Detailed images allow physicians to evaluate various parts of the body and determine the presence of certain diseases. Functional magnetic resonance imaging is a relatively new procedure that uses MR imaging to measure the tiny metabolic changes that take place in an active part of the brain. It has traditionally been used as a diagnostic tool for physicians to examine the anatomy of the brain such as assessing the effects of stroke, trauma, or degenerative disease (such as Alzheimer’s) on brain function as well as to monitor the growth and function of brain tumors.

When a brain area is more active it consumes more oxygen, and to meet this increased demand blood flow increases to the active area. fMRI can be used to produce activation maps showing which parts of the brain are involved in a particular mental process. These are indications that a particular part of the brain is processing information and giving commands to the body. As a patient performs a particular task, the metabolism will increase in the brain area responsible for that task, changing the signal in the MRI image. So by performing specific tasks that correspond to different functions, scientists can locate the part of the brain that governs that function.

fMRI in Psychology Research

There have been several reasons for the increased use of this new tool in psychology research. First, the improvement in fMRI technique during the last decade has made fMRI data more precise and reliable. Second, it is noninvasive, relatively safe, and user-friendly in comparison to other neuroimaging tools. Third, fMRI allows for the continuous collection of data, which is useful for research purposes that require the tracking of ongoing processes.

The need for objective measures within the field has increased its popularity among researchers. Compared to the traditional questionnaire methods of psychological evaluation, fMRI is far less biased.

Virtual Reality Research and fMRI

One area of research currently being investigated is using fMRI to evaluate the effectiveness of virtual reality (VR) techniques to improve current VR systems that aid in creating more effective treatments for patients. Previous studies have consistently shown that the combination of VR with traditional therapies results in more successful outcomes for patients with a wide range of diagnoses. The most common measures used today to determine the effectiveness of VR therapies are self-report, simple cognitive testing, and physiological measurements including skin conductance, peripheral skin temperature, respiration rate, and heart rate.

Some of our early work showed that peripheral physiology did not always correlate with brain activity. We saw examples during VR therapy where signs of physiological arousal were desynchronous in the neural correlates and observed peripheral physiological levels, indicating that some patients manifested peripheral arousal while others exhibited central arousal. These different arousal
patterns are helpful in planning the therapeutic approach for these patients. We also noted distinct patterns of EEG waves which suggest differences in the perception of realness when patients are exposed to a virtual environment.

Early work by Pine and colleagues used fMRI to map brain regions engaged during memory-guided navigation in a VR environment in adolescents and adults. By 2004, Hoffman and colleagues had demonstrated direct modulation of human brain pain responses by VR distraction. Another early study by Lee and colleagues evaluated cue induced smoking cravings, concluding from fMRI-highlighted areas of the brain that virtual environments were more immersive and evoked smoking craving more effectively than traditionally used methods. An unexpected finding in this study showed that even when patients are motionless in the MRI experience, virtual walking can activate the cerebellar motor cortex.

By combining treatment with imaging of the brain itself, not only can the severity of the disorder be evaluated, and the treatment adjusted accordingly, but also outcomes may be improved through the creation of VR scenarios tailored to how the brain responds to stimuli. Use of brain imaging with VR provides an opportunity to see what is actually occurring in the brain before, during, and after treatment in a way that has never been possible in the past and which can help to create more effective and appropriate treatments in the future. An update to a 2008 report on fMRI-VR studies is contained in the table that follows.