Combining virtual reality and non-invasive deep-brain electrical stimulation, researchers have improved healthy individuals’ spatial memory – the kind that helps you remember where you left the car keys. The approach has great potential for treating cognitive decline due to disease or injury without drugs or surgery.
Aging can dull our ability to navigate using spatial memory, the form of memory responsible for recording and recovering the information needed to remember the location of objects in our environment. Neurodegenerative disorders, such as dementia, similarly can cause deterioration of this ability.
In a new study, researchers from two labs at Switzerland’s EPFL have joined forces to combine non-invasive deep brain stimulation of the part of the brain responsible for spatial memory with virtual reality (VR) to improve navigation in healthy participants.
“By finding a way to improve spatial memory without surgery or medication, we are addressing a serious concern for a large and growing population – the elderly – as well as brain trauma patients and those affected by dementia,” said Friedhelm Hummel, head of the Hummel Lab and the study’s co-corresponding author.
Olaf Blanke’s Laboratory of Cognitive Neuroscience (LCNO) collaborated with the Hummel Lab – both are at EPFL’s Neuro X Institute – which meshed Hummel’s expertise in non-invasive brain stimulation with Blanke’s research into spatial navigation in VR environments. Together, they developed a unique neuro-technological setup.
Four electrodes were placed on the heads of healthy individuals to stimulate the brain’s hippocampus and the entorhinal complex, deep structures that are crucial to spatial memory. This technique, called transcranial temporal interference electric stimulation (tTIS), non-invasively sends pulses into the brain without causing discomfort to the patient. Then, VR goggles were fitted, and participants were asked to navigate through a series of virtual locations and remember key landmarks. This all took place inside a functional magnetic resonance imaging (fMRI) machine, which recorded brain activity in real time.
“When [electrical] stimulation was applied, we observed a clear improvement of the participants’ recall time – the time it took to start moving toward where they remember the object to be,” said Elena Beanato, Chair of Neuroengineering at the Neuro X Institute and the study’s co-leading author. “This leads us to believe that by stimulating the hippocampus, we temporarily increased brain plasticity, which, when combined with training in a virtual environment, leads to better spatial navigation.”
The researchers say their findings show that the approach has great promise as a non-invasive treatment for patients with cognitive impairment following a traumatic brain injury (TBI) or due to dementia.
“The alliance of tTIS, virtual reality, and fMRI offers a highly controlled and innovative approach to studying the brain’s response to stimulation and its impact on cognitive functions,” said Olaf Blanke, who was a co-corresponding author with Hummel. “In the long term, we envision using this approach to develop targeted therapies for patients suffering from cognitive impairments, offering a non-invasive way to enhance memory and spatial abilities.”
The study was published in the journal Science Advances.
Source: EPFL
