Healthy feedback: An interview with Stéfanie Enriquez-Geppert

Every quarter, we share articles published in the BCN Newsletter and we are happy today to share an interview with Dr. Stéfanie Enriquez-Geppert, who recently started working at the Psychology Department as Assistant Professor in Neuropsychology. The interview was conducted and written by Anna Leonte, a BCN MSc student.


 

Anna Leonte: You are a newly appointed assistant professor in the Department of Clinical and Developmental Neuropsychology. What were your first impressions of conducting research in Groningen?

Stéfanie Enriquez-Geppert: Earlier in 2016, I was invited by André Aleman (Neuroimaging Centre, NIC) to give a talk about a neuroscientific training approach for the improvement of specific cognitive functions. At that time, I already noticed that executive functions are a vivid scientific topic not only at the NIC but also at the Department of Clinical Neuropsychology, which makes it very easy for me to discuss my own research with fellow scientists. Exchanging information on such levels really makes it an exciting and valuable experience. I also have noticed that most of the researchers strive to relate basic and applied research to daily life activities, such as the relationship between cognitive dysfunctions and driving ability. This scientific translation is an interesting approach as it addresses the question of whether and how our research can affect and improve day-to-day life.

Another characteristic I have positively been impressed by is the explicit promotion of collaborations between different departments. Within the university, symposiums are organized regularly to offer scientists a platform for exchanging their views and discuss certain topics. I think it’s quite special to be able to connect and work so easily with other groups and departments, and this benefits research enormously. I feel very welcomed and am quite happy to be here.

 

I think it’s quite special to be able to connect and work so easily with other groups and departments, and this benefits research enormously.

 

AL: I noticed that you have worked in many different labs and have visited several countries where you worked on your research. Do you believe that going abroad and working in different labs is something every researcher must do?

SE-G: Yes, I believe that working in different research labs forms an important aspect in a scientist’s career. Each lab has its own way of how research is organized and performed. Given that each lab has its own field of expertise, research approaches and techniques as well as preferences for hard- and software products, working in different labs promotes the development of new and fresh ideas. The collection of such experiences can give insight in intercultural competences as well as the advantages and disadvantages of various techniques. In this way, one gets used to take different perspectives and learn how to add or apply newly acquired skills to one’s own studies. To give you a concrete example: during my PhD research stay in Norway, I got to know a new and advanced data analysis method that we applied to MRI data I collected in the past. Later, we used this knowledge to adapt the method also for EEG data.

Apart from the personal and professional development, changing labs enables the use of resources that are unavailable in one’s own country. My research stay in Cambridge allowed us to study not only a very specific but also a large pool of subjects, namely a group of specific lesion patients in a very short time. Of course, it is uncomfortable in the beginning to leave one’s familiar surroundings and stable social network. However, I really believe that for going abroad the benefits outweigh the negative. It’s a nice way to connect to other scientists and broaden one’s network, and I especially recommend it to young scientists.

 

Of course, it is uncomfortable in the beginning to leave one’s familiar surroundings and stable social network. However, I really believe that for going abroad the benefits outweigh the negative.

 

AL: Now that you are here in Groningen, what will you be working on?

SE-G: The neural correlates of executive functions and their impairments form my main research interests. One of my work foci will be the testing of novel neurofeedback techniques to reduce cognitive impairments in patients. Back as a post-doctoral fellow in Oldenburg, I investigated whether executive functions are plastic and could be trained for improvement. The use of neuroscientific approaches allowed us to develop new tools for the training of executive functions based on what we already know about the brain. It has been shown that there exists a relationship between executive dysfunctions and the prevalence of several clinical disorders such as ADHD, schizophrenia, Parkinson’s disease, and Mild Cognitive Impairment (MCI), disorders that are extensively investigated here in the Department of Clinical Neuropsychology and the NIC. It is exciting to observe that neurofeedback could serve as a technique to train executive functions. We noticed that there is a lot of expertise that could be combined, which led us to make the decision to collaborate. Shortly after, positions became available at the RuG. It really was a lucky coincidence!

 

AL: Could you tell us more about neurofeedback and how you use this method in your studies?

SE-G: In a nutshell, neurofeedback is a method in which subjects learn to regulate their own brain activity measured with MRI, NIRS and EEG. The combination of learning mechanisms and the accessibility of brain activity enables subjects to gain control over their own brain activity thereby improving behavioural outcomes.

In the case of EEG neurofeedback, one could utilize brain oscillations that are associated with cognitive processing. Some oscillations are suggested to serve as a medium through which the brain communicates. This was shown on a single-cell level in experiments by Womelsdorf with macaque monkeys carrying out executive functions tasks. Especially with executive functioning, a clear brain rhythm can be discerned: theta waves. Frontal-midline(fm) theta – an oscillation usually measured at frontal midline electrode positions with EEG – serves as the “working language” of the brain by integrating information originating from computations of different brain regions. Whenever executive functions are needed or successfully implemented, fm-theta increases in amplitude or power. This relationship is so prevalent that power values of the oscillations can be used to predict behavioural outcomes, as some fellow scientists have shown. This is of course an interesting scientific observation because the question of what effects on behaviour would the manipulation of these power values have arises. Trying to tackle this issue, we established a protocol of a neurofeedback training. Subjects visited our lab for several days and learned how to voluntarily increase their theta activity. Executive functions were assessed before and afterwards by means of a neuropsychological test battery. Comparisons between a group that received true feedback and a group that received a mock training showed indeed a change: after 8 sessions, subjects were able to increase their fm-theta power and this effect was transferred to task performances on executive functioning. In the past, findings were inconclusive about whether every type of oscillation could be manipulated using neurofeedback. So for us it was very exciting that we were able to show that fm-theta can be trained and even had an effect on cognition.

 

AL: Now that executive functions are shown to be plastic and can be improved, how can this be helpful to people who struggle with daily life situations?

SE-G: The improvement of executive functions by neurofeedback is still at an early stage. Facing the worldwide demographic changes regarding ageing and the burden of disorders associated with executive impairments, a next step will be to apply the neurofeedback training to patient groups and the ageing population who are negatively affected by the consequences of their cognitive impairments. From the literature, we know that there is a positive correlation between age and a decrease in executive functioning, which in turn is associated with the decreased ability of older people to live on their own. This increase in cognitive impairments poses a challenge that many patients, caregivers and the society in general must face. The application of hypothesis-driven research to daily life activities is central to such a possible study and the science community will eventually have to figure out how such interventions can be implemented in real life in order to be maximally helpful and effective for the affected population.

 

AL: You are improving subjects’ executive functions by training them to regulate their fm-theta brain activity. I wonder, however, whether executive functions solely rely on fm-theta waves?

SE-G: Indeed, theta waves are crucial for executive functioning but they are not the only type of oscillations important for these cognitive processes nor are power increases the only mechanisms associated to successful performance. It is known that some oscillations are the driving force behind other oscillations, suggesting that executive functioning might not solely rely on theta waves but on the combination of different oscillations and their computations across different brain areas of a network. Power increases of fm-theta form one mechanism that we investigate in our studies. In regard to neurofeedback research, one of the next steps is the training of connectivity. We assume that theta oscillations are generated in the midcingulate cortex serving as a central driver in the network to implement executive functions. Previous experiments have shown that the midcingulate cortex is working together with the lateral prefrontal cortex. Having this in mind, future neurofeedback protocols can be developed that eventually will lead to a better and more specific training of executive functions.

 

AL: As you explained in the beginning, neurofeedback can be used as a therapeutic tool for disorders such as ADHD. I can imagine that for ADHD patients who have trouble sustaining attention, it can be quite difficult to follow the training, which in turn might affect the outcome. Does this pose a problem to your research?

SE-G: You are right to assume this. Conducting neurofeedback is similar to all other EEG experiments. Participants should try to sit still, avoid movement and excessive eye blinking. And this can pose a real challenge for specific patient groups with motor agitation such as schizophrenic patients. In contrast to standard EEG experiments, however, neurofeedback underlies online analyses meaning that the data can’t be processed afterwards to get rid of artifacts. Every time a participant is moving or blinking, trials have to be excluded and learning time is lost. It’s something you have to expect when working with patients and stresses the importance of adapting the protocol to patient groups for instance by including online correction methods. This is not the standard for most software products, however, and much more work is needed to improve such methods. It would be very unfavorable to ignore the effect of movements on the EEG. In that case, there is the risk that subjects wouldn’t learn to self-regulate the brain activity but instead would learn the association between muscle tension and the enforcement signal. The neurofeedback sessions would turn out useless. On top of that, neurofeedback often has received justified scientific criticism when used without a control as a therapeutic tool. As a result, it’s difficult to figure out if the reduced ADHD symptoms for example indeed derive from the neurofeedback training or just stem from the fact that the ADHD participant learned to sit still during sessions. Thus, one has to be aware of such pitfalls and use scientific criticism, which is very helpful, constructive and required to scientifically move forward. The increase in knowledge about brain mechanisms along with a continuous technical development makes me really curious about how neurofeedback will develop in the next 7 years!

 

Note: Text and photos by Anna Leonte

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Tassos Sarampalis on Twitter

Dr. Sarampalis is a lecturer at the Psychology department of the University of Groningen. He began his career in psychoacoustics in the UK where he worked with Deb Fantini and Chris Plack, before moving to California to work on hearing devices, first with Monita Chatterjee and then with Erv Hafter. His current research interests involve understanding the contributions of cognition in complex hearing situations and the interactions of cognition and hearing impairment. For more information, you can visit his website.

Note: Photo by Sander Martens


Select Publications

Hogenelst, K., Sarampalis, A., Leander, N. P., Müller, B. C., Schoevers, R. A., & Aan Het Rot, M. (2016). “The effects of acute tryptophan depletion on speech and behavioural mimicry in individuals at familial risk for depression.” Journal of Psychopharmacology (Oxford, England). http://doi.org/10.1177/0269881115625156

Pals, C., Sarampalis, A., van Rijn, H., & Başkent, D., (2015). “Validation of a simple response-time measure of listening effort.” J. Acoust. Soc. Am. 138(3), EL187-EL192.

Pals, C., Sarampalis, A., & Başkent, D. (2013). “Listening Effort with Cochlear Implant Simulations.” Journal of Speech, Language, and Hearing Research.

Sarampalis, A., Kalluri, S., Edwards, B., Hafter, E. (2009). “Objective measures of listening effort: Effects of background noise and noise reduction,” Journal of Speech Language, and Hearing Research, 52, 1230-1240.

Hafter, E.R., Sarampalis, A., and Louie, P. (2007). “Auditory attention and filters,” in Auditory Perception of Sound Sources, edited by W. A. Yost (Springer-Verlag, New York).

Chatterjee, M, Sarampalis, A., and Oba. S.I. (2006). “Auditory stream segregation with cochlear implants: A preliminary report,” Hearing Research, 222, 100-107.


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