MedNeuros on the Loose: PhD Retreat 2016

Next week the second MedNeuro PhD retreat will take place. Let's have a look at the report from last year.

It all began when an email was sent inviting students to help in the organization of the first ever MedNeuro PhD retreat.
Having formed a team of organizers, several meetings were held together with the representative of the MedNeuro office. The retreat was organized by MedNeuro PhD students with the aim of reinforcing the communication and interaction among the PhD students amidst the exchange of scientific ideas.
The enthusiastic response of students led to a total of 33 registered participants. On D-day, our bus took off at 4 pm en route to Schloss Wahlsdorf, 2 hours south of Berlin. In the bus, each participant received the booklet for the retreat which contained the program schedule, as well as some instructions.
Our graduate school has remained very international over the years, with a diversity of nationalities from across the globe represented. Most students work in labs scattered across Berlin on the Charité campuses, with the majority on campus Mitte. A quick survey showed that most participants are in the middle of their PhDs, although a few students are just beginning and very few almost finishing.

Hitting the Town In Wahlsdorf
When we arrived at Schloss Wahlsdorf, we had a grill party for supper – lots of meat with servings of mixed greens and bread. The quietness of the location with its few inhabitants was a great advantage for socializing and brainstorming. The cool breeze of the night with its accompanying stars in the sky encouraged us to stay outside longer, socializing over bottles of beer and wine. This facilitated the interaction among participants, which was one of the main reasons for organizing the retreat.
The speed dating session that night permitted practically all participants to interact with the others. This already closed the gap between participants making each one feel comfortable and at home. Of course, on a day like this, after embarking on such a long journey, while some preferred to go early to bed, others waited a little while to enjoy the night with the stars and cool breeze. It was full of smiles, laughter and giggling.

From the Bench...
This was the day assigned to the talks and poster sessions for the exchange of scientific knowledge. The organizers ensured that each talk had 5 minutes of discussion and each poster 3 minutes. It was very inspiring to see how the students listened attentively and participated actively in the discussions that arose after each talk. Furthermore, the poster and talk sessions unraveled the dynamism of neuroscience topics in the PhD program, ranging from electrophysiology to clinical studies. To relax our minds after the scientific program, we had a game session combining mime, puzzles, a quiz and making music from some selected scientific words.

... to the Boardroom
We had an interactive table discussion about careers with Rob Thompson, an entrepreneur and well-renowned trainer. His approach was quite different from what most of us are used to. Participants raised questions or topics which were of interest to them and we dealt with them accordingly. We learnt some tips for getting the job we want and building your network. We also learnt how to deal with difficult colleagues and work in a team. The talk was exciting and had a mock job interview with some participants acting as recruiters.
Around 5 pm we prepared to head back to Berlin bringing our 2-day retreat to a successful end.
This was really a retreat to remember and we look forward to making it an annual event. Just in case you missed it, watch out for the next PhD retreat.

The organizing team is grateful to all for your support and enthusiasm shown before and during the retreat. We thank the team (Valérie, Mariana, Priscilla, Fenia, Laura and Veronika) and the MedNeuro office for the financial support for making this retreat see the light of the day, and of course the wonderful participants without whom the retreat would not have been successful.

by Priscilla Koduah, PhD Student AG Paul
this article originally appeared December 2016 in Vol. 09 Issue 4: From Cradle to Grave

Is it True that People Born in Summer Need Less Sleep than People Born in Winter?

Why do some people seem to need less sleep than others? Why is it so easy for some people to get up in the morning and for others it's easier to stay up late at night?

As far as we know, there is no data on the association between sleep patterns and birth dates. I even asked an expert on the topic: Prof. Dr. Till Rönneberg from LMU Munich. However, he told me that this has not been investigated in depth. What has been thoroughly investigated though is why some people are early birds and some are night owls. This has to do with our inner clock that has evolved to help us anticipate the daily changes in our environment, such as light-dark cycles or temperature cycles. Almost everyone’s inner clock is happily ticking away with an approximately 24-hour period (that is why it is termed “circadian clock”- circa dias - almost a day). However, the ticking speed varies. Imagine you have a fast inner clock. This means that you would be too early for everything: you wake up early, eat early and get tired early; you would be an early bird, or as the scientific community terms it - an early chronotype. The opposite is also true; late chronotypes have a slow inner clock, so they are “late” for everything.
The interesting thing is that our chronotype varies throughout our life; we all start off as very early chronotypes, our clocks become gradually slower until puberty and then getting earlier again during the rest of our lives. Not only is our chronotype age-dependent, but also sex-dependent.
These differences in individual chronotypes are definitely something which we have to keep in mind when discussing school hours or office hours. These are often much too early especially for school children in the midst of puberty.
Last but not least, I want to mention an important feature of our inner clock, and that is that it is able to synchronize to our environment through light. This means that it can entrain the 24-hour day-night cycle provided it receives enough light input. To cut it short, the more light we get, the easier it is for night owls to get up in the morning and the longer early birds can stay up at night.

Reference

Rönneberg and Merrow, Cold Spring Harb Symp Quant Biol, 2007

by Veronika Lang
this article originally appeared 2013 in CNS Volume 6, Issue 4, Integrative Medicine

Do you also sometimes wonder about the simple neuroscientific questions in everyday life, but don’t really feel like looking them up right away? For questions like this, just mail us your question (cns-newsletter@charite.de) and Dr. Harebrained will give us his explanation in the next issue!

A Smart Pinocchio or Merely a String Marionette?

Almost every day as the clock ticks closer to one, with a strong appetite, I leave my desk thinking of my lunch plans. A nearby Persian restaurant, it might be! Sometimes I go there, but most often, I end up going to the Mensa. Why? It is cheaper and I can choose from a variety of good dishes. Although it does not take more than few seconds to do so, I always appreciate the luxury of being able to freely decide on everything for lunch. But am I perhaps completely deluded? 

Just across the street from the Mensa is the Bernstein Center for Computational Neuroscience (BCCN), where Professor John-Dylan Haynes’ group has conducted a remarkable experiment questioning the nature of conscious thoughts and intentions involved in our decisions [1] (Check out  Unconscious Determinants of Free Decisions by Filip Morys).
Is free will just an illusion? This has been an old philosophical debate starting even before the term neuroscience was coined. The free will argument rests on the assumption that we consciously generate our own thoughts. The traditional counterargument against the free will proponent is philosophical materialism. Materialists claim that mental states can only change due to a change in brain activity, which is a physical system constrained by the laws of physics. Neuroscience studies reach beyond solely supporting the materialists’ argument. Even if we think of our minds as immaterial souls, this should not change how we view our volition. It does not matter whether unconscious activities are physical or divine in nature; they are still unconscious [2,3].

A bereitschaftspotential is detected before a subject consciously makes a decision

The shocking results of Dr. Haynes’ group are not an anomaly, but consistent with a history of similar experiments. In 1983, the prominent physiologist Benjamin Libet used EEG to show that a certain cortical motor activity known as Bereitschaftspotential is detected 300 milliseconds before a subject consciously decides to move. Recently, scientists from Harvard University have provided more compelling evidence using direct recording methods. Recording the activity of just 256 neurons in the motor cortex is sufficient to predict up to 80% of a subject’s voluntary decisions 700 milliseconds before being consciously aware of it [4]. These findings seem very difficult to reconcile with the common sense conception of free will. Every day, I think I make a conscious decision about my lunch - where and what I eat. Most probably, before I feel as if I am deciding, my neurons have already determined what I will do. You can imagine a fancy experiment where a mobile fMRI is fixed on my head and connected to a computer at the BCCN. If a researcher can know the place and type of food I am going to decide on 7 seconds before I consciously decide, how can I still think that I have free will?  This applies not only to deliberate decisions, but also spontaneous intentions that pop up such as having tea after lunch. Why not coffee? I just do not know. I consciously witness my thoughts but I cannot influence them.

by Andreas Bolli Power Blog

In response to this support for determinism, philosophers’ approaches have been divided into two main streams in the free will-determinism debate [2,3]. Incompatibilists like Sam Harris think that free will is incompatible with determinism. If our intentions and decisions are predetermined unconsciously as shown by findings from neuroscience research, then free will is merely an illusion. For Harris, believing in free will and determinism is paradoxical, like claiming, “A puppet is free as long as he loves his strings” [2]. On the other hand, compatibilists such as prominent philosopher Daniel Dennett assume no contradiction between free will and determinism; neuroscientific findings do not by any means invalidate this compatibility [4]. The compatibilist view prompts me to think of Pinocchio in the famous novel “The Adventures of Pinocchio” by Carlo Collodi. Pinocchio is a wooden puppet turned into a real boy. He consciously makes decisions. However, Pinocchio is determined by his wooden nature and by the fact that his nose grows when he lies.

 The debate is lead by two parties, the incompatibilists and the compatibilists

Despite their different opinions, Dennett agrees with Harris that we do not consciously access at least part of our neural processes involved in making decisions. However, these unconscious neurophysiological processes are still our own as much as other conscious neural processes. We have to avoid setting up a dichotomy between our conscious self and other aspects of our brain's neurophysiology. As conscious beings, we really deliberate, decide and act, even if part of this process is cooked up unconsciously. This does not entail any incoherence in the concept of free will. I might not know why I intended to drink a cup of tea after lunch; I only witness my thoughts consciously, but I can also interfere with them unconsciously by continuing to remind myself. It is only the stage when my brain is evaluating different inputs in order to make a choice that I cannot influence. You might be partially unconscious of your brain processes while being in control of your actions. When driving a car you are in control even if you are not attentive to details. You know that your unconscious intentions will generally make the right decisions to get you home safely. It is this reflexive repetitive nature of our thinking that maintains an indirect control over our brains’ decisions [3].
The complexity of the free will debate reflects the enigmatic nature of how we perceive ourselves as conscious, mindful, and rational beings in a world consisting of mindless, unconscious, and unperceptive physical matter. The notion of free will is easy to accept intuitively, as we feel a genuine authorship of our own thoughts, and this feeling is what gives life some of its sweet, and sometimes sour, taste.

[1] Soon et al, Nature Neurosci, 2008

[2] Harris, Free will, 2012

[3] Dennett, Freedom evolves, 2003

[4] Fried et al, Neuron, 2011

By Mostafa Nashaat Abdelhamid, PhD Alumni Berlin School of Mind and Brain

this article originally appeared 2014 in CNS Volume 7, Issue 1, Mind and Brain

Free Will - An Interview with Professor John-Dylan Haynes

Professor John-Dylan Haynes devotes part of his research to free will. He works at the Bernstein Center for Computational Neuroscience, part of Charité – Universitätsmedzin Berlin. Filip Morys asked him about his view on the free will.

FM: What is your opinion on free will – do we have it or not?
JDH: First of all, you have to define what you understand when you mean free will. There are different things people associate with free will. The most important distinction you can make is between freedom from external constraints versus freedom from internal constraints. So if someone is pointing a gun at your head, you are not free to decide the way you want to react. But if no one is pointing the gun at your head, there might still be no freedom in the sense that you can’t change the course of the events because you are determined by a causal chain of events happening in your brain.
Humans tend to be dualistic; they tend to think that their mind is something separate from their body. The fact that there exists a field of  'psychosomatics' already suggests that they think that the body is something different from the mind. I believe that the mind is something that is realized by the body, specifically by the brain. It takes place in the carrier medium of the brain and it follows the laws of nature. So our mind is a natural process. But most people, including us scientists in our day-to-day lives, follow dualistic thinking patterns. We think that when we make a decision to do something, that this decision somehow happens in a separate space, independent from our brain. We believe that our brain and body only come into play when we want to execute our decisions, to make our choices become reality. According to what we know from modern neuroscience, this view is definitely wrong.

DECISION DOES NOT START IN THE MIND, INSTEAD IT EMERGES FROM PRIOR BRAIN ACTIVITY.

Our own research suggests that a decision does not start in the mind, instead it emerges from prior brain activity. The brain seems to be the starting point of the causal chain leading to the conscious decision. If the decision really starts in the brain at a time when you do not even notice it happening, then to me this suggests that one aspect of freedom does not exist; Our mind is not able to overcome the laws of nature. Many philosophers disagree with this interpretation, but I am not claiming that there are not other ways of defining freedom. As a psychologist, I am more interested in the ways which people actually think about freedom, and not the ways in which we can redefine our concept of freedom to be compatible with natural sciences.

Prof. Dr. John-Dylan Haynes, Bernstein Center for Computational Neuroscience

 

FM: I read an interview where you said that we could trace our decisions to the moment of big bang, is that true?
JDH: Oh I did not say that. It is a statement on our website and people cite it, which is very funny. It reads: “Decisions don't come from nowhere but they emerge from prior brain activity. Where else should they come from? In theory it could be possible to trace the causal pathway of a decision all the way back to the big bang. Our research shows that we can trace it back 10 seconds. Compared to the time since the big bang this is not very long.”
This is of course a highly provocative and exaggerated statement, which I put up to provoke counter reactions. I have to admit that I enjoy the Darwinism of ideas, where you put up strong points just to see what kind of arguments people come up with to pull them down. Of course I don’t believe that it’s practically ever going to be possible to work your way backwards in the causal chain of the world back to the big bang. The point serves more as a reminder that there is nothing mysterious about predicting (or better 'postdicting') backwards in time, even if according to physics and thermodynamics working backwards will be more difficult. If there are laws governing processing in our brains then it should be possible – at least to some degree – to unwrap the previous steps in the processing chain. Obviously, you can imagine very specific cases, where, for example, a few hundred synapses converge onto one neuron. Then, the neuron does not know from which cell it originally got input. But in neuroimaging with population-level signals, it appears possible to work your way backwards in time.

FM: I think you definitely succeeded in provoking the counter reactions. Do you think it would be correct to say your research has proven that there is no free will?
JDH: To be precise, I do not think we have proven that there is no such thing as free will. I think our data suggests that one specific intuition we have about the freedom of our will might not be true. But a single experiment will never be able to finally solve such a problem forever. There is still a lot to do to convince the skeptics. Our experiments do not have perfect predictive accuracy, we have not shown causation, we do not know whether people are able to find ways to overrule the neural precursors of their choices, and we have mainly studied very simple choices, not the complex kind of life-changing choices people care about. We are addressing some of these limitations right now.

FM: But don’t you think that it is dangerous pursuing this path? I mean there were already some studies suggesting that when we tell people that they do not have a free will…
JDH: You mean the Schooler and Vohs experiment published in Psychological Science in 2008 [1]? The basic finding was that people behave less ethically if they stop believing in free will. Specifically, they found that people cheated more in math tests after reading a text that claimed there is no free will. This poses a challenge: in humanism, you want to educate people to the good and truth. In this case, bringing people the truth made them behave badly. So you have the choice to decide if the truth is more important or if ethical behavior is more important. I do not know where I position myself there. As a scientist I think I have to say the truth is more important and society should adapt to it.

PEOPLE CANNOT THINK OF THEIR MIND AS SOMETHING THAT HAPPENS IN THEIR BRAIN.

I think the whole discussion on free will is just a distraction from a more important point: determinism. No matter how hard the data are, people cannot think of their mind as something that happens in their brain and as something that follows the deterministic laws of nature. I think we have no good way of thinking about ourselves in these non-dualistic terms. It is very difficult to integrate your scientific views into your day-to-day intuitions about the mind.

FM: Thank you, John! 

Reference
[1] Vohs and Schooler, Psychol Sci., 2008

by Filip Morys
this article originally appeared 2014 in CNS Volume 7, Issue 1, Mind and Brain

Unconscious Determinants of Free Decisions

In a famous paper, Soon and colleagues tried to prove that decisions are created in our brain long before we consciously know about them [1]. The paper "Unconscious determinants of free decisions in the human brain" was published in Nature Neuroscience in 2008, and has been widely discussed ever since.

The authors used a very simple button-pressing task in their experiment – participants were supposed to press a left or a right button whenever they felt like it. Simultaneously, a string of single letters was viewed on a screen and subjects were told to remember the letter that was shown when they made the decision to press the button. The investigators recorded brain activity using functional MRI and then analyzed the behavioral and imaging data. In short, the authors were able to predict decisions (left versus right button presses) more than 8 seconds before the participants consciously made their decisions.
For a person who has never heard about this study, these results probably come as a shock. Someone else, by an investigation of my brain activity, knows what I will do in the future even before I know it myself! Although this is not yet completely possible, it could happen with the further development of neuroimaging and data analysis techniques.

Multivoxel Pattern Analysis  
From a technical point of view, the study used an incredibly interesting and sophisticated method of analyzing the functional MRI data, namely multivoxel pattern analysis (MVPA, searchlight decoding method [2]). It is different than the classical, activation-based analysis approach (univariate analysis) in that it takes into consideration the spatial relationships between the activation of certain voxels. To put it more simply, activation-based analysis analyzes whether certain voxels are significantly active for certain conditions, whereas MVPA investigates whether changes in brain signals, called spatial patterns, correspond to certain experimental conditions. Thus, the latter method is more sensitive.

No Free Will?
Soon and colleagues showed that the button presses could be decoded from medial and left frontopolar cortex and posterior cingulate cortex with accuracies reaching 60%. This means that in 60% of cases, the experimenters were able to correctly predict which button a subject would press, a result which was statistically significant [1]. Could these results shed light on the concept of free will? As Prof. John-Dylan Haynes (a co-author of the paper) says, one experiment cannot rule out the entire concept, yet it opens up a new direction for future research. The results of this particular experiment might undermine the concept of free will and support the determinists, who claim that freedom of choice is illusory, because all our actions are determined by preceding events that we cannot influence. If we are unable to consciously make our decisions, as the paper suggests, we cannot really talk about free will at all.

Yes Free Will?
However, we cannot forget the widespread criticism this experiment received. Many researchers claimed that there were a number of flaws that were not taken into consideration by the authors. In 2012, Lages and Jaworska designed similar experiments to see whether the decoding accuracies reached by Soon and colleagues might derive from response dependencies between single trials [3]. They performed a behavioral experiment in order to show that similar accuracies could be reached. The authors reached decoding accuracies of 61.2% for responses based on preceding trials. Since classification analysis can perform better than chance by using preceding responses only, Soon’s results may also have been based on response bias, and may not have fully reflected the true nature of brain activity preceding the conscious decisions in our brains. Lages and Jaworska further claim that the multivariate pattern analysis might have picked up the neural correlates of the intention to switch or stay with the button press, which may occured much earlier in time than the intention to press the button itself. However, Soon and colleagues controlled for this response bias by excluding a large number of participants who did not meet the criterion of equal distribution of left and right button presses. Lages and Jaworska argue that this may have reduced generalizability of the results.
In all of this debate, there is one aspect that cannot be stressed enough: a single experiment does not rule out the possibility that free will does not exist. There are certain possibilities, for example the results might indeed be artefacts and represent something different than unconscious determinants of free decisions in our brains. Another explanation is that we do have free will, but that it influences the decision-making process at the end only, and modulates unconscious decisions that our brains took prior to the action.

Ultra-High Field Free Will
Another study worth mentioning is a replication of Soon's study performed by Bode and colleagues in 2011 [4]. It involved the same task as the previously described study, but the researchers used an ultra-high field MRI scanner (7T) and applied questionnaires after the testing paradigm. In this study, the authors used correlation measures in order to check whether the subjects used any fixed button press sequences, proving that the decisions were more or less random (however, the authors state that due to the low number of trials per functional run, the tests have limited informational value). The results show that no conscious process biased the decisions. Additionally, the researchers were able to decode the button presses before the decision reached consciousness from the frontopolar cortex (with accuracies reaching 57%), a region that was not informative of condition after the decision was made.

ARE WE JUST MINDLESS MACHINES CONTROLLED BY OUR BRAINS?

As terrifying as it may seem, next time you make a decision, you will know that (maybe) it is not really your conscious and free decision, but one that has been made by your brain without the participation of your consciousness whatsoever. So are we just mindless machines controlled by our brains? Do we have any say in our decisions at all? 


[1] Soon et al, Nat Neurosci, 2008 
[2] Kriegeskorte et al, PNAS, 2006
[3] Lages and Jaworska, Front Psychol, 2012
[4] Bode et al, PLoS ONE, 2011

by Filip Morys
this article orignially appeared 2014 in CNS Volume 7, Issue 1, Mind and Brain