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

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

Resisting Temptations and the Power of Suggestion

Have you ever struggled to resist a delicious chocolate bar while you were on a diet? Or have you tried to resist drinking the sixth tequila shot which you knew would make you feel miserable the next day? Resisting temptations is difficult. However, a recent study published in Social Cognitive & Affective Neuroscience indicates that there are methods to help you.

Our research team at the Charité hypothesized that hypnotic suggestions and/or autosuggestions (giving suggestions to oneself) may be able to reduce the attractiveness of unhealthy temptations, or more specifically, snack food.
We invited 32 participants who were responsive to hypnosis and assigned them to two groups. One group was hypnotized by a professional hypnotist, while the other group used autosuggestion. Participants in the hypnosis group were suggested to experience disgust whenever they would encounter a color cue after hypnosis, namely green (half of the participants) or blue (the other half). They were further suggested that they would experience disgust only regarding specific snacks, namely either sweet snacks (half of the participants) or salty snacks (the other half). This was done to assess if hypnosis can target specific stimuli, rather than merely inducing a general feeling of disgust. In the autosuggestion group, participants were instructed to make the disgust association (regarding specific snacks and the cue color) on their own, and they were given as much time for this as the hypnotized participants. Afterwards, participants entered a functional magnetic resonance imaging (fMRI) scanner and carried out a virtual auction on sweet and salty snacks (e.g. Mars bars, Snickers bars). These snacks were shown on a background that was blue for half of the time and green for the rest of the time.

Experimental procedure and the paradigm used in the scanner. Source: Ludwig et al, Soc Cogn Affect Neurosci, 2013

We found that participants of both groups were less willing to pay for the snacks targeted by hypnosis or autosuggestion (salty or sweet) when shown on the relevant cue color (blue or green background, depending on the participant). Surprisingly, there were no behavioral differences between the hypnosis and the autosuggestion group. Also, on a self-report questionnaire, participants of both groups indicated that they had indeed experienced disgust regarding the targeted snacks. However, participants subjected to hypnosis described the effects as more automatic, physical, and genuine (not merely simulated) compared to participants who had used autosuggestion. Finally, the fMRI data analysis showed that the ventromedial prefrontal cortex (vmPFC) was activated less when participants (in both groups) made decisions about targeted snacks shown on the cue color compared to the other snacks. The vmPFC is known to correlate with the perceived attractiveness of stimuli. Thus, the fMRI data are consistent with the idea that the targeted snacks were indeed perceived as less attractive than the other types of snacks following the interventions. Interestingly, hypnosis affected vmPFC activation more than autosuggestion.

Effects on VMPFC were stronger in the hypnosis group compared to the autosuggestion group. Source: Ludwig et al, Soc Cogn Affect Neurosci, 2013

In sum, both hypnosis and autosuggestion can decrease the attractiveness of unhealthy snacks. Moreover, neural and self-report evidence indicate that hypnosis has stronger effects than autosuggestion. Future studies should test the longevity of these effects and should determine whether the differences in brain activation and self-report between the groups are relevant for real-life behavior. The next time you want to resist chocolate, take some time to relax and suggest to yourself that it is disgusting - you might be surprised how powerful a suggestion can be.

Reference

Ludwig et al, Soc Cogn Affect Neurosci, 2013

By Dr. rer. nat. Vera Ludwig, Postdoctoral Fellow, Divison of Mind and Brain Research at the Charité.
this article was originally published 2014 in CNS Volume 7, Issue 1, Mind and Brain 

Coma - A Classical Disorder of Consciousness

Three years ago Michael Schumacher suffered a traumatic brain injury during a skiing accident and was put into a medically induced coma. Mid 2014 he was showing "moments of consciousness" and moved from intensive care into a rehabilitation ward. In November 2014, it was reported that Schumacher was "paralysed and in a wheelchair"; he "cannot speak and has memory problems". Not much more is known about his beeing. Let's have a closer look at this disorder of concisousness.


Every now and then, popular media reports stories of miraculous coma recoveries. Even in modern and motor criteria [1].

Michael Schumacher 2010  by ph-stop via flickr

neurology, disorders of consciousness are little understood and among the least curable. They are classified into coma, vegetative state, and minimally conscious state [1]. Coma is characterized by a lack of arousal and wakefulness - patients do not respond to even rigorous stimulation, whereas the vegetative state is marked by wakefulness without awareness. The minimally conscious state is characterized by a minimal but obvious behavioural evidence of awareness. To assess the conscious state of a patient, the Glasgow coma scale is used to classify the severity of unconsciousness based on eye opening, verbal response,
Coma may occur after functional impairments from toxic or metabolic causes, or structural injuries such as lesions of the ascending reticular activating system (connecting the upper brainstem to the cortex). Coma prognosis is determined by the etiology and severity of injury [2]. If applicable, treatment consists of a reversal of the cause, e.g. stopping brain swelling or reversing metabolic abnormalities.

COMA  CAN LAST FROM HOURS TO YEARS

Most coma patients regain consciousness over hours to weeks, while others transition into a vegetative state. Recovery is usually gradual, and seldom leads to full neurological recovery. Patients acquire more and more of their former abilities but are often left with residual cognitive impairment. Physiological recovery depends on functional restoration of cortico-thalamo-cortical connections, restoration of a neurotransmitter balance and recovery of neuronal plasticity [2].
To date, there is no accepted pharmacological therapy for coma patients, but recent studies suggest that some drugs may contribute to consciousness recovery by restoring neurotransmitter balances, leading to an increase in synaptic plasticity and functional connectivity [3]. Among them are CNS stimulants such as some antidepressants and dopaminergic agents, for example amantadine, but also CNS depressants such as zolpidem - having a rather acute effect suggesting rapid neurotransmitter changes, or baclofen - likely playing a role in plasticity and reported to result in dramatic recovery from the vegetative state [3].
In summary, coma is a severe disorder of consciousness that can last from hours to years. Ongoing research is investigating what happens in the damaged brain during recovery and how drugs can induce recuperation from disorders of consciousness.


[1] Bernat, Lancet, 2006
[2] Goldfine and Schiff, Neurol Clin, 2011
[3] Pistoia et al, CNS Drugs, 2010


by Claudia Willmes, PhD Student AG Eickholt / AG Schmitz
this articel was originally published March 2014 in Volume 07, Issue 1"Mind and Brain".