The Power of Images
Watching the Brain Think
Interview with Hans-Jochen Heinze
Imaging methods have revolutionised brain research and turned it into a topic of public debate. Kosmos talked to neurologist Hans-Jochen Heinze about why the colourful pictures of the brain are so suggestive, what new therapies they can pave the way to and how brain research could also help the healthy in future.
Kosmos: Professor Heinze, up to about twenty years ago, brain researchers had to make do with preparations, measurements of brain currents and X-ray photos. Today, it is possible to look at colourful, three-dimensional pictures of the scene of the action. Can you still remember your "first time" you experienced the new options?
Heinze: That was in the 80s, when I was a post-doc in the USA. Up to then, brain research had concentrated almost exclusively on the EEG, on recording electric brain activity. When we then saw PET images of the brain in action, we thought we could now forget about our previous results and methods. The pictures showed a network of active brain structures that we would so far have only been able to anticipate indirectly, from the brain surface. To us all, it was obvious that this approach amounted to a revolution in brain research.
Kosmos: So now you could virtually watch the brain think ...
Heinze: Within certain restraints, we had already been able to watch the brain think with our old technology. Our initial suspicion that functional imaging could render electrophysiology obsolete proved unfounded. Rather, it is only the combination of both methods that enables us to understand the spatio-temporal architecture of advanced brain functions.
Kosmos: Is it also thanks to these colourful and impressive images that brain research has attracted so much attention?
“A 'designer brain' optimised to meet material priorities would without doubt be a highly reprehensible development.”
Heinze: Of course these images are suggestive. For instance, a high level of activity is represented in deep red, while low activity is in blue. Here, the fact that our brain responds especially well to contrasts and conspicuous colour stimuli is taken advantage of. If you were to merely write numbers into the image instead of colours, the statements would be exactly the same from a scientific angle. But that would not be particularly illustrative and would be of little help in quickly gaining an understanding of the results.
Kosmos: You can watch how the human brain responds to certain stimuli, for instance which images trigger certain emotions. That would be an interesting application in advertising ...
Heinze: ... and is already being used by some firms. If you look at advertising, there are several levels of processing in the brain only a very small share of which people are aware of and of which nothing is learnt via classic methods of market research such as test demonstrations and interviews. In contrast, imaging could help visualise some of these processes.
Kosmos: This would get the advertising people a lot closer to the "glass consumer". But in what way can doctors and patients benefit from the new technology?
Heinze: It helps us detect the causes of certain diseases. For instance, we can discover in which areas of the brain and at which level of information processing faulty perceptions, deficits or hallucinations are generated. Behavioural disorders and pathological processes in certain nerve cell populations can thus be assigned to each other.
Kosmos: Does this also lead to new therapies?
Heinze: There are several applications in cognitive neurology and psychiatry, such as the treatment of certain neuro-psychiatric diseases like those of people with an obsessive disorder. Some of these people are unable to suppress the compulsion to inflict severe injuries upon themselves and cannot be treated with conservative methods. Here, it is assumed that changes in activity in certain brain areas such as the Nucleus Accumbens play an important role in this disease. This is where a new, invasive therapy comes in. Having established the exact position of this area with imaging methods, one then regulates activity in a sub-area of the Nucleus Accumbens using electric stimulation via a stereo-tactically inserted electrode. Sometimes, the results are dramatic. The compulsion will ebb, and some of the patients are once again able to pursue their professions.
Kosmos: All this raises the question whether we have a free will. Are we ultimately merely slaves of neuronal thunderstorms in our heads? Compulsive acts would only be one extreme example ...
Heinze: Yes, this is a frequently discussed question nowadays, although of course, it is by no means new. Is our thinking and acting the result of causal neural activity, and don't we therefore have to forget the issue of guilt and rewrite the chapter on morals? I believe that such a conclusion isn't justified. Not that I have any doubts that thinking, deciding and acting is linked to neural activity and therefore physical laws. But I believe that these contexts are far too complicated for us to be able to comprehend them with our present level of knowledge if not with our cognitive capacity in general. With state-of-the-art science, it wouldn't be appropriate to describe our personal perception of responsibility and freedom, the basis of our morals, as a neural "deception".
Kosmos: Nevertheless, these issues have been elaborately discussed in the German feature pages. Is the importance of your subject regarding philosophical principles being overestimated?
Heinze: Sometimes, perhaps. At any rate, I would assess the role of cognitive neuro-science more from a pragmatic angle. It is supposed to contribute to diagnosing and treating disorders in neural processes so that the human being is enabled to objectively understand and value the world within his abilities and plan and implement alternative concepts of life.
Kosmos: Do the alternative concepts of life include treating the brains of the healthy as well sooner or later? The recently discovered agent to enhance the memory could be an initial step in this direction ...
Heinze: Scientists really are already working on this. Some of these approaches, such as enhancing certain types of memory performance, are not unrealistic. Older people in particular could benefit from this, for we know that from the age of 60 years on, changes in the storage and retrieval of information frequently occur among healthy people as well. The Old and the New is experienced differently from in youth.
Kosmos: Optimising the human brain would raise grave ethical issues and probably bring determined opponents into the arena, at least as much as genetic engineering ...
Heinze: Of course this has to be considered very carefully. A "designer brain" optimised to meet material priorities would without doubt be a highly reprehensible development. But I believe that such scenarios are hardly realistic. Intelligence, creativity, compassion and morals are based on extremely complex processes.We may be able to identify individual factors that lead to grave disorders if a dysfunction occurs. But this would by no means justify turning the argument on its head and claiming that modifications of individual factors, for instance through drugs, would improve and enrich cognitive performance and the personality as a whole. Rather, "optimising the human brain" is conditional on factors that would still be evident even without neuro-science: good general education and upbringing, an intact family and an optimistic, caring society.
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