Manfred's Column

 

 

Manfred Spitzer, M.D., Ph.D. is Medical director, professor and chairman (Head of Department) of the newly established Psychiatric Hospital at the University of Ulm (Universitätsklinik für Psychiatrie), Germany.

His research activities focus on the interface between cognitive neuroscience and psychopathology, using multimodal neuroimaging techniques, such as event related potentials, functional magnetic resonance imaging, transcranial magnetic stimulation and experimental neuropsychological methods to study psychiatric symptoms, syndromes and disorders.

In 2004 he established the Transfer Center for Neuroscience and Learning (Transferzentrum für Neurowissenschaften und Lernen [ZNL]), for which he is director.

His teaching activities include the weekly main lecture in psychiatry at the University of Ulm and seminars on topics in cognitive neuroscience and psychiatry.

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The following articles have been translated into English with the courtesy of Manfred Spitzer from his works as published in the "Nervenheilkunde" series, Schattauer Publishers, Stuttgart, New York.

Better Than Thought: Learning, Dopamine and Neuroplasticity  - January 2006

  • The dopamine system is associated with various disorders. For example, if a part of the brain called the striatum lacks dopamine, a person shows the symptoms of Parkinson’s disease: tremor while at rest, muscle and limb rigidity and difficulty with initiating movement (akinesia). By contrast, too much dopamine causes hyperkinesias. Furthermore, in schizophrenia a lack of dopamine in the frontal brain is associated with schizophrenic “negative” symptoms, i.e. the absence of normal social or interpersonal behaviours, like a low level of emotional arousal (flat affect). By contrast, too much dopamine with schizophrenia causes “positive” symptoms, i.e. the presence of abnormal behaviours, such as delusions, hallucinations or disordered thoughts.

Brain versus the gut: Experience versus strength  - December 2005

  • Living organisms take up and metabolise substances that are rich in energy and their development and activities are limited by the corresponding balance between the uptake and the consumption of energy. In mammals, the brain and the gut both consume a large amount of energy. In humans, the brain consumes about 20% of the total energy ingested. From an evolutionary viewpoint, an organism needed to choose between an energy consuming alimentary system requiring little mental capacity – i.e. one where large amounts of difficult-to-digest food were consumed – or an energetically more favourable alimentary system, which could be sustained by more easily digested food (animal proteins), but which would also require a higher mental capacity and thus a larger brain. It is for this reason that mammals have either large guts or large brains; they cannot afford to have both (1). This difference in specialisation goes along with a difference in the sources of nutrition: a large gut was needed by herbivores because the vegetation they eat is difficult to digest, while carnivores required a large brain in order to hunt successfully.

Post and pop-out: About the neuroplasticity of cortical maps in postal workers - November 2005

  • The cortex of the human brain is organised into map-like areas and each “map” represents certain functions. For example, a part of the brain known as the somatosensory cortex is like a body map for sensory sensations. Touching the skin of the thumb activates a group of neurons in the brain and, within this map for sensory representations, these represent the sensation of touch on the thumb. If one now touches the skin of the index finger, a group of neurons in the cortex is activated and these are close to the group of neurons activated by the touch of the thumb. If the skin of the middle finger is then touched, a group of neurons in the cortex is activated and these are close to the group of neurons activated by the touch of the index finger. Thus the touching of body parts that are close to each other activates brain areas that are close to each other, and the touching of body parts is represented by the activation of a map-like pattern of groups of neurons in the brain. 

Learning, LTP and the hippocampus - September/October 2005

  • From an evolutionary perspective, the hippocampus is an old part of the brain, which lies deep in the temporal lobe and has, for a long time, been associated with learning and memory. Two studies shed a new light on this structure. In one, it has been proven that the hippocampus is also involved in unconscious learning, and in the other, the relationship between the modification of synaptical strengths through LTP (long-term potentiation) and the hippocampus and learning, respectively, has been more closely linked

Learning during sleep: off-line reprocessing - July/August 2005

  • Readers might have made the following observation: despite learning or practising something assiduously (e.g. juggling), you are still not able to perform it correctly. Disappointed by the results of your efforts, you forget about it and are surprised when you come back to it some time later that it works perfectly.

Learning in the womb: hearing, touching and smelling - June 2005

  • It has often been asserted that human foetuses are exposed to environmental stimuli that have a lasting effect. The effects thereof are often negative: medication, viral infections or a malnourished mother might have a harmful effect on the foetus. But environmental stimuli might also have positive influences, as anecdotes tell. For example, during her pregnancy, King Heinrich IV of Germany’s mother had a musician come every morning to play in close proximity to her. At that time, people believed that the foetus could hear the music and that music would have an influence on the person’s later character by preventing him or her from becoming bad humoured. According to historians, this worked for Heinrich IV: he was good humoured all his life.

The focus of attention and working memory - May 2005

  • Imagine you are traversing city streets. While driving, you need to focus on important information, e.g. a red light or pedestrians walking into the street, while ignoring irrelevant information, such as the type of tree lining the road. To achieve such a feat, selective attention is required. Now imagine that, while driving, you are constantly going over the street name and number of your destination in your mind. This process requires working memory, which is where the brain temporarily stores information used in reasoning and planning. Thus, in order to get safely to your goal, you need two higher cognitive capabilities, selective attention and working memory.

From Neurons to Delusions - April 2005

  • From neurons to delusions — to the reader this may sound either like a categorical mistake or like plain exaggeration – or both. Nevertheless, at present it is possible to see connections between the function of neurons on the one hand, and higher cognitive functions and their pathology on the other hand, which even a few years ago were impossible to envision. The study of these connections has transformed psychiatry into one of the most exciting fields of present day research.

Descartes, glutamate and the fifth taste - March 2005

  • Imagine the following scenario: Physiologists claim that there are only four basic colors: violet, blue, green and yellow. We see these colors and nothing but these colors. The light sensitive cone has been discovered and the basis of color vision has been clarified. We, lay persons as regards to process of seeing, believe in science and see exactly these colors. However, sometimes things look somehow more colorful and in fact really beautiful, as for example some flowers and some landscapes during sunset. At other times, things don't look as colorful and beautiful. Because we know from physiology that there are only the colors mentioned above, we can account for the differences in color vision by making the assumption that sometimes there is some color amplifier in the light, and sometimes there isn't. The assumption of a color amplifier that is more or less present together with the colors that we see accounts for all the phenomena of color vision.

Engagement rings, parasites and brains - February 2005

  • According to an unwritten law of American culture, the engagement ring should cost about two months salary. Once we assume that this custom is not the result of highly successful manipulative advertising strategies of the diamond monopolist DeBeers, we may ask, why does this custom exist? In particular, why does it exist in a society that prides itself in claiming that it economically optimizes practically all aspects of life? A diamond costs the giver a fortune but leads to very little benefit for the recipient. It is therefore quite the opposite of a reasonable investment. Why, we may ask again, are there such unreasonable investments, especially in a country where wise investment is regarded as as the ultimate goal of so many acivities?

Violence on TV: We Must Stop Watching - January 2005

  • During my second visiting professorship at Harvard University, my family and I lived quite close to the campus. This had the advantage that I could walk to my office and my children could attend a public school located close by just a few houses down the street. Soon after school started — my oldest son went to first grade — we received a letter from the school principle which all parents of new pupils received, had to sign and hand back to the school. Among other items, this letter stated that we should take care that our son would not bring a gun into the school. My wife and I were shocked. Of course, we complied.

How many H2O molecules are wet? Pseudo categorical mistakes and the scope of empirical research - December 2004

  • If you ask an educated person, how many water molecules it takes such that they become wet the most likely answer you will get is this: (a) H2O molecules are a conceptual construction within the framework of chemistry for the purpose of describing facts and processes about the transformation of matter. Chemical formulas enable us to calculate how much hydrogen and oxygen is needed to synthesize water, and vice versa, i.e., how much of the gases you get when you use energy to split the water molecule.

To have an idea versus to justify it: Why medicine is more than science - November 2004

  • Ideas from philosophy of science rarely generate much enthusiasm in medical students. The subject appears to be dry, detached from reality and clinical medical practice. A look behind the scenes of philosophy of science which admittedly consist of a rather opaque mixture of methods, jargon, schools of thought and logic, however, teaches some important lessons and brings about vistas on useful concepts for the understanding of medical practice. In what follows let us discuss the example of the difference between having an idea and justifying it which has been a subject of discussions about the growth of knowledge by philosophies of science.