Giulio Tononi

Giulio Tononi (* Trento, Trentino -Alto Adige, Italy) is a psychiatrist and neuroscientist. He has been a professor of psychiatry at the University of Wisconsin - Madison and is head of the Center for Sleep and Consciousness. Tononi developed with Chiara Chirelli the synaptic homeostasis hypothesis (synaptic homeostasis hypothesis), which states that the deep sleep to be necessary to restore a basic level of synaptic activity. His second research topic is about how consciousness comes about; Tononi has developed to the Integrated Information Theory ( theory of integrated information ).

Biography

Tononi studied medicine and specialized in the field of psychiatry at the Scuola Superiore Sant'Anna in Pisa. He also earned a PhD in neurobiology and graduated with a theme about the regulation of sleep. Before moving to Madison, he conducted research at the Neurosciences Institute in New York and in San Diego.

Synaptic Homeostasis Hypothesis

" Essentially, the sleep is the price we have to pay for the plasticity [ neural ] ... "

According to this theory in the waking state information is incorporated into the power structures of the nerve cells, that is, the synapse strength increases, and it also caused synaptic Neuverknüpfungen. This is done by the so-called long-term potentiation. In deep sleep (more precisely, in the non -REM sleep ) but there is a kind of co-ordination of certain neuronal groups that are characterized by long-wave potentials (occurring in the EEG, the so-called delta waves ) apparent power and is responsible for ensuring that the synapse connection strength and number decreases again ( synaptic downscaling ). The fact that only the more strongly potentiated synapses survive, important and unimportant will be selected.

Integrated Information Theory

"Everyone knows what consciousness is: It is what every night disappears as soon as we fall into a dreamless sleep, and come back as soon as we wake or dream. In this sense, the term consciousness is synonymous with experience. "

According to this theory arises consciousness when sufficient " integrated" information is available. His concept of integration Tononi leads to the following comparison: Before a screen, which is alternately bright lights and dark, both a man and a photodiode can, as in a camera, recognize the two states. The difference lies in how much information is generated: The photodiode detects ' light ' or ' dark ' and thus generates 1 bit of information. A human being is different ' light ' not only of ' dark ', but by a vast variety of other ways, such as a red screen, a green screen, a film frame, a sound, a thought, etc.. During the countless photodiodes a camera work independently, the human brain makes his distinctions as an integrated system. How hard you tried, you can not reduce it to separate sensations of its color and its shape conscious perception, for example, a red apple. Tononi refers to the extent of integrated information as Φ ( Phi ); when all the individual components work independently, Φ = 0

Tononi writes: " Using computer simulations [ can ] be shown that highly integrated information requires a network that combines functional specialization with functional integration. Exactly this kind of architecture is characteristic of the thalamocortical system in mammals: Various parts of the cerebral cortex are specialized in different functions: from the level of lobes to the areas, the groups of neurons, and perhaps even down to the individual neurons. In addition, there is a wide network of contacts, which allows these parts to interact with each other ... So do not you agree with the observation that the thalamocortical system is exactly that part of the central nervous system, whose heavy damage pulls a loss of consciousness after himself. Conversely, the value of, Integrated Information ' in systems is low, which are based on small, quasi- independent modules. This will be the reason why the cerebellum despite its immense number of neurons hardly contributes something to the emergence of consciousness. "

Tononi and Gerald M. According to Edelman, a re-entry mechanism is unique feature of the integration .. Reentrant signals within the cerebral cortex or between the cerebral cortex and thalamus to establish a coherent process of active neurons, which is generally stable, although his neural composition alters constantly. Such self-sustaining dynamic processes within the thalamocortical system are of considerable importance for the understanding of consciousness. To conscious experience to maintain the functional cluster must also be highly complex. Refers to those clusters of Tononi Edelman and a flexible or dynamic nuclear structure (Dynamic core), there is mostly, if not exclusively in the thalamocortical system.

The American neuroscientist Christof Koch, according to one could view the IIT as a scientific form of panpsychism.

Awards

In 2005, Tononi the NIH Director's Pioneer Award was awarded for his work on the mechanisms and functions of sleep; in 2008 he received the David P. White Chair in Sleep Medicine and the Distinguished Chair in Consciousness Science.