EMBL/EMBO Joint Conference 2006
Wolf Singer, Max-Planck-Institute for Brain Research, Frankfurt, Germany
Wolf Singer is Director at the Max Planck Institute for Brain Research in Frankfurt and Founding Director of the Frankfurt Institute for Advanced Studies (FIAS). He studied medicine at the Universites of Munich and Paris, received his M.D. from the Ludwig-Maximilians-University and his Ph.D. from the Technical University in Munich. Until the mid-eighties his research interests were focused on the experience-dependent development of the cerebral cortex and on mechanisms of use-depedent synaptic plasticity. Subsequently, his research concentrated on the binding problem that arises from the distributed organization of the cerebral cortex. The hypothesis forwarded by Dr. Singer is that the numerous and widely distributed subprocesses which constitute the basis of cognitive and executive functions are coordinated and bound together by the precise temporal synchronization of oscillatory neuronal activity.
Dr. Singer has signed more than 254 articles in peer-reviewed journals, contributed more than 191 chapters to books, has written numerous essays on the ethical and philosophical implications of neuroscientific discoveries, and published 2 books. He is the recipient of numerous awards including the IPSEN Prize for Neuronal Plasticity, the Ernst Jung Prize for Medicine, the Zülch Prize for Brain Research, and the Communicator Prize of the German Research Foundation. He is member of numerous national and international academies, including the Pontifical Academy of Sciences. He served as President of the European Neuroscience Association, as Chairman of the Board of Directors of the Max Planck Society, and as member of numerous Advisory Boards of scientific organizations and editorial boards of journals.
The role of coherence in higher cognitive processes
In principle, neurons can encode information in at least two ways, i) by varying the amplitude of their response (rate code) and/or ii) by adjusting the precise timing of individual discharges (temporal code). It is proposed that cortical networks use both coding strategies in parallel, exploiting their respective advantages. Evidence is presented that precise coordination of spike timing across neuronal assemblies is frequently associated with an oscillatory patterning of discharge sequences in the beta and gamma frequency range and the synchronisation of distributed responses with millisecond precision.
This synchronisation appears to be exploited to i) jointly raise the saliency of responses to sensory stimuli in the context of perceptual grouping (binding), ii) read out grouping criteria residing in the functional architecture of cortical networks during the free exploration of visual scenes, iii) prepare as a function of attention and response anticipation the hand-shaking between distributed cortical regions , iv) determine the occurrence and polarity of use dependent synaptic modifications and v) gate the access of sensory signals to consciousness. Recent data indicate further that cognitive functions requiring dynamic binding are disturbed in schizophrenia patients and that these deficits go along with a reduced ability to precisely synchronize responses across distributed cortical networks. The possibility is suggested that some of the dissociative symptoms characteristic of this disease result from impaired binding functions.