From Amoeba to Cognition Frankfurt Institute of Advanced Studies April 16, 2003 Christoph von der Malsburg Institut für Neuroinformatik und Fakultät für Physik und Astronomie Ruhr-University Bochum, Germany and Computer Science Department and Program in Neuroscience University of Southern California Los Angeles
Amoeba
Euglena
History of life
Repertoire of single-celled animals 1 Metabolism Production, transformation and breakdown of molecules Synthesis of molecules under genetic control Regulation, e.g., of ionic concentrations Transport of molecules, inside, in and out of cell Electrical “behavior” Circadian rhythm Reproduction
Repertoire of single-celled animals 2 Behavior Sensing (light, sound, chemical milieu) Self-shaping (pseudopodia, mitosis) Motility, esp. chemotaxis Feeding: ingestion and digestion Aggression, flight Signalling Collaboration (e.g., slime mold, biofilms)
Amoeba aggregation 2
Spiral waves
Ants
Neuron 1
Neuron 2
Synapse
The Ontogenetic “Riddle” Information content of the genome: 10 9 bits Information content of the brain’s wiring: bits (10 10 neurons, hence ld = 33 bits per connection, times synapses = bits of information) Solution: genetically controlled self-organization
Rettec anatomical schema A Model for the Ontogenesis of Retinotopy (Willshaw and Malsburg, 1976)
Rettec functional schma Chemotaxis Synaptic plasticity controlled by electrical signals
Hebbian Plasticity Correlation-controlled Synaptic Plasticity (“Hebbian Plasticity”) Time 10 sec
Meister (Prenatal ferret retina, M. Meister et al.)
Network Self-Organization NetworkSignals Signal Dynamic Synaptic Plasticity
Rettec functional schma
Rettec principle 2
Rettec development
Visual system schema
Levay stripes
Binoc 1 A Model for the Ontogenesis of Ocularity Domains (Biol. Cybernetics, 1977)
Binoc 2
H&W orient
Devalois 2
73 projection A model for the development of orientation- specific neurons (Kybernetik, 1973) Retina Cortex Connection Strength
73 stimuli Retinal Stimuli
Meister (Prenatal ferret retina, M. Meister et al.)
73 cell 70 Re-organization of a cortical receptive field
73 cortex post
73 orientmap
Devalois 1
Gabors
Olshausen-and Field: Schema Development of connections strengths Φ i (x,y) under 2 constraints: Preservation of information (ability to reconstruct) Sparsity Natural images
Olshausen-Field Gabors
Points of Conclusion: Retinotopy, orientation specificity as paradigms of network self-organization and CNS ontogenesis Ontogenesis of CNS and cellular repertoire Amount of genetic information
Invariant object Recognition (As paradigm of a cognitive function) imagemodel
van Essen
Rubfig 1 Image DomainModel Domain Model Window Object recognition
Rubfig 2 Image DomainModel Domain Model Window Objection recognition 2
Temporal binding Rapid, Reversible Synaptic Plasticity Time 10 msec
Network Self-Organization NetworkSignals Signal Dynamic Synaptic Plasticity
Image-to-jets
Maryl-representation
2D mapping formation
Face recognition rates ModelProbeSizeRecogniti on rate * Other systems frontalDiff expression large transform 12485% frontalDiff expression small transform %98% (=245/250)(Wiskott et al 97) frontal30° rotation in depth %66.4% (=73/110)(Wiskott & Malsburg 96) * After 3 iterations
Marylin
Points of Conclusion: Evolution as a game of varying the eurkaryote’s repertoire Ontogenesis as a refinement of old cellular behavioral patterns reproduction, differentiation cellular migration, chemotaxis chemical signalling, reaction-diffusion patterns putting out of “pseudopodia” Brain function as a fast version of the same game again Network Self-Organization the central process
Outlook The flexibility of the human brain shows that fundamental principles are at work Similar conclusions may be drawn from the rapid development of human society Elucidating the general principles of organization is the challenge of our times This issue has at present no academic home
Molecular Biology
The Software Crisis NIST Study 02: yearly US loss due to SW failure: $60 Billion
Human: Detailed Communication Machine : Creative Infrastructure: Goals, Methods, Interpretation, World Knowledge, Diagnostics Algorithms: deterministic, fast, clue-less Algorithmic Division of Labor Algorithmic DOL
Human: Loose Communication Machine : Goal Definition Creative Infrastructure: Goals, Methods, Interpretation, World Knowldege, Debugging Data, „Algorithms“ Organic Computers
Self-Organization in Need of Development The ideas of self-organization have created a revolution, but they are now in need of forceful further development! Underdeveloped aspects: Control of the control parameters (Ashby’s super-stability) Explicit representation of goals Cascades of organization (description of unfolding systems) Escaping geometry (e.g., network self-organization)
Physics to the Rescue!! Physics has a proven track-record of understanding complex phenomena on the basis of simple paradigms and principles Physics is in possession of highly relevant methodology (statistical mechanics, systems of non-linear differential equations) Physics has a very successful system of education Physics is on the look-out for a new application field