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Computers with Brains? A neuroscience perspective Khurshid Ahmad, Professor of Computer Science, Department of Computers with Brains? A neuroscience perspective Khurshid Ahmad, Professor of Computer Science, Department of Computer Science Trinity College, Dublin-2, IRELAND October 29 th , 2009. https: //www. cs. tcd. ie/Khurshid. Ahmad/Teaching/Computers. Brains. pdf 1

Brain – The Processor! http: //www. cs. duke. edu/brd/Teaching/Previous/AI/pix/noteasy 1. gif 2 Brain – The Processor! http: //www. cs. duke. edu/brd/Teaching/Previous/AI/pix/noteasy 1. gif 2

Brain – The Processor! Neural computing systems are trained on the principle that if Brain – The Processor! Neural computing systems are trained on the principle that if a network can compute then it will learn to compute. Multi-net neural computing systems are trained on the principle that if two or more networks learn to compute simultaneously or sequentially , then the multi-net will learn to compute. Our project is to build a neural computing system comprising networks that can not only process unisensory input and learn to process but that the interaction between networks produces multisensory interaction, integration, enhancement/suppression, and information fusion. Tim Shallice (2006). From lesions to cognitive theory. Nature Neuroscience Vol 6, pp 215 (Book Review: Mark D’Esposito (2002). Neurological Foundations of Cognitive Neuroscience 3

What humans do? 4 What humans do? 4

What animals do? Dendritic computation. The task of a brainstem auditory neuron performing coincidence What animals do? Dendritic computation. The task of a brainstem auditory neuron performing coincidence detection in the sound localization system of birds is to respond only if the inputs arriving from both ears coincide in a precise manner (10– 100 μs), while avoiding a response when the input comes from only one ear. London, Michael and Michael Häusser (2005). Dendritic Computation. Annual Review of Neuroscience. Vol. 28, pp 503– 32 5

What computer scientists do? The study of the behaviour of neurons, either as 'single' What computer scientists do? The study of the behaviour of neurons, either as 'single' neurons or as cluster of neurons controlling aspects of perception, cognition or motor behaviour, in animal nervous systems is currently being used to build information systems that are capable of autonomous and intelligent behaviour. 6

What animals do? Neurons are known to be involved in much more sophisticated computations, What animals do? Neurons are known to be involved in much more sophisticated computations, such as face recognition [. . ]. An algorithm to solve a face recognition task is one of the holy grails of computer science. At present, we do not know precisely how single neurons are involved in this computation. An essential first step is feature extraction from the image, which clearly involves a lot of network pre-processing before features are fed into the individual cortical neuron. The flowchart implements a three-layer model of dendritic processing […] to integrate the input. The way such a flowchart is mapped onto the real geometry of a cortical pyramidal neuron remains unknown. 7 London, Michael and Michael Häusser (2005). Dendritic Computation. Annual Review of Neuroscience. Vol. 28, pp 503– 32

What animals do? Neurons, and indeed networks of neurons perform highly specialised tasks. The What animals do? Neurons, and indeed networks of neurons perform highly specialised tasks. The dendrites bring the input in, the soma processes the input and then the axon outputs. However, it appears that the dendrites also have processing power: it is the equivalent of the wires that connects your computer to its printer and the network hub performing computations – helping the computer to perform computations!!! London, Michael and Michael Häusser (2005). Dendritic Computation. Annual Review of Neuroscience. Vol. 28, pp 503– 32 8

What humans think about what computers will do? http: //www. longbets. org/1 9 What humans think about what computers will do? http: //www. longbets. org/1 9

What humans do? They have an intricate brain 10 What humans do? They have an intricate brain 10

Neural Nets and Neurosciences Observed Biological Processes (Data) Neural Networks & Neurosciences Biologically Plausible Neural Nets and Neurosciences Observed Biological Processes (Data) Neural Networks & Neurosciences Biologically Plausible Mechanisms for Neural Processing & Learning (Biological Neural Network Models) Theory (Statistical Learning Theory & Information Theory) http: //en. wikipedia. org/wiki/Neural_network#Neural_networks_and_neuroscience 11

Real Neuroscience Cognitive neuroscience has many intellectual roots. The experimental side includes the very Real Neuroscience Cognitive neuroscience has many intellectual roots. The experimental side includes the very different methods of systems neuroscience, human experimental psychology and, functional imaging. The theoretical side has contrasting approaches from neural networks or connectionism, symbolic artificial intelligence, theoretical linguistics and information-processing psychology. Tim Shallice (2006). From lesions to cognitive theory. Nature Neuroscience Vol 6, pp 215 (Book Review: Mark D’Esposito (2002). Neurological Foundations of Cognitive Neuroscience 12

Real Neuroscience Brains compute. This means that they process information, creating abstract representations of Real Neuroscience Brains compute. This means that they process information, creating abstract representations of physical entities and performing operations on this information in order to execute tasks. One of the main goals of computational neuroscience is to describe these transformations as a sequence of simple elementary steps organized in an algorithmic way. The mechanistic substrate for these computations has long been debated. Traditionally, relatively simple computational properties have been attributed to the individual neuron, with the complex computations that are the hallmark of brains being performed by the network of these simple elements. London, Michael and Michael Häusser (2005). Dendritic Computation. Annual Review of Neuroscience. Vol. 28, pp 503– 32 13

Real Neuroscience I compute, therefore I am (intelligent): I can converse in natural languages; Real Neuroscience I compute, therefore I am (intelligent): I can converse in natural languages; I can analyse images, pictures (comprising images), and scenes (comprising pictures); I can reason, with facts available to me, to infer new facts and contradict what I had known to be true; I can plan (ahead); I can use symbols and analogies to represent what I know; I can learn on my own, through instruction and/or experimentation; I can compute trajectories of objects on the earth, in water and in the air; I have a sense of where I am physically (prio-perception) I can deal with instructions, commands, requests, pleas; I can ‘repair’ myself; I can understand the mood/sentiment/affect of people and groups I can debate the meaning(s) of life; 14

Real Neuroscience I cannot compute, therefore I am (not intelligent? ): I cannot add/subtract/multiply/divide Real Neuroscience I cannot compute, therefore I am (not intelligent? ): I cannot add/subtract/multiply/divide with consistent accuracy; I forget some of the patterns I had once memorised; I confuse facts; I cannot recall immediately what I know; I cannot solve complex equations; I am influenced by my environment when I make decisions, ask questions, pass comments; I will (eventually) loose my faculties and then die!! 15

Real Neuroscience I can and annot compute because of my nervous system I use Real Neuroscience I can and annot compute because of my nervous system I use language, can see things, represent knowledge, learn, plan, reason …. Because of my nervous system? I cannot do arithmetic consistently, cannot recall and/or forget…. Because of my nervous system? 16

DEFINITIONS: Artificial Neural Networks (ANN) are computational systems, either hardware or software, which mimic DEFINITIONS: Artificial Neural Networks (ANN) are computational systems, either hardware or software, which mimic animate neural systems comprising biological (real) neurons. An ANN is architecturally similar to a biological system in that the ANN also uses a number of simple, interconnected artificial neurons. 17

DEFINITIONS: Artificial Neural Networks Artificial neural networks emulate threshold behaviour, simulate co-operative phenomenon by DEFINITIONS: Artificial Neural Networks Artificial neural networks emulate threshold behaviour, simulate co-operative phenomenon by a network of 'simple' switches and are used in a variety of applications, like banking, currency trading, robotics, and experimental and animal psychology studies. These information systems, neural networks or neuro-computing systems as they are popularly known, can be simulated by solving first-order difference or differential equations. 18

The real neurons are different! Real neurons co-operate, compete and inhinbit each other. In The real neurons are different! Real neurons co-operate, compete and inhinbit each other. In multi-modal information processing, convergence of modalities is critical. Multisensory Cross-modal Enhancement Facilitation Cross-modal Facilitation Inhibition. Dependent From Alex Meredith, Virginia Commonwealth University, Virginia, USA Cross-modal Suppression 19

Computation and its neural basis Much of modern computing relies on the discrete serial Computation and its neural basis Much of modern computing relies on the discrete serial processing of uni-modal data Much of the computing in the brain is on sporadic, multimodal data streams 20

Computation and its neural basis Analysis of neuroscience experiments is carried out with simple Computation and its neural basis Analysis of neuroscience experiments is carried out with simple models without the capability of learning Neural computing emphasises the learning aspects of behaviour 21

Computation and its neural basis Decision making invariably involves fusion of multi -modal data Computation and its neural basis Decision making invariably involves fusion of multi -modal data streams in the brain involving emotion and reasoning Learning to make decisions in noisy environments is something very human; key areas are image annotation, sentiment analysis 22

Computation and its neural basis Network Spatial awareness Language Explicit memory/emotion Face-Object recognition Working Computation and its neural basis Network Spatial awareness Language Explicit memory/emotion Face-Object recognition Working memory-executive function Epicentre 1 Epicentre 2 Posterior Parietal Cortex Frontal eye fields Wernicke’s Area Broca’s area Hippocampal-entorhinal complex The Amygdla Mid-temporal cortex Temporo-polar cortex Lateral pre-frontal cortex Posterior Parietal Cortex (? ) 23

What computers can do? Artificial Neural Networks In a restricted sense artificial neurons are What computers can do? Artificial Neural Networks In a restricted sense artificial neurons are simple emulations of biological neurons: the artificial neuron can, in principle, receive its input from all other artificial neurons in the ANN; simple operations are performed on the input data; and, the recipient neuron can, in principle, pass its output onto all other neurons. Intelligent behaviour can be simulated through computation in massively parallel networks of simple processors that store all their long-term knowledge in the connection strengths. 24

What computers can do? Artificial Neural Networks According to Igor Aleksander, Neural Computing is What computers can do? Artificial Neural Networks According to Igor Aleksander, Neural Computing is the study of cellular networks that have a natural propensity for storing experiential knowledge. Neural Computing Systems bear a resemblance to the brain in the sense that knowledge is acquired through training rather than programming and is retained due to changes in node functions. Functionally, the knowledge takes the form of stable states or cycles of states in the operation of the net. A central property of such states is to recall these states or cycles in response to the presentation of cues. 25

DEFINITIONS: Artificial Neural Networks 26 DEFINITIONS: Artificial Neural Networks 26

What can computers do? Computers help you in visualising the un-built environment http: //search. What can computers do? Computers help you in visualising the un-built environment http: //search. eb. com. elib. tcd. ie/eb/art-68188/Moores-law-In-1965 -Gordon-E-Moore-observed-that-the 27

What can computers do? Computers help you in visualising the un-built environment http: //search. What can computers do? Computers help you in visualising the un-built environment http: //search. eb. com. elib. tcd. ie/eb/art-68188/Moores-law-In-1965 -Gordon-E-Moore-observed-that-the 28

What can computers do? Computers help you in visualising the un-built environment http: //search. What can computers do? Computers help you in visualising the un-built environment http: //search. eb. com. elib. tcd. ie/eb/art-68188/Moores-law-In-1965 -Gordon-E-Moore-observed-that-the 29

What can computers do? Robots, containing sophisticated computers, can perform a variety of tasks What can computers do? Robots, containing sophisticated computers, can perform a variety of tasks in an automated factory, in bomb disposal and other applications. Robots need to be looked after – be energized, helped to navigate, tasks to be assigned, but ………. http: //www. nytimes. com/2009/07/26/science/26 robot. html 30

What can computers do? Robots, containing sophisticated computers, can perform a variety of tasks What can computers do? Robots, containing sophisticated computers, can perform a variety of tasks in an automated factory, in bomb disposal and other applications. Robots need to be looked after – be energized, helped to navigate, tasks to be assigned, but, but ………. http: //www. nytimes. com/2009/07/26/science/26 robot. html & http: //www. imdb. com/media/rm 969447936/tt 0062622 31

What can computers do? 32 What can computers do? 32

What can computers do? 33 What can computers do? 33

What can computers do? Tera Road. Runner = 100, 000 Laptops (running simultaneously and What can computers do? Tera Road. Runner = 100, 000 Laptops (running simultaneously and Giga exchanging information pico second by pico second) http: //www. ibm. com/ibm/ideasfromibm/us/roadrunner/20080609/index. shtml 34

Computers dealing with problems in neuroscience Dealing with idiosyncratic behaviour: Letting the autistic child/adult Computers dealing with problems in neuroscience Dealing with idiosyncratic behaviour: Letting the autistic child/adult have feedback on self http: //affect. media. mit. edu/pdfs/07. Teeters-sm. pdf 35

Computers dealing with problems in neuroscience Dealing with idiosyncratic behaviour http: //affect. media. mit. Computers dealing with problems in neuroscience Dealing with idiosyncratic behaviour http: //affect. media. mit. edu/pdfs/07. Teeters-sm. pdf 36

How do computers do what computers do? The number of chips on the same How do computers do what computers do? The number of chips on the same area has doubled every 18 -24 months; and has increased exponentially. However, the R&D costs and manufacturing costs for building ultra-small, high-precision circuitry and controls had an impact on the prices http: //search. eb. com. elib. tcd. ie/eb/art-68188/Moores-law-In-1965 -Gordon-E-Moore-observed-that-the 37

The ever growing computer systems (1997) http: //www. transhumanist. com/volume 1/moravec. htm 38 The ever growing computer systems (1997) http: //www. transhumanist. com/volume 1/moravec. htm 38

The ever growing computer systems (1997) http: //www. transhumanist. com/volume 1/moravec. htm 39 The ever growing computer systems (1997) http: //www. transhumanist. com/volume 1/moravec. htm 39

The ever growing computer systems (1997) http: //www. transhumanist. com/volume 1/moravec. htm 40 The ever growing computer systems (1997) http: //www. transhumanist. com/volume 1/moravec. htm 40

The ever growing computer systems Tera The industry took 35 years to reach 1 The ever growing computer systems Tera The industry took 35 years to reach 1 GB (in 1991), 14 years more to reach 500 GB (in 2005), and just two more years to reach 1 TB (2007) Library of Congress Minerva Web Presence Giga http: //www. transhumanist. com/volume 1/moravec. htm & http: //www. loc. gov/webarchiving/faq. html http: //en. wikipedia. org/wiki/File: Cmos-chip_structure_in_2000 s_(en). svg 41

The ever growing computer systems The cost of computation is falling dramatically – an The ever growing computer systems The cost of computation is falling dramatically – an exponential decay in what we can get by spending $1000 (calculations per second): In 1940: In 1950: In 1960: In 1970: In 1980: In 1990: In 2000: 0. 01 1 100 500 -1000 10, 000 100, 000 1, 000 http: //search. eb. com. elib. tcd. ie/eb/art-68188/Moores-law-In-1965 -Gordon-E-Moore-observed-that-the 42

The ever growing computer systems The cost of data storage is falling dramatically – The ever growing computer systems The cost of data storage is falling dramatically – an exponential decay in what we can get by spending the same amount of money: In 1980: 0. 001 GB In 1985: 0. 01 In 1990: 0. 1 In 1995: 1 In 2000: 10 In 2005: 100 In 2010: 1000 http: //search. eb. com. elib. tcd. ie/eb/art-68188/Moores-law-In-1965 -Gordon-E-Moore-observed-that-the 43

The ever growing computer systems: Supercomputers of today 300 to 1400 Trillion Floating Point The ever growing computer systems: Supercomputers of today 300 to 1400 Trillion Floating Point Operations per Second http: //www. transhumanist. com/volume 1/moravec. htm 44

The intelligent computer: Turing Test http: //en. wikipedia. org/wiki/File: Cmos-chip_structure_in_2000 s_(en). svg 45 The intelligent computer: Turing Test http: //en. wikipedia. org/wiki/File: Cmos-chip_structure_in_2000 s_(en). svg 45

What humans think about what computers will do? http: //www. longbets. org/1 46 What humans think about what computers will do? http: //www. longbets. org/1 46

What can computers do? 47 What can computers do? 47

What can computers do? Aaron, an expert system that can ‘paint’ has had ITS What can computers do? Aaron, an expert system that can ‘paint’ has had ITS exhibition in major galleries Here is Aaron’s Liberty & Freinds based on the Statute of Liberty http: //crca. ucsd. edu/~hcohen/cohenpdf/furtherexploits. pdf 48

What can computers do? Aaron, an expert system that can ‘paint’ has had ITS What can computers do? Aaron, an expert system that can ‘paint’ has had ITS exhibition in major galleries Here is Aaron’s Theo http: //crca. ucsd. edu/~hcohen/cohenpdf/furtherexploits. pdf 49

What can computers do? http: //crca. ucsd. edu/~hcohen/cohenpdf/furtherexploits. pdf 50 What can computers do? http: //crca. ucsd. edu/~hcohen/cohenpdf/furtherexploits. pdf 50

What can computers do? http: //crca. ucsd. edu/~hcohen/cohenpdf/furtherexploits. pdf 51 What can computers do? http: //crca. ucsd. edu/~hcohen/cohenpdf/furtherexploits. pdf 51

What computers cannot do? The Vision Problem 1967 -1997 Thirty years of computer vision What computers cannot do? The Vision Problem 1967 -1997 Thirty years of computer vision reveals that 1 MIPS can extract simple features from real-time imagery-tracking a white line or a white spot on a mottled background. 10 MIPS can follow complex gray-scale patches--as smart bombs, cruise missiles and early self-driving vans attest. 100 MIPS can follow moderately unpredictable features like roads-as recent long NAVLAB trips demonstrate. 1, 000 MIPS will be adequate for coarse-grained three-dimensional spatial awareness--. 10, 000 MIPS can find three-dimensional objects in clutter-- Hans Moravec (1998). When will computer hardware match the human brain? Journal of Evolution and Technology. 1998. Vol. 1 (at http: //www. transhumanist. com/volume 1/moravec. htm) 52

What computers cannot do? The Vision Problem – The story continues (2009) http: //www. What computers cannot do? The Vision Problem – The story continues (2009) http: //www. electronicspecifier. com/Industry-News/New-SH 7724 -processors-add-HD-video-playback-and-recording-support-to-Renesas. Technologys-popular-SH 772 x-series-of-low-power-multimedia-processors. asp 53

What computers cannot do? The Vision Problem – The story continues (2009) Processors add What computers cannot do? The Vision Problem – The story continues (2009) Processors add HD video playback and recording support to Renesas Technology's popular SH 772 x series of low power multimedia processors News Release from: Renesas Technology Europe Ltd 27/05/2009 Renesas has announced the release of the SH 7724, the third product in the SH 772 x series of low power application processors designed for multimedia applications such as audio and video for portable and industrial devices. When operating at 500 MHz, general processing performance is 900 million instructions per second (MIPS) and FPU processing performance is 3. 5 giga [billion] floating-point operations per second (GFLOPS). http: //www. electronicspecifier. com/Industry-News/New-SH 7724 -processors-add-HD-video-playback-and-recording-support-to-Renesas. Technologys-popular-SH 772 x-series-of-low-power-multimedia-processors. asp 54

What a smart computer does: Represents knowledge! A Hierarchical Network • canary is-a bird What a smart computer does: Represents knowledge! A Hierarchical Network • canary is-a bird can fly, has wings, has feathers animal ostrich runs fast, cannot fly, is tall is-a can breathe, can eat, has skin is-a can sing, is yellow is-a fish can swim, has fins, has gills salmon lays eggs; swims upstream, is pink, is edible 55

What a smart computer does: Represents knowledge and reasons with it! Modern taxonomy recognises What a smart computer does: Represents knowledge and reasons with it! Modern taxonomy recognises five kingdoms, into which the five million species of the world are organised: DOG SUGAR MAPLE BREAD MOULD INTESTINAL BACTERIUM POND ALGAE KINGDOM Animalia (animals) Plantae (plants) Fungi (fungi) Prokaryoke (bacteria) Protoctista PHYLUM Chordata Magnoliphyk Zygomycota Omnibacteria Chlorophyta CLASS Mammalia Rosidae Zygomycetes Enterobacteria Evanjugatae FAMILY Canidae Aceraceae Mucoraceae (E. coli does not have a family classification) Zygnematale GENUS Canis Acer Rhizopis Escherichia Zygnemataceae SPECIES C. familaris A. saccharum R. stolonifer E. coli S. crassa ORDER Carnivora Eubacteriales 56 Zygnematales Sapindale Macorales (algae, protozoa, slim moulds)

What humans do? Create new knowledge and keep contradictions in Modern taxonomy recognises five What humans do? Create new knowledge and keep contradictions in Modern taxonomy recognises five kingdoms, into which the five million species of the world are organised and then goes onto incorporate, in this fixed species world, EVOLUTION Cladistics, or phylogenetic systematics, for me and you! Willi Henning proposed a method for implementing Darwin’s concepts of ancestors and descendants in a taxonomic description. 57

What humans do? Create new knowledge and keep contradictions in Modern taxonomy recognises five What humans do? Create new knowledge and keep contradictions in Modern taxonomy recognises five kingdoms, into which the five million species of the world are organised and then goes onto incorporate, in this fixed species world, EVOLUTION Cladistics, or phylogenetic systematics, for me and you! Willi Henning proposed a method for implementing Darwin’s concepts of ancestors and descendants in a taxonomic description. LAMPREY D SHARK A SALMON B x y z t 0 t 1 LIZARD C t 2 Lizard (LZ) & salmon (SN) are more closely related to each other is to shark (SK) LZ & SN share a common 58 ancestor

What humans think about what computers do? Minerva is a robot which was evaluated What humans think about what computers do? Minerva is a robot which was evaluated in action by people outside a laboratory 59

What humans think about what computers do? Minerva is a robot which was evaluated What humans think about what computers do? Minerva is a robot which was evaluated in action by people outside a laboratory 60

What humans do? Talk, listen, read and write Language can be viewed as 'a What humans do? Talk, listen, read and write Language can be viewed as 'a communicative process based on knowledge. Generally when humans use language, the producer and comprehender are processing information, making use of their knowledge of the language and of the topics of conversation. Language is a process of communication between intelligent active processors, in which both the producer and the comprehender(s) perform complex cognitive tasks Winograd, Terry. (1983). Language as a Cognitive Process. Wokingham: Addison-Wesley Inc. , 61

What humans do? Talk, listen, read and write 62 What humans do? Talk, listen, read and write 62

What humans do? Talk, listen, read and write 63 What humans do? Talk, listen, read and write 63

DEFINITIONS: Artificial Neural Networks In a restricted sense artificial neurons are simple emulations of DEFINITIONS: Artificial Neural Networks In a restricted sense artificial neurons are simple emulations of biological neurons: the artificial neuron can, in principle, receive its input from all other artificial neurons in the ANN; simple operations are performed on the input data; and, the recipient neuron can, in principle, pass its output onto all other neurons. Intelligent behaviour can be simulated through computation in massively parallel networks of simple processors that store all their long-term knowledge in the connection strengths. 64

DEFINITIONS: Neurons & Appendages A neuron is a cell with appendages; every cell has DEFINITIONS: Neurons & Appendages A neuron is a cell with appendages; every cell has a nucleus and the one set of appendages brings in inputs – the dendrites – and another set helps to output signals generated by the cell 65

DEFINITIONS: Neurons & Appendages A neuron is a cell with appendages; every cell has DEFINITIONS: Neurons & Appendages A neuron is a cell with appendages; every cell has a nucleus and the one set of appendages brings in inputs – the dendrites – and another set helps to output signals generated by the cell The Real Mc. Coy 66

DEFINITIONS: Neurons & Appendages The human brain is mainly composed of neurons: specialised cells DEFINITIONS: Neurons & Appendages The human brain is mainly composed of neurons: specialised cells that exist to transfer information rapidly from one part of an animal's body to another. This communication is achieved by the transmission (and reception) of electrical impulses (and chemicals) from neurons and other cells of the animal. Like other cells, neurons have a cell body that contains a nucleus enshrouded in a membrane which has double -layered ultrastructure with numerous pores. Neurons have a variety of appendages, referred to as 'cytoplasmic processes known as neurites which end in close apposition to other cells. In higher animals, neurites are of two varieties: Axons are processes of generally of uniform diameter and conduct impulses away from the cell body; dendrites are shortbranched processes and are used to conduct impulses towards the cell body. The ends of the neurites, i. e. axons and dendrites are called synaptic terminals, and the cell-to-cell contacts they make are known as synapses. Dendrite Axon Terminals Soma Nucleus SOURCE: http: //en. wikipedia. org/wiki/Neurons 67

DEFINITIONS: The fan-ins and fan-outs 1010 neurons with 104 connections and an average of DEFINITIONS: The fan-ins and fan-outs 1010 neurons with 104 connections and an average of 10 spikes per second = 1015 adds/sec. This is a lower bound on the equivalent computational power of the brain. – – Asynchronous firing rate, c. 200 per sec. + 4 10 fan-in summation 4 10 fan-out 1 - 100 meters per sec. 68

 ANN’s: an Operational View Neuron xk x 1 wk 2 x 3 wk ANN’s: an Operational View Neuron xk x 1 wk 2 x 3 wk 4 S Activation Function yk wk 3 x 4 Summing Junction Output Signal Input Signals x 2 wk 1 bk 69

 ANN’s: an Operational View x 1 x 3 x 4 wk 1 wk ANN’s: an Operational View x 1 x 3 x 4 wk 1 wk 2 Summing Junction Activation Function S yk wk 3 wk 4 bk A schematic for an 'electronic' neuron Output Signal Input Signals x 2 Neuron xk 70

Biological and Artificial NN’s Entity Biological Neural Networks Artificial Neural Networks Processing Units Neurons Biological and Artificial NN’s Entity Biological Neural Networks Artificial Neural Networks Processing Units Neurons Network Nodes Input Dendrites Network Arcs (Dendrites may form synapses onto other dendrites) (No interconnection between arcs) Axons or Processes Network Arcs (Axons may form synapses onto other axons) (No interconnection between arcs) Synaptic Contact Node to Node via Arcs Output Inter-linkage (Chemical and Electrical) Plastic Connections Weighted Connections Matrix 71

Biological and Artificial NN’s Entity Biological Neural Networks Output Artificial Neural Networks Dendrites bring Biological and Artificial NN’s Entity Biological Neural Networks Output Artificial Neural Networks Dendrites bring inputs All inputs arrive from different locations: instantaneously and are so does the brain wait for summed up in the same all the inputs and then computational cycle: start up the summing distance (or location) exercise or does it perform between neuronal nodes many different is not an issue. intermediate computations? 72

 The Mc. Culloch-Pitts Network. Mc. Culloch and Pitts demonstrated that any logical function The Mc. Culloch-Pitts Network. Mc. Culloch and Pitts demonstrated that any logical function can be duplicated by some network of all-ornone neurons referred to as an artificial neural network (ANN). Thus, an artificial neuron can be embedded into a network in such a manner as to fire selectively in response to any given spatial temporal array of firings of other neurons in the ANN. Artificial Neural Networks for Real Neuroscientists: Khurshid Ahmad, Trinity College, 28 Nov 2006 73

 The Mc. Culloch-Pitts Network Consider a Mc. Culloch-Pitts network which can act as The Mc. Culloch-Pitts Network Consider a Mc. Culloch-Pitts network which can act as a minimal model of the sensation of heat from holding a cold object to the skin and then removing it or leaving it on permanently. Each cell has a threshold of TWO, hence fires whenever it receives two excitatory (+) and no inhibitory (-) signals from other cells at a previous time. Artificial Neural Networks for Real Neuroscientists: Khurshid Ahmad, Trinity College, 28 Nov 2006 74

The Mc. Culloch-Pitts Network Heat Sensing Network 1 + 3 + Heat Receptors Cold The Mc. Culloch-Pitts Network Heat Sensing Network 1 + 3 + Heat Receptors Cold + Hot + B + + A + 2 + + + 4 Cold 75

 The Mc. Culloch-Pitts Network Heat Sensing Network Truth tables of the firing neurons The Mc. Culloch-Pitts Network Heat Sensing Network Truth tables of the firing neurons when the cold object contacts the skin and is then removed 1 + + Hot Heat Receptors Cold Time Cell 2 Cell a Cell b Cell 3 Cell 4 INPUT HIDDEN OUTPUT 1 No Yes No No 2 No No Yes No No No 3 No No No Yes No No 4 No No Yes No + + B + + A + + 2 Cell 1 INPUT 3 + + 4 Cold 76

The Mc. Culloch-Pitts Network Heat Sensing Network ‘Feel hot’/’Feel cold’ neurons show to create The Mc. Culloch-Pitts Network Heat Sensing Network ‘Feel hot’/’Feel cold’ neurons show to create OUTPUT UNIT RESPONSE to given INPUTS that depend ONLY on the previous values. This is known as a TEMPORAL CONTRAST ENHANCEMENT. The absence or presence of a stimulus in the PREVIOUS time cycle plays a major role here. The Mc. Culloch-Pitts Network demonstrates how this ENHANCEMENT can be simulated using an ALL-OR-NONE Network. 77

Indexing and Annotation In multi-modal information processing, convergence of modalities is critical. Surveillance experts Indexing and Annotation In multi-modal information processing, convergence of modalities is critical. Surveillance experts become experts because they are very good at the convergence. Surveillance experts LEARN how to mix modalities Multisensory Cross-modal Enhancement Facilitation Cross-modal Facilitation Inhibition. Dependent From Alex Meredith, Virginia Commonwealth University, Virginia, USA Cross-modal Suppression 78

词图 CITU 2) (C System A multi-modal image annotation and retrieval system that can 词图 CITU 2) (C System A multi-modal image annotation and retrieval system that can learn to annotate images using artificial neural network systems 79

词图 CITU 2) (C System Manual annotation Image analysis Image content and free text 词图 CITU 2) (C System Manual annotation Image analysis Image content and free text Image preprocessing Feature extraction Frequency analysis Free text Image content Image segmentation Language processing Database Image feature Image and linguistic Features Linguistic feature Cross modal associations Collocations Feature extraction Cross modal learning 80

Ontogenesis of numerosity An unsupervised multinet alternative: Simulating Fechners’ Law Ahmad K. , Casey, Ontogenesis of numerosity An unsupervised multinet alternative: Simulating Fechners’ Law Ahmad K. , Casey, M. & Bale, T. (2002). Connectionist Simulation of Quantification Skills. Connection Science, vol. 14(3), pp. 165 -201. 81

Ontogenesis of numerosity An unsupervised multinet alternative: Simulating Fechners’ Law Ahmad K. , Casey, Ontogenesis of numerosity An unsupervised multinet alternative: Simulating Fechners’ Law Ahmad K. , Casey, M. & Bale, T. (2002). Connectionist Simulation of Quantification Skills. Connection Science, vol. 14(3), pp. 165 -201. 82

Simulation of Aphasic Naming A modular connectionist architecture was developed, in which semantic-lexical and Simulation of Aphasic Naming A modular connectionist architecture was developed, in which semantic-lexical and phonological knowledge are instantiated using self-organising Kohonen maps, while connections between them are implemented using Hebbian networks; a linear connectionist network (Madaline) is used to simulate non-word repetition. The Hebbian connections were lesioned in order to reproduce the patient’s naming errors. John Wright and Khurshid Ahmad (1997). ‘Connectionist Simulation of Aphasic Naming’. BRAIN AND LANGUAGE Vol. 59, pp 367– 389 (1997) 83

Ontogenesis of numerosity An unsupervised multinet alternative: Simulating Fechners’ Law Ahmad K. , Casey, Ontogenesis of numerosity An unsupervised multinet alternative: Simulating Fechners’ Law Ahmad K. , Casey, M. & Bale, T. (2002). Connectionist Simulation of Quantification Skills. Connection Science, vol. 14(3), pp. 165 -201. 84

Ontogenesis of multi-modal behaviour Jacob Martin, Alex M. Meredith, and Khurshid Ahmad. (2009) ‘Modeling Ontogenesis of multi-modal behaviour Jacob Martin, Alex M. Meredith, and Khurshid Ahmad. (2009) ‘Modeling multisensory enhancement with self-organizing maps’. Frontiers in Computational Neuroscience (June 2009), Volume 3 (Article 8), pp 1 -10. 85

Sentiment analysis of Irish Newspaper Texts and the Irish Stock Exchange Index. 86 Sentiment analysis of Irish Newspaper Texts and the Irish Stock Exchange Index. 86

Computers and Brain: A neuroscience perspective “Professor Jefferson's Lister Oration for 1949, from which Computers and Brain: A neuroscience perspective “Professor Jefferson's Lister Oration for 1949, from which I quote. "Not until a machine can write a sonnet or compose a concerto because of thoughts and emotions felt, and not by the chance fall of symbols, could we agree that machine equals brain-that is, not only write it but know that it had written it. No mechanism could feel (and not merely artificially signal, an easy contrivance) pleasure at its successes, grief when its valves fuse, be warmed by flattery, be made miserable by its mistakes, be charmed by sex, be angry or depressed when it cannot get what it wants. " Alan Turing (1950) ‘Computer Machinery and Intelligence’. Mind Vol. LIX (No. 2236), pp 433 -460. 87