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COGNITION, BRAIN, AND CONSCIOUSNESS
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COGNITION, BRAIN, AND
CONSCIOUSNESS
Introduction to Cognitive Neuroscience
Edited by
B J. B
ERNARD AARS
N M. G
ICOLE AGE
AMSTERDAM • BOSTON (cid:127) HEIDELBERG (cid:127) LONDON (cid:127) NEW YORK (cid:127) OXFORD
PARIS (cid:127) SAN DIEGO (cid:127) SAN FRANCISCO (cid:127) SINGAPORE (cid:127) SYDNEY (cid:127) TOKYO
Academic Press is an imprint of Elsevier
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Academic Press is an imprint of Elsevier
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Front cover:For centuries, epileptic episodes have been known to evoke striking visual experiences. The
outside cover art shows an acrylic painting by artist Craig Getzlaff, called Brainstorms #20. The artist writes,
“In these paintings, I am trying to communicate to the public and to myself what an immense experience an
epileptic seizure really is” (p. 27). The painting comes from a collection called Visions: Artists living with
epilepsy(Source:Schachter, 2003, with kind permission).
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Contents
Preface xiii 2.1 The ‘inner senses’ 33
2.2 Output functions 34
List of contributors xvii
2.3 Only a fleeting moment ... 34
2.4 Understanding Clive Wearing
Chapter 1 Mind and brain in the functional framework 37
2.5 The importance of immediate memory 38
Bernard J. Baars
3.0 Limited and large-capacity functions 39
1.0 Introduction 3 3.1 Dual task limits 39
2.0 An invitation to mind-brain science 3 3.2 Some very large brain capacities 41
3.0 Some starting points 4 3.3 Why are there such narrow
3.1 Distance: seven orders of magnitude 4 capacity limits? 42
3.2 Time: ten orders of magnitude 6 3.4 Measuring working memory 42
3.3 The need to make inferences – 4.0 The inner and outer senses 44
going beyond the raw observations 7 4.1 The mind’s eye, ear and voice 45
3.4 The importance of convergent measures 10 4.2 The imagery sketchpad may use visual
3.5 Major landmarks of the brain 10 regions of cortex 46
4.0 Some history, and ongoing debates 13 4.3 Is inner speech like outer speech? 47
4.1 The mind and the brain 13 4.4 Is there only one working memory? 47
4.2 Biology shapes cognition and emotion 15 5.0 The central executive 48
4.3 Cajal’s neuron doctrine: the working 5.1 Executive effort and automaticity 49
assumption of brain science 16 5.2 Executive and spontaneous attention 51
4.4 Pierre-Paul Broca and the localization of 6.0 Action 52
speech production 16 7.0 Consolidation of short-term events
4.5 The conscious and unconscious mind 23 into long-term memory 53
5.0 The return of consciousness in the sciences 24 7.1 Is working memory just re-activated
5.1 How conscious and unconscious permanent memory? 54
brain events are studied today 24 8.0 Summary 55
5.2 History hasn’t stopped 26 9.0 Study questions and drawing practice 56
6.0 Summary 27 9.1 Study questions 56
7.0 End of chapter exercises 28 9.2 Drawing exercises 56
7.1 Study questions 28
7.2 Drawing exercise 29
Chapter 3 Neurons and their connections
Bernard J. Baars
Chapter 2 Aframework
1.0 Introduction 59
Bernard J. Baars
1.1 Real and idealized neurons 60
1.0 Introduction 31 1.2 Excitation and inhibition 61
2.0 Classical working memory 32 1.3 Neural computation 63
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2.0 Working assumptions 63 5.1 Why we need multiple tests of
2.1 Starting simple: receptors, brain function 116
pathways and circuits 65 5.2 Brain damage and causal inferences 117
3.0 Arrays and maps 67 6.0 Summary 118
3.1 Maps flow into other maps 69 7.0 Chapter review 118
3.2 Neuronal arrays usually have two- 7.1 Drawing exercises and study questions 118
way connections 71
3.3 Sensory and motor systems
work together 72 Chapter 5 The brain
3.4 Temporal codes: spiking patterns and Bernard J. Baars
brain rhythms 73
3.5 Choice-points in the flow of information 74 1.0 Introduction 121
3.6 Top-down or expectation-driven 1.1 The nervous system 122
processing 75 1.2 The geography of the brain 123
4.0 How neural arrays adapt and learn 76 2.0 Growing a brain from the bottom up 126
4.1 Hebbian learning: ‘Neurons that fire 2.1 Evolution and personal history are
together, wire together’ 76 expressed in the brain 126
4.2 Neural Darwinism: survival of the 2.2 Building a brain from bottom to top 127
fittest cells and synapses 79 3.0 From ‘where’ to ‘what’: the functional
4.3 Symbolic processing and neural nets 80 roles of brain regions 132
5.0 Coordinating neural nets 82 3.1 The cerebral hemispheres: the left-right
5.1 Functional redundancy 83 division 132
6.0 Summary 84 3.2 Output and input: the front-back
7.0 Study questions and drawing exercises 85 division 136
7.1 Study questions 85 3.3 The major lobes: visible and hidden 138
7.2 Drawing exercises 85 3.4 The massive interconnectivity of the
cortex and thalamus 142
3.5 The satellites of the subcortex 144
Chapter 4 The tools: Imaging the living brain 4.0 Summary 146
Bernard J. Baars and Thomas Ramsøy 5.0 Chapter review 146
5.1 Study questions 146
1.0 Introduction 87 5.2 Drawing exercises 146
1.1 Brain recording: more and less direct
measurements 88
1.2 The time-space tradeoff 91 Chapter 6 Vision
2.0 Arange of useful tools – measuring Frank Tong and Joel Pearson
electric and magnetic signals 93
2.1 Single-unit recording 93 1.0 Introduction 149
2.2 Animal and human studies cast 1.1 The mystery of visual experience 149
light on each other 96 1.2 The purpose of vision: knowing
2.3 Electroencephalography (EEG) 96 what is where 150
2.4 Magnetoencephalography 101 1.3 Knowing what: perceiving features,
2.5 Zapping the brain 101 groups and objects 151
3.0 fMRI and PET: indirect signals for 1.4 Knowing where things are 152
neural activity 106 2.0 Functional organization of the visual system 152
3.1 Pros and cons of PET and fMRI 106 2.1 The retina 152
3.2 Regions of interest 107 2.2 Lateral geniculate nucleus (LGN) 155
3.3 The resting brain is not silent 113 2.3 Primary visual cortex (V1) 156
3.4 Empirically defining cognitive 2.4 Extrastriate visual areas – outside of V1 158
functions: the creative key 114 2.5 Area MT 158
4.0 Conscious versus unconscious brain events 115 2.6 The ventral and dorsal pathways:
5.0 Correlation and causation 115 knowing what and where 159
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2.7 Areas involved in object recognition 161 4.4 The link between speech perception and
2.8 Lateral occipital complex (LOC) 162 production 212
2.9 Fusiform face area (FFA) 162 4.5 Damage to speech perceptual systems 213
2.10 Parahippocampal place area (PPA) 162 4.6 Aworking model for speech perception
3.0 Theories of visual consciousness: in the brain 215
where does it happen? 162 5.0 Music perception 216
3.1 Hierarchical and interactive 5.1 Stages of music processing 216
theories of vision 163 5.2 Aseparate system for music perception? 217
4.0 Brain areas necessary for visual 6.0 Learning and plasticity 217
awareness: lesion studies 164 6.1 Plasticity due to deprivation 217
4.1 Consequences of damage to early 6.2 Plasticity due to learning 218
visual areas 164 6.3 Plasticity due to expertise 219
4.2 Extrastriate lesions – damage outside 7.0 Auditory awareness and imagery 219
area V1 165 7.1 Auditory awareness during
4.3 Damage to ventral object areas 166 sleep and sedation 219
4.4 Damage to dorsal parietal areas 168 7.2 Auditory imagery 221
5.0 Linking brain activity and visual experience 170 8.0 Summary 222
5.1 Multistable perception 170 9.0 Chapter review 222
5.2 Binocular rivalry: what you see is 9.1 Study questions 222
what you get activated 171 9.2 Drawing exercise 222
5.3 Visual detection: did you see it? 172 9.3 Exploring more 223
5.4 Constructive perception: more to
vision than meets the eye... 173
5.5 Neural correlates of object recognition 175 Chapter 8 Attention and consciousness
6.0 Manipulations of visual awareness 175 Bernard J. Baars
6.1 Transcranial magnetic stimulation 176
6.2 Unconscious perception 177 Introduction 225
7.0 Summary 178 2.0 Adistinction between attention and
8.0 Study questions and drawing exercises 180 consciousness 225
2.1 Cortical selectionand integration 226
2.2 Selective attention: voluntary and
Chapter 7 Hearing and speech automatic 228
Nicole M. Gage 3.0 Experiments on attention 228
3.1 Methods for studying selective
1.0 Introduction 183 attention 230
1.1 Amodel for sound processing 184 4.0 The brain basis of attention 233
1.2 Sound and hearing basics 186 4.1 Attention as biased competition among
2.0 The central auditory system 190 neuron populations 233
2.1 Auditory pathways 191 4.2 Guiding the spotlight 234
2.2 Auditory cortex 192 4.3 Salience maps help guide attentional
3.0 Functional mapping of auditory selection 234
processing 197 4.4 Executive (voluntary) attention 235
3.1 Primary auditory cortex 197 4.5 Visual attention may have evolved
3.2 The role of the planum temporale in from eye movement control 236
sound decoding 197 4.6 Maintaining attention against distraction 236
3.3 Cortical auditory ‘what’ and 4.7 Attention and consciousness 240
‘where’ systems 199 5.0 The brain basis of conscious experience 240
4.0 Speech perception 207 5.1 Conscious cognition 240
4.1 Background and history 208 5.2 Unconscious comparisons 241
4.2 Early theories of speech perception 210 5.3 Binding features into conscious objects 243
4.3 Functional mapping of speech-specific 5.4 Visual feature integration in
processes 211 the macaque 244
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5.5 Conscious events recruit widespread brain 6.3 Different types of working memory 284
activation 246 6.4 Prefrontal cortex – storage or process
5.6 Fast cortical interactions may be needed for control? 285
conscious events 250 6.5 Combining prefrontal and MTLregions for
6.0 Asummary and some hypotheses 251 working memory 286
7.0 Study questions 253 7.0 Retrieval and metacognition 286
7.1 False retrieval 287
7.2 Hemispheric lateralization in retrieval 287
Chapter 9 Learning and memory 7.3 Theta rhythms may coordinate memory
Morris Moscovitch, Jason M. Chein, Deborah Talmi, and retrieval 288
Melanie Cohn 8.0 Other kinds of learning 288
9.0 Summary 289
1.0 Introduction 255 10.0 Drawings and study questions 290
1.1 Afunctional overview 258
1.2 Learning and memory in the functional
framework 258 Chapter 10 Thinking and problem-solving
1.3 Implicit and explicit memory 260 Bernard J. Baars
2.0 Amnesia 261
2.1 HM: the best-studied amnesia patient 261 1.0 Working memory 294
2.2 Asummary of amnesia 264 1.1 Working memory overlaps with attention,
2.3 Spared functions in amnesia: implicit and conscious events and episodic recall 295
procedural memory 264 2.0 Explicit problem-solving 296
2.4 Spared implicit learning 266 2.1 Executive control in problem-solving 298
3.0 Memories are made of this 267 3.0 Mental workload and cortical activity 301
3.1 Electrically evoked autobiographical 4.0 Using existing knowledge 303
memories 267 4.1 Practice and training may change
3.2 Long-term potentiation and long-term connectivities in the brain 304
depression: excitatory and inhibitory 4.2 Semantic memory 304
memory traces 269 4.3 Abstract concepts, prototypes, and
3.3 Consolidation: from temporary to networks 305
permanent storage 270 4.4 Knowledge comes in networks 306
3.4 Rapid consolidation: synaptic mechanisms, 4.5 Conceptual deficits 308
gene transcription, and protein synthesis 273 4.6 Judgments of quantity and number 309
3.5 System consolidation: interaction between the 5.0 Implicit thinking 310
medial temporal lobes and neocortex 273 5.1 Feelings of knowing 311
4.0 Varieties of memory 273 6.0 Summary and conclusions 313
4.1 Episodic and semantic memory: 7.0 Drawings and study questions 314
‘Remembering’ versus ‘knowing’ 274
4.2 Episodic memories may turn into semantic
memories over time 277 Chapter 11 Language
4.3 Episodic and semantic memory are often Bernard J. Baars
combined 277
5.0 MTLin explicit learning and memory 278 1.0 Introduction 317
5.1 Divided attention interferes with 2.0 The nature of language 318
learning 278 2.1 Biological aspects 320
6.0 Prefrontal cortex, consciousness and working 2.2 Language origins 325
memory 279 2.3 Speech versus language 325
6.1 Working with memory: the frontal lobe 3.0 The sounds of spoken language 325
works purposefully withmemory 282 4.0 Planning and producing speech 328
6.2 Prefrontal cortex in explicit (conscious) and 5.0 Evolutionary aspects of speaking and
implicit (unconscious) learning and listening 330
memory 283 6.0 Words and meanings 331
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4.0 Summary 409 6.0 Other topics in neuron modeling 459
5.0 Chapter review 409 6.1 Hebbian learning 459
5.1 Study questions 409 6.2 Activation functions 459
5.2 Drawing exercises 409 7.0 More than one neuron 459
7.1 The perceptron 460
7.2 Limitations of the perceptron 460
Chapter 15 Development 7.3 The multilayer perceptron 461
Nicole M. Gage and Mark H. Johnson 7.4 Cognition and perceptrons? 461
8.0 Recursive or dynamic networks 462
1.0 Introduction 411 8.1 Asimple example of a recursive net 462
1.1 New techniques for investigating the 8.2 Hopfield nets and Boltzmann
developing brain 412 machines 462
1.2 The mystery of the developing brain: old 8.3 Other recursive systems 463
questions and new 413 9.0 Looking back on Part l 465
2.0 Prenatal development: from blastocyst to
baby 413 Part 2: Seeing is believing 465
2.1 Epigenesis 414 10.0 What is to be seen? 465
2.2 The anatomy of brain development 414 11.0 The NRM neuron 465
2.3 Neural migration 416 11.1 The activation and output computation
2.4 Nature and nurture revisited 420 algorithm 465
2.5 Prenatal hearing experience: voice and 11.2 An experiment with a single basic digital
music perception before birth 422 neuron 466
3.0 The developing brain: a lifetime of change 423 11.3 An experiment with a layer of basic digital
3.1 The rise and fall of postnatal brain neuron 467
development 423 12.0 The NRM dynamic neural net 467
3.2 Regional differences in brain 12.1 The state as a label of the input 467
development 424 12.2 The state as an inner image (icon) of the
4.0 Developing mind and brain 425 input 468
4.1 The first year of life: an explosion of 12.3 The inner state as a repository of sensory
growth and development 427 memories 469
4.2 Childhood and adolescence: dynamic and 12.4 The state space of the memory
staged growth 437 network 469
5.0 Early brain damage and developmental 13.0 Acomplex cognitive system in NRM 470
plasticity 448 13.1 What does the model currently tell us? 471
6.0 Chapter Summary 450 13.2 Response to input changes 472
7.0 Chapter review 451 13.3 Response to simulated voice input 472
7.1 Study questions 451 13.4 Recall in the absence of stimulus 473
13.5 Summary of NRM work 473
13.6 Neural models of cognition: conclusion 473
Appendices 14.0 Self-test puzzles and some solutions 474
14.1 Exercises with NRM 474
A Neural models: Aroute to cognitive 14.2 Looking at a more complex system (visual
brain theory awareness) 475
Igor Aleksander 14.3 Beyond the call of duty: stacking and
self 476
Part 1: Traditional neural models 454
1.0 Why two parts? 454
2.0 What is a neural model? 454 B Methods for observing the living brain
3.0 The neuron 455 Thomas Ramsøy, Daniela Balslev, and Olaf Paulson
4.0 The basic artificial neuron (McCulloch and
Pitts, 1943) 456 1.0 Historical background 477
5.0 Learning in a neuron – some basic 1.1 Correlating brain and mind 477
notions 457 1.2 Recording brain activation 478
