5For more details, refer to, among many others, the original paper in which H.M.’s case was first described: William Scoville and Brenda Milner. “Loss of recent memory after bilateral hippocampal lesion.” Journal of Neurology, Neurosurgery, and Psychiatry 20 (1957): 11–21.
For a more recent review, see: Larry Ryan Squire. “The legacy of patient H.M. for neuroscience.” Neuron 61 (11) (2009): 6–9.
Chapter 8
1For a comprehensive description of how visual information is processed along the ventral visual pathway, see: N. K. Logothetis and D. L. Sheinberg. “Visual object recognition.” Annual Review of Neuroscience 19 (1996): 577–621.
And: K. Tanaka. “Inferotemporal cortex and object vision.” Annual Review of Neuroscience 19 (1996): 109–139.
2Beside Christof and Itzhak, this work also involved Gabriel Kreiman, Leila Reddy, and, later, Alexander Kraskov.
3Of course, a horizontal line or a face are also concepts, so depending on what we mean by “concept” one can argue that neurons in V1 and IT respond to concepts as well. Semantics aside, I hope it’s clear what I mean when I say that we found for the first time a neuron firing to a concept—I am referring to the concept of a specific person.
4For more details, see: Rodrigo Quian Quiroga, Leila Reddy, Gabriel Kreiman, Christof Koch, and Itzhak Fried. “Invariant visual representation by single neurons in the human brain.” Nature 435 (2005): 1102–1107.
5The fact that there are more neurons encoding familiar concepts was proved in: I. Viskontas, Rodrigo Quian Quiroga, and Itzhak Fried. “Human medial temporal lobe neurons respond preferentially to personally relevant images.” Proceedings of the National Academy of Sciences 106 (2009): 21329–21334.
6For more details about neuron response to photographs and names (either written or spoken) of people, see: Rodrigo Quian Quiroga, Alexander Kraskov, Christof Koch, and Itzhak Fried. “Explicit encoding of multimodal percepts by single neurons in the human brain.” Current Biology 19 (2009): 1308–1313.
7The neuron in Figure 8.4 responded not only to my photos, but also to photos of three of my colleagues performing experiments at UCLA; another neuron responded to both the Tower of Pisa and the Eiffel Tower; the Jennifer Aniston neuron, when tested the next day, responded also to Lisa Kudrow (another actress from the sitcom Friends); a neuron that responded to Jerry Seinfeld also responded to Kramer (both were characters in the same sitcom); and so on.
More recently, we showed quantitatively that these neurons tend to encode meaningful associations and that they can modify their response patterns to encode new associations on the fly. For more details, see: Emanuela de Falco, Matias Ison, Itzhak Fried, and Rodrigo Quian Quiroga. “Longterm coding of personal and universal associations underlying the memory web in the human brain.” Nature Communications 7 (2016): 13408.
And: Matias Ison, Rodrigo Quian Quiroga, and Itzhak Fried. “Rapid encoding of new memories by individual neurons in the human brain.” Neuron 87 (2012): 220–230.
8The description and implications of how little we remember is the central theme of my 2012 book, Borges and Memory.
9In this formulation of the model, I will set aside technical details and will also refrain from describing the considerable amount of scientific evidence that is consistent with it. For more details, see: Rodrigo Quian Quiroga. “Concept cells: the building blocks of declarative memory functions.” Nature Reviews Neuroscience 13 (2012): 587–597.
10In line with this argument, patients with injuries in the medial temporal lobe have not only a memory deficit but also a shortfall at imagining new situations, since they are able only to envision isolated facts, devoid of context. For more details, see: D. Hassabis, D. Kumaran, S. Vann, and E. Maguire. “Patients with hippocampal amnesia cannot imagine new experiences.” Proceedings of the National Academy of Sciences 104 (2007): 1726–1731.
Chapter 9
1The topic of personal identity has been widely explored in philosophy. See, for example, Chapter 6 of: J. Hospers. An Introduction to Philosophical Analysis. London: Routledge, 1956.
2Aristotle. On the Soul. Translated by J. A. Smith. Oxford: Clarendon Press, 1928, 412b.
3Aristotle. On the Soul, 408b.
4The rejection by medieval scholastic philosophy of Aristotle’s thought was mostly a consequence of the interpretation of his ideas given by the twelfth-century Muslim philosopher Averroës, who denied the immortality of the individual soul. According to Averroës, at the moment of death the soul loses its individuality and becomes part of a universal soul, like drops in the ocean. Thomas Aquinas, on the other hand, took up Aristotle’s distinction between active intellect (the one exclusive to humans that allows reasoning) and receptive intellect (the one we share with animals, which allows sensation) and stated that it is the receptive intellect, both in humans and animals, that disappears upon death, while the active intellect, the individual soul, is indeed immortal as such.
For a discussion on different interpretations of Aristotle’s position on this subject, see: Anthony Kenny. A New History of Western Philosophy. Oxford: Clarendon Press, 2005, Chapters 4 and 7.
And: Bertrand Russell. A History of Western Philosophy. London: Routledge Classics, [1946] 2004, Chapter 19.
5Turing proposed his famous test in: Alan Turing. “Computing machinery and intelligence.” Mind 59 (1950): 433–460.
6For a critical discussion of the Chinese room argument, refer to Searle’s original paper and subsequent commentary by several authors in: J. Searle. “Minds, brains, and programs.” Behavioral and Brain Sciences 3 (1980): 417–457.
7For a popular discussion of Nicky Clayton’s work, see: V. Morell. “Nicky and the jays.” Science 315 (2007): 1074–1075.
For a more detailed and technical discussion, see: U. Grodzinski and N. Clayton. “Problems faced by food-caching corvids and the evolution of cognitive solutions.” Philosophical Transactions of the Royal Society of London B 365 (2010): 977–987.
8For a summary of these works, see: Larry Squire and Stuart Zola-Morgan. “The medial temporal lobe memory system.” Science 253 (1991): 1380–1386.
9For an overview of these works, see: John O’Keefe. “A review of the hippocampal place cells.” Progress in Neurobiology 13 (1979): 419–439.
And: Edvard Moser, Emilio Kropff, and May-Britt Moser. “Place cells, grid cells and the brain’s spatial representation system.” Annual Reviews of Neuroscience 31 (2008): 69–89.
As well as: K. Nakazawa, T. McHugh, M. Wilson, and S. Tonegawa. “NMDA receptors, place cells and hippocampal spatial memory.” Nature Reviews Neuroscience 5 (2004): 361–372.
10For more details, see: Rodrigo Quian Quiroga. “Concept cells: the building blocks of declarative memory functions.” Nature Reviews Neuroscience 13 (2012): 587–597.
11For more details, see, for example: Gordon Gallup, Jr. “Chimpanzees: selfrecognition.” Science 167 (1970): 86–87.
And: Gordon Gallup, Jr. “Self-recognition in primates: a comparative approach to the bidirectional properties of consciousness.” American Psychologist 32 (1977): 329–338.
As well as: J. Plotnik, F. de Waal, and D. Reiss. “Self-recognition in an Asian elephant.” Proceedings of the National Academy of Sciences 103 (2006): 17053–17057.
12Lev Vygotsky. Thought and Language. Cambridge, MA: MIT Press, 1986.
13Daniel Dennett. Kinds of Minds. New York: Basic Books, 1997, 150–151.
14Temple Grandin, a professor at Colorado State University and an expert in animal behavior, asserts that animals are able to see details that human beings overlook by virtue of our abstraction- and inference-based thought. Interestingly, she is autistic, and claims that the attention to detail that she shares with many other autists (and savants) allows her to better understand the way animals think. In her 2006 book Animals in Translation: The Woman Who Thinks Like a Cow (London: Bloomsbury), Grandin in fact makes an interesting parallel between the thought processes of animals and those of people with autism.
; 15Alex Krizhevsky, Ilya Sutskever, and Geoffrey Hinton. “Imagenet classification with deep convolutional neural networks.” Advances in neural information processing systems 25 (2012): 1097–1105.
INDEX
A
abstraction, and language, 151–153, 154
action potentials, 6
Alhazen, 41
amygdala, 113
Andersen, Richard, 98
animals
consciousness and, 150
memory capacity and, 146–148, 150
self-awareness and, 148–150
antiquity, importance of memory in, 74–75, 97
Aquinas, Thomas, 41, 51, 116, 137
Aristotle, 40–41, 51, 100, 116, 137
art, 29–31
artificial intelligence, 142
association agnosia, 48
associations, 100
formation of, 127–131
importance of, 73
Astonishing Hypothesis, The (Crick), 138–139
Atkinson-Shiffrin model, 108
axons, 6
B
Bartlett, Frederic, 56, 57–58, 62, 65, 68, 155
Berkeley, George, 41, 45
Besson, Luc, 86
bits, 21–22
Blade Runner (film), 1–2, 3, 3–4, 10, 142
blindness, followed by sight, 43–46
Bliss, Tim, 13
Borges, Jorge Luis, 51, 52, 81, 152
brain
basics of, 5. See also neurons
percent used, 86, 87
relation with mind, 138
storage capacity of, 64–65
training, 86
transmission of visual information to, 23, 25, 32
vision and, 36, 42, 47
Bruno, Giordano, 77
bytes, 21–22
C
Camillo, Giulio, 76–77
capacity, for memory. See memory capacity
Cartesian dualism, 137, 140, 142, 145
Center of Gaze (Molina), 31
center-surround organization, 37–38, 39, 47
cerebral cortex, 39
Chinese room, The, 144–145
Cicero, 51, 73, 74
Clayton, Nicky, 146
color, 37–38, 116
combinatorial explosion, 17
comprehension. See also understanding
internet and, 95
vs. memory, 82–84, 96–98, 102
computational neuroscience, 9
computers
consciousness and, 140–145
self-awareness and, 134, 142–145
concept neurons, 120–128, 147–148, 153
concepts, 120–131
and language, 153
place as, 148
cones, 36
consciousness, 134. See also self-awareness
animals and, 150
computers/robots and, 140–145
Crick’s study of, 138–139
degrees of, 150
consolidation, 54–55, 59, 99
associations and, 100
context, 56–57, 94
Cotton, Ronald, 60–61
Crick, Francis, 138–139
Critias (Plato), 75
D
declarative memory, 111–113, 125
Deep Blue, 142
deep neural networks, 155
delay match to sample, 146
delay no-match to sample, 147
dendrites, 7
Dennett, Dan, 153
Descartes, René, 41, 136, 137, 140
Dick, Philip K., 3
Do Androids Dream of Electric Sheep? (Dick), 3
dopamine, 7
Down, John Langdon, 82–83
dualism, 136, 137–138, 139, 140. See also Cartesian dualism
E
Ebbinghaus, Hermann, 53–55, 57, 62, 99, 106
education, 97–99, 101–102, 103
emotional memory, 113
entorhinal cortex, 123–124
epilepsy, 87, 109, 118
epileptic focus, 118
episodic memory, 112–113, 130–131
Essay Concerning Human Understanding (Locke), 135
Essay Towards a New Theory of Vision (Berkeley), 45
excitatory neurons, 8
expectations, 66–67
experience, 42, 43–46, 67
explicit memory, 111–113, 125
eye. See also vision; visual information
center-surround organization, 37–38, 39, 47
fovea, 25–26, 36, 39, 47
retina, 35–38, 39
eye tracking, 26
eyewitness testimony, 59–62
F
fabulation, 59
flashbulb memory, 113
Florida scrub jay, 146
forgetting
benefits of, 50–52
importance of, 154–155
lack of capacity for, 79–82
fovea, 25–26, 36, 39, 47
Fried, Itzhak, 119
functionalism, 142
“Funes the Memorious” (Borges), 51, 52, 81, 88
G
Gallup, Gordon Jr., 148
Galton, Francis, 53
Gea, Miguel Ángel, 65
Gedankenexperiment
Chinese room, 144–145
zombie of the philosophers, 140–142
Gregory, Richard, 45–46
Gutenberg, Johannes, 93
H
Haraguchi, Akira, 88
Hebb, Donald, 13, 128
Hebbian cell assemblies, 13
Helmholtz, Hermann von, 41–44, 58, 65–67, 154
hippocampus, 109, 111, 114, 118, 125, 130, 147
Hitchcock, Alfred, 66
H.M (Henry Molaison), 109–111, 118, 123, 125, 147
Hopfield, John, 9
Hopfield networks, 9–12, 15, 16
Hubel, David, 117
humanity, 156
Hume, David, 41
I
Ibn-al-Haytham, 41
identity, 135–136, 139
images, 116
implicit memory, 111
In Search of Lost Time (Proust), 49–50
inferences, unconscious, 42–43, 59, 65–67, 154
inferior temporal cortex (IT), 117
information
measuring, 20, 21–22
organization of, 76
information, visual. See visual information
information overload, 94–95, 102
information theory, 20–21, 23
inhibitory neurons, 8
intelligence, vs. memory, 96–98
interference effects, 15
internet, 92, 93–95, 102
intracranial electrodes, 118–119
iPhone, 24, 32
IT (inferior temporal cortex), 117
J
James, William, 51, 100
Jennifer Aniston neuron, 120. See also concept neurons
Jobs, Steve, 24, 32
K
Kafka, Franz, 135
Kant, Immanuel, 41
Kasparov, Garry, 142
Koch, Christof, 119, 138
Kuffler, Stephen, 37
L
Landauer, Thomas, 62, 64
language, 151–154
learning, 97–99, 101–102, 103
Locke, John, 41, 44–45, 135
Loftus, Elizabeth, 59
Lømo, Terje, 13
long-term memory, 54–55, 57, 106, 111
long-term potentiation (LTP), 13
Lucy (film), 86
Luria, Alexander, 79–82, 153
M
manipulation, 59–62
materialism, 139, 141
meaning, 43–46, 48, 56–57, 65, 155. See also schema
medial temporal lobe, 118
memories, false, 68
memory, 108
definitions of, 2–3
as illusion, 17
importance of in antiquity, 97
improving, 91
as movie, 16
persistence of, 54
types of, 105–114. See also long-term memory; short-term memory
memory capacity, 53–56, 62–63
animals and, 146–148, 150
Shereshevskii’s, 81
memory champions, 88–89
memory training, 88–91
Metamorphosis, The (Kafka), 135
method of loci, 70–73, 75, 76–79, 80–81, 96–97
Metrodorus of Scepsis, 75
Mill, John Stuart, 151–152
Milner, Brenda, 111
mind, 3
as activity of brain, 139–140
relation with body, 137–138
relation with brain, 138
mirror test, 149–150
mnemonics
importance of in antiquity, 74–75
method of loci, 70–73, 75, 76–79, 80–81, 96–97
in Renaissance, 76–79
mnemonists, 88, 89
Molaison, Henry (H.M), 109–111, 118, 123, 125, 147
Molina, Mariano, 31
monism, 136, 140
Moser, Edvard, 147
Moser, May-Britt, 147
motor-skill memory, 113
movies
expectations and, 66
memories as, 16
multitasking, 91
music theory, 65–66
N
neural connectivity, memory and, 12
neural networks, 8–12
neural networks, deep, 155
neural plasticity, 12, 13, 128
neurons, 3, 5–16
concept neurons, 120–128, 147–148, 153
epilepsy and, 87
excitatory neurons, 8
firing of, 6–8
functions of, 14
Hopfield networks, 9–12, 15, 16
inhibitory neurons, 8
involvement in memory, 15–16
number of, 14, 64
place cells, 147
reinforcement of wiring between, 13
retinal ganglion neurons, 36–38
neuroscience, 4
neurotransmitters, 7
nondeclarative memory, 113, 130–131
O
O’Brien, Dominic, 88, 89
off-center neurons, 37–38
O’Keefe, John, 147
On the Soul (Aristotle), 40–41
on-center neurons, 37–38
optical illusions, 43
oratory, 97
in antiquity, 74–75
The Forgetting Machine Page 14