Hawkins - On Intelligence |
30 |
In an
auto
associative memory you don't have to have the entire pattern you want to retrieve in order to retrieve it. |
||||||||||||
Hawkins - On Intelligence |
30 |
The auto-associative memory can retrieve the correct
pattern, as
it was originally stored, even though you start with a messy version of it. |
||||||||||||
Hawkins - On Intelligence |
30 |
With
a sequence
of patterns, similar to a portion of a melody, the auto associative memory can remember the
entire
melody. |
||||||||||||
Hawkins - On Intelligence |
31 |
People
learn practically everything as a sequence of patterns. |
||||||||||||
Hawkins - On Intelligence |
66 |
A neuron collects inputs from its synapses, and combines
these inputs together to decide when to output a spike to other neurons. |
||||||||||||
Hawkins - On Intelligence |
66 |
A typical
neuron can cycle its
functions and reset itself in about 5 ms, or around 200 times per second. |
||||||||||||
Hawkins - On Intelligence |
66 |
The brain is a parallel “computer.
“ It has billions of cells all
computing
at the same time. |
||||||||||||
Hawkins - On Intelligence |
68 |
The brain
does not
compute the answers to problems. It retrieves the answers from memory. |
||||||||||||
Hawkins - On Intelligence |
69 |
The neocortex is not like a
computer, parallel or otherwise. Instead of computing answers to problems, the neocortex uses stored memories to solve problems
and produce behavior. |
||||||||||||
Hawkins - On Intelligence |
70 |
Neocortex
stores sequences of patterns. |
||||||||||||
Hawkins - On Intelligence |
70 |
Neocortex recalls patterns auto-associatively. |
||||||||||||
Hawkins - On Intelligence |
70 |
Neocortex stores patterns in an invariant form. |
||||||||||||
Hawkins - On Intelligence |
70 |
Neocortex stores patterns in a hierarchy. |
||||||||||||
Hawkins - On Intelligence |
70 |
A story is stored in your head in a sequential fashion and can only be recalled in the same sequence. |
||||||||||||
Hawkins - On Intelligence |
70 |
It's almost
impossible to think of anything complex that isn't a series of events or
thoughts. |
||||||||||||
Hawkins - On Intelligence |
71 |
All
memories are like this. You have to walk through the temporal sequence of how you do things. |
||||||||||||
Hawkins - On Intelligence |
71 |
Your memory of the alphabet is
a sequence
of patterns. |
||||||||||||
Hawkins - On Intelligence |
73 |
All
memories are stored in the synaptic connections between neurons. |
||||||||||||
Hawkins - On Intelligence |
73 |
An adult
human neocortex has an incredibly large memory capacity but we can only remember a few at any time and can only do so in a sequence of associations. |
||||||||||||
Hawkins - On Intelligence |
73 |
An autoassociative memory is one that can recall complete patterns when given only a partial or distorted input. |
||||||||||||
Hawkins - On Intelligence |
73 |
Autoassociative
memory can
work for both spatial and temporal patterns. |
||||||||||||
Hawkins - On Intelligence |
74 |
During
conversation we often can't hear all the words we are in a noisy environment. Our brains fill in what they miss with what they expect to hear. |
||||||||||||
Hawkins - On Intelligence |
74 |
Some
people complete of the sentences of others aloud, but in our minds all
of us are doing this
constantly. |
||||||||||||
Hawkins - On Intelligence |
82 |
When
you see,
feel, or hear something, the cortex takes the detailed highly specific input and converts it to an invariant form. |
||||||||||||
Hawkins - On Intelligence |
82 |
Memory storage, memory recall, and memory recognition occur at the
level of invariant forms. |
||||||||||||
Hawkins - On Intelligence |
82 |
An important
function of the neocortex is to use its memory to make predictions. |
||||||||||||
Hawkins - On Intelligence |
84 |
Your brain does this by combining a memory of the invariant structure of her face with the particulars of your immediate experience. |
||||||||||||
Hawkins - On Intelligence |
84 |
The combining of invariant representations and current input to make detailed predictions is exactly what is happening. |
||||||||||||
Hawkins - On Intelligence |
84 |
This combining is a ubiquitous process that happens in every region of cortex. |
||||||||||||
Hawkins - On Intelligence |
84 |
Three properties of cortical
memory (storing
sequences, autoassociative
recall, and invariant
representations) are necessary
ingredients to predict the future based on memories
of the past. |
||||||||||||
Hawkins - On Intelligence |
87 |
The predictions are made in parallel and will just as readily detect an odd texture, a misshapen nose, or an unusual motion. |
||||||||||||
Hawkins - On Intelligence |
87 |
What
we perceive is a combination of what
we sense and of our brain's memory=derived predictions. |
||||||||||||
Hawkins - On Intelligence |
88 |
Visual
areas make
predictions about edges,
shapes, objects, locations, and motions. |
||||||||||||
Hawkins - On Intelligence |
88 |
Auditory
areas make
predictions about tones,
direction to source,
and patterns of sound. |
||||||||||||
Hawkins - On Intelligence |
89 |
somatosensory
areas make
predictions about touch,
texture, contour, and temperature. |
||||||||||||
Hawkins - On Intelligence |
89 |
Correct
predictions result in understanding. |
||||||||||||
Hawkins - On Intelligence |
89 |
Prediction is the primary
function of the neocortex, and the foundation
of intelligence. |
||||||||||||
Hawkins - On Intelligence |
90 |
Rodolfo
Llinas, I of the Vortex, the capacity to predict the outcome of future events is most likely, the ultimate and most common of all global brain functions. |
||||||||||||
Hawkins - On Intelligence |
90 |
There
is an entire subfield of mathematics devoted to Bayesian networks. |
||||||||||||
Hawkins - On Intelligence |
90 |
Bayesian
networks use probability theory to make predictions. |
||||||||||||
Hawkins - On Intelligence |
92 |
When listening
to people speak, you often know what they're going to
say before they finished speaking. |
||||||||||||
Hawkins - On Intelligence |
92 |
People
tend to use common phrases or expressions in much of
their conversation. |
||||||||||||
Hawkins - On Intelligence |
92 |
Prediction is not always exact. Rather, our minds work to make probabilistic predictions concerning what is about to happen. |
||||||||||||
Hawkins - On Intelligence |
93 |
In Western
music, the brain
automatically predicts beats, repeated rhythms, completion of phrases, and end of songs. |
||||||||||||
Hawkins - On Intelligence |
97 |
Intelligence is measured by the capacity to remember and predict patterns in the world including language, mathematics, physical properties of objects, and social situations. |
||||||||||||
Hawkins - On Intelligence |
105 |
To recall
the appropriate
memories, the brain has
to retrieve
patterns by their similarity
to past
patterns (auto associative recall). |
||||||||||||
Hawkins - On Intelligence |
105 |
Memories have to be stored in
an invariant
form so that the knowledge of past events can be applied to new situations that are similar but not identical to the past. |
||||||||||||
Hawkins - On Intelligence |
113 |
As
many if not more feedback connections in visual cortex as there are feedforward connections. |
||||||||||||
Hawkins - On Intelligence |
115 |
Patterns received by the first auditory area can vary widely. A word
can be spoken with different accents, and different pitches, or at different speeds. |
||||||||||||
Hawkins - On Intelligence |
115 |
Higher
up in
the cortex, those low level features don't matter; a word is a word regardless of the acoustic details. |
||||||||||||
Hawkins - On Intelligence |
115 |
We
see the same kind of feedback, prediction, and invariant recall in auditory cortex as we see in the visual system. |
||||||||||||
Hawkins - On Intelligence |
117 |
The downward flow fills in the current input
and makes predictions about what we will experience next. |
||||||||||||
Hawkins - On Intelligence |
119 |
These
predictions can only come about
by massive coordination of patterns streaming up and down the cortical hierarchy. |
||||||||||||
Hawkins - On Intelligence |
119 |
We
have an overarching
sensory system, sights, sounds,
touch, and more combined, all flowing up and down a single multi-branched hierarchy. |
||||||||||||
Hawkins - On Intelligence |
119 |
You
are not
born with any of this knowledge; you learned it through the incredibly large capacity of your cortex to remember patterns. |
||||||||||||
Hawkins - On Intelligence |
120 |
The
way the cortex
processes downward-flowing sensory predictions is similar to how it processes downward-flowing motor commands. |
||||||||||||
Hawkins - On Intelligence |
120 |
Sensory
patterns simultaneously flow
in anywhere
and
everywhere, and then flow back down in any area of the hierarchy, leading to predictions or motor behavior. |
||||||||||||
Hawkins - On Intelligence |
120 |
Seeing, hearing, touching, and acting are profoundly intertwined. |
||||||||||||
Hawkins - On Intelligence |
122 |
V1,V2,
and
V4, each is a collection of many smaller subregions. |
||||||||||||
Hawkins - On Intelligence |
122 |
The largest
region by far is V1, the primary visual area. |
||||||||||||
Hawkins - On Intelligence |
122 |
Next
would be V2. They are large compared to most regions. |
||||||||||||
Hawkins - On Intelligence |
122 |
V1 is made up of numerous separate little cortical areas that are only connected to their neighbors indirectly, through regions higher up in the hierarchy. |
||||||||||||
Hawkins - On Intelligence |
123 |
The cortex now looks similar everywhere. |
||||||||||||
Hawkins - On Intelligence |
123 |
Pick
any
region and you will find many lower regions providing converging sensory input. |
||||||||||||
Hawkins - On Intelligence |
123 |
The receiving region sends projections back to the input regions,
telling them what patterns they should expect to see next. |
||||||||||||
Hawkins - On Intelligence |
123 |
Higher
association
areas unite information from multiple senses such as vision and touch. |
||||||||||||
Hawkins - On Intelligence |
124 |
The most
important result of this
depiction of cortical hierarchy is that every region of cortex forms invariant representations. |
||||||||||||
Hawkins - On Intelligence |
124 |
Now
we can say that invariant representations are ubiquitous. Invariant representations are formed in every cortical region. |
||||||||||||
Hawkins - On Intelligence |
125 |
Association regions above
IT form invariant representations of patterns from multiple senses. |
||||||||||||
Hawkins - On Intelligence |
125 |
All
regions of
the cortex form invariant representations of the world beneath them in the hierarchy. |
||||||||||||
Hawkins - On Intelligence |
125 |
The real
world's nested structure is mirrored by the nested structure of the cortex. |
||||||||||||
Hawkins - On Intelligence |
127 |
The cortex has a clever learning algorithm that naturally finds whatever hierarchical structure exists and captures it. |
||||||||||||
Hawkins - On Intelligence |
127 |
Higher
regions of
the cortex are keeping track of the big
picture while lower areas are actively dealing
with the fast-changing small details. |
||||||||||||
Hawkins - On Intelligence |
128 |
If
the patterns
are related in such a way
that the region can learn to predict what pattern will occur next, the cortical region
forms a persistent representation, or memory, for the sequence. |
||||||||||||
Hawkins - On Intelligence |
129 |
As information
moves up from primary sensory regions to higher levels, we see fewer and fewer changes over time. |
||||||||||||
Hawkins - On Intelligence |
129 |
In primary
visual areas like V1, the set of active cells is changing rapidly as new patterns fall on the retina several times each second. |
||||||||||||
Hawkins - On Intelligence |
129 |
In visual
area IT, self firing patterns are more stable. |
||||||||||||
Hawkins - On Intelligence |
129 |
Each
region of cortex has a repertoire of sequences it knows. |
||||||||||||
Hawkins - On Intelligence |
129 |
Each cortical region has a name for each sequence it knows. |
||||||||||||
Hawkins - On Intelligence |
129 |
The "name" is a group of cells whose collected firing represents the set of objects in the sequence. |
||||||||||||
Hawkins - On Intelligence |
129 |
These
cells remain active as long as the sequences playing, and it is this “name” that
is passed
up to the next region in the hierarchy. |
||||||||||||
Hawkins - On Intelligence |
130 |
We
can imagine region IT at the top of the visual hierarchy relaying
to an association area above it, "I am
seeing a face." |
||||||||||||
Hawkins - On Intelligence |
130 |
One
region might recognize a sequence of sounds that comprise phonograms. |
||||||||||||
Hawkins - On Intelligence |
130 |
The next
higher region recognizes sequences the phonems to create words. |
||||||||||||
Hawkins - On Intelligence |
130 |
The next
higher region recognizes sequences of words to create phrases, and so on. |
||||||||||||
Hawkins - On Intelligence |
130 |
By collapsing
predictable
sequences into named objects at each region in the hierarchy, we achieve more
and more stability the higher we go. |
||||||||||||
Hawkins - On Intelligence |
130 |
This
creates invariant representation. |
||||||||||||
Hawkins - On Intelligence |
130 |
The opposite
effect happens as a pattern moves back down the hierarchy: stable patterns get unfolded into sequences. |
||||||||||||
Hawkins - On Intelligence |
131 |
At
this point the unfolding pattern splits and travels down both
the auditory
section
of
cortex and the motor section of cortex. |
||||||||||||
Hawkins - On Intelligence |
131 |
In
the final bottom region, each phonem is unfolded into a sequence of muscle commands to make sounds. |
||||||||||||
Hawkins - On Intelligence |
131 |
The lower you look in the hierarchy, the faster the patterns are changing. |
||||||||||||
Hawkins - On Intelligence |
131 |
A single
constant
pattern at the top of the motor hierarchy eventually leads to a complex and lengthy sequence of speech sounds. |
||||||||||||
Hawkins - On Intelligence |
133 |
The bottom-up inputs to a region of
cortex are input patterns carried on thousands or millions of axons. |
||||||||||||
Hawkins - On Intelligence |
133 |
The number
of possible
patterns that can exist on
even 1000 axons is larger than the number of molecules in the universe. |
||||||||||||
Hawkins - On Intelligence |
134 |
Both
steps, classification and sequence formation, are necessary to create invariant representations, and each region of cortex does them. |
||||||||||||
Hawkins - On Intelligence |
135 |
You
use the context of known sequences to resolve ambiguity |
||||||||||||
Hawkins - On Intelligence |
135 |
Most
of the time you are aware that you are filling in ambiguous or incomplete information from your memories or sequence |
||||||||||||
Hawkins - On Intelligence |
135 |
By recognizing
a sequence
of patterns, a cortical region
will predict its next input pattern and tell the region below what to expect. |
||||||||||||
Hawkins - On Intelligence |
135 |
A region
of cortex not only learns familiar sequences, it also learns how to
modify its classifications. |
||||||||||||
Hawkins - On Intelligence |
136 |
In cortical
regions, bottom-up classifications and top-down sequences are constantly interacting, changing
throughout your life. |
||||||||||||
Hawkins - On Intelligence |
136 |
Forming
new
classifications and new sequences is how you remember the world. |
||||||||||||
Hawkins - On Intelligence |
136 |
Another
part of the cortical job is
to relay
the “name,” of the
sequence you are seeing to the next level up. |
||||||||||||
Hawkins - On Intelligence |
137 |
The hierarchy of the cortex ensures that memories of objects are distributed over the
hierarchy; they aren't
located in a single spot. |
||||||||||||
Hawkins - On Intelligence |
137 |
Because
each
region of the hierarchy forms invariant memories, what a typical region of cortex learns is
sequences
of invariant. representations, which are themselves sequences of invariant memories |
||||||||||||
Hawkins - On Intelligence |
138 |
Cortical
regions vary greatly in size, the largest being the primary sensory areas. |
||||||||||||
Hawkins - On Intelligence |
138 |
Let's
assume that a typical cortical area is the size of a small coin. |
||||||||||||
Hawkins - On Intelligence |
139 |
The density
and shape of the cells in the cortex vary as you move from top to bottom. |
||||||||||||
Hawkins - On Intelligence |
139 |
These
differences define the layers. |
||||||||||||
Hawkins - On Intelligence |
139 |
Layer 1, the top layer is the most distinct of the six layers.
It has very few cells consisting primarily of
a mat of
axons running parallel to the cortical surface |
||||||||||||
Hawkins - On Intelligence |
139 |
Layers
2 and
3
looks similar. They contain many, tightly packed. pyramidal cells. |
||||||||||||
Hawkins - On Intelligence |
139 |
Layer 4 has a type of
star-shaped
cell. |
||||||||||||
Hawkins - On Intelligence |
139 |
Layer 5 has regular pyramidal cells as well as a class of extra big pyramidal-shaped cells. |
||||||||||||
Hawkins - On Intelligence |
139 |
Layers
6, the bottom layer also has several types of unique neurons. |
||||||||||||
Hawkins - On Intelligence |
139 |
Columns
of
cells run perpendicular to the layers. You can think of columns as being vertical units of cells that work together. |
||||||||||||
Hawkins - On Intelligence |
139 |
The layers within each column are connected by axons that run up and down, making synapses along the way. |
||||||||||||
Hawkins - On Intelligence |
139 |
Columns do not have clear boundaries but their existence can be inferred from several lines of evidence. |
||||||||||||
Hawkins - On Intelligence |
139 |
The cells within each column are strongly connected. |
||||||||||||
Hawkins - On Intelligence |
140 |
Activity spreads up and down within a column of cells. |
||||||||||||
Hawkins - On Intelligence |
140 |
In an
embryo, single precursor cells migrate from an inner brain cavity to where the cortex takes take shape. |
||||||||||||
Hawkins - On Intelligence |
140 |
Each
of these cells divides to create about 100 neurons, called a microcolumn. |
||||||||||||
Hawkins - On Intelligence |
140 |
The human
cortex has an estimated several hundred million
microcolumns. |
||||||||||||
Hawkins - On Intelligence |
140 |
Imagine
a single microcolumn is the width of a human hair. |
||||||||||||
Hawkins - On Intelligence |
140 |
The brush like mat is a simplistic model of the coin size cortical region. |
||||||||||||
Hawkins - On Intelligence |
140 |
And information
flows mostly in the direction of the hairs: horizontally in layer 1 and vertically in layers 2 through
6 |
||||||||||||
Hawkins - On Intelligence |
140 |
At
least 90% of the synapses on cells within each column come from places outside the column itself. |
||||||||||||
Hawkins - On Intelligence |
140 |
Some
connections arrived from neighboring column. |
||||||||||||
Hawkins - On Intelligence |
140 |
Other
connections come from halfway across the brain. |
||||||||||||
Hawkins - On Intelligence |
140 |
Vernon
Mountcastle argued there is a single cortical algorithm, he also proposed a cortical column is the basic unit of
computation in the cortex. |
||||||||||||
Hawkins - On Intelligence |
141 |
It is
believed that the column is the basic unit of prediction. |
||||||||||||
Hawkins - On Intelligence |
141 |
Converging
inputs from
lower
regions
always arrive at layer 4, the main input layer. |
||||||||||||
Hawkins - On Intelligence |
141 |
Layer 4
cells then
send projections up to cells in layer 2 and layer 3 within their column. |
||||||||||||
Hawkins - On Intelligence |
141 |
Layer 6
cells are the downward
projecting output cells from a cortical column and project to layer 1 in the region hierarchically below. |
||||||||||||
Hawkins - On Intelligence |
153 |
The sum
of all these mechanisms allows
the cortex to learn sequences, make predictions,
and form constant representations, or "names," for sequences. |
||||||||||||
Hawkins - On Intelligence |
168 |
The neocortex is responsible for all
complex motor sequences and can
directly control your limbs. |
||||||||||||
Hawkins - On Intelligence |
170 |
Connections between the hippocampus
and the neocortex suggest that the hippocampus is the top region of the neocortex. |
||||||||||||
Hawkins - On Intelligence |
170 |
The hippocampus occupies the peak of the neocortical pyramid. |
||||||||||||
Hawkins - On Intelligence |
170 |
The hippocampus not only sits at the top of the cortical pyramid, but it still connects directly to many
older
parts of the brain. |
||||||||||||
Hawkins - On Intelligence |
170 |
Think
about the information flowing from your eyes, ears, and skin into the neocortex. |
||||||||||||
Hawkins - On Intelligence |
170 |
Each
region of
the neocortex tries to understand the input in the in terms of the sequences it knows. |
||||||||||||
Hawkins - On Intelligence |
170 |
If it
does
understand the input it does
not
pass on the details to higher levels of the hierarchy. |
||||||||||||
Hawkins - On Intelligence |
170 |
If a region
does not understand the current input,
it passes it up the hierarchy until some higher region does understand it. |
||||||||||||
Hawkins - On Intelligence |
170 |
A pattern that is truly novel will escalate further and further up the hierarchy until some higher region does understand it. |
||||||||||||
Hawkins - On Intelligence |
170 |
The net
effect is that when you get to the top of the cortical pyramid, what you have left is
information that can't be understood by prior experience. |
||||||||||||
Hawkins - On Intelligence |
171 |
You
are left with the part of the input that is truly new and unexpected. |
||||||||||||
Hawkins - On Intelligence |
171 |
It is
these unexplained and unanticipated remainders, the new stuff,
that enters the hippocampus and is stored there. |
||||||||||||
Hawkins - On Intelligence |
171 |
This new, fresh information won't be stored forever. Either it will be transferred into the
cortex or it will eventually be lost. |
||||||||||||
Hawkins - On Intelligence |
171 |
The hippocampus has a heterogeneous
structure with several
specialized regions. It's good
at the unique task of quickly storing whatever pattern it sees. |
||||||||||||
Hawkins - On Intelligence |
171 |
You
can instantly
remember a novel event in the hippocampus,
but you will permanently remember something in the cortex only if you experience
it over
and over, either in reality
or by thinking of it. |
||||||||||||
Hawkins - On Intelligence |
171 |
The cortex
has a second
major pathway for passing
information from region to region, up the hierarchy. |
||||||||||||
Hawkins - On Intelligence |
172 |
The alternate path starts with cells in layer 5 which project to the thalamus and then up to the next higher region of cortex. |
||||||||||||
Hawkins - On Intelligence |
172 |
As we
move up the cortical hierarchy, there is a direct path between two regions and an indirect path through
the thalamus. |
||||||||||||
Hawkins - On Intelligence |
173 |
The alternate pathway through the thalamus is likely the mechanism
by which we attend to details that normally we
would not notice. |
||||||||||||
Hawkins - On Intelligence |
173 |
It bypasses the grouping of
sequences in layer 2, sending the raw data to the next higher region of cortex. |
||||||||||||
Hawkins - On Intelligence |
174 |
In
this way unusual events quickly rise to your attention. |
||||||||||||
Hawkins - On Intelligence |
174 |
This
is why we can't avoid focusing
on deformities and other unusual patterns. |
||||||||||||
Hawkins - On Intelligence |
174 |
Often however, errors aren't strong enough to open the alternate pathway. This is why we sometimes don't notice if a word is misspelled as we read it. |
||||||||||||