Summary: "Growing up with Lucy"
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Summary: "On Intelligence"
This article summarizes a number of key concepts that are found in
Jeff Hawkins's book
"On Intelligence". In this book, Hawkins develops a powerfull theory of
how the human brain works and what intelligence is. He focuses on the
neocortex because he thinks all essential aspects of intelligence occur in the
neocortex, but he does agree that other brain structures are important to the
functioning of the neocortex.
According to Hawkins the neocortex is a memory prediction engine. It predicts
spatial- and temporal-patterns. It does not matter where the patterns are
coming from: eyes, ears, touch, muscle or other parts of the neocortex.
The following are interesting citations from the book, at least to me, grouped
Chapter 1 - Artificial Intelligence
Understanding occures when reading a story (whithout any outside
signals), not when aswering questions about it.
Chapter 2 - Neural Networks
There are ten times as many connections feeding information back to the
thalamus as forward to the neocortex.
Auto-associative memory with a time delay to the feedback can replay a
sequence of patterns from a few partial patterns. People learn
everything as a sequence of patterns.
Chapter 3 - The Human Brain
You can lead a pretty normal life without the cerebellum, the brain part
with the largest number of cells.
The cortical sheet comprises 6 layers is 2 mm thick and roughly the size
of a large dinner napkin.
Daniel Fellman and David van Essen made a detailed map of the monkey
The functional regions/areas in the neocortex are hierachical organized
with lateral connections. Information is flowing in both direcions.
The neuroscientist Vernon Mountcastle points out in his paper titled "An
Organizing Principle for Cerebral Function" that the neocortex is
remarkable uniform in appearance and structure.
The neocortex processes signals from the ear the same as the signals
from the eyes, e.i. the neocortex is the same for all sences.
A devoted area for written letters and digits tell us that the neocortex
is still dividing (organizing) itself into task specific area's long
All the information that enters your mind (vision, hearing, touch or
other) comes in as spatial and temporal patterns.
Chapter 4 - Memory
The brain is not a parallel-computer. The brain recognizes an image in
about half a second, or a chain of a hundred neurons long. One hundred
computer instructions are not enough to answer a difficult problem.
The brain retrieves the answer to problems from memory. The entire
neocortex is a memory system. It isn't a computer at all.
There are four attributes of neocortical memory that are different from
- The neocortex stores sequences of patterns.
- The neocortex recalls patterns auto-associative.
- The neocortex stores patterns in an invariant form.
- The neocortex stores patterns in a hiearchy.
To make a specific prediction the brain combines the knowledge of the
invariant structure with the most recent details.
Chapter 5 - A New Framework for Intelligence
Prediction is so pervasive that what we "percieve" - that is, how the
world appears to us - does not come solely from our senses. What we
percieve is a combination of what we sense and what our brains'
Prediction is the primary function of the neocortex, and the foundation
of intelligence. The cortex is an organ of prediction.
Behavior is best understood as a by product of prediction.
A computer-driven robot would fall over, not realizing that anything was
amiss, while a human would know as soon as the foot continues for even a
fraction beyond the spot where the brain had expected it to stop.
Te human brain is more intelligient than that of other animals because it
can make predictions about more abstract kinds of patterns and longer
temporal pattern sequences.
The neocortex evolved to make more efficient use of existing behaviors,
not to create new behaviors.
Chapter 6 - How the Cortex Works
Scientist have been ignoring the feedback connections, but the feedback
is needed to maake predictions. Prediction requires a comparison between
what is happening and what you expect to happen.
Hearing and feeling require a flow of sensorary patterns for
recognition. A single pattern is not enough. The same is true for
vision, which researchers generally ignored.
All predictions are learned by experience.
All cortical areas, including the visual area V1, should be simular,
that is form invariant representations and receive converging inputs
from two or more lower areas. This means that V1 should be considered as
many small regions only connected indirectly, not as a single large
A association area does not need to know where the inputs are comming
from: vision, sound, touch or a combination. Rather, the job of any
cortical area is to find out how its inputs are related, to memorize the
sequence of correlations between them, and to use this memory to predict
how the inputs will behave in the future.
The brain can be said to store sequences of sequences.
By collapsing predictable sequences into "named objects" at each region
in our hierarchy we achieve more and more stability the higher we go.
This creates invariant representatins. The oposite happens as a pattern
moves down the hierarchy: stable patters get "unfolded" in sequences.
The thalamus is responsible for the delayed feedback that lets the
neocortex learn sequences, just like the auto-associative memory models.
If recognition does not occur, an unexpected pattern will keep
propagating up the cortical hierarchy until some higher reqion can
interpret it as part of its normal sequence of events.
The hippocampus occupies the peak of the neocortical pyramid. It
temporarily stores the pattern that are unexplained and unanticipated.
There is a second path up (not down) the hierarchy via de thalamus. The
path is mostly shutdown in the thalamus or else the pattern is directly
passed on. This makes it possible to focus on details.
Chapter 7 - Consciousness and Creativity
All mammals, from rats to cats to humans, have a neocortex. They are all
intelligent, but to differing degrees.
Intelligence can be traced over three epochs, each using memory and
prediction. The first would be when species used DNA as medium for
memory. This include single-cell organisms and plants. The second
epoch began when nature invented modifiable nervous systems that could
quickly form memories. This includes the creation and expansion of the
neocortex. The third epoch is unique to humans and began with invention
of language and the expansion of our large neocortex.
Creativity can be defined as making predictions by analogy, something
that occurs everywhere in cortex. Creativity occurs along a continuum.
Consciousness is the process of the neocortex forming memories.
To imagine something, you merely let your predictions turn around and