Dr. Frank Rosenblatt, 1928-1971
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PhD Experimental Psychology, Cornell, 1956
Developed neural networks called perceptrons
A probabilistic model for information
storage and organization in the brain
 Key properties
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Association or learning
Generalization to new patterns
Distributed memory
Biologically plausible brain model
Cornell Aeronautical Lab (1957-1959), Cornell (1960-71)
Frank Rosenblatt
Dr. Frank Rosenblatt
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Wikipedia portrayal exaggerated
“Rosenblatt was a colorful character at Cornell
in the early 1960s. A handsome bachelor, he drove a classic MGA sports
car and was often seen with his cat named Tobermory.”
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Those who knew him would consider him a rather
shy genius and more of a Renaissance man
Renaissance man because he excelled in a wide variety of subjects,
including psychology (his original field), computing, mathematics,
neurophysiology, astronomy, and music
Frank Rosenblatt
Agenda
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The Mark I Perceptron – Visual System Model
The Tobermory Perceptron – Auditory System Model
Perceptron Computer Simulations
Rosenblatt's Book
Rosenblatt-Minsky Debates and Minsky-Papert Book
Rat Brain Experiments
Hobbies – Astronomy, Climbing, Music, Sailing
Untimely Death
Frank Rosenblatt
The Mark I Perceptron
Visual system model and pattern classifier
Examining A-unit of Mark I
Typical three-layer perceptron: fixed S→A and variable A→R connections
Frank Rosenblatt
The Mark I Perceptron
Visual system model and pattern classifier
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Input (sensory) layer of 400 photosensitive units in a 20x20
grid modeling a small retina
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Association layer of 512 units (stepping motors) each of
which could take several excitatory and inhibitory inputs
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Connections from input to association layer altered through plug-board wiring,
but once wired they were fixed for the duration of an experiment
Connections from association to output layer were variable weights (motordriven potentiometers) adjusted through error-propagating training process
Output (response) layer of 8 units
Frank Rosenblatt
The Tobermory Perceptron
Auditory system model and pattern classifier
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Named after talking cat,
Tobermory, in story by H.H. Munro (aka Saki)
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Large machine
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S-units: 45 band-pass filters and 80 difference detectors
A-units: 1600 A1-units (20 time samples per detector) &
1000 A2-units
R-units: 12, with 12,000 adaptive weights A2→R-units.
Frank Rosenblatt
Perceptron Computer Simulations
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Hardware implementations made good demonstrations but
software simulations were far more flexible
In early 1960s these computer simulations required machine
language coding for speed and memory usage
Simulation software package – user could specify the number
of layers, the number of units per layer, type of connections
between layers, etc.
Computer time at Cornell and NYU
Frank Rosenblatt
Rosenblatt's Book
Principles of Neurodynamics, 1962
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Part I: historical review of brain modeling approaches,
physiological and psychological considerations, and basic
definitions and concepts of the perceptron approach
Part II: three-layer, series-coupled perceptrons –
mathematical underpinnings and experimental results
Part III: multi-layer and cross-coupled perceptrons
Part VI: back-coupled perceptrons
Book used to teach an interdisciplinary course "Theory of
Brain Mechanisms" that drew students from Cornell's
Engineering and Liberal Arts colleges
Frank Rosenblatt
Series-Coupled Perceptrons
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A perceptron is a network of sensory (S), association (A),
and response (R) signal generating units
A series-coupled perceptron is feed-forward S→A→R
An elementary perceptron is a series-coupled perceptron with
one R-unit connected to every A-unit and fixed S→A
connections
Convergence Theorem: Given elementary perceptron,
stimulus world W, and any classification C(W) for which a
solution exists, then if all stimuli in W re-occur in finite time,
the error correction procedure will always find a solution
Frank Rosenblatt
Series-Coupled Perceptrons
Mark I was typical S→A→R perceptron
Connections
S→A: fixed, usually local
A→R: adjustable w training
Frank Rosenblatt
Series-Coupled Perceptrons
A-units usually local biologically-plausible detectors
Frank Rosenblatt
Series-Coupled Perceptrons
Rosenblatt studied three and four-layer series-coupled perceptrons
with two sets of variable weights but was unable to find a suitable
training procedure like back-propagation
Dotted lines
are variable
connections
Frank Rosenblatt
Cross-Coupled Perceptrons
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A cross-coupled perceptron is a system in which some
connections join units of the same type (S, A, and/or R)
Frank Rosenblatt
Back-Coupled Perceptrons
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A back-coupled perceptron is a system with feedback paths
from units located near the output end of the system to units
closer to the sensory end
Frank Rosenblatt
Rosenblatt-Minsky Debates
and Minsky-Papert Book
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Rosenblatt and Marvin Minsky (MIT) debated at conferences the value of
biologically inspired computation, Rosenblatt arguing that his neural
networks could do almost anything and Minsky countering that they could
do little
Minsky, wanting to decide the matter once and for all, collaborated with
Seymour Papert and published a book in 1969, Perceptrons: An
Introduction to Computational Geometry, where they asserted about
perceptrons (page 4), "Most of this writing ... is without scientific value...”
Minsky, although well aware that powerful perceptrons have multiple
layers and Rosenblatt's basic feed-forward perceptrons have three layers,
defined a perceptron as a two-layer machine that can handle only linearly
separable problems and, for example, cannot solve the exclusive-OR
problem
Frank Rosenblatt
Minsky-Papert Book
H.D. Block’s response paper
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The authors address three classes of readers
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Computer scientists specializing in pattern recognition, learning machines,
and threshold logic
Abstract mathematicians interested in the debut of Computational Geometry
Those interested in the general theory of computation leading to decisions
based on the weight of partial evidence, e.g. psychologists and biologists
H.D. Block concludes
1.
2.
3.
Computer scientists “will find the book of little value”
Abstract mathematicians consulted “were not captivated”
“For psychologists and biologists, the level of mathematical maturity
demanded will, I believe, make the book somewhat difficult to read.”
Frank Rosenblatt
Rat Brain Experiments
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Late 1960s – Rosenblatt began experiments in the
Cornell Department of Entomology on the transfer
of learned behavior via rat brain extracts
Rats were taught discrimination tasks such as Ymaze and two-lever Skinner box, their brains
extracted and injected into untrained rats that were
then tested in the discrimination tasks to determine
whether or not there was behavior transfer from
the trained to the untrained rats
Rosenblatt spent his last several years on this
problem and showed convincingly that the initial
reports of larger effects were wrong and that any
memory transfer was at most very small
Frank Rosenblatt
Astronomy
Rosenblatt built a modest observatory on a
hilltop behind his house 6 miles east of
Ithaca. Work began summer 1961, Fecker
12" cassegrain telescope.
He had interest in SETI (Search for
Extraterrestrial Intelligence), wrote a
proposal touting a "Stellar Coherometer” he
designed, and was awarded $75K for the
project.
Current photo – house in background
The observatory was completed about 1966 –
a circular cinderblock structure with dome
housing the telescope
Frank Rosenblatt
Music
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Rosenblatt was an accomplished pianist and had a
grand piano at his house in Brooktondale
He played the well-known classical pieces of Mozart,
Beethoven, etc.
He also composed music and had a penchant of
improvising endlessly on "Three Blind Mice"
Frank Rosenblatt
Practical Joker
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As a graduate student
Frank was a psychology major and Prof. James Gibson
was a well-known faculty member and Frank’s
dissertation advisor. As the story goes, Frank and some
other graduate students drove to the town of Gibson
one night and stole the town's "Gibson" signs, which
they then mounted at the door of Professor Gibson's office.
When Department Chair saw the signs, he remarked to the department
secretary, "Don't you think Gibby's getting a little ostentatious?“
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Traveling to a conference Frank remarked
“Do you think McCulloch sleeps
with his beard under or over the covers?”
Frank Rosenblatt
Rosenblatt – Renaissance man
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Excelled in a wide variety of subjects – psychology (his
original field), computing, mathematics, neurophysiology,
astronomy, and music
He had two research reputations
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neural networks with his perceptron work
neurophysiology with the rat brain experiments
When learning a new subject (to paraphrase Rodman Miller)
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In a few weeks he knew a little
In a few months he knew a great deal
Soon thereafter he was discussing topics with experts in the field
Frank Rosenblatt
Untimely Death
Sailboat accident on his 43rd birthday
He “was a most gifted
human being ... had
made his entire life a
contribution to mankind”
Congressional Record
Frank Rosenblatt