Perera – Reaction timing instrumentation
Paper presented in a symposium at the 1999 meeting of
the Eastern Psychological Association in
Chaired by Dr. Haupt and entitled (il Simposio?): The Muller - Wundt Controversy over the Measurement of Reaction Time.
QUOTATION FROM THE
Appropriate because of the current bombing of
BUILDING MUSEUMS ON THE INTERNET:
THE HIPP CHORONOSCOPES
Hipp Reaction Time Setup
Tuning Fork Escapement - Problems
Start and Stop Solenoids - Problems
CALIBRATION OF THE HIPP
IMPROVEMENTS AND CHANGES IN THE HIPP DESIGN
Smoked-drum / tuning fork
Barnard Pendulum Chronoscope
THE HUMAN FACTOR
Cattell with Wundt
THE COLUMBIA PSYCHOLOGY DEPARTMENT
Keller's Introductory Classes
Emphasis on wiring diagrams
Knowledge of electronics
Knowledge of Army Surplus
FINAL SOLUTIONS TO THE TIMING PROBLEM
Quartz Crystal Oscillator
Hard to Interface
APPROXIMATE TEXT OF PAPER:
Copyright (c) 1999 Thomas Perera Ph. D.
Draft of paper for EPA presentation,
I would like to start out by reading
an adaptation of the introduction to the magnificent book: Sense, Mind, and Measure: The Collection of
Old Scientific Instruments of the laboratory for Experimental Psychology,
"The Methods and spirit of Wundt's Laboratory were spread by many renowned European and American Psychologists. It is through an understanding of the methodology of Wundt's Laboratory that we can gain an insight into the development of Experimental Psychology itself."
"The Psychological instruments which were the last word in technology have vanished from modern psychological laboratories. After multiple rennovations and house cleanings, most modern laboratories show no signs of any of the early apparatus."
"I do regret that we have replaced that bountiful variety of switches, outlets, dials, wires, rods, tubes, supports, motors, threads, pens, those often imaginitive forms made of brass, wood, glass, rubber, plastic, and what-not for the boring monotony of computer screens and keyboards."
"That is why we have worked so hard to preserve and restore the psychological apparatus in our museum."
(THE CAPITALIZED HEADINGS ARE THE SLIDES WHICH I PRESENTED)
Lacking the wealth of original
instruments in the
BARNARD WEB HIPP
I have been searching out and restoring some of the earliest research apparatus from the forgotten storerooms of Barnard College of Columbia University and I have made photographs and descriptions of the various instruments accessible to everyone on the internet as the "Barnard College History of Psychology Collection".
Barnard's most prized exhibit is
this wonderful Hipp Chronoscope. It
was used at
** HIPP TYPES & OPERATION
WOODEN COVERED MECHANISM
There were many primarily cosmetic refinements of the Hipp Chronoscope and in its direct descendants as shown in these slides during it's 100 year production from the 1840's to the 1940's.
HIPP SETUP: WORD STIMULUS, VOICE RESPONSE
Here is a complete early reaction time experimental setup. A word stimulus is suddenly exposed and the subject responds by speaking loudly at this electromechanical voice key. The Hipp does the timing.
HIPP FRONT VIEW
Let me describe the operation of the Hipp and the intracacies of its mechanism. This front view shows the two dials. The upper one reads in milliseconds and the lower one increments one step for each (100ms) complete revolution of the upper dial. The mechanism is powered by a heavy weight which hangs down below the mechanism.
START AND STOP LEVERS
Some Hipp Chronoscopes were equipped with a key to start the mechanism as shown here. Others such as the Barnard Hipp which I will be demonstrating are started by simply pulling on a string. The string pulls the start lever and gives one of the gears a real kick-start which overcomes the resistance of the vibrating tuning fork escapement and starts it oscillating.
CLOSE-UP OF TUNING FORK ESCAPEMENT:
The tuning fork escapement had to oscillate at 1000 Hz and this required a very delicate adjustment as you will hear when I demonstrate it. All too easily, the frequency could shift to 500 Hz and the experimenter had to be constantly on guard to listen for this event and discard affected trials. This was one of the more easily managed sources of timing error with the Hipp Chronoscopes.
START AND STOP SOLENOIDS
PULL-IN / RELEASE TENSION SPRING FINE ADJUSTMENT DIAL
PULL-IN / RELEASE KYMOGRAPHIC TRACINGS
The major problem affecting accuracy came from the need to exactly equalize the rise and fall times of the start and stop solenoids. These solenoids moved this tiny bar from the stationary clutch face to the moving clutch face and back again. Adjustments were made by varying the return-spring tension using these fine calibrated settings.
Keeping the Hipp calibrated was a tedious and difficult task. Due to variations in the above parameters and in the wet batteries used to power the solenoids, it was necessary to calibrate the Hipp every 20 or 30 trials.
THE "CROW'S FOOT WET
The batteries consisted of Zinc and Copper electrodes immersed in a solution of copper sulfate. I have one such battery for you to inspect up here at the front of the room. Changes in room temperature, electrolyte concentration, and deposits on the electrodes caused the voltage and current output of the batteries to vary widely.
** CALIBRATION OF THE HIPP
The device which was used most frequently for calibrating the Hipp Chronoscope was the Control Hammer. The Control Hammer provided an accurate and repeatable set of contact-closures as a hammer literally fell past the electrical contacts. Due to limitations of size, it could only be used to calibrate time intervals up to 160 ms.
CONTACT PENDULUM CALIBRATOR
The Contact Pendulum was a second
device used for calibrating chronoscopes and chronographs for longer time
intervals than 160ms. It was capable of
generating accurate signals separated by up to 2.5 seconds. Its operation was based on the constant
oscillation period of a pendulum of known length. Dr. Galanter
reports that at
The Hipp continued to be used for 100 years but improvements were made and the improved instruments found their way into psychological research labs as their finances allowed.
FURTHER EVOLUTION OF THE HIPP
The first improvement was to replace the weight-driven mechanism with a wind-up spring driven mechanism while retaining the 1000 Hz tuning fork escapement.
Next, a Foucault swinging weight governor was used to regulate the speed of the spring-driven mechanism. This produced a device called the D'Arsonoval Chronoscope.
The next evolutionary step in chronoscope design was the Dunlap or John's Hopkins Chronoscope which used a synchronous electric motor which synchronized itself to the pulses produced by a tuning-fork oscillator.
DUNLAP CHRONOSCOPE IN EXPERIMENTAL SETUP
In this slide you can see a complete reaction time setup with the tuning
fork that drove the Dunlap Chronoscope over on the right. Professor Galanter was responsible for such a Dunlap Chronoscope at
Finally, the Springfield Electric Company began producing the Standard Electric Timer which is still being sold. It was/is a Hipp-like mechanism with a constantly running synchronous electric motor which derived its extreme accuracy from the stability of the 60 Hz line voltages.
The electrically-operated clutch mechanism simply freed-up or stopped a wheel which was constantly trying to rotate as a result of the constantly-running electric motor. This mechanism was therefore very similar to the original Hipp mechanism.
Electronic counters eventually
replaced the electromechanical
** CHRONO 'GRAPHS'
PICTURE OF CHRONOGRAPH & HIPP
ELECTRICAL TUNING FORK AND SINE WAVE TRACING ON SMOKED DRUM
ChronoGRAPHS which wrote a tuning-fork produced stream of timing oscillations on a black smoked sheet of paper and imposed start and stop signals on the oscillations were introduced in the same time frame as the Hipp. They provided reliability and high degrees of accuracy but were extremely tedious to use because of the need to count each of the 1000 oscillations-per-second marks in a measured time interval. Because of this, 50, 100, and 200 Hz models were common.
For psychology departments that didn't have the money to buy the expensive Hipp Chronoscopes or Kymographic Chronographs, equipment manufacturers made devices that converted a standard phonograph into a chronograph.
** PENDULUM CHRONOSCOPES
WEB BARNARD PENDULUM
This is a very early reacton timer. Presenting the visual stimulus also releases a pendulum which swings along a calibrated scale until the subject stops it by pressing this bar which pinches the pendulum and brings it to a stop.
BARNARD PENDULUM STIMULUS / TRIGGER
BARNARD PENDULUM HAND - CALIBRATED SCALE
BARNARD PENDULUM ADDED-ON SOLENOID ELECTROMAGNETIC STOP
As you can see the pendulum apparatus was modified by the addition of electromagnets to allow electrical signals to instantaneously stop it's swing.
WEB BARNARD VERNIER CHRONOSCOPE
CLOSE-UP OF EXPERIMENTER'S AND SUBJECT'S FINGERS ON KEYS
Another pendulum based mechanism was this vernier chronoscope. The two pendulums are set to slightly different lengths using a calibration rod which precisely positions each one at the proper length. One has an oscillation period of .80 sec and one has a period of .78 sec. The experimenter presses a button which starts the left one swinging and this is the stimulus to which the subject responds by pressing a button and releasing the second pendulum. The experimenter then counts the number of swings before they become synchronized and this number gives the number of 1/50'ths or .02's of a second that the two start times differ from each other.
** THE GALVANOMETER CHRONOSCOPE
MIRROR GALVANOMETER CHRONOSCOPE
Another type of chronoscope was made from a mirror galvanometer. It was appropriate only for very brief time intervals. An electrical voltage was impressed on a sensitive mirror galvanometer
when the stimulus was presented. The galvanometer began to swing and to move a reflected beam of light. When the subject responded, the galvanometer decellerated and the position that the beam of light reached at the point of reversal of direction gave an accurate indication of the duration of the voltage from stimulus onset to response onset.
** THE HUMAN FACTOR IN REACTION TIME RESEARCH
CATTELL AND WUNDT
Finally, I would like to mention an all-but-forgotten aspect of improving accuracy in reaction time research. Clearly, the most accurate reaction timing devices are irrelevant if the subject daydreams, slouches, fidgets, and dozes during the experiment. Every fidget increases the variability of the individual reaction times. A highly trained and motivated subject, then, may be as important as the
refinements in instrumentation accuracy.
Cattell, shown standing on the right started out as a student of Wundt's in the 1880's and gradually set out on his own to bring accurate reaction time research to the United States, first at Pennsylvania in 1887 and then at Columbia in 1890.
As a young man, he dedicated himself to becoming a 'professional' reaction time subject. In the same manner as an olympic athlete trains for the olympics, Cattell trained for his research sessions.
He insisted that "inexperienced persons, children, or the insane be barred from participation." Cattell followed a strict and repetitive personal schedule from day to day consisting of constant exercise, personal discipline, and planned repetitiveness.
PORTRAIT OF A MUCH OLDER CATTELL
In this portrait which hangs in the
Psychology Department at
** THE TRADITION OF TECHNICAL
KELLER'S INTRODUCTORY CLASS
These electronic counters could be bought for a small fraction of their original cost either directly from the Government or from Radio Row in New York City, a dilapidated series of surplus stores which, sadly, were torn down to allow the construction of the world trade center.
In those days, one's skills in electronics, mechanical construction, draftsmanship, and photography were as revered as one's knowledge of psychology. Notice that the left side of the blackboard is filled with cumulative record graphs and the right side has a complex electrical wiring diagram...
diameter of the propellor shaft while under weigh to allow the installation of undersize shaft seals and stop a leak. (These skills might account for the survival of his U-boat in a war where most were lost.
He brought these skills and the
associated Helmholtz, Muller tradition of
"PRECISE" German workmanship to
Prone to screaming outbursts of rage at our ineptitude with 'HIS' lathes, he terrified both students and faculty alike into emulating his obsession with precision and accuracy.
** FINAL SOLUTIONS TO THE TIMING PROBLEM
When I entered the field of psychology over 40 years ago, the issues surrounding accurate timing had finally been solved.
Ten years earlier, the development of the Atomic Bomb for WW-2 had required the development of high speed electronic counting circuits capable of capturing and counting the brief and rapid emissions of radioactive particles at rates of up to 100,000 events per-second.
DECADE COUNTER SYSTEM
Still earlier, in the 1920's, radio engineers had discovered that quartz crystals could be made to oscillate at extremely stable frequencies of 100,000 cycles per second and higher.
When the 100,000 cycles-per-second crystal oscillator was fed into a high speed counter, it became a clock which counted time in super-accurate steps of 1/100,000 of a second. (A hundredth of a
millisecond.) For measuring reaction times, all that remained was to turn on the clock when the stimulus was presented, and turn it off when the response occurred.
ELECTRONIC DECADE TIMER - PRINTER ATTACHED
One problem with these new counter/timers
was that they were extremely expensive.
This is the first timer brought into the
Another problem was that psychologists had no training in electronics and found it extremely difficult to interface the electromechanical relay programming equipment they had been using with the delicate high rise-time high-impedance pulse requirements of the electronic circuits.
LATER STYLE ELECTRONIC TIMER
EARLY HUNTER TIMER
LATER HUNTER KLOCK-COUNTER TIMER
These devices eliminated the early problems with reaction timing and allowed precise and repeatable measurements.
DISTRIBUTE THE BIBLIOGRAPHY AND WEB SITE LISTING
DEMONSTGRATION OF HIPP CHRONOSCOPE
DEMONSTRATION OF PENDULUM CHRONOSCOPE
DEMONSTRATION OF VERNIER CHRONOSCOPE
THE BARNARD COLLEGE HISTORY OF PSYCHOLOGY COLLECTION.
This collection consists of color photographs and descriptions of major early psychological research instruments.