INFORMATION TRANSMISSION UNDER CONDITIONS OF SENSORY SHIELDING
by Harold E. Puthoff, Ph.D., and Russell Targ,
Stanford Research Institute, Menlo Park, California.
Harold E. Puthoff is a
senior research engineer at the Stanford Research Institute and a specialist in
laser physics. He holds patents in the areas of lasers and optical devices, and
is co- author of Fundamentals of Quantum Electronics, a text bridging quantum
mechanics, engineering, and applied physics.BR
Russell Targ is a senior
research physicist at the Stanford Research Institute and an expert in the field
of plasma physics. He is the inventor of the tunable plasma oscillator at
microwave frequencies, the FM laser, and the high-power gas-transport laser. His
publications include more than two dozen articles on lasers, plasma physics, and
psychic research.
Published in Nature, VOL 252, No. 5476, Oct. 18, 1974, pp.
602-607.
For completeness, all of the investigations conducted at SRI on
Geller and on other subjects are presented here.
WE PRESENT results of
experiments suggesting the existence of one or more perceptual modalities
through which individuals obtain information about their environment, although
this information is not presented to any known sense. The literatures and our
observations lead us to conclude that such abilities can be studied under
laboratory conditions.
We have investigated the ability of certain people to
describe graphic material or remote scenes shielded against ordinary perception.
In addition, we performed pilot studies to determine if ectroencephalographic
(EEG) recordings might indicate perception of remote happenings even in the
absence of correct overt responses.
We concentrated on what we consider to
be our primary responsibility - to resolve under conditions as unambiguous as
possible the basic issue of whether a certain class of paranormal perception
phenomena exists. So we conducted our experiments with sufficient control,
utilizing visual, acoustic, and electrical shielding,
to ensure that all
conventional paths of sensory input were blocked. At all times we took measures
to prevent sensory leakage and to prevent deception, whether intentional or
unintentional.
Our goal is not just to catalogue interesting events, but to
uncover patterns of cause-effect relationships that lend themselves to analysis
and hypothesis in the forms with which we are familiar in scientific study. The
results presented here constitute a first step toward that goal; we have
established under known conditions a data base from which departures as a
function of physical and psychological variables can be studied in future work.
Remote Perception of Graphic Material
First, we conducted
experiments with Mr. Uri Geller in which we examined his ability, while located
in an electrically shielded room, to reproduce target pictures drawn by
experimenters located at remote locations. Second, we conducted double-blind
experiments with Mr. Pat Price, in which we measured his ability to describe
remote outdoor scenes many miles from his physical location Finally, we
conducted preliminary tests, using EEGs, in which subjects were asked to
perceive whether a remote light was flashing, and to determine whether a subject
could perceive the presence the light, even if only at a non-cognitive level of
awareness.
In preliminary testing Geller apparently demonstrated an ability
to reproduce simple pictures (line drawings) that had been drawn and placed in
opaque sealed envelopes he was not permitted to handle. But since each of the
targets was known to at least one experimenter in the room with Geller, it was
not possible on the basis of the preliminary testing to discriminate between
Geller's direct perception of envelope contents and perception through some
mechanism involving the experimenters, whether paranormal or subliminal.
So
we examined the phenomenon under conditions designed to eliminate all
conventional information channels, overt or subliminal. Geller was separated
from both the target material and anyone knowledgeable of the material, as in
the experiments of Reference 4.
In the first part of the study a series of
thirteen separate drawing experiments was carried out over seven days. No
experiments were deleted from the results presented here. (For all target
drawings and Geller's responses see Plates 1 and 2.)
At the beginning of the
experiment either Geller or the experimenters entered a shielded room, so that
from that time forward Geller was at all times visually, acoustically, and
electrically shielded from personnel and material at the target location. Only
following Geller's isolation from the experimenters was a target chosen and
drawn, a procedure designed to eliminate pre-experiment cueing. Furthermore, to
eliminate the possibility of pre-experiment target forcing, Geller was kept
ignorant as to the identity of the person selecting the target and as to the
method of target selection. This was accomplished by the use of three different
techniques: (1) pseudorandom technique of opening a dictionary arbitrarily and
choosing the first word that could be drawn (Experiments 1-4); (2) targets,
blind to experimenters and subject, prepared independently by SRI scientists
outside the experimental group (following Geller's isolation) and provided to
the experimenters during the course of the experiment (Experiments 5-7, 11-13);
and (3) arbitrary selection from a target pool decided upon in advance of daily
experimentation and designed to provide data concerning information content for
use in testing specific hypotheses (Experiments 8-10). Geller's task was to
reproduce with pen on paper the line drawing generated at the target location.
Following a period of effort ranging from a few minutes to half an hour, Geller
either passed feel confident) or indicated he was ready to submit a drawing to
the experimenters,in which case the drawing was collected before Geller was
permitted to see the target.
Table 1. Summary: Remote perception of graphic
material
Experiment Date Geller location Target location Target Figure
1
8/4/73 Shielded room #1a Adjacent room(4.1 m)b Firecracker 1a
2 814/73
Shielded room #l Adjacent room(4.1 m) Grapes 1b
3 8/5173 Shielded room #l
Office (475 m) Devil lc
4 8/5/73 Room adjacent to Shielded room#l Solar
system 1d
shielded room #l (3.2 m)
5 8/6/73 Room adjacent to Shielded
room#l Rabbit No drawing
shielded room #l (3.2 m)
6 8/7/73 Shielded room
#l Adjacent room(4.1 m) Tree No drawing
7 8/7173 Shielded room #l Adjacent
room(4.1 m) Envelope No drawing
8 818/73 Shielded room #l Remote room (6.75m)
Camel 1e
9 818173 Shielded room #l Adjacent room(4.1 m) Bridge 1f
10
8/8/73 Shielded room #l Adjacent room(4.1 m) Seagull 1g
11 8/9173 Shielded
room #2c Computer (54 m) Kite (computer 2a
CRT)
12 8110173 Shielded room
#2 Computer (54 m) ChurchBR (computer 2b
memory)
13 8/10173 Shielded room
#2 Computer (54 m) Arrow through 2c
heart (computer
CRT, zero
inten-
sity)
(a)EEG Facility shielded room (see
text).
(b)Perceiver-target distances measured in meters.
(c)SRI Radio
Systems Laboratory shielded room (see text).
To prevent sensory cueing of
the target information, Experiments 1 through 10 were carried out using a
shielded room in SRI's facility for EEG research. The acoustic and visual
isolation is provided by a double-walled steel room, locked by means of an inner
and outer door, each of which is secured with a refrigerator-type locking
mechanism. Following target selection when Geller was inside the room, a one-way
audio monitor, operating only from the inside to the outside, was activated to
monitor Geller during his efforts. The target picture was never discussed by the
experimenters after the picture was drawn and brought near the shielded room. In
our detailed examination of the shielded room and the protocol used in these
experiments, no sensory leakage has been found.
The conditions and results
for the ten experiments carried out in the shielded room are displayed in Table
1 and Plate 1. All experiments except 4 and 5 were conducted with Geller inside
the shielded room. In Experiments 4 and 5, the procedure was reversed. For those
experiments in which Geller was inside the shielded room, the target location
was in an adjacent room at a distance of about 4 m, except for Experiments 3 and
8, in which the target locations were, respectively, an office at a distance of
475 m and a room at a distance of about 7 m.
A response was obtained in all
experiments except Numbers 5-7. In Experiment 5, the person-to-person link was
eliminated by arranging for a scientist outside the usual experimental group to
draw a picture, lock it in the shielded room before Geller's arrival at SRI, and
leave the area. Geller was then led by the experimenters to the shielded room
and asked to draw the picture located inside the room. He said that he got no
clear impression and therefore did not submit a drawing. The elimination of the
person-to-person link was examined further in the second series of experiments
with this subject.
Experiments 6 and 7 were carried out while we attempted
to record Geller's EEC during his efforts to perceive the target pictures. The
target pictures were, respectively, a tree and an envelope. He found it,
difficult to hold adequately still for good EEG records, said that he
experienced difficulty in getting impressions of the targets, and again
submitted no drawings.
Experiments 11-13 were carried out in SRI's
Engineering Building, to make use of the computer facilities available there.
For these experiments, Geller was secured in a double-walled, Copper-screen
Faraday cage 54 m down the hall and around the corner from the computer room.
The Faraday cage provides 120 dB attenuation for plane wave radio frequency
radiation over a range of 15 kHz to 1 GHz. For magnetic fields the attenuation
is 68 dB at 15 kHz and decreases to 3 dB at 60 Hz. Following Geller's isolation,
the targets for these experiments were chosen by computer laboratory personnel
not otherwise associated with either the experiment or Geller, and the
experimenters and subject were kept blind as to the contents of the target pool.
For Experiment 11, a picture of a kite was drawn on the face of cathode-ray
tube display screen, driven by the computer's graphics program. For Experiment
12, a picture of a church was drawn stored in the memory of the computer. In
Experiment 13, target drawing, an arrow through a heart (see Plate 2(c)), was
drawn on the face of the cathode-ray tube and then the display in was turned off
so that no picture was visible.
To obtain an independent evaluation of the
correlation between target and response data, the experimenters submitted the
data for judging on a "blind" basis by two SRI scientists who were not otherwise
associated with the research. For the ten cases in which Geller provided a
response, the judges were asked to match the response data with the
corresponding target data (without replacement). In those cases in which Geller
made more than one drawing as his response to the target, all the drawings were
combined as a set for judging. The two judges each matched the target data to
the response data with no error. For either judge such a correspondence has an a
priori probability, under the null hypothesis of no information channel, of P =
1/(10!) = 3 X 10-7.
A second series of experiments was carried out to
determine whether direct perception of envelope contents was possible without
some person knowing of the target picture.
One hundred target pictures of
everyday objects were drawn by an SRI artist and sealed by other SRI personnel
in double envelopes containing black cardboard. The hundred targets were divided
randomly into groups of twenty for use in each of the three days' experiments.
On each of the three days of these experiments, Geller passed. That is, he
declined to associate any envelope with a drawing that he made, expressing
dissatisfaction with the existence of such a large target pool. On each day he
made approximately twelve recognizable drawings, which he felt were associated
with the entire target pool of 100. On each of the three days, two of his
drawings could reasonably be associated with two of the twenty daily targets. On
the third day, two of his drawings were very close replications of two of that
day's target pictures. The drawings resulting from this experiment do not depart
significantly from what would be expected by chance.
In a simpler experiment
Geller was successful in obtaining information under conditions in which no
persons were knowledgeable of the target. A double-blind experiment was
performed in which a single 3/4-inch die was placed in a 3 x 4 x 5-inch steel
box. The box was then vigorously shaken by one of the experimenters and placed
on the table, a technique found in control runs to produce a distribution of die
faces that does not differ significantly from chance distribution. The
orientation of the die within the box was unknown to the experimenters at that
time. Geller would then write down which die face was uppermost. The target pool
was known, but the targets were individually prepared in a manner blind to all
persons involved in the experiment. This experiment was performed ten times,
with Geller passing twice and giving a response eight times. The eight times he
gave a response, he was correct each time. The distribution of responses
consisted of three twos, one four, two fives, and two sixes. The probability of
this occurring by chance is approximately one in 10^6.
In certain situations
significant information transmission can take place under shielded conditions.
Factors that appear to be important and are therefore candidates for future
investigation include whether the subject knows the set of targets in the target
pool, the actual number of targets in the target pool at any given time, and
whether the target is known by any of the experimenters.
It has been widely
reported that Geller has demonstrated the ability to bend metal by paranormal
means. Although metal bending by Geller has been observed in our laboratory, we
have not been able to combine such observations with adequately controlled
experiments to obtain data sufficient to support the paranormal hypothesis.
Remote Viewing of Natural Targets
A study by Osis (5) led us
to determine whether a subject could describe randomly chosen geographical sites
located several miles from the subject's position and demarcated by some
appropriate means (remote viewing). This experiment carried out with Price, a
former California police commissioner and city councilman, consisted of a series
of double-blind, demonstration-of-ability tests, involving local targets in the
San Francisco Bay area, which could be documented by several independent judges.
We planned the experiment believing that natural geographical, places or manmade
sites that have existed for a long time are more potent targets, for paranormal
perception experiments than are artificial targets prepared in the laboratory.
This is based on subject opinions that the use of artificial targets involves a
"trivialization of the ability" as compared with natural preexisting targets.
In each of nine experiments involving Price as subject and SRI experimenters
as a target-demarcation team, a remote location was chosen in a double-blind
protocol. Price, who remained at SRI, was asked to describe this remote
location, as well as whatever activities might be going on there.
Several
descriptions yielded significantly correct data pertaining to, and descriptive
of, the target location.
In the experiments a set of twelve target locations
clearly differentiated from each other and within thirty minutes' driving time
from SRI had been chosen from a target-rich environment (more than 100 targets
of the type used in the experimental series) prior to the experimental series by
an individual in SRI management, the director of the Information Science and
Engineering Division, not otherwise associated with the experiment. Both the
experimenters and the subject were kept blind as to the contents of the target
pool, which were used without replacement.
An experimenter was closeted with
Price at SRI to wait thirty minutes to begin the narrative description of the
remote location. The SRI locations from which the subject viewed the remote
locations consisted of an outdoor park (Experiments 1 and 2), the double-walled
copper-screen Faraday cage discussed earlier (Experiments 3 and 4, and 6-9), and
an office (Experiment 5). A second experimenter would then obtain a target
location from the division director from a set of traveling orders previously
prepared and randomized by the director and kept under his control. The target
demarcation team (two to four SRI experimenters) then proceeded directly to the
target by automobile without communicating with the subject or experimenter
remaining behind. Since the experimenter remaining with the subject at SRI was
in ignorance both as to the particular target and as to the target pool, he was
free to question Price to clarify his descriptions. The demarcation team then
remained at the target site for thirty minutes after the thirty minutes allotted
for travel. During the observation period, the remote-viewing subject would
describe his impressions of the target site into a tape recorder. A comparison
was then made when the demarcation team returned.
Price's ability to
describe correctly buildings, docks, roads, gardens, and so on, including
structural materials, color, ambiance, and activity, sometimes in great detail
indicated the functioning of a remote perceptual ability. But the descriptions
contained inaccuracies as well as correct statements. To obtain a numerical
evaluation of the accuracy of the remote viewing experiment, the experimental
results were subjected to independent judging on a blind basis by five SRI
scientists who were not otherwise associated with the research. The judges were
asked to match the nine locations, which they independently visited, against the
typed manuscripts of the tape-recorded narratives of the remote viewer. The
transcripts were unlabeled and presented in random order. The judges were asked
to find a narrative that they would consider the best match for each of the
places they visited. A given narrative could be assigned to more than one target
location. A correct match required that the transcript of a given date be
associated with the target of that date. Table 2 shows the distribution of the
judges' choices.
Table 2.
Distribution of correct selections by judges A,B,C,D, and E
In remote viewing experiments Descriptions chosen by judges Places
visited by judges 1 2 3 4 5 6 7 8 9 Hoover Tower 1 ABCDE D
Baylands Nature
Preserve 2 ABC E D D
Radio Telescope 3 ACD BE
Redwood City Marina 4 CD
ABDE E
Bridge Toll Plaza 5 ABD DCE
Drive-in Theater 6 B A c E
Arts and
Crafts Garden Plaza 7 ABCE
Church 8 c AB
Rinconada Park 9 CE AB
Of
the 45 selections (5 judges, 9 choices), 24 were correct. Bold type indicates
the description chosen most often for each place visited. Correct choices lie on
the main diagonal. The number of correct matches by Judges A through E is 7, 6,
5, 3 and 3, respectively. The expected number of correct matches from the five
judges was five; in the experiment 24 such matches were obtained. The a priori
probability of such an occurrence by chance, conservatively assuming assignment
without replacement on the part of the judges, is P = 8 x 10^-10.
Among all
possible analyses, the most conservative is a permutation analysis of the
plurality vote of the judges' selections, assuming assignment without
replacement, an approach independent of the number of judges. By plurality vote,
six of the nine descriptions and locations were correctly matched. Under the
null hypothesis (no remote viewing and a random selection of descriptions
without replacement), this outcome has an a priori probability of P = 5.6 x
10^-4, since, among all possible permutations of the integers one through nine,
the probability of six or more being in their natural position in the list has
that value. Therefore, although Price's descriptions contain inaccuracies, the
descriptions are sufficiently accurate to permit the judges to differentiate
among the various targets to the degree indicated.
EEG Experiments
An experiment was undertaken to determine
whether a physiological measure such as EEG activity could be used as an
indicator of information transmission between an isolated subject and a remote
stimulus. We hypothesized that perception could be indicated by such a measure
even in the absence of verbal or other overt indicators. (6,7)
It was
assumed that the application of remote stimuli would result in responses similar
to those obtained under conditions of direct stimulation. For example, when a
normal subject is stimulated with a flashing light, his EEG typically shows a
decrease in the amplitude of the resting rhythm and a driving of the brain waves
at the frequency of the flashes. (8) We hypothesized that if we stimulated one
subject (a sender) in this manner, the EEG of another subject (a receiver) in a
remote room with no flash present, might show changes in alpha (9-11 Hz)
activity, and possibly EEG driving similar to that of the sender.
We
informed our subject that at certain times a light was to he flashed in a
sender's eyes in a distant room, and if the subject perceived that event,
consciously or unconsciously, it might be evident from changes in his EEG
output. The receiver was seated in the visually opaque, acoustically and
electrically shielded double walled steel room previously described. The sender
was seated in a room about 7 m from the receiver.
To find subjects who were
responsive to such a remote stimulus, we initially worked with four female and
two male volunteer subjects, all of whom believed that success in the
experimental situation might be possible. These were designated "receivers." The
senders were either other subjects or the experimenters. We decided beforehand
to run one or two sessions of thirty-six trials each with each subject in this
selection procedure, and to do a more extensive study with any subject whose
results were positive.
A Grass PS-2 photostimulator placed about 1 m in
front of the sender was used to present flash trains of ten-seconds' duration.
The receiver's EEG activity from the occipital region (Oz), referenced to linked
mastoids, was amplified with a Grass 5P-1 preamplifier and associated driver
amplifier with a band pass of 1-120 Hz. The EEG data were recorded on magnetic
tape with an Ampex SP 300 recorder.
On each trial, a tone burst of fixed
frequency was presented to both sender and receiver and was followed in one
second by either a ten-second train of flashes or a null flash interval
presented to the sender. Thirty-six such trials were given in an experimental
session, consisting of twelve null trials - no flashes following the tone -
twelve trials of flashes at six flashes per second and twelve trials of flashes
at sixteen flashes per second, all randomly intermixed, determined by entries
from a table of random numbers. Each of the trials generated an eleven-second
EEG epoch. The last four seconds of the epoch were selected for analysis to
minimize the desynchronizing action of the warning cue. This four-second segment
was subjected to Fourier analysis on a LINC 8 computer.
Spectrum analyses
gave no evidence of EEG driving in any receiver, although in control runs the
receivers did exhibit driving when physically stimulated with the flashes. But
of the six subjects studied initially, one subject (H.H.) showed a consistent
alpha blocking effect. We therefore undertook further study with this subject.
Data from seven sets of thirty-six trials each were collected from this
subject on three separate days. This is all the data collected to date with this
subject under the test conditions described above. The alpha band was identified
from average spectra; then scores of average power and peak power were obtained
from individual trials and subjected to statistical analysis.
Table 3.
EEG data for H. H. showing average power and peak power in the 9-11 Hz band, as
a function of flash frequency and sender Flash
Frequency 0 6 16 0 6
16
Sender Average power Peak power
J.L 94.8 84.1 76,8 357.7 329.2
289.6
R.T. 41.3 45.5 37.0 160.7 161.0 125.0
No
sender
(subject
informed) 25.1 35.7 28.2 87.5 95.7 81.7
J.L. 54.2 55.3
44.8 191.4 170.5 149.3
J.L. 56.8 50.9 32,8 240.6 178.0 104.6
R.T. 39.8
24.9 30.3 145.2 74.2 122.1
No sender
(subject not
informed) 86.0 53.0
52.1 318.1 180.6 202.3
Averages 56.8 49.9 43.1 214.5 169.8 153.5
-12%
-24%(P0.04) -21% -28%(P0.03)
Each entry is an average over 12
trials
Of our six subjects, H.H. had by far the most monochromatic EEG
spectrum. Plate 3 shows an overlay of the three averaged spectra from one of
this subject's thirty-six-trial runs, displaying changes in her alpha activity
for the three stimulus conditions. (See Plate 3.)
Mean values for the
average power and peak power for each of the seven experimental sets are given
in Table 3. The power measures were less in the sixteen-flashes-per-second case
than in the zero-flashes-per-second in all seven peak power measures and in six
out of seven average power measures. Note also the reduced effect in the case in
which the subject was informed that no sender was present (Run 3). It seems that
overall alpha production was reduced for this run in conjunction with the
subject's expressed apprehension about conducting the experiment without a
sender. This is in contrast to the case (Run 7) in which the subject was not
informed.
Siegel's two-tailed t approximation to the nonparametric
randomization test (9) was applied to the data from all sets, which included two
sessions in which the sender was removed. Average power on trials associated
with the occurrence of sixteen flashes per second was significantly less than
when there were no flashes (t= 2.09, d.f. = 118, P 0.04). The second measure,
peak power, was also significantly less in the sixteen-flashes-per-second
conditions than in the null condition (t = 2.16, d.f. = 118, P 0.03). The
average response in the six-flashes-per-second condition was in the same
direction as that associated with sixteen flashes per second, but the effect was
not statistically significant.
Spectrum analyses of control recordings made
from saline with a 12 k ohm resistance in place of the subject with and without
the addition of a 10 Hz, 50 micro volt test signal applied to the saline
solution, revealed no indications of flash frequencies, nor perturbations of the
10 Hz signal. These controls suggest that the results were not due to system
artifacts. Further tests also gave no evidence of radio frequency energy
associated with the stimulus.
Subjects were asked to indicate their
conscious assessment for each trial as to which stimulus was generated. They
made their guesses known to the experimenter via one-way telegraphic
communication. An analysis of these guesses has shown them to be at chance,
indicating the absence of any supraliminal cuing, so arousal as evidenced by
significant alpha blocking occurred only at the noncognitive level of awareness.
We hypothesize that the protocol described here may prove to be useful as a
screening procedure for latent remote perceptual ability in the general
population.
Conclusion
From these experiments we conclude that:
1. A
channel exists whereby information about a remote location can be obtained by
means of an as yet unidentified perceptual modality.
2. As with all
biological systems, the information channel appears to be imperfect, containing
noise along with the signal.
3. While a quantitative signal-to-noise ratio
in the information theoretical sense cannot as yet be determined, the results of
our experiments indicate that the functioning is at the level of useful
information transfer.
It may be that remote perceptual ability is widely
distributed in the general population, but because the perception is generally
below an individual's level of awareness, it is repressed or not noticed. For
example, two of our subjects (H.H. and P.P.) had not considered themselves to
have unusual perceptual ability before their participation in these experiments.
Our observation of the phenomena leads us to conclude that experiments in
the area of so-called paranormal phenomena can be scientifically conducted, and
it is our hope that other laboratories will initiate additional research to
attempt to replicate these findings.
REFERENCES
1. Pratt, J., J. B.
Rhine, C. Stuart, and J. Greenwood, Extrasensory Perception after Sixty Years
(New York: Henry Holt, 1940).
2. Soal, S. and F. Bateman, Modern Experiments
in Telepathy (London: Faber and Faber, 1954).
3. Vasiliev, L. L.,
Experiments in Mental Suggestion (Hampshire, England: ISMI Publications, 1963).
4. Musso, J. R. and M. Granero, Journal of Parapsychology, 37, 13-37, 1973.
5. Osis, K., ASPR Newsletter, No. 14, 1972.
6. Tart, C. T.,
"Physiological Correlates of Psi Cognition." International Journal of
Parapsychology, V, No. 4, 1963.
7. Dean, E. D., International Journal of
Neuropsychiatry, 2, 1966.
8. Hill, D. and C. Parr, Electroencephalography: A
Symposium on Its Various Aspects (New York: Macmillan, 1963).
9. Siegel, S.,
Nonparametric Statistics for the Behavioral Sciences (New York: McGraw-Hill,
1956), pp. 152-56.
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