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Japanese Psychological Research
2002, Volume 44, No. 4, 228–233
Short Report
Re-acquisition of upright vision while wearing
visually left–right reversing goggles1
SHORT REPORT
Munksgaard
HIROKAZU YOSHIMURA2
Department of Psychology, Meisei University, Hodokubo, Hino, Tokyo,
191-8506, Japan
Abstract: The present research aimed to identify the important factor that makes it
difficult to re-acquire upright vision when wearing visually transposed goggles. The author
wore left-right reversing goggles and up-down reversing goggles each for 14 days in 1986
and in 1990, respectively. When lying on one side with the left-right reversing goggles on,
the observer could get upside-down vision, which made it possible to compare the difficulty
of attaining upright vision when wearing up-down reversing goggles. The only difference
between the two situations is the dimension of the body image to be exchanged: The
observer had to exchange the left and right halves of his body in the former situation and
had to exchange along the top-bottom axis of body in the latter situation. Introspective data
revealed that attaining an upright sense is easier in the former situation; this means that
the asymmetrical structure of our body in the top-bottom dimension is an important factor
in the difficulty of re-acquiring upright vision.
Key words: upright vision, visual transposition, perceptual adaptation, left-right reversal,
up-down reversal.
The problem of upright vision has been
explored only through visual up-down reversal
or inversion (180-degree rotation) experiments that contain the visual reversal of the
up-down dimension. The present research,
however, demonstrates that left-right reversal
vision experiments are effective when the
observer lies on his side. The left-right reversing goggles do not reverse up and down along
the vertical body axis; thus, we may think the
goggles do not affect the upright vision. This
notion, however, is true only when the
observer is standing upright. When the
observer lies down, the situation changes drastically. In that condition, the left-right reversing
goggles transpose vision in the up-down (ceilingfloor) dimension, thus producing upside-down
vision. The upside-down impression when lying
on one’s side in the left-right reversal experiments is common to the impression when
standing in the up-down reversal experiments
in the sense that the visual information of ceiling and floor contradicts the gravity information. In this article, “upright vision” indicates
that the observer sees the ceiling upward and
the floor downward in space, resulting in perception consistent with body orientation.
Generally speaking, it takes a long time to
re-acquire upright vision when wearing updown reversing or inverting goggles. Since
1
Preparation of this article was supported by the Japanese Ministry of Education, Science, and Culture Grant-in-Aid
for General Scientific Research Grant no. 09610074 allocated to Hirokazu Yoshimura.
I wish to thank Dr R Dyck of Capital University and Dr D Erickson of Ohio State University for their polite and
careful proofing of my English manuscript.
2
Correspondence concerning this article should be sent to: Professor Yoshimura Hirokazu, Department of Psychology, Meisei University, Hodokubo 2-1-1, Hino-shi, Tokyo 191-8506, Japan (Email: [email protected]).
© 2002 Japanese Psychological Association. Published by Blackwell Publishers Ltd.
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Re-acquisition of upright vision
Stratton’s (1897) experiment, researchers in
this field have recognized that upright vision
could be re-acquired by unifying the seen and
felt sense of the body. In their experiments,
the observers barely achieved unstable upright
vision after wearing inverting or up-down
reversing goggles for a long time: Stratton
(1897) wearing for 8 days, Peterson and Peterson (1938) for 14 days, Snyder and Pronko
(1952) for 30 days, and Dolezal (1982) for
14 days.
There are three factors that may explain the
reason for the difficulty in unifying the seen
and felt sense of the body in visual up-down
reversal experiments. First, the ceiling (sky) –
floor (ground) axis, which defines the up-down
dimension of space, has a very distinguishable
meaning; therefore, “up” and “down” should
not be exchangeable (compared to the similarity of the left and right sides). Second, the
information from gravity disturbs the exchange.
Third, the asymmetrical structure of our body
in the top–bottom axis, as compared to the
highly symmetrical structure in the left-right
axis, should make it more difficult to reverse
the up-down body axis.
When the observer wearing the left-right
reversing goggles lies down on either side,
the first two factors are preserved but the
condition for the last factor changes drastically. When the observer lies down, he
should visually reverse the left-right halves of
the body, but not the asymmetrical upperlower parts. The purpose of the present research
was to estimate the importance of the last
factor for unifying the seen and felt sense of
the body. This can be realized by comparing
the difficulty of re-acquiring upright vision
between the two kinds of visual reversal
experiments.
Method
Subject
The observer was the author, who wore the
left-right reversing goggles for 14 days (from
Day 1 to Day 15) in 1986, and the up-down
reversing goggles for the same period in
1990.
229
Goggles
Both the left-right reversing and up-down
reversing goggles were hand-made with two
acrylic right-angle prisms, 60 mm hypotenuse
face × 43 mm lateral face × 40 mm length. In order
to reverse the vision, a pair of the right-angle
prisms was set immediately in front of each
eye. The prisms were mounted on a light wood
frame and fixed to the head by a cloth band.
The binocular visual field of the left-right
reversing goggles was set at about 75 degrees
horizontally and 55 degrees vertically, overlapping at the center by about 15 degrees; the
up-down reversing goggles were set at about 80
degrees horizontally and 44 degrees vertically,
overlapping at the center by about 12 degrees.
The total weight for each was about 160 g.
Procedure
During the time of the experiments, the
observer wore the prism goggles continually,
except when sleeping or taking a bath; then he
wore a sleeping-mask to exclude visual stimuli.
The observer spent most of his time in or near
his house, and at the university, where he was
taken by car. The results of several different
tests done periodically during the wearing time
are reported in other articles (Yoshimura,
1996, 1999).
The present article focuses on the introspective data concerning the re-acquisition of
upright vision reported by the observer. The
observer carried a portable tape recorder
throughout the experiments and recorded his
perceptual impressions, including the behavioral strategies he employed.
Results and discussion
Introspection reported in the experiment
using up-down reversing goggles
On the first day, the observer perceived himself to be standing upright and the scene to be
upside down. In spite of the prolonged wearing
time, this impression essentially did not change,
as the following introspection points out.
Day 10. When walking under the room light
facing forward, I felt as if my body would
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230
H. Yoshimura
have touched the light suspended from the
ceiling. Still, I am standing upright and the
scene was upside down.
The sense of being upright was limited to
the specific situation and it was unstable, as
suggested from the following introspection.
Day 13. I’m now lying on my stomach and
looking forward. The field of vision is mostly
occupied by the images of the closest parts
of the tatami. Then, I look at my four-yearold son who is sitting at his low desk. He
looks normal in the right side up position,
not upside down. I think he looks upright
for two reasons. First, most of the field of
vision is occupied by tatami mats, which
indicate the ground of space; in turn, these
become the frame of reference for perceiving the orientation of the desk, chair, and
the child’s body. Second, the lying-down position should be advantageous for unifying
the seen and felt sense of the body because
the two are much closer to each other
when in that position than when standing
upright.
Under this situation, the observer need not
exchange asymmetrical upper and lower parts
of the body to unify the seen and felt sense.
The unification of the body sense was limited
to this situation in the present experiment.
In other research that used the prism- or
lens-type goggles, the observer remained in
the same unstable adaptation stage, where
they perceived a strange sense of the body
experiencing partial upright vision. For example, as the subject of his own experiment,
Dolezal (1982) wrote, “The top of the head
was judged to be closer to the ground than any
other part of the head. The visually perceived
location of my head was variable, though my
effective point of observation was mostly
judged to be just inches above the ground”
(p. 205). The observers would represent such
a strange body image because of the difficulty
to reverse the upper and lower parts of the body
completely. Including my experiment, reports
indicate that it is not easy to re-acquire secure
© Japanese Psychological Association 2002.
and stable upright vision in the up-down visual
reversal experiments. The only exception is
Kohler’s (1964) experiment, in which the subject
M wore a mirror-type up-down reversing goggles
for 10 days and reported the re-acquisition of
stable upright vision. Kohler, however, did
not refer to the unification of the seen and
felt sense of the body, although it should be
critical for upright vision. Dolezal (1982)
criticized the verbal ambiguity in Kohler’s
experiment and concluded that Kohler’s data
cannot be interpreted (p. 270).
Introspection reported during the
experiment wearing left-right reversing
goggles
Four years before the above experiment, I
myself wore the left-right reversing goggles for
14 days. On the 13th day of the experiment,
the observer had a critical experience with the
upright vision. He then lived in the world of
perfectly left-right reversed mental maps in
contrast to the before-wearing, normal vision
world. Suppose he was facing the door and
there was a window to his right and the next
room to his left. On Day 13, he perceived the
opposite: In his mental map, the window
would be to his left and the next room to his
right. When he was lying on tatami mats (see
Figure 1), he experienced a curious but valuable event.
Day 13. I’m now lying on my back with my
legs to the entrance of the tatami room.
Then I perceive that the window is to my
left and the next room is to my right. I
clearly visualize this and cannot imagine it
otherwise. When I change my position to
lying on my actual right, the window comes
into the field of vision. Now, in spite of lying
on my right side, I perceive as if I were lying
on my left side. It is reasonable to think that
it would be difficult to misperceive the side
of the body touching the tatami when lying
on either side because of the correct proprioceptive information received from touching one’s face and body to the tatami mat.
However, my vivid mental map, which informs
me that the window should be to my left,
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Re-acquisition of upright vision
231
Figure 1. The room arrangements in which the observer is lying on his side facing the window.
leads to the misperception that I’m lying on
my left side. When lying on my left side and
facing to the window, do I see the image
upside down? No, tatami mats are perceived
as lower than the window. They are seen to
be right side up.
In Figure 2, the disappearance of upside
down impressions is demonstrated. Physically,
the observer is lying on his right side and gets
the image of the parts of the window and
tatami mats shown in the balloon of Figure 2
(“physical arrangement”). In his field of vision,
the window image is seen near to his right ear
and that of tatami mats is seen near to his left.
But subjectively, he perceives he is lying on his
left side as shown in Figure 2 (“subjective
arrangement”). The relationships of the
images of the window and tatami mats to the
head (to the left-right ears) are common to
the physical and subjective situations. Now, he
perceives lying on his left side and sees the
tatami mat leftward in the field, which, in turn,
means that tatami mats are downward and that
the window is upward. There is no contradiction, and the upside down impression has disappeared. While he was living in the left-right
reversed mental map with the left-right
reversed body image, he re-acquired upright
vision. In this article, “mental map” represents
the environmental arrangements around the
observer and “body image” indicates the
observer’s own representation of his own posture.
Until the 13th day the observer had not perceived the upright vision when lying on tatami
mats. Instead, he had repeatedly experienced
the confusion of the body image with the leftright reversed mental map from the second day
of the experiment as shown in the following.
Day 12. Now I’m watching television lying
down in the tatami room. As the TV display
is seen near to my feet, I try to move my
body to catch it in front of the face. But I
can’t do it. I lose my sense of direction in
the room.
The critical point in realizing upright vision
is how to get the body image to be lying on the
left side although the observer is lying on his
actual right side. On Day 13, the observer used
a smart strategy to facilitate the unification of
the seen and felt sense of the body. At this
time, the observer’s mental map was perfectly
left-right reversed. By lying on his back and
turning the whole body repeatedly from his
right side to his left side and passing through
© Japanese Psychological Association 2002.
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232
H. Yoshimura
Figure 2. Demonstration of the disappearance of the upside-down impression.
the lying-on-his-back position, he could unify
the two sense of the body. Mediated by the
dynamic visual information in the field of
vision, such as visual-flow direction and the
occlusion-disocclusion relationship contingent
on the body’s turning, the observer easily
achieved unification.
Why is it difficult to re-acquire upright
vision when wearing visually up-down
reversing goggles?
Supported by the strategy unifying the seen
and felt sense of the body, the observer wearing
left-right reversing goggles could re-acquire
upright vision within 2 weeks. In contrast,
when wearing up-down reversing goggles, the
same observer could not get secure upright
vision within the 2-week prism wearing period.
What is the factor that differentiates between
the two visual transpositions?
In the Introduction, I pointed out three factors that might make it difficult to unify the
body sense: distinctive meaning of ceiling (sky)
© Japanese Psychological Association 2002.
– floor (ground), competition of the information from gravity, and the asymmetrical structure of the human body. The third factor would
be nullified when the observer lies on his side
wearing left-right reversing goggles, leaving
the other two factors intact. In this situation,
the observer re-acquired clear upright vision.
The present research indicates that the reacquisition of upright vision would be facilitated by the mental map that represents the
surroundings left-right reversed from actual
arrangements. As shown in Figure 1, the
observer facing the window represented the
posture holding the left-right reversed mental
map in mind. Without the reversed map, he
should have perceived the actual side when
lying down, based on the strong proprioceptive
information given from the face and body
touching to the tatami mats, which, in turn,
should have resulted in the persistence of the
upside-down impression.
This notion, induced from the introspection, can
also be deduced from theoretical considerations.
JPR_024.fm Page 233 Wednesday, September 4, 2002 4:35 PM
Re-acquisition of upright vision
Upright vision should coincide with the representation of the observer’s seen and felt
bodies. Harris (1965, 1980), for example, speculates that adaptation to the visually transposed world can be achieved by changing the
proprioception to the positions that coincide
with vision. The lack of symmetry of the upper
and lower parts of the body makes it difficult
to exchange them when wearing up -down reversing goggles. However, it becomes much easier
when the observer lies on his side wearing leftright reversing goggles. Harris (1965), indeed,
insisted his proprioceptive change hypothesis
by using the left-right visual reversal experiments, not the up-down reversal experiments.
The finding of the present research should
be valuable because it was revealed by comparing the two experiments imposed on the
same observer for the same goggles-on period
in similar situations. The observer experienced
only a partial and unstable upright impression
in the up-down reversal experiment. In the
left-right reversal experiment, he got a clear
upright impression, even though it was limited
to the situation of lying on tatami mats.
In conclusion, the symmetrical structure of
our body in the left-right dimension is a facilitating factor to unify the seen and felt sense
of the body which, in turn, would lead to
upright vision in the visually transposed world.
233
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(Received Oct. 26, 1999; accepted Sep. 29, 2001)
© Japanese Psychological Association 2002.