Coincident Orientation Viewpoint-Dependence
COINCIDENT ORIENTATION OF OBJECTS AND
VIEWPOINT-DEPENDENCE IN SCENE RECOGNITION1,2
JING LI1
Department of Psychology, Nanjing Normal University
KAN ZHANG
State Key Laboratory of Brain and Cognitive Science
Institute of Psychology, Chinese Academy of Sciences
1
Address correspondence to [Dr. Jing Li, School of Education Science, Ninghai Road No. 122, Nanjing Normal
University, Nanjing, 210097, China or e-mail (florenze@qq.com)]
2The
project was supported by National Natural Science Foundation of China (30800304) and China Postdoctoral
Science Foundation (20100481162).
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Coincident Orientation Viewpoint-Dependence
Summary.—Viewpoint-dependence is a well-known phenomenon in which participants’
spatial memory is better for previously experienced points of view than for novel ones. In the
current study, partial-scene-recognition was used to examine the effect of coincidentorientation of all the objects on viewpoint-dependence in spatial memory. When objects in
scenes had no clear orientations (e.g., balls), participants’ recognition of experienced
directions was better than that of novel ones, indicating that there was viewpoint-dependence.
However, when the objects in scenes were toy bears with clear orientations, the coincident
orientation of objects (315°), which was not experienced, shared the advantage of the
experienced direction (0°), and participants were equally likely to choose either direction
when reconstructing the spatial representation in memory. These findings suggest that
coincident orientation of objects may affect egocentric representations in spatial memory.
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Coincident Orientation Viewpoint-Dependence
Recent research on spatial cognition and memory suggests that humans represent
their environment through two systems, an egocentric system based on the
relationship between self and objects, and an allocentric system based on the
relationships among objects (e.g., Easton & Sholl, 1995; Mou & McNamara, 2002;
Mou, McNamara, Valiquette, & Rump, 2004). Viewpoint-dependence is a closely
studied phenomenon in spatial memory. Participants’ performance is better for
experienced points of view than for novel ones in spatial memory and recognition
tasks because they can take a ‘snapshot’ of the scene from that direction. This has
been shown for two- and three-dimensional scenes under a variety of circumstances
(e.g., Diwadkar & McNamara, 1997; Simons & Wang, 1998; Wang & Simons, 1999;
Shelton & McNamara, 2001; Wang, Crowell, Simons, Irwin, Kramer, Ambinder, et al.,
2006) as well as for mental images created from verbal descriptions (e.g., Franklin &
Tversky, 1990).
Scene recognition tasks are widely used in the research on viewpoint-dependence
(e.g., Diwadkar & McNamara, 1997; Shelton & McNamara, 1997). In this paradigm,
participants learn the locations of several objects on a table from a single viewpoint.
They then make old-new recognition judgments in test scenes in which old objects are
presented from multiple directions, mixed with previously unseen objects.
Recognition is better for the experienced than for novel directions. Mou, Fan,
McNamara, and Owen (2008) developed a partial-scene-recognition task which
replicated the viewpoint-dependence effect for a small portion of the learned scene.
According to Gestalt principles, concurrent orientation of objects should be an
excellent spatial cue (Koffka, 1935; Beck, 1966), which may make people think about
the scene as if viewed from a different direction rather than that experienced. This has
been shown in the course of frame of reference construction, with a
judgment-of-relative-direction task (Marchette & Shelton, 2010). In the research,
participants learned a scene in which all the toy animals orient in the same direction
for a learning view, and then with the scene removed, the participants recalled the
layout of objects from different perspectives, followed as “Imagine you are standing
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Coincident Orientation Viewpoint-Dependence
at object A and facing B, and then point to C”. The experimental result suggested that
people chose not only the learning view but also the orientation of objects to construct
the frame of references.
But Marchette and Shelton (2010) also suggested that this effect might not hold for
scene recognition tasks because performance on a judgment-of-relative-direction and
scene recognition task based on different spatial representations (Valiquette &
McNamara, 2007). The judgment-of-relative-direction task requires careful
recollection of abstract spatial relations and the use of mental transformations for
imagining different directions. Scene recognition may rely more heavily on direct
memory for one’s original perception of a space. However, the different effect of
coincident orientation in different spatial tasks, if any, has not been experimentally
verified. There is a possibility that the spatial memory of a scene has been changed
totally as a result of the coincident orientation, not only the construction of frame of
reference in allocentric system, but also the egocentric experience in scene
recognition.
The current research used a partial-scene-recognition paradigm to examine the
effect of coincident object orientation on the viewpoint-dependence effect. To fit
short-term memory limits, the 7±2 rule (Miller, 1956), and to avoid possible
interference from the existence of a symmetric axis, asymmetric scenes consisting of
nine objects were used in current research. The partial-scene-recognition performance
under two conditions, objects with no clear orientation and objects with clear
orientations, was compared to examine the effect of coincident orientation.
METHOD
Participants
Sixty-four undergraduates and graduates (32 men, 32 women) from Chinese
Academy of Sciences, Beijing Forestry University, the University of Sciences &
Technology Beijing, and China Agricultural University, ranging in age from 20 to 29
years (M age= 23 yr., SD=2) participated in the experiment and received 15 CNY (2.5
USD) for compensation. They majored in Psychology, Biology, Computer Science,
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Coincident Orientation Viewpoint-Dependence
and Management. All participants reported they had normal or corrected-to- normal
eyesight and no apparent color blindness. The experiment was carried under the
approval of the authors’ IRB, and all the participants were notified the experiment
would do no harm to them, and they could quit during the experiment if they felt
uncomfortable anytime.
Materials and Design
All materials for both the learning and testing phase were displayed in a 3m×3m
room, in which all walls were covered with black curtains. The relative placement of
the learning stimuli is shown in Fig. 1A. The learning layout consisted of a
configuration of nine objects placed on a circular table (50 cm in diameter, 60 cm
above the floor) in the middle of the room. The distances between Objects 1 and 4, 3
and 4, 3 and 7, 4 and 5, 4 and 8, 5 and 9, 7 and 8, and 8 and 9 were all 16 cm. Object
2 was at the midpoint of the line between Objects 1 and 3, and Object 6 was at the
midpoint of the line between Objects 4 and 9. The direction from Object 8 to 1 was
defined as 0°, and all the directions were defined counterclockwise, for example, the
direction from Object 7 to 4 was 315°. Participants’ learning position was 75 cm away
from the edge of the learning layout and 100 cm from the center of the layout.
Therefore, someone with an eye height of 160 cm would see the center of the layout
at a 45° angle.
There were two types of objects presented in the layout, toy balls with no clear
orientation (see Fig. 1B) and bears with clear orientations (see Fig. 1C). Each ball in
the layout was 5 cm in diameter, and they were all different colors. The sizes of toy
bears were approximately same as the toy balls, and they shared the same orientation
of 315°.
There were 96 trials in the testing phase. On each trial, participants saw three of the
nine objects from the learned layout. All photographs were taken from the point of
view of a person whose eye height was 160 cm. The triplets used combined the
following sets of objects: 1-3-5, 1-3-9, 1-4-5, 1-4-9, 1-5-9, 3-5-7, 3-5-8, 3-5-9, 3-7-8,
4-5-7, 4-7-9, and 5-7-8 (Mou, et al., 2008). Each triplet was presented from eight
5
Coincident Orientation Viewpoint-Dependence
directions (0 to 315° in 45° increments), and 96 images were generated in total. Half
of these images were used as targets, and the others were turned into mirror images as
distractors. Therefore, there were 48 target trials and 48 distractor trials. The numbers
of targets and distractors were the same for all testing directions. The stimuli were
presented using E-prime 1.1 on a Dell Latitude D500 laptop connected to a 19–in.
LCD monitor. The distance between the participant and the screen was 1 m, and the
participant’s visual angle was 12°.
FIG. 1 The placement of learning scene objects (A is the placement of the learning stimuli, B
is the learning layout consisted of nine toy balls from 0 degree point of view, and C is the
learning layout consisted of nine toy bears from 0 degree point of view.)
The experiment was a two-factor mixed design. The between-subject independent
variable was the object type presented in the layout (ball and bear). According to the
participants’ sex, age, and major, they were divided in two approximately
homogenous groups, Group A and B. There were 32 participants (16 men, 16 women)
in each group. Group A learned the layout consisting of balls, while Group B learned
the one consisting of bears. The within-subject independent variable was tested
direction (0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315°). The dependent measures
were response time and accuracy. Response time was measured as the time between
stimulus presentation and the participant’s response.
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Coincident Orientation Viewpoint-Dependence
Procedure
In the learning phase, the participant was blindfolded, led to the learning position,
and placed facing the direction aligned with 0° in Fig. 1. After removing the blindfold,
the participant was asked to stand in that position with body and head steady and learn
the locations of the objects. There were no constraints on learning time or order. Once
the participant reported that he had memorized the locations, the nine toys on the table
were randomly arranged on the table by the experimenter. Then the participant was
asked to reconstruct the layout three times as confirmation. In addition, for Group B,
the bears were presented in a line and at different angles, to ensure that participants
could recognize them from different directions.
In the testing phase, each participant was taken to the testing computer after correct
layout reconstruction, seated in the testing chair facing the screen, with a mouse in the
right hand. The participant clicked the left button to indicate that a scene was part of
the learned layout (target) and the right button to indicate that it was not (distractor),
regardless of viewpoint. Participants were instructed to respond as rapidly as possible
without sacrificing accuracy. Each scene disappeared immediately following the
response, and the next scene was then shown on the screen.
RESULTS
The mean accuracy of responses in all the trials was 86.0%. In the toy ball and bear
conditions, the values were 85.3% and 86.6%, respectively. Table 1 presents the mean
accuracy and the correct response time of targets for toy balls and bears separately.
The tendency of accuracies was almost the same as correct response speed of targets,
and there was no evidence of speed-accuracy trade-offs. In the interest of brevity, only
the correct response time of targets were analyzed (after Mou, et al., 2008) with
regard to the variable of object type and test direction while the accuracies were used
as reference to screen the data.
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Coincident Orientation Viewpoint-Dependence
Table 1 Means and SDs for accuracies (ACC) and correct response times of targets (RT,
msec.) by different test directions for ball and bear conditions
BALL
BEAR
0°
45°
90°
135°
180°
225°
270°
315°
ACC
0.91
0.85
0.87
0.84
0.83
0.82
0.84
0.87
(SD)
(0.12)
(0.20)
(0.16)
(0.15)
(0.14)
(0.19)
(0.18)
(0.16)
RT
4731
5991
5768
5964
6754
6580
5736
6435
(SD)
(1890)
(2270)
(2599)
(2116)
(2962)
(2472)
(2317)
(2843)
ACC
0.91
0.87
0.82
0.84
0.81
0.88
0.90
0.90
(SD)
(0.13)
(0.15)
(0.16)
(0.16)
(0.20)
(0.14)
(0.15)
(0.11)
RT
4200
4924
6176
5029
5868
5074
4925
3925
(SD)
(1429)
(2082)
(2315)
(1836)
(2629)
(2041)
(2114)
(1426)
The results of a repeated measures ANOVA suggested that the effect of object type
(F1,62 = 7.01, p = .01, ηp2 = .10) was statistically significant, and the correct response
to targets in bear condition was quicker than in the ball condition (mean RT increase
was 980 msec.). The effect of test direction was also significant (F7,434 = 5.65, p < .01,
ηp2 = .09), but there was significant interaction between the object type and test
direction (F7,434 = 3.09, p < .01, ηp2 = .05, cf. Fig. 2).
A simple-effect analysis was done for the interaction between object type and test
direction. The results show that for the balls with no clear orientation, the effect of test
direction was significant (F7,434 = 3.65, p < .01). The correct response to targets of 0°
test direction was significantly quicker than all other test directions (all |t|s > 2.30, all
ps < .03, cf. Table 2). The phenomenon suggests viewpoint-dependence in the toy ball
condition. Perhaps participants took a ‘snapshot’ of the whole spatial layout from the
experienced point of view and stored it in memory.
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Coincident Orientation Viewpoint-Dependence
BALL
BEAR
Response Tine (msec.)
8500
7000
5500
4000
2500
0
45
90
135
180
225
270
315
Tested Direction (deg.)
FIG. 2 Correct response times of targets for all test directions in ball and bear conditions
(Error bars reflect 95% confidence intervals.)
Table 2 The absolute value of paired T-test between every two directions. The numbers in
the right upper triangle are the results in ball condition, while the others are in bear
condition.
0°
0°
45°
2.93**
90°
135°
180°
225°
2.60*
3.08**
3.01**
3.56**
2.31*
3.45**
0.46
0.07
1.31
1.34
0.51
0.91
0.40
1.64
1.41
0.08
1.30
1.39
1.34
0.54
0.91
0.32
1.70
45°
2.01*
90°
4.61***
3.08**
135°
2.66*
0.27
2.39*
180°
3.30**
2.12*
0.68
1.84
225°
2.18*
0.33
2.56*
0.10
1.61
270°
1.85
0.01
2.68*
0.27
2.09*
0.32
315°
0.97
2.68*
5.21***
2.91**
3.90***
2.69*
★
★
1.69
* indicates p < .05, ** indicates p < .01, *** indicates p < .001, and ★ indicates p < 0.10.
9
270°
★
★
315°
0.45
0.28
1.93
2.35*
★
Coincident Orientation Viewpoint-Dependence
For the bears with clear orientations, the effect of test direction was also significant
(F7,434 = 5.09, p < .01). The correct response to targets of 0° test direction was
significantly or marginally significantly quicker than all other test directions except
315° (all |t|s > 1.85, all ps < .08, cf. Table 2), and the one of 315° test direction was
significantly quicker than all other test directions except 0° (all |t|s > 2.35, all ps
< .03). But the difference between the response times to targets of 0° and 315° test
direction was not statistically significant (t31 = 0.97, p = .34). These results
demonstrated an advantage for both the experienced direction (0°) and the coincident
orientation of the learned objects (315°) in toy bear condition. In additional, a
single-participant analysis (after Mou, Zhao, & McNamara, 2007) was performed.
The tendency of correct response time of targets showed that 15 participants had
better performance for the experienced direction than the object-orientation direction,
and the other 17 participants performed conversely. Participants with a coincident
orientation advantage stated that they were attracted by the orientation of the objects,
so they imagined themselves facing the objects as they learned the scene. This result
suggested that participants were almost equally likely to choose either direction as
their focus when memorizing the layout and that coincident orientation of objects
could affect viewpoint-dependence.
DISCUSSION
In the experiment, toy balls and bears were presented in partial-scene-recognition
task. The viewpoint-dependence effect was replicated for the scene consisted of balls,
demonstrating that observers would memorize the whole scene from the experienced
point of view when the objects did not have a clear orientation. When bears all facing
the same direction were used, the direction they orientating shared the advantage of
the experienced point of view. The result suggested that the advantage of viewpoint in
scene recognition performance was affected by coincident orientation of objects,
which caused a change in the choice of a direction for the mental representation of the
whole spatial layout, weakening the advantage of the experienced direction.
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Coincident Orientation Viewpoint-Dependence
Although the orientation of objects affected viewpoint-dependence, it could not
completely erase the importance of the experienced direction. The advantages of the
two directions coexisted when there was only one learning position without extra
learning limits (Mou, et al., 2008), something rarely found in other studies (e.g.,
Diwadkar & McNamara, 1997; Valiquette & McNamara, 2007). Individual
differences or other factors (e.g., regional difference, see Li & Zhang, 2009) would
determine whether people would construct their spatial representations using the
experienced direction or the orientation of objects; the possibilities to choose the two
directions were about equal. However, whether they choose only one direction or two
directions to construct their representations remains unknown and requires further
consideration, taking participant’s sex, regional differences, and other factors into
consideration.
There was an unexpected result, that the recognition performance in the bear
condition was significantly better than in the ball condition, probably caused by the
information richness supplied by bears’ faces. Participants could more easily
memorize the scene consisting of bears, as they could name and distinguish the bears
quickly and correctly, which reduced the response time. Besides, it should also be
noted that information about the bears’ faces was more complete from 315° than from
0°, so it is possible that performance was affected by this aspect of the situation.
However, the mean response time for 135°, opposite the object orientation direction
and with less facial information than at 90° and 180°, was marginally significantly
shorter than response time for the latter two directions (|t|s > 1.83, ps < .10). This
suggests that facial information was not the determining factor for better performance
in scene recognition, and it should be discussed in further studies.
There was a limitation that the linear increase of recognition response time with the
difference in angle between the tested point of view and the experienced one was not
significant in this research (cf. Table 2). The reason might be the number of objects in
the scene was still too large for the participants to remember, and the difficulty for
mental rotations in memory resulted in the different performance compared with
classic researches. Another limitation was that the amount of difference between the
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Coincident Orientation Viewpoint-Dependence
object orientation and experienced direction was small, minimizing any difficulty
participants might have in imagining the scene from the former direction. Further
study should vary the difference between the two.
To summarize, coincident orientation of objects appears to be an important spatial
cue in scene recognition. In the current study, results strongly supported the effect of
coincident object orientation on viewpoint-dependence in a partial-scene-recognition
task. Orientation coincidence affects not only allocentric but also egocentric
experience when reconstructing the spatial representation of those objects in memory.
REFERENCES
Beck, J. (1966) Effect of orientation and of shape similarity on perceptual grouping.
Perception & Psychophysics, 1, 300-302.
Diwadkar, V. A., & McNamara, T. P. (1997) Viewpoint dependence in scene
recognition. Psychological Science, 8, 302-307.
Easton, R. D., & Sholl, M. J. (1995) Object-array structure, frames of reference, and
retrieval of spatial knowledge. Journal of Experimental Psychology: Learning,
Memory, and Cognition, 21, 483-500.
Franklin, N., & Tversky, B. (1990) Searching imagined environments. Journal of
Experimental Psychology: General, 119, 63-76.
Koffka, K. (1935) Principles of Gestalt psychology. New York: Harcourt, Brace.
Li, J., & Zhang, K. (2009) Regional differences in spatial frame of reference systems
for people in different areas of China. Perceptual and Motor Skills, 108, 587-596.
Marchette, S. A., & Shelton, A. L. (2010) Objects properties and frame of reference in
spatial memory representations. Spatial Cognition & Computation, 10, 1-27.
Miller, G. A. (1956) The magic number seven plus or minus two: some limits on our
capacity for processing information. Psychological Review, 63, 81-97.
Mou, W., Fan, Y., McNamara, T. P., & Owen, C. B. (2008) Intrinsic frames of
reference and egocentric viewpoints in scene recognition. Cognition, 106, 750-769.
12
Coincident Orientation Viewpoint-Dependence
Mou, W., & McNamara, T. P. (2002) Intrinsic frames of reference in spatial memory.
Journal of Experimental Psychology: Learning, Memory, & Cognition, 28,
162-170.
Mou, W., McNamara, T. P., Valiquette, C. M., & Rump, B. (2004) Allocentric and
egocentric updating of spatial memories. Journal of Experimental Psychology:
Learning, Memory, & Cognition, 30, 142-157.
Mou, W., Zhao, M., & McNamara, T. P. (2007) Layout geometry in the selection of
intrinsic frames of reference from multiple viewpoints. Journal of Experimental
Psychology: Learning, Memory, & Cognition, 33, 145-154.
Shelton, A. L., & McNamara, T. P. (1997) Multiple views of spatial memory.
Psychonomic Bulletin & Review, 4, 102-106.
Shelton, A., & McNamara, T. P. (2001) Systems of spatial reference in human
memory. Cognitive Psychology, 43, 274-310.
Simons, D. J., & Wang, R. F. (1998) Perceiving real-world viewpoint changes.
Psychological Science, 9, 315-320.
Valiquette, C. M., & McNamara, T. P. (2007) Different mental representations for
place recognition and goal localization. Psychonomic Bulletin & Review, 14,
676-680.
Wang, R. F., Crowell, J. A., Simons, D. J., Irwin, D. E., Kramer, A. F., Ambinder, M.
S., Thomas, L. E., Gosney, J. L., Levinthal, B. R., & Hsieh, B. B. (2006) Spatial
updating relies on an egocentric representation of space: effects of the number of
objects. Psychonomic Bulletin & Review, 13, 281-286.
Wang, R. F., & Simons, D. J. (1999) Active and passive scene recognition across
views. Cognition, 70, 191-210.
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