Object Location Memory
In A Virtual Environment Versus A Written Narrative
Robert E. Little
A Thesis Submitted In
Partial Fulfillment of the Requirements For The Degree of Bachelor of Arts
Saint Anselm College
to Franklin and Tversky's classic study (1990), readers construct
a mental model representing the spatial relations explicitly given in a
text or narrative. Their theory known as the spatial framework model
states that the accessibility of objects depends on their position along
three differentially accessible axes defined with respect to your body.
Therefore, readers will be fastest at making up/down decisions followed
by right/left decisions, and lastly up/down decisions. The purpose
of this study was to replicate Franklin and Tverksy's classic study using
a new narrative describing an office and determine whether their model
would predict performance in a virtual environment. It was hypothesized
that the mental models derived from indirect sources such as text would
be similar to those derived from direct visual experience using a virtual
environment. A total of 20 participants ranging in age from 18-22
were recruited from their Introductory Psychology classes to take part
in this study. Half of the participants were tested in the narrative
condition and half of the participants were tested in the virtual environment
condition. Reaction times and error rates were recorded for all participantsÕ
responses to factual statements regarding the location of objects within
each condition (i.e., up/down; right/left; front/back). The results
showed that participants in the virtual reality condition were faster to
respond to these statements compared to participants in the narrative condition.
Participants responded fasted to up/down statements, followed by front/back
statements and finally right/left statements. The results suggest
that both indirect and direct experience produce similar mental models
supporting the spatial frameworks theory originally proposed by Franklin
and Tversky (1990).
I would like to thank the Psychology Department as a whole for their understanding
and support. I could not have accomplished this without you all, for everyone
has assisted me in some way. You have all realized that this has
been the most difficult time that I have ever had to experience for various
reasons, and your understanding has helped get me through it. Thank you
Prof. Krachunas for your understanding and flexibility, and you, Prof.
Flannery for your guidance, both with the study and with everything else.
I would also like to thank you, Dad, for your unconditional love and support
throughout my life, in good times and in bad. You have stood by me like
no other, and I hope you are proud of this accomplishment. Finally, I would
like to thank you Christalle, for being so brave through your ordeals.
Your strength has given me the motivation to take action in my own life,
and to do what needs to be done at any cost. Even in your darkest hour,
you were selfless in the sense that you knew what I needed to do for my
own future, and you stood patiently, waiting for the support that you so
desperately needed. This is for you.
knowledge of space that an individual acquires throughout his/her lifetime
is attained by both direct and indirect experience of the world. In everyday
life, we hear or read about a particular event or situation through a number
of sources. And from them, we form concepts of space from language. By
hearing or reading language describing a place, object, or event, the recipient
of the information can only indirectly experience it through anothers interpretation.
Experience through language is an indirect source of spatial information,
while visual, first hand experience is considered to be direct. Through
direct experience, an individual constructs his/her own concepts and beliefs
according to stimuli that is seen, rather than depicted. Because of this,
memory of spatial information is believed to be encoded in memory through
dissimilar cognitive processes, depending upon if the information was obtained
through direct or indirect experience .
To assist in memory acquisition of spatial information, individuals create
cognitive maps, or mental models, used to code and simplify the way a spatial
environment is arranged. When reading a description of a scene in which
a person is surrounded by objects, people create spatial frameworks. Spatial
frameworks are mental models that serve as a mental scaffolding (Bryant,
1997) on which information can be arranged and rearranged. The scaffolding
is based on spatial concepts that define direction in terms of body axes
and enduring physical and perceptual regularities to which the mind has
adapted. The processes by which a spatial framework serves as a mental
scaffold may not be well understood, but clearly they are determined by
the nature of a real or virtual world. These frameworks are similarly used
to remember observed physical scenes, either ones a person has actually
been in or model scenes from the outside.
studies suggest that individuals may spontaneously use such mental models
for verification and retrieval of spatial information at a later time.
Mental models may include information about spatial properties such as
relative position and relative distance. According to Franklin and Tversky
(1990), readers of written descriptions would retain more than a surface
trace or a precise prepositional record of the text. Furthermore,
they propose that in order to keep track of the locations of objects in
narratives, people form three-dimensional mental spatial frameworks based
on their conceptions of space from interactions with the perceptual world.
Researchers investigating memory for discourse have proposed that, in order
to comprehend language derived from text, readers construct mental or situation
models embodying spatial relations explicitly given in the text well as
those inferable from the text. (Bransford, Barclay & Franks, 1972)
Until 1992, few theories had been developed regarding spatial memory.
study by Franklin and Tversky (1992) participants read narratives describing
themselves in realistic three-dimensional environments in which they were
periodically reoriented, and their response times for accessing information
about objects in various directions with respect to themselves were measured.
Three classes of models making different predictions about behavior in
this task were considered within the study to explain possible findings,
however results only allowed for the spatial framework model.
Framework Model (Franklin & Tversky, 1990) reflects peoples conceptions
of space based upon ones typical interactions with it. They hypothesized
that readers of their narratives would construct a three dimensional spatial
framework, a mental model, or knowledge structure used to store, retrieve,
and verify locations of objects relative to their own bodies. (Bryant &
Tversky, 1992) A spatial framework reflects the way people normally
conceive of their perceptual world, based on their interactions with it.
This theory (Franklin & Tversky, 1990) states that the accessibility
of objects depends on their position along three differentially accessible
axes defined with respect to your body, including left-right, above-below,
and front-back. Spatial frameworks predict accessibility of spatial relations
from memory primarily on the basis of the relative asymmetry of the body
axes, such that highly asymmetric axes lead to faster retrieval of information.
(Bryant & Wright, 1995) According to the spatial framework analysis,
objects located on the vertical head/feet axis should be more accessible
to the observer because they are both properties of the world and body.
Also, this axis is physically asymmetric and normally correlated with gravity.
As observers navigate the world, vertical spatial relations among objects
remain largely constant with respect to the observer whereas spatial relations
in the horizontal plane change. (Bryant & Tversky, 1992) In other words,
objects on the horizontal axis were not recalled as rapidly as those found
on the vertical axis, because the left-right dimension is physically asymmetric
and was not likely to have any gravitational significance to the observer.
Asymmetries due to gravity and constancy (Bryant & Tversky, 1992) under
typical horizontal navigation render the vertical axis as dominant.
Finally, the front/back dimension is physically asymmetric, and the observer
is perceptually and behaviorally oriented front-wards. The objects
that are located on this axis depend on the direction currently faced by
the observer. According to the spatial framework model, the objects located
on above/below axis would be the fastest to recall, because of its correlation
with body asymmetry and gravity. Responses showed that the above/below
axis allowed for the fastest recall, which suggests that subjects used
a spatial framework in constructing mental representations to serve in
study by Bryant, Tversky and Franklin (1992) further investigated the spatial
framework model. Similar to Franklin and Tverskys pioneering study, subjects
read narratives and were then probed for the locations of objects.
Each narrative was described from one of two perspectives, an internal
perspective of an observer within the scene, surrounded by objects, or
an external perspective of an observer outside the scene, with objects
in front. Results showed that for the internal spatial framework,
readers were faster to questions of front or back, reflecting the perceptual
and biological asymmetries that favor an observers front. (Bryant &
Tversky, 1992) For the external spatial framework, all objects were in
front of the observer and readers were equally fast to questions front
and behind. They concluded that the difference between internal and external
spatial framework reflects the different perceptual experience of observers
in the two perspectives.
More recent studies have continued to test various hypotheses regarding
spatial memory within dynamic scenes or environments, rather than static
configurations. A possible reason for this is due to the idea that
three- dimensional environments simulate experience and encourage participants
to use mental models. technological advances have allowed researchers to
conduct more complex studies, which require a more life like representation
of a particular environment. The most highly used advancement in this area
of experimentation is virtual reality. Virtual reality is a computer simulated
three-dimensional environment that people can interact with and explore
in real time. It has been used for various studies within many disciplines,
and it has been found to be especially useful in experimental psychology.
Recently, there has been a growth of interest in VEs as a tool for investigating
spatial learning. This study calls for the creation of an environment,
which contains various objects in an array. Rather than isolating a particular
setting, and keeping the locations of the objects constant, virtual reality
was a welcomed experimental device, because it permits the creation of
environments of varying complexity and allows interactive navigation. (Belinguard
& Peruch, 2000) Virtual reality is beneficial because manipulating
the structure of a real environment is difficult or even impossible. The
potential benefits of VEs as training media for optimizing environment
behavior interactions have been accepted for many years; for example, in
flight simulation and battlefield training (Wilson, 1999). The two most
popular ways to present a virtual environment are via a head-mounted display,
which updates the image in synchrony with movements of the users head,
and via the conventional computer monitor or large screen projection system.
is evidence of substantial similarities in the spatial knowledge that is
acquired in real and virtual environments. Wilson (1999) claims that spatial
information is learned using the same cognitive processes in both real
and virtual environments. He had concluded that one factor that may promote
learning in both conditions is the observers active involvement in the
exploration. Certain factors were found to influence the active-passive
dichotomy, such as attention. A lack of attention while learning can effect
ones ability to recall information. The environments that are created for
studies of this nature are usually simulations of actual settings in which
the observer is most likely accustomed to, except what is actually being
seen are computer graphics, which seem to be lifelike, due to their three-dimensional
appearance. However, because the possible confound of attention, we have
used a rather interesting environment, in hopes of keeping the interest
of the participant.
present study, half of the subjects experienced the environment according
to how it was described in a narrative. The findings of the previously
mentioned study suggest that an active participant is more likely to have
developed a more detailed mental representation of the environment.
With this idea, it could be hypothesized that those subjects within the
present study who read the narratives would have more rapid, accurate responses
than those who passively experienced the same setting at the control of
within the present study is to compare spatial memory among subjects whom
have read a description of an environment with subjects whom have experienced
that very same environment. Prior evidence suggests that spatial
mental models derived from text are similar to those derived from direct
experience, however we hypothesize that this claim is consistent within
a virtual environment. Similar to a study done by Franklin &
Tversky, this task was designed to capitalize on peoples life long experience
of encountering objects while navigating in complex environments. (Franklin
& Tversky, 1990). Results may support the idea that the spatial
framework model also applies how individuals encode the locations of objects
while navigating through an environment, rather than reading a description
of the very same setting. The research reported here investigates whether
the theories proposed by previous studies will be consistent in comparing
the recall of objects within a virtual environment versus reading a narrative
of the same setting. Presenting a three-dimensional environment with virtual
reality is used here to retest if the spatial framework theory is consistent
within that condition.
of interest is if the responses of an observer of the virtual environment
will form create mental models according to the spatial framework model,
or any other theories that were proposed within the investigations of Tversky,
Franklin, and Bryant. In comparing recall in both conditions, results may
show that different concepts in mental imagery may govern memory and perception
of space. This study attempts to demonstrate that the mental spatial framework
model is employed within visuo-spatial memory, as it has been found as
the explanation in how individuals encode spatial information from language/text.
A total of 20 (10 male, 10
female) participants from a small, liberal arts college in the northeast
were recruited for this study. Each participant received credit for their
introductory psychology course upon completing this study. Participants
ranged in age from 18 to 20, with the average age = 18.0 years. All participants
provided full consent prior to testing.
A printed narrative was created that described an environment containing
various objects. The story was written in the second person from an internal
viewpoint, meaning the observer was immersed within the setting, rather
than viewing it from a distance. The objects were common to the environment
being described. The narrative was comprised of descriptive sentences,
which oriented the reader toward a particular object. Also, a number of
filler sentences were placed within the text. The narrative totaled 358
words, which was printed in courier new, bold lettering, then laminated.
(See Appendix A.)
Environment: A personal computer was used for the virtual reality portion
of the study. Superscape, a virtual world development program, was used
to create the environment. The depicted environment was a rectangular shaped
room, with the walls to the left and right being longer than the front
and back wall. The room contains familiar objects in various locations
on one of two levels. (See Appendix B.) for views 1-4)
Mental Model Task:
The mental model task was created using Superlab LT. Using this program,
a total of nine statements were presented upon a computer screen in random
succession, and all represented a particular object that was described
in a given location within the environment. All statements described the
possible location of an object in relation to the participant. All three
axis, left-right, above-below, and front-back were equally represented.
There was intentionally no practice trial, which will be explained in greater
detail within the discussion. This program was used to record and measure
response rate and accuracy for all 9 statements. Responses were measured
in milliseconds and accuracy was recorded as correct (C) or error (E).
(See Appendix C for probe statements)
the first experiment, half of the participants were verbally instructed
to read the narrative, and then were informed they would be answering a
series of questions regarding the story. They were told to read the story
only once, at whatever pace they were most comfortable. When the participant
had completed reading the story he/she was instructed that they would not
be able to refer back to the story for the next phase of testing. Upon
completion, the participant was presented with a number of statements regarding
the narrative on a computer screen. They were requested to evaluate whether
the statement was true or false, according to how an object was presented
within the narrative. Furthermore, the participant was to press the 1 key
if the statement was true, and the 2 key if the statement was false. Subjects
were told to respond to each statement at their own pace, without the opportunity
to refer to previous statements. Subjects were unaware that response times
and accuracy were being recorded and measured.
presented one sentence at a time, and the participant advanced to the next
statement by pressing either response key, regardless of accuracy.
During each trial, no feedback from the experimenter was given.
In the second experiment,
half of the participants were tested using a virtual environment.
In our testing protocol, the experimenter moved the participant along the
same pathway as described in the narrative. The virtual room was identical
to the setting illustrated within the narrative. The experimenter led the
subject slowly around the room once. Exploration time (approximately two
minutes) was intended to be similar to that of the duration of time in
which it would take an average skilled reader to complete the narrative.
This was measured by timing a group of 8 random participants, who did not
take part in the core study. Upon completion of the exploration,
the subject was presented with the same statements as those who had read
the narrative. Identical verbal instructions from the narrative portion
of the experiment were given to those within this phase of the study.
All participants were fully
debriefed regarding the specific goals set forth for this study.
A 2 Condition (Virtual Reality; Narrative) by 3 Question Type (Up/Down;
Right/Left; Front/Back) Analysis of Variance (ANOVA) was computed for reaction
time scores. A significant main effect for condition was observed,
F(1, 18)=4.84, p<.05. Reaction times were faster for participants in
the virtual reality group (M=5852.67, SE=703.63 compared to the control
group (M=3661.79, SE=703.63), irrespective of question type. There
was also a significant main effect for question type, F(2, 36)=9.05, p<.001.
Planned comparisons (dependent t tests) showed that reaction times were
significantly faster (p<.05) for up/down (M=3449.00, SE=489.71) versus
right/left (M=6240.52, SE=809.62). In addition, reaction times were
significantly faster (p<.05) for front/back (M=4582.17, SE=655.03) versus
right/left (M=6240.52, SE=809.62). There was no significant difference
between up/down and front/back reaction times. Finally, there was
not a significant interaction between condition and question type for reaction
times. Note, the same pattern of results for reaction time was observed
when restricting the data analysis to correct responses.
A 2 Condition
(Virtual Reality; Narrative) by 3 Question Type (Up/Down; Right/Left; Front/Back)
Analysis of Variance (ANOVA) was also computed for error scores.
There were no significant effects to report for this analysis. This
may be due to the fact that error rates were relatively low for each question
(e.g., up/down 1=25%, up/down 2=10%, up/down 3=10%; right/left 1=25%, right/left
2=25%, right/left 3=30%; front/back 1=10%, front/back 2=25%, front/back
The results of this experiment suggest that both indirect and direct experience
produce similar mental models, supporting the spatial framework theory
originally proposed by Franklin and Tversky (1990). However, the absence
of correlation between response times in both conditions does not allow
us to draw any conclusions about the effect of language versus visuo-spatial
learning in spatial memory.
the predicted pattern of response times, based on asymmetries of the human
body axes and the correlation of the above/below axis with gravity, were
similar within both experimental conditions. As in Franklin and Tversky's
study, the above/below dimension was the fastest in object location recall,
thus supporting the notion that the subjects encoded spatial information
according to the spatial-framework model. The data also disproved the idea
that subjects would have more rapid response rates in the virtual reality
phase of testing, because they experienced the environment directly. It
was found that active, or direct experience through exploration of a virtual
environment does not promote memory for information regarding objects and
reason for lack significant findings could be that participants who had
experienced the virtual reality were led around the environment just as
described within the narrative. We believe that response times and accuracy
rates would have differed significantly if the participants were instructed
to actively explore the room with no guidance from the experimenter. Most
likely, they would have taken a different route through the environment,
and therefore objects would be located differently in relation to themselves
as described in the text. For example, if the participant (non-guided exploration)
had began the navigation by walking to the right of the room, up the stairs,
and to the left, the grandfather clock would be to the persons right, instead
of the left as described in the narrative. If in future research, a subject
is instructed to actively explore an environment, then the narrative must
be modified by describing objects in relation to other objects, rather
than to the observer. The reason for this is simple; the locations of objects
in relation to the observer change as he/she moves within the environment.
By describing the objects according to their relationship (position/distance),
their locations will be consistent within both conditions. A problem with
this alteration is that it will not test the spatial framework model, because
objects are not described relative to a body axis, so therefore if the
testing conditions were modified, so would the hypothesis. The spatial
framework model is a mental model, or knowledge structure used to store,
retrieve, and verify locations of objects relative to their own bodies,
not other objects. A new study could involve a narrative that describes
the location of an object(s) according to its position in relation to another
object, as well as participants freely exploring a virtual environment.
The testing procedure would be similar to the present study, however, the
statements would illustrate the location of an object not in relation to
the observers position.
research, we began with the premise that participants will employ the spatial
framework theory while learning the locations of objects while actively
and directly exploring a virtual environment. It was surprising that participants
on the average had similar response times within both conditions. Our assumption
was that reaction times would be faster for those within the virtual environment
condition, because of direct experience of the same environment as depicted
within the narrative.
did suggest that participants did employ the spatial framework model in
both conditions, because as hypothesized, reaction times would be fastest
for the above/below axes as previously demonstrated in studies by Franklin
and Tversky (1990,1992). Subjects were able to form an understanding of
physical properties such as asymmetry and gravity by reading a description
and through active exploration through imagery, hence the basis of the
mental spatial framework theory. All other theories were considered in
analyzing data, however our findings support the spatial framework theory
in both conditions within the experiment.
there was no significant differences between reaction times for both the
narrative and the virtual reality conditions, this leaves very little to
be said. If there was indeed a significant correlation, some possible
issues to be raised would include how the virtual environment contained
more stimuli that was not described in the narrative, which would flood
observers with unnecessary information. Many possibilities exist, however,
since there was no correlation, these possibilities are irrelevant to our
our results were similar to the classic study by Franklin and Tversky.
We are able to further conclude from this experiment that participants
employed a spatial framework while encoding spatial information in reading
a description and through actual exploration of a virtual environment.
More research is needed to further exemplify how mental spatial frameworks
are used in mental imagery for virtual environments versus narration/language.
More specifically, it is important that we determine whether the acquisition
and recall of spatial information is faster through direct experience.
Once this has been determined, we may be able to enhance the way in which
we learn and store spatial information. Enhancing spatial ability would
greatly benefit our performance in everyday tasks, at work, at home, on
the field, or in the classroom.
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