Spatial perception presentation

1. Living in Two Spaces
Effect of Attention on
Perception of Haptic Space
Rachel Franz & Siyan Zhao

2. Difference between Haptic Space
and Physical Space
What we sense is parallel when we can't see is
different from what is physically parallel

Parallel in haptic
space
Parallel in physical
space
Kappers, A. M. (2007). Haptic space processing–allocentric and
egocentric reference frames. Canadian Journal of Experimental
Psychology, 61(3), 208-218.

3. Our Question
How does attention affect what we perceive as
parallel by touch alone?

4. Systematic Deviations
Pattern is
always the
same

5. Why do we see this pattern?
First, some definitions:

Egocentric reference frame

Mental representation
of space from our
own perspective

6. Why do we see this pattern?
Allocentric reference frame:
Our mental
representation of
space that is
independent of our
perspective


...same house,
different
representations.

7. Both reference frames contribute to our
perception of what is parallel
Why do we see this pattern?
Kappers, A. M. (2004). The contributions of egocentric and
allocentric reference frames in haptic spatial tasks. Acta
psychologica, 117(3), 333-340.

8. Why do we see this pattern?
In this task:

Allocentric reference frame
-same as physical space, more accurate

Egocentric reference frame
-less accurate

9. Where is the egocentric reference
frame located?
For 8 out of 10 participants, the hand centered model was
weighted more

10. The oblique effect
Interesting effect occurs at 45 and 135 degrees


90135
Allocentric reference frame
4590
Egocentric reference frame
Allocentric reference frame

11. The oblique effect
Interesting effect occurs at 45 and 135 degrees


Participants more
accurate for oblique
orientations!
45
90
Egocentric reference frame
Allocentric reference frame

12. How were reference frames
manipulated in other studies?
Zuidhoek et al. (2003)
Time delay -> + allocentric

Newport et al. (2002)
Vision -> + allocentric


Our study

Attention -> + egocentric



4590
Egocentric reference frame
Allocentric reference frame

13. Based on our question..
How does attention affect what we perceive as
parallel by touch alone?

14. Hypothesis
●Attention causes subjects to place more
importance on their egocentric reference
frame

15. Method - IV, DV
●Within-subject design
●Independent Variable: Attention
●Dependent Variable: Weight of allocentric
and egocentric reference frame

16. Method - Setup
Target bar (static)
Test Bar
Participants sat here

17. Method - Setup
Target bar (static)
Test Bar
Participants sat here

18. Method - Operationalization
●IV: To focus participants' attention on their
hands, we trace the outline of their hands in
treatment condition (~20 sec). For control
condition, participants sat for 20 seconds

●DV: The degree of deviation of the test bar
from the target bar
Target bar Test bar

19. Method - Participants
19 Carnegie Mellon University Students:
12 were from a Research Method class
7 outside of the class

20. Result
The treatment group performed significantly better (p =
0.02, t(18) = 2.54)

21. Large variation supports oblique
effect
Some people
performed better
Treatment
Control

22. Conclusion
●Blindfolded participants who had their
hands traced had a better sense when
objects were parallel.

23. Conclusion
Participants put
more weight on
their egocentric
reference frame
after we traced
their hands.
4590
Egocentric reference frame
Allocentric reference frame

24. Alternative Explanation
Attention caused increased awareness of hand
orientations

25. Limitations
Who gave more weight to their egocentric
reference frame?

Gender?

26. Directions for future research
Did the allocentric participants also give more
weight to egocentric reference frame?

What happens when people don't attend to
spatial properties of their hands?

27. Contribution
The egocentric reference frame can be
manipulated

Attention can affect egocentric reference frame