s
at iv e
itt ed
on C om
m
rC re
m Pe r
st Po
Li c
C om
m
un de rC r
m Pe r se U s: er
Department of Psychology
In multiple-object tracking participants track several moving target objects among identical distractor objects (Pylyshyn & Storm, 1988). Recently it was shown, that the human visual system uses motion information for keeping track of targets. A texture on an object that moved in the opposite direction than the object impaired tracking performance (St. Clair, Huff, & Seiffert, 2010). In this study, we examined the temporal interval at which motion information is integrated in dynamic scenes.
iv e
de
un itt ed m
:U se
rs te Po s 00 10 .F ns e
00
0
Li ce on s
F1 e.
m
en s
om
on s
om m
C
e iv
Poster presented at the ECVP 2012, Alghero, Italy
re at
itt ed
Li c
C
e
iv
at
St. Clair, R., Huff, M., & Seiffert, A. E. (2010). Conflicting motion information impairs multiple object tracking. Journal of Vision, 10(4), 1–13. doi:10.1167/10.4.18.Introduction
un de rC
itt ed
m
Pe r
se
Pylyshyn, Z. W., & Storm, R. W. (1988). Tracking multiple independent targets: Evidence for a parallel tracking mechanism. Spatial Vision, 3(3), 179–197.
re
un
se
:U
Contact:
[email protected]
Pe r
e. ce ns Li s on m om C e
at iv
re
de
Pe r
rC
m
Schematic illustration of a 1000 ms segment in the “alternate” conditions
References
We show that motion integration can take as short as 100 ms. Further, we show that there is a linear relationship between the proportion of opposite motion and tracking performance. That is, increasing the proportion of opposite motion within the alternate conditions decreased tracking performance. We suggest that texture motion might cause shifts in perceived object locations thus influencing tracking performance.
te rs
iv e se
00
F1 0
s on m om
C
e
at iv
re rC de
un
itt ed
• Motion integration did take place in the “alternate“ conditions, as can be seen by the decrease in tracking performance with increasing proportions of opposite texture motion.
:U
U
s:
er
st
Po
• The number of transients between “same” and “opposite” texture motion does not influence visual tracking performance.
Li
e
re at iv
rC
de
un
itt ed
rm
• Visual tracking performance decreased with increasing proportion of “opposite” motion.
er s
itt ed m Pe r se U s: er st
Po
0
00
F1
e. ce ns
C om
• An interval length of 100 ms was sufficient for motion integration to take place within our visual tracking task.
If motion integration takes place within the alternate conditions, we should see a linear relationship between the proportion of “opposite” motion and tracking performance. Increasing the proportion of “opposite” motion should decrease tracking performance.
Pe
un
rs :U se te
Po s 0 00 F1 se . ce n Li
m
re
on
at
s
• In the “alternate” conditions, incongruent texture motion was present for only half of the time, leading to a performance between the “same” and “opposite” conditions.
Experiment 2
Po s
rC re
Pe rm
st e
Po
0
00 F1 e. ce ns Li on s
om m C iv e
• Conditions in which texture motion was incongruent to the spheres’ motion impaired tracking performance.
“same” and “opposite”: the texture moved in the same or opposite direction of the sphere’s movement, respectively. “alternate”: the texture motion alternated between “same” and “opposite”.
Conclusion
rC re
rs
itt ed
Dependent variable: Tracking performance (proportion correct)
at
:U
un
se
0
00
F1
e.
ce ns
Li on s
om m
C
rC
de
Independent variable: Texture motion: “same”, “alternate 100”, “alternate 500”, “alternate 2000”, “opposite”
Results and Discussion
Critical manipulation: Texture motion (“same”, “alternate”, “opposite”)
Results and Discussion
de
Pe r
Experiment 1
Po
en
Theoretical Background
General Method
at
itt ed
m
st
se
er
.F
s:
10
de
un
Markus Huff & Frank Papenmeier
U
00
se
The use of motion information in multiple object tracking
