Jordan Becker
K361 – 301
Bimanual Coordination
Lab #5
Index of circularity is a measure of how ‘circular’ a shape is, specifically a line versus a
circle. By measuring the horizontal diameter and the vertical diameter and dividing the
horizontal by the vertical distances. This should give a number between 0 and 1. A line
should have an IC of 0 while a perfect circle has an IC of 1. (Lab Notes, 2008).
IC = Hmax ÷ Vmax
H0: I hypothesize that shapes drawn with my left hand will have better indices of
circularity (0 for lines, 1 for circles) than my right hand. Lines will show better IC’s than
circles in bimanual incongruent trials. Incongruent trial IC’s will be depolarized
m
er as
compared to congruent IC’s in bimanual trials. Bimanual IC’s will be depolarized
compared to unimanual IC’s.
co
eH w
*Just in case, I mean closer to .5 by depolarization: a movement away from the poles of 0
o.
and 1.
rs e
ou urc
Analysis:
1. Measured maximum horizontal and vertical distances with ruler in classes. I
ignored single outliers.
o
2. I calculated the IC by dividing Hmax by Vmax.
aC s
3. See table 1.
vi y re
Discussion:
1. Franz et al. saw a spatial magnet effect which pulled lines and circles being drawn by
opposite limbs more toward each other’s respective shape (IC ~ 0.6) (lab notes, 2008).
ed d
Also noted in Franz et al. results was that in both the bimanual circle and bimanual line
ar stu
tasks, no changes in movement path were shown to occur (lab notes, 2008). Thus, both
hands could draw circles simultaneously or lines simultaneously with a similar motion
and path as when drawn by one hand. Handedness did not exhibit an effect on results and
is
whether dominant or non-dominant hand drew circle or line did not matter such that the
spatial magnet effect remained (lab notes, 2008).
Th
My results show that during bimanual circle/line tasks there was a pull on both
shapes for both hands, yet it was not as drastic as in the Franz experiment with effects
only pulling .1 to .2 from the baselines. I would say there is a partial spatial magnet effect
as presented by Franz et al. Handedness effects are discussed below.
sh
2. Left hand circles were better than right hand circles for unimanual conditions (0.936
LH vs. 0.832 RH). Left hand lines were better than right hand lines for unimanual
conditions (0.072 LH vs. 0.161 RH).
This study source was downloaded by 100000823516103 from CourseHero.com on 07-06-2021 12:22:12 GMT -05:00
https://www.coursehero.com/file/35628/K361-lab-5/
K361 – 301
Bimanual Coordination
Lab #5
Index of circularity is a measure of how ‘circular’ a shape is, specifically a line versus a
circle. By measuring the horizontal diameter and the vertical diameter and dividing the
horizontal by the vertical distances. This should give a number between 0 and 1. A line
should have an IC of 0 while a perfect circle has an IC of 1. (Lab Notes, 2008).
IC = Hmax ÷ Vmax
H0: I hypothesize that shapes drawn with my left hand will have better indices of
circularity (0 for lines, 1 for circles) than my right hand. Lines will show better IC’s than
circles in bimanual incongruent trials. Incongruent trial IC’s will be depolarized
m
er as
compared to congruent IC’s in bimanual trials. Bimanual IC’s will be depolarized
compared to unimanual IC’s.
co
eH w
*Just in case, I mean closer to .5 by depolarization: a movement away from the poles of 0
o.
and 1.
rs e
ou urc
Analysis:
1. Measured maximum horizontal and vertical distances with ruler in classes. I
ignored single outliers.
o
2. I calculated the IC by dividing Hmax by Vmax.
aC s
3. See table 1.
vi y re
Discussion:
1. Franz et al. saw a spatial magnet effect which pulled lines and circles being drawn by
opposite limbs more toward each other’s respective shape (IC ~ 0.6) (lab notes, 2008).
ed d
Also noted in Franz et al. results was that in both the bimanual circle and bimanual line
ar stu
tasks, no changes in movement path were shown to occur (lab notes, 2008). Thus, both
hands could draw circles simultaneously or lines simultaneously with a similar motion
and path as when drawn by one hand. Handedness did not exhibit an effect on results and
is
whether dominant or non-dominant hand drew circle or line did not matter such that the
spatial magnet effect remained (lab notes, 2008).
Th
My results show that during bimanual circle/line tasks there was a pull on both
shapes for both hands, yet it was not as drastic as in the Franz experiment with effects
only pulling .1 to .2 from the baselines. I would say there is a partial spatial magnet effect
as presented by Franz et al. Handedness effects are discussed below.
sh
2. Left hand circles were better than right hand circles for unimanual conditions (0.936
LH vs. 0.832 RH). Left hand lines were better than right hand lines for unimanual
conditions (0.072 LH vs. 0.161 RH).
This study source was downloaded by 100000823516103 from CourseHero.com on 07-06-2021 12:22:12 GMT -05:00
https://www.coursehero.com/file/35628/K361-lab-5/
