CogSci2012	

The nature of the training effects of mental rotation :the limit for transfer to novel orientation!
Haruna Terada and Hiromi Morita, University of Tsukuba, Japan.	

INTRODUCTION	
Repeating mentally rotating a figure increases the speed ofmental rotation of the figure (Bethell-fox & Shepard, 1988).
Although there are some studies about what causes the trainingeffects (e.g., Wallace and Hofelich, 1992; Tarr and Pinker, 1989;
Heil et. al., 1998), the underlying mechanisms remain unclear. !
We investigated whether the training effects of mental rotation!

transfer to un-trained orientation and un-trained direction. If thetraining effects depend on the orientation of the figure, it issuggested that the training improves retrieving therepresentation of the figure in respective orientation. If thedirection dependent training effects are observed, it is suggested
that the training improves rotation process.!

METHOD!
Procedure	

Participants	Design	35 (14 females) students aged 19-24 years
old (mean age was 21.9 years old) wereparticipated. They had normal or correctedto-normal vision. !

Training	Old	  dir(new	  ori	  	  	  	  	  	  )	  Old	  dir(novel	  ori	  	  	  	  	  	  )	  New	  dir(novel	  ori	  	  	  	  	  	  )	  Start	  (	  Sample	  orienta6on)	

Stimulus	
2 sets of 2D polygons were used. Each set
has 4 polygons. One set was used fortraining, and the other was used for test. !
The assignment of the figure sets wascounterbalanced across the participants.!

NEXT KEY	
2000 ms!

Un-trained section	

Conditions

ROTATION TIME!

Normal	NEXT KEY	DECISION TIME!

Mirror	  image	

Participants performed the mirror-normal
discrimination task. They pressed the leftarrow key when they saw normal figure andpressed the right-arrow key when they saw
mirror-reversed figure, as quickly andaccurately as possible.!

Decision time was limited to 1000ms.!
When it was beyond 1000ms, an !
alert was presented.!

Factors
Direction	 Orientation	 Figure	

Training Training

YES or NO KEY	

Tasks	

Trained section	

200 ms!

!
Alert!
1000ms!

Test

OldOldOld

Old dir(new ori)

Old

NewOldOld dir(novel ori)Old

NovelOld

New dir(novel ori)New

NovelOld

Old dir(new fig)

Old―NewNew dir(new fig)

New―New

RESULTS AND DISCUSSION	5 participants were excluded from the analyses; a participant whodid not finish the experiment and 4 participants whose decisiontime depended on the orientation more than rotation time did,suggesting that they rotated in the decision time despite they
were instructed to rotate in rotation time. Only trials with correct
responses were included in the analyses. We calculated slopes
and intercepts of rotation time for each participant for eachcondition. The mean error rate was 6.85%.!

1400!

* p<.05 **p<.01 *** p<.001	 n.s. p>.10	 12!
Intercept!

Slope!

10!

1000!
800!

*	***	

n.s.	

n.s.	

8!

6!

600!
4!
400!
200!
0!

***	n.s.	
**	

2!
n.s.	

0!

Slope [ms/degrees]	

Intercept [ms]	

1200!

About Orientation	

The slopes and the intercepts showed a significant main effect within
the one factor ANOVA ( 3 levels; Training 6, Old dir (new ori) and Old
dir(novel ori) ) [slope: F(1,29)=36.850, p< .001, intercept: !
F(1,29)=10.277, p<.01]. !
Multiple comparisons revealed significant differences for slopes andintercepts (see figure). The slope for Old dir(novel ori) condition waslarger than that for Training 6 and Old dir(new ori). This suggests thatthe training effects well transfer to the orientation covered in thetraining and poorly transfer to the orientation not covered. Sinceintercept is considered to reflect encoding for preparing rotation foreach figures, it is suggested that encoding process was continuously
improving in the test phase. !

About Direction	
There is no significant difference between Old dir(novel ori) and New
dir(novel ori) nor between Old dir(new fig) and New dir(new fig). Thismeans that the training effects do not depend on the direction.!

CONCLUSION!
We investigated the transfer of the training effects ofmental rotation to un-trained orientation and un-traineddirection. Results were that the training effects transfer tothe new orientation of the trained figure, but not to thenovel orientation. They also transfer to un-trained directionof rotation. This suggests that the training of mentally
rotating improves the retrieving process of the figuresand not rotating process.!