1. Individual Differences in Spatial Perception and Cognition: Mary Hegarty University of California, Santa Barbara

2. Structural geology, as I understand it.. Identifying patterns in noisy data Constructing 3-d “mental models” from 2-d displays Imagining internal structure e.g., a slice through a 3-d structure Imagining geological processes in three dimensions Inferring process from structure

3. The Problem.. Students differ in their ability to “think spatially” that is.. –Imagine three dimensional structures –Mentally manipulate spatial representations –Infer dynamic processes from static structures This limits their ability to learn structural geology

4. Outline of My Presentation Individual differences in spatial abilities Possible causal factors Training of spatial abilities Focus on cross sections problem Conclusions

5. Individual Differences in Spatial Abilities

6. History of Measurement of Spatial Abilities Practical goal: Personnel selection Concrete manipulation to abstract spatial abilities Debates about the structure of intelligence: one intelligence or many? Factor analysis

7. One Spatial Ability or Many? A recent meta analysis (Carroll, 1993) - Perceptual Speed - Spatial Relations - Spatial Visualization - Closure Speed - Flexibility of Closure

8. Perceptual Speed Closure Speed Flexibility of Closure

9. Spatial Relations (Speeded Rotation) Spatial Visualization

10. Competencies Underlying Spatial Abilities Speed of Processing Working Memory Strategies Speeded Rotation Angle of Rotation Response Time High Ability Low Ability

11. Demographics and Causal Factors

12. Causal Factors Classic Debate: Nature: Evolution, heredity, hormones Nurture: Experience, training, education Where this has played out: Sex differences in spatial abilities

13. Linn & Peterson (N =172 studies) Males’ score – Females’ score ------------------------------------- Pooled Standard Deviation –Spatial perception.44* –Speeded rotation.73* –Spatial visualization.13 n.s. Sex Differences in Some but not All Spatial Abilities

14. More Recent Meta Analysis (N = 286) (Voyer, Voyer & Bryden, 1995) Card Rotations (.31) 3-D Mental Rotations (.67) Embedded Figures (.18) Paper Folding (.12) Sex Difference No Sex Difference

15. Possible Causal Factors Nature Evolutionary pressures on males and females Heredity (twin studies) Hormones –In development –Across menstrual, daily and yearly cycles Nurture Different rearing practices (toys etc) Navigation and home range Cultural differences Cohort effects

16. Beyond Sex Differences “ As a society, our focus should e on the optimization of spatial ability in all individuals, rather than a focus on rank ordering of the sexes” “ this long-standing debate concerning the causes of sex differences in certain spatial abilities, although scientifically interesting, has diverted attention from a much more important point; that there is currently plenty of evidence to conclude that spatial skill is trainable, for both sexes” Newcombe, Mathason, and Terlecki (2003)

17. Training of Spatial Abilities

18. Several isolated studies, short term, no large systematic research program Types of Studies: –Effects of learning subject matter content –Effects of Practice –Teaching Strategies –“Visualizing” what people have to imagine

19. Can Spatial Abilities be Trained? Several studies have shown that spatial abilities can be improved by a small amount of training Issues of how far this training tranfers More extensive, longer range studies needed

20. Does Initial Spatial Ability determine Final Success? Studies of spatial abilities in skill acquisition –Spatial ability may be more important at early stages of training –Students of all abilities able to learn, but at different rates Is this true for all spatial tasks?

21. Focus on Cross Sections

22. Importance of Cross-Sections engineerin g microbiology cognitive neuroscience astronomy anatomy meteorologyphysics geology

23. Problem Object to be understood has an internal 3-D structure Representation medium (printed page or computer screen) is 2-D

24. Three Dimensional Perception Depth Cues Pictorial: e.g. linear perspective, occlusion Binocular: e.g., binocular disparity Motion based: e.g., motion parallax

25. 3-D Perception Only pictorial cues available in a static diagram Animation can also provide motion-based cues –Motion parallax –Accretion and Deletion

26. Current Research Program Task: Draw the cross-section that would result when a 3-dimensional structure is sliced Measured spatial ability Animations available –Interactive –Non-interactive

27. What Students Represent Imagine the object is sliced at the line and draw the cross section

28. Preliminary Results Drawing performance highly correlated with spatial ability Performance improves, especially for low-spatial individuals –When they are shown an “instructional” video, of how to draw a cross-section –When they are exposed to an interactive animation Similar results found in research on instructional animations in anatomy

29. Conclusions

30. There are large individual differences in spatial perception and visualization ability These abilities are influenced but unlikely to be completely determined by nature Means of nurturing spatial abilities need more systematic study I’m interested in learning what has worked for you…