1. Sex differences and estrogen effects on memory and spatial ability Danerys Encarnacion, Kristin Law and Mark Schmidt

2. Program overview  Background on sex differences  Background on estrogen effects  Examples of measures used  Hypotheses  Results  Discussion

3. Sex differences  Men outperform women in: 1. Spatial Ability 2. Mathematical Reasoning 3. Deductive Reasoning

4. Sex differences  Women outdo men in: 1. Spatial Memory 2. Verbal Performance 3. Perceptual speed

5. Concepts measured  Spatial Ability  Spatial Memory  Verbal Emotional Memory

6. 2 Categories of Spatial Ability Spatial orientation: Measures the ability to judge the spatial position and relationship of stimuli relative to the observer. Ex) map reading Spatial visualization: Measures the ability to manipulate stimuli mentally without distorting the spatial configuration or the stimulus elements. Ex) mental rotation

7. Mental Rotation Test  Measures the ability to rotate a 2D or 3D figure rapidly and accurately. This measure produces the most significant sex differences of any spatial task.  Used this measure as a constant.

8. Mental Rotation Exercise

9. Spatial Memory  Definition: Memory for location of unfamiliar objects.  Unfamiliar object are used to control verbal labels.  Two types of Spatial Memory Tasks measured  Location-Exchange  Location-Shift

10. Location-Exchange Task  Measures memory of the original position of objects after the location of pairs of objects were exchanged.  Given 1 minute to study the original array of objects then asked to put an X through the objects that have moved. (Example)

14. Location-Shift Task  Measures memory of the original position of objects after the locations of objects were shifted to sites previously unoccupied by another object.  Instructions are the same as location- exchange.

18. Verbal Emotional Memory  Consisted of 2 short stories that have 3 separate measures within them. 1. Neutral Content: 21 units; Ex) Karen 2. Emotional Content: 5 units; Ex) scared 3. Behavioral Content: 6 units; Ex) screamed loudly

19. Verbal Emotional Memory  Also measured 3 types of memory 1. Immediate recall 2. Delayed recall (15 minutes later) 3. Cued recall

20. 28 Day Menstrual Cycle Menstrual Phases 1. Menstrual Phase: 1-5 days (low estrogen) 2. Follicular Phase: 6-18 days (medium estro) 3. Luteal Phase: 19-24 days (high estrogen) 4. Premenstrual: 24-28 days (low estrogen)

22. Birth Control Factor  50% of the participants were on birth control.  Meaning that estrogen stays medium throughout the follicular and luteal phases impairing ovulation.  50% of the participants not on birth control had irregular cycles, meaning that their estrogen levels did not follow the 28 day format so they could not be measured accurately.

23. Birth Control Solution  Women were divided into 2 groups 1. Low estrogen (prementrual and menstrual) 2. High estrogen (follicular and luteal phases)

24. Method Participants: -Male and female undergraduate students (N=51) -50% of women were on birth control pills

25. Method Tests -PANAS Questionnaire (current mood) -Location-Exchange (spatial memory) -Location-Shift (spatial memory) -Paragraph recall (verbal emotional memory) -Mental Rotation Test (spatial transformation) -Menstrual Questionnaire (current cycle stage)

26. Hypothesis 1  Men will outperform women on mental rotation.  Women will perform better when estrogen is low.

27. Hypothesis 2  Women will outperform men on spatial memory.  Women will excel the most when estrogen is high.

28. Hunter-Gatherer Theory  An evolutionary theory that bases its foundation on the idea that men were hunters and women were gatherers in early human history which caused these differences in cognition to evolve.

29.  Hunting and tracking require men to have good spatial orientation and transformation abilities to be able to pursue prey across unfamiliar territory and to set traps in correct locations.  Gathering requires good spatial memory abilities in order to locate food sources among vegetation as well as to relocate them the next year.

30. Estrogen effects on Cognition Estrogen has been found to interfere in spatial transformation tasks such as mental rotation. Estrogen aids verbal memory. -Menopausal women receiving estrogen replacement therapy show enhancement in short and long-term memory.

31. Estrogen effects on cognition - Men given estrogen supplements also showed improvement in verbal memory compared to those without supplements.

32. Hypothesis 3  Women will outperform men on verbal emotional memory.  Women will score higher when estrogen is high.

33. Results

34. Mental Rotation  Men did outperform women in mental rotation.  Women performed better when estrogen was low.  Hypothesis 1 was supported.

36. Spatial Memory  Women outperformed men on the location- shift task but not on the location-exchange task.  Women excelled when estrogen was low not high as was predicted.  Hypothesis 2 was partially supported.

39. Verbal Emotional Memory  Significant sex differences were not found in verbal emotional memory.  The general pattern found was that women were scoring higher was expected.  Hypothesis 3 was not supported.

44. Discussion What to change next time: 1. Use blood tests to measure menstrual phase accurately. 2. Use a repeated measures design which would use the same women at least four different times across their menstrual cycle.

45. Do you have any questions?