Brain Teasers

1. Brain Teasers • Brought to you by: • Yifat Tamir • David Anderson • Kaylie Dienelt • Mirelle Phillips Are Dartmouth students this anxious under time pressure?

2. Introduction • Getting admitted to Dartmouth College requires the combination of high SAT scores, strong grades, and involvement in extra-curricular activities. • Performing well on a test such as the SAT correlates with an ability to maintain high performance under time pressure. • But does time pressure help or hinder cognitive performance?

3. Choosing the Brain Teaser Task: Somewhat cerebral, but still fairly simple Short and sweet Lack of associated prior sense of anxiety Two groups: one low-pressure (untimed) and one high-pressure (time limit) HP group was told the mean time needed to complete brain teaser task for participants in LP scenario. Does this foster a sense of competition or anxiety? Selection of Participants: Two experimenters assigned to each subject group 30 LP, 30 HP subjects Random selection of participants across a number of campus locations (collis, hop, baker, novack) Each participant tested individually so as not to increase any group-oriented competitiveness Results would be analyzed both for time and response accuracy The Test: Nervous yet?

4. The Test: Exposed 123safety456 • 0________________Ph.D. B.Sc. B.A.

5. Hypotheses: Will they freak out?? • Null Hypothesis:There will be no difference in the mean amount of time it takes for each group to complete the task. • Alternate Hypothesis: There will actually be a difference in the mean amount of time it takes for each group to complete the task.

6. Our Beautiful Thoughts: Can they handle the PRESSURE? • We hypothesized two possibilities for the effects of pressure: • Subjects may take more time to complete the task due to anxiety induced by time-pressure • Subjects may take less time to complete the task because they are already motivated to perform well in high-pressure, competitive situations (by virtue of being Dartmouth students). • These effects could have confounded each other, confusing the difference between our means and increasing variance.

7. Holy Platypus! What Brilliance! But are there any significant effects? Results: • The average time for the LP group was 198 seconds (3 min. 18 sec.) with a standard deviation of 89 seconds. • Average time for HP group (once told the average for LP) was 221 seconds (3 min. 41 sec.) with a standard dev. of 144 seconds. • But what about accuracy?!

8. Mathematical Shizzy: Graphical Comparison of Performance across Subject Groups

9. Shooting in the Dark: Accuracy across experimental situations

10. Accuracy Issues: Did some punks like to hit it and quit it, or did they like to stay and play? • Average number of correct answers in the low-pressure group was 5.13 (out of 7) with a standard deviation of 1.5. • Average number of correct answers in the high pressure group was 5 with a standard deviation of 1.5. • No real statistically significant difference between group accuracy Our friend Sir Mix-a-Lot • ******************************* • Had to remove one subject from LP group: only answered two teasers • Removed three subjects from HP group: two only answered a limited number of teasers, and one was a huge outlier (4 standard deviations away from mean) • Subject pool became 29 for LP and 27 for HP.

11. Significance: means and sd’s- F-test and t-test • To calculate the t-score for the difference between two means, we used t = (x1 – x2)/ (s12/n 1 + s2.52/ n2.5) • Our critical region required that t ≤ +1.671 or t ≥ -1.671 • t = 0 = No significance • To calculate the difference in variance between the two samples, we used F = s12/ s22 • To be significant at a 5% level, F would have to be in the range of 1.87-1.91 • F = 1.27 = No significance

12. Discussion: Robbed of rightful results with the rebus • The problem with the “3 degrees below zero” rebus. • How the rebus might have skewed the data in two directions: • students who spent too much time on one rebus (more time) • students who just gave up (less time) • Perhaps we need a cognitive measure that would make time much more of a salient factor than accuracy. • 0________________ • Ph.D. B.Sc. B.A. Ridiculous Rebus

13. Discussion Part Deux: Faster, Hotter, and More All-Encompassing • Sampling Problems • Self-Selection: • After seeing the task, people could choose not to participate and it is likely that people who are not familiar with or do not like brain teasers would opt not to participate • Location: • Public area, Presence of other students: increased sense of anxiety or competition (respectively) • Ideally, subjects would be isolated in a small room

14. Conclusion: Overly verbose suggestions for further, equally-awesome projects The results of the study indicate that applying pressure in the form of an implied time constraint does not significantly affect cognitive performance. • Potential mplications for the SAT and other high-stakes testing, suggesting that there is not much truth to the claim that cognitive performance is negatively affected by time constraints. On the other hand, no one was really invested in our little task, so who really knows what would happen under real pressure. • However, certain common characteristics of our participants should be noted. As we might be able to assume at Dartmouth, the participants in such an elite academic environment tend to have been trained to perform well under timed conditions. • Therefore, we would recommend that future projects be performed on a large population of students from many different grade-levels and institutions, that a more time-oriented cognitive task be chosen, and that the subjects be truly isolated in the testing situation.