1. 1 of 35Timing Timing Exercises (1-3) E-Prime 2002 Workshop Files on My Documents\My Experiments\Workshop\E-Prime Exercises E-Prime Timing Exercises Copyright Psychology Software Tools Inc. 2002 These materials may be used for local educational purposes only. all other use requires approval in writing. Please send requests to info@pstnet.com

2. 2 of 35Timing List of Exercises  1. Varying Probe Duration – TimingParadigm3  2. Cumulative Timing of a Repeating Sequence of Events – TimingParadigm4  3. Continuous sequences of events at high rate with short stimulus times – TimingParadigm5

3. 3 of 35Timing General Rule For Timing  Set the timing of the critical event to be equal the intended time rounded to the nearest millisecond and set prerelease equal to greater than the longest time to get ready for the next display.  Examples assume 60 Hz, 16.67ms refresh subtract set the prerelease to 17 ms and refresh time of

4. 4 of 35Timing Timing Exercise 1  1. Open My Documents\My Experiments\Workshop\E- Prime Exercises\ TimingParadigm3 and run to create an EDAT file  2. Verify Display.RefreshRate  3. Use E-DataAid to arrange columns to check timing accuracy  4. Copy columns into Excel  5. Perform calculations using Excel This exercise presents a masking experiments presenting displays for 1-3 refreshes (17-50ms). In this exercise you will:

5. 5 of 35Timing Timing Exercise 1- Verify Refresh Rate  1. Use E-DataAid to O pen My Documents\My Experiments\Workshop\E-Prime Exercises\ TimingParadigm3-3- 1.EDAT (which was previously created)  2. Verify Display.RefreshRate

6. 6 of 35Timing Timing Exercise 1 – Arrange Columns  3. Select Arrange Columns tools, click Remove All.  4. Next to the Select button type *.OnsetTime; ProbeDuration; Time* and click Select  5. Click Add and click OK

7. 7 of 35Timing Timing Exercise 1- Copy to Excel  5. Arrange columns move Mask.OnsetTime after Probe.OnsetTime. Click on column heading to select then click & drag to move  6. Select all columns, copy, open Excel and paste.To select cells  click on Fixation.OnsetTime heading and drag across to TimeProbetoMask.  Go to Edit and select Copy  Open Excel  Paste (Ctrl-V) the cells into the first cell of the spreadsheet

8. 8 of 35Timing Timing Exercise 1- Calculate Results  7. Calculate the Probe to Mask time  Create a Probe-Mask column  In first cell of that column type the formula: =C2-B2  Copy formula down to last row  Notes the times are about 17,33, and 50 ms  Compare to TimeProbeToMask column, they should be the same

9. 9 of 35Timing Timing Exercise 1- Calculate Results  8. Calculate the Fixation to Probe time  Create a Fixation-Probe column  In first cell of that column type the formula: =B2-A2  Copy formula down to last row  Note the times are ~516 ms  Compare to TimeFixationToProbe column, they should be the same

10. 10 of 35Timing Timing Exercise 1- View Results  If you know how to use Excel pivot tables, create a pivot table by selecting columns ProbeDuration to Mask- Probe, on Data menu, choose pivot table, press Next twice, choose Layout, Copy and drag ProbeDuration to row and Mask-Probe to data twice, double click and select Average and StdDev as on the left  Open My Documents\My Experiments\Workshop\E-Prime Exercises\TimingExercises excel spreadsheet and select Exercise1Pivot tab  View the calculated means and SD of Probe and Mask time  View the Pivot table of Probe-Mask based on ProbeDuration OR:

11. 11 of 35Timing What would your report to a Journal?  Have Assistant verify your “Timing Report” before moving on. Please put the display into this form and raise your hand. Explain what would your put in a journal. Assistant Initials ___ In this experiment the displays were presented with means and standard deviations for the probe to mask times of ___________________________

12. 12 of 35Timing Exercise 1a (Optional) – Use Script to Log Time Between Stimulus Onsets  You can add an Inline object and add script to calculate and log the onset to onset time for later analysis in E-DataAid.

13. 13 of 35Timing  Timing Exercise 1 Study Questions Could you at this point answer these questions? 1. What would expect if you ran this exercise on a 100 Hertz monitor if it is set up for a 60 Hertz monitor? 2.What if the PreRelease were set to 0 what would you expect the times to be on a 60 Hertz monitor? 3.How might you put in code to detect if the times were different from the intended time by more than a millisecond and log the problem? 4.How might you put in code to be sure that the program is running on a 60 Hertz monitor? Short Answers are included in the Exercise Appendix

14. 14 of 35Timing Timing Exercise 2 This exercise contrasts event mode and cumulative mode timing. Cumulative mode minimizes cumulative time error in an experiment. In this exercise you will:  1. Run My Documents\My Experiments\Workshop\E-Prime Exercises\TimingParadigm4AllModes and analyze the timing.  2. Use E-DataAid to output graphs and table for Excel  3. Report the problem errors in timing

15. 15 of 35Timing Timing Exercise 2 – Create or Open EDAT file  1. Either run TimingParadigm4AllModes. es or use the existing file.  2. In E-DataAid o pen My Documents\My Experiments\Workshop\E- Prime Exercises\TimingParadigm4 and run or open TimingParadigmAllModes100- 1.EDAT file for data (which was previously created) with E-DataAid.

16. 16 of 35Timing Get Cumulative Time Graph  3. Click Calculate  4. Move over Trial, TimingMode, PreRelease, TimingCumu lativeError to cells  5. Click Run

17. 17 of 35Timing Examine Timing Send Excel  6. Select Plot  7. Click Excel Plot

18. 18 of 35Timing Examine Timing Data  8. Look at timing data note difference from intended

19. 19 of 35Timing Zoom in on Timing Error  9. Click on Excel Graph change chart mode to line graph.  10. Click on the Y-axis and right click and set max Y to 50. Note differences in errors

20. 20 of 35Timing Use E-DataAid to Output Timing Table  11. Return to E- DataAid, change Analysis  Set Rows to  TimingMode  PreRelease  Set Data to  TimeCumulativeError Time  TimeFixationToProbe  TimeProbeToMask  TimeProbeOnsetTo Onset mean  Time ProbeOnsetTo Onset SD of Sample

21. 21 of 35Timing Export Table to Excel  12. Export to Excel by selecting StatView format and Excel Copy

22. 22 of 35Timing Identify Poor Timing  13. Identify poor timing cases (off by a refresh cycle). Note cumulative 100 ms prerelease correct, errors in all other cases.

23. 23 of 35Timing How would your run your experiment? How would you report it?  Have Assistant verify your “Timing Report” for a cumulative experimiment. In this experiment we used ______ timing mode with the stimulus to stimulus time mean of ______ and SD of ______.  Please put the display into this form and raise your hand. Explain what would your put in a journal. Assistant Initials ___

24. 24 of 35Timing Timing Exercise 2a (optional) - Run Timing Paradigm4 In Cumulative Mode, Change Event, Rerun  1. Open TimingParadigm4.es file (My Documents\My Experiments\Workshop\E-Prime Exercises).  2. Run the program with subject number 1.  3. Change the Timing Mode on the TrialProc displays (TrialInstructions, Fixation, Probe, Mask, FeedbackDisplay1) to Event and Prereleases to “0” or load TimingParadgim4EventTimeNoPreRelease.es.  4. Run the experiment with subject number 2.

25. 25 of 35Timing Plot Cumulative Time Errors Cumulative Mode With PreRelease  5. Make table and graph of TimeCumulativeError by Block Cumulative Run 1-1  Open Program E-DataAid  Open data file TimingParadigm4-1-1.edat  Click Calculate  Move Block to row  Move TimeCumulativeErrorTime to Data  Click Run  Click Plot  Click Excel Plot  6. Note time variation within one refresh and not not increasing

26. 26 of 35Timing Plot Cumulative Time Errors Event Mode Without PreRelease  7. Make table and graph of TimeCumulativeError by Block Evente Run 2-1  Close E-Data Aid Windows  Open data file TimingParadigm4-2-1.edat  Click Calculate  Move Block to row  Move TimeCumulativeErrorTime to Data  Click Run  Click Plot  Click Excel Plot  8. Note time variation is increasing with every refresh

27. 27 of 35Timing Compare Results from Both Modes  9. Note characteristics of data  Cumulative mode errors within a refresh (maximum of 7ms no cumulative drift)  Event mode increase by significant amount with each event causing substantial cumulative drift (in this example an average of 47 ms with a maximum of 710 ms) Cumulative Mode PreRelease Event Mode No PreRelease

28. 28 of 35Timing Timing Exercise3  1. Open My Documents\My Experiments\Workshop\E-Prime Exercises\TimingParadigm5 and run  2. Note Steps involved in Caching Images  2. Note Steps involved in Caching Images  3. Use E-DataAid to select TargetDuration and OnsetToOnset  4. Plot the difference between Target and Actual Time

29. 29 of 35Timing Steps to Caching Images Create CanvasCacheCreate CanvasCache Load CacheLoad Cache Display CacheDisplay Cache

30. 30 of 35Timing Arrange Columns  1. Open TimingParadigm5-3-1.edat file  2. Select Arrange Columns tools, click Remove All  3. Select TargetDuration and OnsetToOnset, click Add and OK  4. Copy two columns to Excel

31. 31 of 35Timing Chart Results in Excel  In Excel select both columns and click on Graph Wizard  Make line chart of time  Note error target versus intended

32. 32 of 35Timing View Results  Note error target versus intended

33. 33 of 35Timing View Results  Determine max speed presentation with disk reads and caching.

34. 34 of 35Timing  Timing Exercise 2 Cumulative Time Could you at this point? 1.Specify when to use Cumulative Time and Event Time methods? 2.Analyze the timing of a cumulative experiment and report accurately the timing precision in a journal article? 3.Specify the disadvantage of using PreRelease and when must you be careful about it? Short Answers are included in the Exercise Appendix

35. 35 of 35Timing  Timing Exercise 3 Caching Questions Could you at this point? 1.Specify the range of display times in which prerelease is sufficient for the computer to keep up and caching is not necessary? 2.Determine the maximal rate at which you could display images before the computer can not keep up? 3.Add new images to TimingParadigm 5 to allow rapid presentation of those images? Short Answers are included in the Exercise Appendix