Experimental Psychology

Give all relevant details,  (approximate size of letters, fact that everyone used different computers, viewing distance was up to participant, number of words — 60 study words, 120 test words with 20 in each of the 6 conditions (3 contrasts by 2 types of test words–new vs. old) , etc.).  Sub-sections should include

Participants(specify number, rough mix of genders, fact that all are students, etc.)

Equipment(pc computers using custom program)

Design( all related measures (since every Participant (P)  participated in every condition), 3 (Contrasts) by 2 (old vs. new) for  a 3 x 2 design.

Procedure  Specify step-by-step what each P does

Psychology 465 Experimental Psychology


Sixth Assignment – Cognitive Ease


1. Run the Cognitive Ease Experiment. Change the default settings, such that the middle brightness is 140 instead of 120. Read the carefully before proceeding, since there are no practice trials. There are two phases: (1) Study Phase: Words will be presented at a rate of one every two seconds. Just read and study them, (2) Test Phase: Words will be flashed on for 100 ms in either low, medium or high contrast. Enter 1 if the word had been presented earlier during the study phase, else press 2.


2. Save your results, both reaction time and accuracy, by copying and pasting. A sample Results screen is shown at the end of this document. Copy and paste your own Results screen at the end of you assignment. Go to this link and add your data, all across a single row, and then save the file




3. There is no Background Information document for this assignment. Everything you need is in this document.


4. Do a complete APA-style report, leaving out only the Abstract section Some hints by section follow:





(Please collect your own data before reading this)


The classic experiment was performed by Whittlesea, Jacoby, & Girard (1990) who found that test words that were presented without clarity were less likely to be responded to as having been seen before regardless of whether they actually had been. The basic idea is that clarity produces a sense of cognitive ease, and cognitive ease in turn evokes a sense of familiarity. In another class (you can simply refer to this as a pilot study without putting it in the References), I had tried to replicate his experiment unsuccessfully. However, I had used short durations to reduce clarity whereas they had used dynamic visual noise. Luo (1993) reported that shorter durations did not work, so my earlier study confirmed that. In this experiment, I would like to see if reduced contrast will work in the same way as visual noise. So this is a genuine new experiment, I think (you may find that it has been done in the process of searching the literature).


You can include the two articles I have already mentioned (found in the References section at the end of this document). You should also include two additional primary sources, using a citation search, based on either Whittlesea, Jacoby, & Girard (1990) or Luo (1993) (or one of each) as the starting point. To do a citation search, use PsycINFO find the article, click on the article and then click on “Times Cited in Database” at the left. This will give you a list of all articles that have cited the article you have found. Not all of these article will be relevant. Your job is to find two that are and to incorporate them into the Introduction.


Remember that the Introduction (and indeed the whole report) should avoid use of ‘I’, ‘We’, etc. Also, you should give the general background first, then lead up to the purpose of the current study.


We did not replicate



Give all relevant details, (approximate size of letters, fact that everyone used different computers, viewing distance was up to participant, number of words — 60 study words, 120 test words with 20 in each of the 6 conditions (3 contrasts by 2 types of test words–new vs. old) , etc.). Sub-sections should include


Participants (specify number, rough mix of genders, fact that all are students, etc.)


Equipment (pc computers using custom program)


Design ( all related measures (since every Participant (P) participated in every condition), 3 (Contrasts) by 2 (old vs. new) for a 3 x 2 design.


Procedure Specify step-by-step what each P does.



(You can analyze the results once there are at least 18 people who have put their data into the spreadsheet. Leave out your own data)


Complete a table like the following for the group means. Note that even though we are recording RT, you are analyzing only the Percent Yes:


There is one key thing that you need to do first. We are interested in looking at the “Yes” responses. For the old words, “Yes” responses are correct, so simply use the numbers in the spreadsheet For the New Words, “No” responses are the correct ones, so to get the “Yes” responses, you will need to subtract the Percent Correct from 100.


Percent Yes
  Low Contrast Medium Contrast High Contrast Means


64.25 67.45 62.6 64.766
New 28.45 26.3 26 26.91




46.875 44.3  





Prepare a graph for Percent Yes as a function of Contrast, with separate lines for the two conditions of Old vs New.


Prepare a second graph for Percent Yes as a function of Contrast, averaging over the two conditions of Old vs New (so that there is only one line).


You should analyze the Results with ezANOVA, and report them in standard format.


(Tiny amount of extra credit) Analyze the RT values, just as you did for the percent correct, except of course there is no need to adjust the values for the new words.


Please include everything into a single document. Cut and paste the output of ezANOVA into the document, in an Appendix.




This should be in your own words, and not necessarily in the following order or format, but:


1. We are predicting a significant main effect for Type of Test Word (Old vs. New). If people were paying any attention at all, the re should be more “Yes” responses to the old as opposed to the new words. This is not a particularly interesting finding but it does serve as a good check.


2. We are predicting a main effect of Contrast; there should be more “Yes” responses for higher contrast words regardless of whether the words were old or new. At least, this is what we are testing for—it may turn out that contrast is no more effective than duration at evoking a sense of cognitive ease.


3. It is also not clear what should be predicted for the interaction of Contrast and Type of Test Word. If there is no interaction, that simply means that the effect of contrast is the same for both Old and New test words. If there is an interaction, describe it and see if you can make sense out of it.


4. If you analyzed the RT values, and want a tiny additional bit of extra credit (up to a maximum grade of 100), discuss the RT vaues.




Luo, C. R. (1993). Enhanced feeling of recognition: Effects of identifying and manipulating test items on recognition memory. Journal Of Experimental Psychology: Learning, Memory, And Cognition19(2), 405-413. doi:10.1037/0278-7393.19.2.405


Whittlesea, B. W., Jacoby, L. L., & Girard, K. (1990). Illusions of immediate memory: Evidence of an attributional basis for feelings of familiarity and perceptual quality. Journal Of Memory And Language29(6), 716-732. doi:10.1016/0749-596X(90)90045-2

Macintosh HD:Users:ZeinabHazime:Desktop:Screen Shot 2019-02-19 at 3.32.39 PM.png


ANOVA: Design 2 Within Subject Factors


rt F(1,19) = 6.05 p<0.023632 SS=144490.80 MSe=23870.12


F(2,38) = 1.93 p<0.159187 SS=74590.85 MSe=19329.22


Greenhouse-Geisser{0.7030} p<0.1735244 Huynh-Feldt{0.742} p<0.1717508


rt* F(2,38) = 1.76 p<0.185385 SS=82218.75 MSe=23326.77


-Note: ezANOVA does not compute sphericity correction for interactions.


453532.200000003: 734510.483333334: 886417.25: 1705239.66666666


Eta rt = 0.036821


Eta = 0.019353


Eta rt* = 0.021290