PSY 321:  Cognitive Processes
Serial Position Effect

In this experiment you will be asked to learn two lists of words, each consisting of 30 words.  After reading a set of instructions, you will see a plus sign ("+") called the fixation point.  You are to look directly at the fixation point.  The fixation point will appear for 500 ms ("ms" is the abbreviation for millisecond, which is 1 / 1000 of a second.  500 ms is 500 / 1000 or 1/2 of a second.)  Then the word will appear where the fixation point was for one second.  The word will disappear for one second.  Then the process will start over for the second word -- fixation for 500 ms, word for 1000 ms, and nothing for 1000 ms.  The process repeats until all 30 of the words have been displayed.

You may or may not then be asked to count backwards from a given number by three for 30 seconds.  For example, you may be given the number 857 and asked to count backwards by three -- 857, 854, 851, 848, etc. until you are told to stop.

Next, you will be asked to type all the words that you can remember.  When you are done recalling, you will be asked if you typed each of the 30 words that you studied.

The whole process will then repeat.  The words will be different.  If you had to count backwards by 3 at the end of the first list, you will not have to do so at the end of the second list.  If you did not have to count backwards by 3 at the end of the first list, you will have to do so at the end of the second list.  Once you have finished recalling the words and scoring whether you recalled each individual word, a summary of your results will be displayed.  You will also be asked to submit your results to the server so that they can be added to the results from the other students.

The words in the study are all five letters long, consist of a single syllable, occur frequently in printed English (at least 150 times per 1,000,000 printed words), and have high concreteness (on a scale of 100 to 700, with 700 being very concrete, all the words are at least 550.)  They were generated from the MRC Psycholinguistic Database.