Part A: Choice Reaction Time (Hick-Hyman Law)

  1. Select one person in the group to be the subject and another to be the experimenter. If there are three team members, one can be the observer or can trade off with the experimenter (the subject should not change).
  2. For the first part (pure choice reaction time), the experimenter will develop a scheme for presenting the white and blue lights at random to the subject, making sure that at least 30 trials are included and both colors are presented the same number of times (i.e., equally likely). Use the attached sheet to record the presentation scheme and be sure the subject does not see the presentation scheme.
  3. Following the presentation scheme developed in step 2, the experimenter will set the CRT to display the first color and press the “initiate” button.
  4. The subject will rest his hands so that the index finger of each hand is resting on the button associated with the white and blue lights. When the light comes on, the subject will depress the button associated with the light as quickly as possible.
  5. When the subject has depressed the correct button, the experimenter will record the time on the timer display. (Note: the timer shows cumulative times.)
  6. Repeat steps 3-5 until the entire presentation scheme has been completed. Note: to make sure the subject is not able to figure out the color to be presented by counting the “clicks”, be sure to “flip” the color selector several times before stopping on the chosen color.
  7. Determine the average reaction time for the 30 trials.
  8. Develop a second scheme using all 4 colors, making sure that the order of appearance is random and that each color is equally likely to appear.
  9. Repeat steps 3-7, this time using all 4 colors and allowing the subject to place his hands so that he/she can best react to the light as they are lit.
  10. Using the times from steps 7 and 9 to solve for a and b in the equation:

RT = a + bH.

  1. Develop one final scheme in which the colors are not equally likely to appear. Predict the reaction time you would expect to see for this scheme.
  2. Repeat steps 3-7 with the final scheme and compare your result to the predicted value.
  3. Plot the reaction time data against the information content for both subjects on the same graph. (Using H as the abscissa and RT as the ordinate.)

Part C: Combining Reaction and Movement Times

  1. Select one person to be the subject. The other is the timekeeper.
  2. Start the experiment with Layout 1 2. Shuffle the deck of cards completely (mathematicians and game theorists say 7 riffle shuffles are required).
  3. Place the deck face up in the rectangle marked “DECK” and have the subject stand centered on the deck and at a comfortable distance from the work table. The subject will use his/her preferred hand to pick up the cards one at a time and place them in the rectangle marked “DISCARD”. Time the subject from the time he/she touches the first card to the time the last card is placed on the pile. Divide the total time by 52 to determine the average time per card.
  4. Shuffle the cards.
  5. Have the same subject repeat step 3, but this time using Layout 2 and putting the red and black cards in separate piles. Time the subject the same as in step 3.
  6. Using the time from step 3 as the simple reaction time (a) and the time from step 5 as the choice reaction time when H = 1 (two equally likely choices), solve for b in the equation:

RT = a + bH.

  1. Predict the reaction time for 4 equally likely alternatives (H = 2).
  2. Shuffle the cards and repeat step 3, but this time use Layout 3 and separate the cards by suit (aces, clubs, hearts, and diamonds). Compare the time for this with the time predicted in step 6.
  3. Plot the reaction time data against the information content for both subjects on the same graph. (Using H as the abscissa and RT as the ordinate.)
  4. Shuffle the deck of cards completely. Create a layout similar to layout 1 but with the “discard” space set twice the distance from the “deck”. Call this distance D2. (The distance in layout 1 will be D1.)
  5. The subject will use his/her preferred hand to move the cards one at a time to the new “discard” rectangle. Time the subject from the time he/she touches the first card to the time the last card is placed on the pile. Divide the result by 52 to determine the average movement time per card. Call this time MT2.
  6. Call the time from step 3 MT1. Using MT1 and MT2 determine the movement time equation for this subject using cards.
  7. Create a new layout and division for card sorting.
  8. Using the reaction time equation from step 6 and the movement time equation you calculated in step 12, predict the total time required to sort cards using the layout and division you created in step 13.
  9. Repeat step 3 using the layout and division you created in step 5. Compare the result to your predicted time.
  10. Graph the results.