CNP DRL

From Pheno Wiki
Revision as of 17:13, 1 June 2011 by Stigge (Talk | contribs)

Jump to: navigation, search

go back to HTAC


Basic Task Description

The deterministic reversal learning task (DRLT) is a computerized measure of reversal learning, a form of behavioral/cognitive flexibility that has been widely investigated in both animal and human studies (Robbins et al., 2000). This particular task version was modeled after a paradigm originally used to examine genetic associations with reversal learning in BXD strains of mice (Laughlin et al., 2011). Participants are presented with two doors and instructed that they will receive monetary rewards based on which door they choose. The initial side of reinforcement (right or left) is randomly selected by the computer. If participants select the door associated with the reward, they immediately see two quarters appear in place of the door and hear a rewarding sound (cash register noise). Rewarded selections also present a running total of earnings on the bottom of the screen. If participants select the door that is not associated with the reward, they immediate see an empty white box in place of the door and hear a negative sound (buzzing noise). Once participants have consistently selected the reinforced door, the reward contingencies for the doors are reversed. After this reversal, participants need to consistently select the newly reinforced door in order to complete the task. The primary dependent variable is the number of errors that are made after reversal.

Task Procedure

This DRLT was programmed in E-Prime 2.0. Participant responses are made on computer keyboard, with three keys marked for use in this task: A (left), H (middle), and '(right). At the beginning of the task, instructions are presented on the screen in yellow, size 20 Arial font, with a black screen background. The instructions are as follows:

"In this game, you have an opportunity to win money by

looking behind doors. Do your best to find as much money as possible.

You will actually be given the money that you earn in this task.

You may only use the index finger of your dominant hand to respond,

and you must respond as quickly as you can.

You may NOT use two hands on this task.

On the keyboard, you'll see three marked keys: left, middle, and right.

To start each play of the game,

PRESS AND HOLD THE MIDDLE KEY DOWN,

and release the key only when you see doors appear to the left and right.

Then choose one of the doors to open by pressing either the left or right keys.

You will get money based on which door you choose.

Before we start the game, let's take a moment to practice the key presses..."

Participants are then shown another instruction slide that prepares them for the practice trials:

"In the following trials you will practice making quick key presses.

You'll hear a sound to let you know if your responses are fast enough.

Please tell your experimenter when you are ready to begin the practice trials."

Practice block trials provide a basic orientation to the trial format and response keys in order to shape prompt responding during the task. Practice trials begin with a box in the center of the screen with the word "Press" and the words "Press and hold the middle button" at the top of the screen. Once the participant presses the middle key, the word "Hold" appears in the center box and the words "Wait until you see the doors!" appears at the top of the screen. The "Hold" cue remains on the screen for either 2000 ms or 2500 ms, during which time participants must keep the middle key pressed down. If they release the middle key prematurely during this time, they receive the following feedback and the trial restarts: "Oops! Make sure to wait for the doors. Let's try again." Following the "Hold" delay, two doors appear on the left and right sides of the screen. The doors remain on the screen for up to 4000 ms or until the participant presses the left or right key. While the doors are present, the "Hold" cue is then replaced by "Left or Right?" which prompts the participants to press either the left or right key. If a left or right keypress is made within 2000 ms, then participants are given feedback of "Good Job!" in the center box, along with a positive noise (fanfare). If participants take too long to respond (more than 2000 ms), they receive the following feedback in the center of the screen: "Oops! Please respond more quickly. Let's try again." Feedback slides are all presented for a total of 2000 ms. After three consecutive responses within the 2000 ms time limit, the practice trials end and the following instructions are presented on the screen:

"Now that you are familiar with pressing the keys, we can start the game.

In this game, you'll need to choose either the left or the right door to win money.

Please tell your experimenter when you are ready to begin."

Experimental block trials follow general parameters similar to the practice trials, and begin with a box in the center of the screen with the word "Press." If participants do not press the middle button within 5000 ms, they receive the following feedback in the center of the screen: "Please press the middle key to begin the next trial." After pressing the middle key, the word "Hold" appears in the center box and remains on the screen for either 1000 ms, 1500 ms, 2000 ms, or 2500 ms. These 4 durations for the "Hold" cue are randomized across all trials. If they release the middle key prematurely during this time, they receive the following feedback and the trial restarts: "Oops! Make sure to wait for the doors. Let's try again." Following the "Hold" delay, two doors appear on the left and right sides of the screen. The doors remain on the screen for up to 2000 ms or until the participant presses the left or right key. While the doors are present, the "Hold" cue is then replaced by "Left or Right?" which prompts the participants to press either the left or right key. If participants take too long to respond (more than 2000 ms), they receive the following feedback in the center of the screen: "Oops! Didn't get your response in time. Let's try again." If participants press the right or left key will still pressing the middle key (i.e., using two different fingers to respond), they receive the following feedback in the center of the screen: "Oops! Please remember to use only one finger and do not respond before the doors appear. Let's try again." Feedback slides are all presented for a total of 2000 ms.

For each experimental block of trials, the computer randomly selects either the left or right door to be initially associated with reward. Participants receive $0.50 each time they select the rewarded door. As soon as the participant presses the key corresponding to the side of the rewarded door, then they immediately see two quarters appear in place of the door and hear a rewarding sound (cash register noise). Rewarded selections also present a running total of earnings on the bottom of the screen. If participants select the door that is not associated with the reward, they immediate see an empty white box in place of the door and hear a negative sound (buzzing noise). The timing of the reversal is based on a performance criterion. Of note, this criterion has been revised since the task was initially employed (the initial version of this task (DRLT) used a performance criterion of 9 out of 12 correctly-completed trials, computed as a moving window). The current version of the task (DRLT_v2) uses a performance criterion of 5 consecutive correctly-completed trials.

Task Structure Detail

This is what we had worked on before, but could use updating. We'd like to capture a schema that can handle each of the tasks in the CNP, so please think general when editing -fws

  • Task Structure (please given an overview of the task procedures here [i.e., overall design, block, trial, and within-trial event structure and timing])
    • The DRLT has two instructional screens at the outset, followed by practice trials and the experimental session comprised of pre-reversal and post-reversal blocks of trials.
      • Two instructional screens. Screens are advanced with a left mouse click from the examiner.
        • 1. Basic task description.
        • 2. Introduction to the practice trials.
      • Practice trials (repeated until 3 consecutive trials with responses < 2000 ms).
        • Press Cue Slide (infinite until middle key is pressed).
        • Hold Cue Slide (randomized duration of 2000 ms or 2500 ms).
          • Early Response Feedback (3000 ms) presented if participants release the middle key prematurely.
        • Door Slide (4000 ms).
          • No/Slow Response Feedback (2000 ms) presented if participants do not respond to doors within 2000 ms.
      • Instruction screen reminds participants of the rules and introduces the experimental trials.
      • Experimental trials (up to 60 trials).
        • Press Cue Slide (5000 ms or until middle key is pressed).
          • No Response Feedback (2000 ms) presented if participants do not press the middle key within 5000 ms.
        • Hold Cue Slide (randomized duration of 1000, 1500, 2000, or 2500 ms).
          • Early Response Feedback (3000 ms) presented if participants release the middle key prematurely.
        • Door Slide (2000 ms).
          • No/Slow Response Feedback (2000 ms) presented if participants do not respond to doors within 2000 ms.
          • One Finger Feedback (2000 ms) presented if participants respond to doors while still pressing the middle key.
      • End. Thank you screen presented. Grand Total Earnings also displayed.
    • Timing
      • Instruction screens are static until advanced by examiner with a left mouse click.
      • Press Cue Slides (5000 ms until until middle key is pressed).
      • Hold Cue Slides (1000, 1500, 2000, or 2500 ms).
      • Door Slides (2000 ms or until left or right key is pressed).
      • Feedback Slides (2000 ms).
      • The ending thank you screen is static until advanced by the examiner with left mouse click.
  • Stimulus Characteristics
    • sensory modality: Visual. Doors are gray and appear slightly opened against a black opening. Feedback during the task is black text in size 24 Arial font.
    • functional modality: visuoperceptual and linguistic (understanding of text).
    • presentation modality: computer display, audio, directions are assisted by examiner.
  • Response Characteristics
    • responses required: middle key for beginning each trial, left or right key press for selecting door.
      • effector modality: Manual button press.
      • functional modality: Manual button press.
    • response options (e.g., yes/no, go/no-go, forced choice, multiple choice [specify n of options], free response): press, hold, left or right door.
    • response collection (e.g., examiner notes, keyboard, keypad, mouse, voice key, button press): Button press and recording of responses in Eprime 2.0.

Task Schematic

2 Door Slide.JPG

Correct Trial.JPG

Incorrect Trial.JPG

Task Parameters Table

File:.png

Stimuli

Stimuli consisted of two doors simultaneously presented in the center of the left and right halves of a gray screen. Visual reward feedback was an image of two quarters, which appeared in place of the correct door. Visual non-reward feedback was an empty white square, which appeared in place of the incorrect door.

Auditory reward feedback was a cash register sound that lasted approximately 500 ms. Auditory non-reward feedback was a buzzer sound that lasted approximately 500 ms.

A fixation stimulus was a small white square that appeared in the middle of the screen and prompted participants to either "Press" the middle key to begin each trial, "Hold" the middle key to wait for the doors, or select "Left or Right?" once the doors appeared.

Dependent Variables

The primary dependent variables associated with this task have been the total number of trials to criterion during acquisition and reversal conditions (Laughlin et al., 2011). Other dependent variables that may be of interest include the number of reversal errors, mean RT on reversal error trials, and overall change in RT across the final 5 consecutive correct trials in acquisition and reversal conditions.

Table of all available variables.

File:.png

Cleaning Rules

If any of the derived variables listed above are missing, participants should be flagged for exclusion. Additionally, participants who are outliers in the number of trials administered for acquisition or reversal conditions should be flagged, as well.


Code/Algorithms


History of Checking Scoring:

Data Distributions

References