CNP ANT

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Basic Task Description

Attention is a complex cognitive function, dependent on interacting neural systems of the brain. According to the Attention Network Theory, the systems can be subdivided into an alerting or vigilance network, a network of orientation or selection, and an executive or conflict network. A range of experimental, neuroimaging, and clinical studies have supported the theory and Berger and Posner as well as Fan et al. have argued that the attention network model is of special interest in studies of attentional disorders, e.g. the Attention Deficit Hyperactivity Disorder (ADHD).

The three networks have been widely explored by using cue-target reaction time (RT) tasks and tasks evoking a conflict. Recently, Fan, Posner and collaborators developed an experimental task called the Attention Network Task (ANT), combining a cue-target and a flanker test to obtain measures of the efficiency and accuracy of the three networks. Recent studies have used different versions of ANT to study cognitive characteristics associated with ADHD. A study by Booth used the original child version and found no differences between children with ADHD and control children on any of the three networks. An Event Related Potential (ERP) study by Rodriguez demonstrated a deviant ERP activation pattern on the alerting and conflict networks in young adults with the DSM-IV defined inattentive subtype of ADHD. A deviant activation pattern was also found in a Functional magnetic resonance imaging (fMRI) study by Konrad and colleagues. This affected all three networks, but the behavioral data showed that only the conflict network was less efficient in ADHD children than in control children. These results suggest that the neural basis of the attentional networks may be affected in children with ADHD, even when this is not reflected in behavior measures.


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 experiment you will see arrows pointing either to the left or to the right. Sometimes the central arrow will be surrounded by other arrows. Your task is to pay attention to the central arrow. Press the “Left arrow” button if the central arrow points to the left. Press the “Right arrow” button if the central arrow points to the right. Press the correct button as quickly as possible.

There will be a cross (+) in the center of the screen and the arrows will appear either above or below the cross. Try to stare at the cross throughout the whole experiment. You will get two practice blocks before the experiment begins.

Press the SPACEBAR to do some practice."

Following successful practice trials, participants are then shown another instruction slide that prepares them for the rest of the trials:

"Good job! When you are ready, you can Press ‘s’ to begin the real test."

Experimental block trials (acquisition and reversal conditions) 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.

At the beginning of the acquisition block, 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 left and right sides 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.

DRLT Variable Table.JPG

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 for follow up.

Code/Algorithms


History of Checking Scoring:

  • David Kaufman independently checked Stone's results in September 2010 and May 2011 and found his results to be accurate.

Data Distributions

References

Laughlin RE, Grant TL, Williams RW, Jentsch JD. (2011). Genetic dissection of behavioral flexibility: reversal learning in mice. Biol Psychiatry, 69: 1109-16.

Robbins TW. (2000). Chemical neuromodulation of frontal-executive functions in humans and other animals. Exp Brain Res, 133:130-138.