Protocol - Attentional Bias
The Dot Probe Task is a computer-administered protocol in which a pair of face or word stimuli (one either negative/threatening [e.g., angry] or positive [e.g., happy] and one neutral) are briefly presented side-by-side on a computer screen. Both faces/words are then removed, and a single dot (e.g., "*"; "."; or ":") is briefly presented on either side of the computer screen, replacing either an emotional or a neutral stimulus. Respondents indicate whether the dot was on the left-hand or right-hand side of the screen. This is sometimes interspersed with trials involving two neutral faces/words. Scores are generated by subtracting response times when probes replace neutral stimuli from response times when probes replace emotional stimuli in trials that include an emotional and neutral stimulus pair. Alternatively, if trials involving a pair of neutral stimuli are included, subtraction can be made from this baseline (i.e., dot on neutral stimulus in a neutral-emotional pair versus dot on neutral stimulus in a neutral-neutral pair).
The Dot-Probe Task stimuli often are threat related (e.g., DEAD) and neutral (e.g., DATA) words. Threat-related and neutral faces also can be used; they can be obtained from the Center for Productive Aging (Minear and Park, 2004) and NimStim (Tottenham et al., 2009) databases. The faces selected as stimuli for the Dot Probe Task should reflect the racial and ethnic diversity of the study population.
Summary of the Dot Probe Task:
Each dot probe trial begins with the presentation of a central fixation cross (e.g., "+") for 500 milliseconds. The fixation cross is then replaced with two stimuli (e.g., words or faces) side by side on a computer screen. One of the stimuli is threat-related (e.g., the word "DEAD" or an angry face) and one is threat-neutral (e.g., the word "DATA" or a blank face). After 1,000 milliseconds, both stimuli are removed and a probe (e.g., ".", "*", or ":") is shown in the location of one of the stimuli. Participants indicate as quickly as possible which probe was shown. The participant’s response clears the screen and the next trial begins 500 milliseconds later.
Participants are administered 152 trials. Incongruent trials are those in which the dot replaces the threat-related stimulus. Congruent trials are those in which the dot replaces the threat-neutral stimulus. Neutral trials are those in which the participant is presented with a neutral-neutral pair of stimuli.
Emotional bias scores can be calculated by subtracting response times to congruent stimuli (when probes replace neutral stimuli) from response times to incongruent stimuli (when probes replace threat-related stimuli). Emotion bias scores can be further divided into threat and happy bias scores. A positive score indicates bias away from that emotion, while a negative score indicates bias toward that emotion. Alternatively, a condition with neutral-neutral stimulus pairs can be used as the baseline. Doing so allows for disambiguation of attentional capture versus attentional disengagement.
Participants who respond more quickly on average when the probe replaces the threat-related stimuli demonstrate an attention bias toward threat. Participants who respond more quickly on average when the probe replaces the threat-neutral stimuli demonstrate attention avoidance toward threat.
Personnel and Training Required
The Dot Probe Task can be administered by research assistants trained in the ethical and competent use of behavioral tests.
Investigators will need a copy of E-Prime ® software (http://www.pstnet.com/eprime.cfm) in order to open and invoke the Dot Probe Task. Future implementations may be available for open source presentation platforms.
|Specialized requirements for biospecimen collection||No|
|Average time of greater than 15 minutes in an unaffected individual||No|
Mode of Administration
Adults, ages 18 and older
The Dot Probe Task is a brief, validated, and widely used measure of attentional bias.
|caDSR Common Data Elements (CDE)||Psychopathology Attentional Bias Assessment Score||4588736||CDE Browser|
|Human Phenotype Ontology||Abnormal fear/anxiety-related behavior||HP:0100852||HPO|
Process and Review
Protocol Name from Source
The Dot Probe Task can be obtained through the Laboratory for Research on Anxiety and Trauma at Tel Aviv University: http://people.socsci.tau.ac.il/mu/anxietytrauma/research/ .
Bar-Haim, Y., Holoshitz, Y., Eldar, S., Frenkel, T. I,, Muller, D., Charney, D. S,, Pine, D. S., Fox, N. A., & Wald, I. (2010). Life-threatening danger and suppression of attention bias to threat. American Journal of Psychiatry, 167(6), 694-698.
Bar-Haim, Y., Lamy, D., Pergamin, L., Bakermans-Kranenburg, M. J., van Ijzendoorn M. H. (2007).Threat-related attentional bias in anxious and nonanxious individuals: A meta-analytic study. Psychological Bulletin, 133(1), 1-24.
Eldar, S., Apter, A., Lotan, D., Edgar, K. P., Naim, R., Fox, N. A., Pine, D. S., Bar-Haim, Y. (2012). Attention bias modification treatment for pediatric anxiety disorders: A randomized controlled trial. American Journal of Psychiatry, 169(2), 213-220.
Mathews, A., & MacLeod, C. (1985). Selective processing of threat cues in anxiety states. Behavior Research and Therapy, 23(5), 563-569.
Minear, M., & Park, D. C. (2004). A lifespan database of adult facial stimuli. Behavior Research Methods, Instruments, & Computers, 36(4), 630-633.
Tottenham, N., Tanaka, J. W., Leon, A. C., McCarry, T., Nurse, M., Hare, T. A., Marcus, D. J., Westerlund, A., Casey, B. J., & Nelson, C. (2009). The NimStim set of facial expressions: Judgments from untrained research participants. Psychiatry Research, 168(3), 242-249.
Wald, I., Degnan, K. A., Gorodetsky, E., Charney, D. S., Fox, N. A., Fruchter, E., Goldman, D., Lubin, G., Pine, D. S., & Bar-Haim, Y. (2013). Attention to threats and combat-related posttraumatic stress symptoms: Prospective associations and moderation by the serotonin transporter gene. JAMA Psychiatry, 70(4), 401-408.
|Variable Name||Variable ID||Variable Description||dbGaP Mapping|
|PX631001000000||Protocol 631001 - proprietary. Check DCW for more||N/A|
November 21, 2014
A computer-administered task to measure the respondent’s attention bias toward or away from threat-related cues.
Individuals with anxious psychopathology (e.g., generalized anxiety disorder, social phobia, posttraumatic stress disorder) preferentially direct attention toward threat-related cues. This protocol is potentially relevant to Research Domain Criteria (RDoC) aims.
Threat, Attention, Attention bias, Anxiety, Dot Probe Task, Trauma, Fear, PTSD, Post-traumatic Stress Disorder