The dot-probe paradigm is a test used by cognitive psychologists to assess selective attention. According to Eysenck, MacLeod & Mathews, the dot-probe task was inspired by some data collected by Halkiopoulos, one of Michael Eysenck's students, in 1981, assessing attentional biases to threatening auditory information, when threatening and non-threatening information was presented simultaneously to both ears in a dichotic listening task. The method was adapted to the visual modality by MacLeod, Mathews and Tata. In many cases, the dot-probe paradigm is used to assess selective attention to threatening stimuli in individuals diagnosed with anxiety disorders. Biases have also been investigated in other disorders via this paradigm, including depression, post-traumatic stress disorder and chronic pain. Attention biases toward positive stimuli have been associated with a number of positive outcomes such as increased social engagement, increased prosocial behavior, decreased externalizing disorders, and decreased emotionally withdrawn behavior.
Procedure and method
During the dot-probe task, participants are situated in front of a computer screen and asked to stare at a fixation cross on the center of the screen. Two stimuli, one of which is neutral and one of which is threatening, appear randomly on either side of the screen. The stimuli are presented for a predetermined length of time, before a dot is presented in the location of one former stimulus. Participants are instructed to indicate the location of this dot as quickly as possible, either via keyboard or response box. Latency is measured automatically by the computer. The fixation cross appears again for several seconds and then the cycle is repeated. Quicker reaction time to the dot when it occurs in the previous location of a threatening stimulus is interpreted as vigilance to threat.
Clinical uses
Researchers have recently begun using a modified version of the dot-probe task to retrain the attentional bias. In this version, the probe replaces the neutral stimuli 100% of the time or the salient stimuli 100% of the time. Over the course of a number of trials the attentional bias for salient stimuli can be reduced or enhanced. This method of retraining the attentional bias is called attentional retraining.
