Attentional bias is the tendency for a person's perception to be affected by selective factors in their attention. Attentional biases may explain an individual's failure to consider alternative possibilities when occupied with an existing train of thought. For example, cigarette smokers have been shown to possess an attentional bias for smoking-related cues around them, due to their brain's altered reward sensitivity. Attentional bias has also been associated with clinically relevant symptoms such as anxiety and depression.
In decision making A commonly studied experiment to test for attentional bias is one in which there are two variables, a factor (A) and a result (B). Both can be either present (P) or not present (N). This results in four possible combinations:
Both the factor and result are present (AP/BP) Both the factor and result are not present (AN/BN) While the factor is present, the result is not (AP/BN) While the result is present, the factor is not (AN/BP)
The four combinations can be shown in table form as follows:
A present (A) A not present (A') B present (B)AP/BPAN/BP B not present (B')AP/BNAN/BN
A common question which follows the structure of the above experiment is: "Does God answer prayers?" Due to attentional bias, theists tend to say "yes". They focus on the present/present (A/B) cell, as their religious beliefs in a deity cause them to fixate on the occasions when they were given what they asked for, thus they use the justification: "Many times I've asked God for something, and he's given it to me." Similarly, due to attentional bias, atheists equally tunnel on data from the present/absent (A/B', A'/B) cells: "Has God ever given me something that I didn't ask for?" or "Have I asked God for something and didn't receive it?" This experiment too supports Smedslund's general conclusion that subjects tend to ignore part of the table depending on their specific attentional biases.
The scenarios can be illustrated below in a similar table to above:
Asked God for A (A) Did not ask God for A (A') A was fulfilled (B)A/BA'/B A was not fulfilled (B')A/B'A'/B'
When making decisions, attentional biases toward positive stimuli have been associated with numerous positive outcomes, such as increased social engagement, increased prosocial behaviour, decreased externalizing disorders, and decreased emotionally withdrawn behavior. In contrast, individuals with clinically relevant symptoms, such as anxiety disorder and chronic pain are shown to prioritize threat cues over reward cues. In one experiment, faces with varying valences were presented (neutral, threatening, and happy) with a forced-choice reaction time at two exposure durations, 500 and 1250msec. For individuals with high trait anxiety, there was strong evidence for an attentional bias favoring threatening facial expressions. Additionally, increased dysphoria correlated with the tendency to avoid happy faces. This tendency leads to a spiraling effect, as one will only see negative faces, which induces greater anxiety, which exacerbates the aforementioned tendency to avoid positive stimuli – a form of the vigilance-avoidance pattern.
Notably, there is also a difference in attention biases between anxious and depressed individuals. Word pairs were shown to the subjects, with a dot probe following a word of each pair (dot probe paradigm). One-half of the word pairs were presented on the subliminal level, and the other half were presented on the supraliminal level, and then the response time was measured. As expected, the anxious and depressed groups showed an attentional bias towards negative words compared to the normal control group. On a supraliminal level, the depressed group showed greater vigilance for threat stimuli than the anxious group. However, for subliminal threat stimuli, the anxious group showed a greater vigilance, which implies an anxiety-related bias on the subconscious level.
In addictive behaviour Research from the past two decades has established that addictive behaviour is strongly correlated to the attentional bias for substance-related cues, in how the latter characterizes the former. An example of this is smoking and smoking-related cues.
Research (using the Stroop paradigm) tested the effect of mixing smoking related words (cigarette, puff, and smoke) with: negative connoting words (sick, pain and guilty), positive connoting words, (safe, glad, and hopeful) and neutral connoting words (tool, shovel, and hammer). Results showed a strong correlation between a slower reaction time and the degree of negative language employed when discussing smoking. The results indicate attentional bias, suggesting the influence negative language has had on the individual attitude towards smoking. When asked to think of the negative consequences of smoking, as the negative language evoked underlying negative feelings toward smoking, they displayed fewer cravings than the smoker subjects who were encouraged to smoke. The experiment illustrates the influence of attentional bias on environmental smoking cues and how these could contribute to a smokers' inability to quit. As stated earlier individuals' attentional biases are influenced by subliminal stimuli, so in the smoker's case, they are more subject to substance-related stimuli such as observing other smokers or noticing ads for cigarettes. The stimuli evoke expectancy of substance availability, which creates a further attentional bias for substance-related stimuli and induces craving for the substance.
Similar Stroop paradigm studies have concluded that attentional bias is not dependent on smoking itself, but rather the person who is the smoker displays attentional bias. A recent study required one group of smokers to refrain from smoking the night before and another less than an hour before. Abstinence from smoking created a slower reaction time, but a smoke break between study sessions showed increased reaction time. Researchers say this shows that nicotine dependence intensifies attention, but does not directly depend on smoking itself due to lack of evidence. The longer reaction time suggests smokers craving a cigarette linger on smoking-related words. Smokers and smokers attempting to quit displayed the same slower reaction time for smoking-related words, which supports research that implies attentional bias is a behavioral mechanism versus a dependency mechanism, due to the fact that the smokers were slowed down by smoking-related words and negative words, but not slowed down by positive and neutral words.
Drug addiction is also an example of attentional bias in that certain memories or objects can prompt intense cravings for one's drug of choice. It is easier for individuals who experience this to relapse and begin their drug use again, because the urges given off by that initial stimuli can prove to be too strong to curb. There are some ways that individuals could overcome attentional bias, and a solution is stimuli-related therapy. This type of therapy would give those struggling with addiction and relapse an opportunity to overcome the initial fear associated with a particular object. A study conducted by a group of researchers in the Netherlands found that by giving participants an opportunity to attend therapy sessions during their treatment for drug addiction, more participants remained drug-free compared to those who relapsed.Marissen, M. A. E., Franken, I. H. A., Waters, A. J., Blanken, P., van den Brink, W., & Hendriks, V. M. (2006). Attentional bias predicts heroin relapse following treatment. Addiction, 101(9), 1306–1312. Therefore, the conclusion can be drawn that with exposure therapy, the number of patients who will leave a treatment facility and relapse decreases. The Stroop Test also showed in this study that between the control group and the treatment group the only major component of the test was time; researchers made the claim that those who received treatment reacted a lot faster to certain drug-related stimuli versus those in the control group who did not. This means that when experiencing attentional bias, treated addicts seemed to brush off the memories a little easier compared to those who had not received proper treatment. In other words, certain steps need to be taken in treatment facilities across the country to ensure that drug addiction no longer rises, or continues to ruin people's lives. Also, a therapy of this kind should be closely monitored and mandatory to ensure the smallest number of relapses occur after treatment.
In body image disturbance There is evidence that people with body image disturbance show attentional biases related to body size and food. For example, people with anorexia nervosa tend to direct their attention disproportionately towards thin bodies. Attentional bias towards thin bodies has also been reported in non-clinical samples, with individuals with higher levels of body dissatisfaction disproportionately attending to thin bodies.
Measurements There are two different forms of attentional bias that can be measured:
Within-subject bias When there is a significant difference between an anxious individuals' attention bias towards threat-related stimuli and attention bias towards neutral stimuli (which usually favors threat-related stimuli)
Between-subject bias When there is a significant difference between non-anxious and anxious individuals' attention bias towards and neutral stimuli and threat-related stimuli
Measurement paradigms There are four main paradigms used to measure attentional bias:
Stroop paradigm The Stroop paradigm was the first measure of attentional bias. It also uses reaction time, only in this case utilizing colors. The subject would have to read the color of the word (e.g. brown), however, the name of the word would be a different color (e.g. red). Variations involve the opposite, where one would have to read the name of the word, but the color of the word would differ.
Dot-probe paradigm The dot-probe paradigm/task is the gold standard in attentional bias research, considered an upgraded version of the dot-probe paradigm. Two stimuli of difference valences are presented simultaneously for a fixed time. Then, a probe replaces one of the two stimuli, which the participants have to respond to – by classifying the probe or responding to the location.
Posner paradigm The Posner paradigm or Posner cueing task is similar to the dot-probe paradigm. It is a sight test, which assesses the individual's ability to switch and focus on different stimuli presented. The subject focuses on a specific point, then attempts to react as quickly as possible to target stimuli presented to the sides of the specified point.
Visual search paradigm The visual search is a less used method of assessing attentional bias. It involves measuring one's ability to spot and discern particular objects among other objects.
While the other options are valid methods, they all tap into different aspects of attention bias. Because of this, some methods are less used when looking into specific aspects of attentional bias. For example, in a posner cueing task, the cues were either a neutral, angry or happy, facial expression. There were both valid (targets appearing in the same location as the cue/face) and invalid trials (The target appearing in a different location to the cue/face). Surprisingly enough, in the invalid tests, individuals' response times increased to the same degree of attentional bias for both negative stimuli and positive stimuli, contrary to hundreds of other studies.
Mechanisms