Extrinsic Affective Simon Task (EAST)

Background

The Extrinsic Affective Simon Task (EAST) is a cognitive-behavioral test designed to measure a person's automatic, implicit attitudes or biases toward specific concepts, objects, or social groups. It was developed by psychologist Jan De Houwer in 2003 as an alternative to the widely known Implicit Association Test (IAT).

Unlike the IAT, which requires participants to switch between different categorization rules in different blocks of trials, the EAST measures associations within a single mixed block. The basic task of the EAST is to categorize stimuli (e.g. flowers vs. insects) based on completely neutral features such as their color, e.g. using the Q-key for 'green' and the P-key for 'blue' words. Crucially, during a training block where participants categorize white-colored affective words such as 'health' (positive valence) or 'mean' (negative valence) with the Q-key (positive) and P-key (negative), the response keys are conditioned to be the 'Good' key (Q) and the 'Bad' key (P). The main measure of the test is then to compare response times for the different target categories when they are presented in 'green' (associated with 'Good' key) vs. when they are presented in 'blue' (associated with 'Bad' key). The idea is that when a concept is implicitly associated with 'negativity' in a person's mind, participants would take a measurable longer time (and potentially make more errors) to categorize these stimuli when they are printed in 'green' and require the 'good' key. Differences in reaction time to categorize items of the same target category correctly with the 'good' and 'bad' response keys (depending on their color) are therefore used to calculate EAST scores separately for each target category. Latencies of trials that required the positive key are subtracted from latencies that require the negative key. Positive EAST scores indicate that participants were faster to categorize items of the same category with the positive than with the negative response keys and thus positive EAST scores are interpreted to indicate a positive attitude towards that category. Negative EAST scores suggest the opposite. Because EAST scores are computed separately and independently for each tested concept, the EAST can be be used to test attitudes towards single concepts.

The Millisecond EAST script is written as a template and uses the simple target categories 'positive' and 'negative' words. These target categories can easily be exchanged for others.

Task Procedure

The Millisecond EAST procedure starts out with two practice blocks. The first practice block runs 20 trials with 10 white-colored positive words and 10 white-colored negative words, presented in random order. Participants are asked to categorize the positive words with the Q-key and the negative words with the P-key (Note that response key assignment can be counterbalanced). This practice block is crucial to associate the Q-key with 'good' and the P-key with 'bad'. In a second practice block of 20 trials, participants practice the color assignments and are asked to categorize 5 target category1 (here: positive) green-colored words, 5 target category1 (here: positive) blue-colored words, 5 target category2 (here: negative) green-colored words and 5 target category2 (here: negative) blue-colored words (all presented in random order). Participants are asked to sort words by using the 'Q' key (the 'good' key) for green words and the 'P' key (the 'bad' key) for blue words. The test runs 3 blocks of 30 trials each. Each test block runs a mixture of white (affective) words (to be categorized by valence as during the first practice block) and colored words. Specifically, each test block runs 5 positive white words (positive attribute words), 5 negative white words (negative attribute words), 5 target category1 (here: positive) green words, 5 target category1 (here: positive) blue words, 5 target category2 (here: negative) green words, and 5 target category2 (here: negative) blue words; all in random order. Each trial starts with a fixation stimulus for 350ms, followed by the word. The word is presented until a categorization response is made. Error feedback (if applicable) is presented for 400ms. Each trial ends with a blank 200ms intertrial interval.

What it Measures

The Extrinsic Affective Simon Task (EAST) measures implicit attitudes

Psychological domains

• Implicit Cognition: Cognitive Processes not under conscious control
• Social Cognition: People's thoughts and perceptions of themselves and others in the social world

Main Performance Metrics

• EAST Scores, separately for each category: Categorization latency difference scores to positively-keyed and negatively-keyed stimuli; positive scores signify a positive bias

Psychiatric Conditions

The EAST is used with the following patient groups

• Depression
• Anxiety
• Trauma and Phobias
• Substance Abuse
• Eating Disorders

References

Search Google Scholar for peer-reviewed, published research using the Inquisit Extrinsic Affective Simon Task (EAST).

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De Houwer, J. (2003). The Extrinsic Affective Simon Task. Experimental Psychology, 50, 77-85.

De Houwer, J., Crombez, G., Kostner, E. H. W., De Beul, N. (2004). Implicit alcohol-related cognitions in a clinical sample of heavy drinkers, 35, 275-286.

Huijding, J., de Jong, P. J. (2005). A Pictorial Version of the Extrinsic Affective Simon Task: Sensitivity to Generally Affective and Phobia-Relevant Stimuli in High and Low Spider Fearful Individuals. Experimental Psychology, 52, 289-295.

Ellwart, T., Becker, E. S., Rinck M. (2005). Activation and measurement of threat associations in fear of spiders: an application of the Extrinsic Affective Simon Task. Journal of Behavior Therapy and Experimental Psychiatry, 36, 281-299.

Schmulke, S. C & Egloff, B. (2006). Assessing Anxiety with Extrinsic Simon Tasks, Experimental Psychology, 53, 149-160.

De Jong, P. J., Wiers, R. W., van de Braak, M. Huijding, J. (2007). Using the Extrinsic Affective Simon Test as a measure of implicit attitudes towards alcohol: Relationship with drinking behavior and alcohol problems, 32, 881-887.

Voss, A & Klauer, K. C. (2007). Cognitive Processes in the Extrinsic Affective Simon Task: A Task-Set Switching Account of EAST Effects. Experimental Psychology, 54, 71-82.

Vancleef, L. M. G., Peters, M. L., Gilissen, S. M. P., De Jong, P. J. (2007). Understanding the Role of Injury/Illness Sensitivity and Anxiety Sensitivity in (Automatic) Pain Processing: An Examination Using the Extrinsic Affective Simon Task. The Journal of Pain, 8, 563-572.

Stahl, C. & Unkelbach, C. (2009). Assessing Automatic Activation of Valence: A Multinomial Model of EAST Performance . Experimental Psychology, 54, 99-112.

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