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Personal values colour understanding of sentences within milliseconds
27 July 2009
Universiteit van Amsterdam (UVA)
Moral-ethical and political beliefs colour the way people read opinion questions. This ‘colouring’ process takes place well before people become aware of their answers to such questions. This phenomenon was recently discovered through brain measurements conducted by researchers from the Max Planck Institute for Psycholinguistics and the universities of Amsterdam and Utrecht. The results of their research will be published in the scientific journal Psychological Science (available on-line July 27).
The researchers based their questions on existing political programmes from a range of parties. Questions focused on issues such as euthanasia, abortion, sperm donation, the legal sale of marihuana, gay marriage and women’s emancipation. Researchers had participants read sentences such as ‘I find euthanasia an acceptable practice’ or ‘I think the growing emancipation of women is a negative trend’. The researchers found that evaluative words such as ‘acceptable’ or ‘negative’ triggered an almost immediate response in the brain. The response differed depending on the participants’ views on the issue in question.
Brain responds rapidly and intuitively
The researchers conclude that existing views and beliefs influence our understanding of language before we even fully process a sentence. This research sheds new light on the way the human brain processes language: instead of reading carefully before forming an opinion, the brain responds intuitively within a mere 200 milliseconds of having more or less grasped what the sentence fragment read so far is suggesting. This response then influences further interpretation. In addition to its significance to language researchers, the study also opens up new avenues for scientific research on how political and ethical beliefs affect our thought processes.
In the EEG experiment, two groups of participants with diametrically opposed value systems (orthodox Christian versus non-Christian) assessed statements on a scale ranging from ‘agree’ to ‘disagree’. The statements had been selected to evoke highly different responses from the two groups. Participants’ brain responses were measured as they read the questions (before actually answering them) by means of electroencephalography (EEG, ‘brain waves’). As it turned out, the brain’s response varied depending on whether the statement agreed or clashed with the reader’s value system. Words indicating that the sentence would most likely be at odds with the person’s core beliefs (such as ‘I find euthanasia an acceptable ...’ for strict Christian respondents) evoked two characteristic EEG brain waves: the LPP effect (‘Late Positive Potential’) and the N400 effect. The LPP brain wave signifies an emotional response, evoked in previous studies mainly by means of emotionally charged pictures. The N400 effect is a well-known brain response to an unlikely or impossible meaning (for example, ‘I’m drinking a pizza’). Unlike previous studies, the effect here was determined by the participant’s political and ethical beliefs: statements that were entirely acceptable to one participant proved problematic for others, evoking a strong emotional response. This effect of personal value systems had never been identified before.
At odds with standard models
Another surprise was the speed with which the effect could be identified in the EEG: the first brain response could be seen within a mere 200 milliseconds (one fifth of a second), counting from the first word in the sentence that indicated that the sentence was going in the ‘wrong’ direction, given the particular participant’s value system. Contrary to what is often thought in the scientific community, brain processes relating to beliefs, views and emotions are activated extremely rapidly as we read - so quickly, in fact, that they can immediately affect our understanding of language. These new insights into the near-instantaneous influence of personal values on our understanding of language are at odds with current standard models for language comprehension. The findings may also be relevant for the development more effective questionnaires, and for scientific research on belief systems.
The researchers also identified an effect relating to the strength of our moral-ethical and political beliefs. In accordance with normal questionnaire procedures, respondents were asked to indicate the extent to which they agreed with specific statements (slightly/strongly). The ‘unlikely meaning’ response (N400) could only be clearly identified when participants were given a statement they strongly disagreed with. Further studies will have to be conducted to identify the exact cause of this phenomenon.