Whether Positive Schizotypy In Non-Clinical Participants Could Predict False Perceptual Experiences.

Psychology Article Assignment

Summary

The primary question in this study was whether positive schizotypy (reports of hallucinatory and delusional-like experiences) in non-clinical participants could predict false perceptual experiences. It was theorized that biases help in the generation of hallucinations or false perceptions (Tsakanikos & Reed, 2005). For example, because a specific thing is present, it triggers associations and provokes images or perceptions based on that bias. Likewise, if an associated event occurred without the trigger, the trigger may have assumed to have been there as the cause, even if it had not been. The experimenter decided to test this with a word detection task in which a sample group of undergraduate students who had normal or corrected-to-normal vision, no psychiatric or neurological history and were on no medication participated. This was to ensure that the medication that most schizophrenic patients would be taking would not invalidate the findings. In measuring the construct of schizotypy, the O-LIFE (the Oxford-Liverpool Inventory for Feelings and Experiences) scale was primarily used in which were four scales of classification: unusual experiences, cognitive disorganization, introversive anaerobia and impulsivity nonconformity. Participants took a survey based on this scale to see their schizotypical potential either before their task experiment of after. Participants were subjected to 64 continuous trials of animated images, half portrayed words and the other half non-words. The letters were white in grey boxes against a black background. These boxes were presented as three dimensional and given the appearance of motion, most notably a looming effect toward the observer. Each animation equaled 74 frames at a rate of 9 frames/s, thus presented in such a way that disallowed the formation of a reasonable response bias Participants were put into individual cubicles with a computer after being randomly assigned to one of two conditions; in the loose condition participants answered "yes" to a real word or "no" to a non-word and in strict condition the real words were read aloud and non-words ignored. Within each condition half of the participants received the psychotypy inventory (survey) and the detection task. The dependent variables were accuracy, false perceptions and false alarms. The most important result was that accuracy was significantly higher in the loose condition than in the strict, but the amount of erroneous responses were lower in strict than in loose, correlating significantly with positive schizotypy. In the end, positive schizotypy was the only significant predictor variable for incorrect "yes" responses (false alarms) and had a weak correlation with accuracy. In summary, participants who portrayed schizotypical tendencies on the survey were more likely to have false perceptions of the words in the trials. From this result, the experimenter concluded that by understanding why people misinterpret what they see to this degree, psychologists would not only be able to improve cognitive-behavioural therapy but allow for early detection and prevention.

Personal Review

If the goal of this experiment was to determine whether positive schizotypy could predict false perceptual experiences in non-clinical participants aged 18 to 24 years, this would have been a much more reliable article. This experiment was not meant to have its results confined to said age group however, rather it was meant to be applied universally. It is with this lack of external validity that I find the experiment to be most flawed. My first point on the matter concerns the characteristics common to this age group, namely that they were all undergraduates. Being an undergraduate, whether in college or university, is a notably stressful part of life as one not only must study and excel in school, but often must work as well thereby taking on more at once than most people do. This busy schedule may lead to less sleep and a greater dependency on not necessarily medicine but caffeine and energy drinks, which can causes further fatigue (Scott, 2006). On top of balancing work and school, there is the traumatic event of moving to another city away from home and it should be noted that the process of moving causes as much stress as might the death of a family member (Dion, 2005). The average age of the participants was 19 years, meaning they were most likely in their first year of school, which only amplifies the mentioned stressors. It is not unusual for people to show what may be referred to as positive schizotypical characteristics temporarily when severely stressed (Barlow & Durand & Stewart, 2006) but the experimenter said that the strongest correlation was with positive schizotypy and false alarm; thinking a non-word was a word after being shown it at a rate of 9 frames/s can easily be attributed to one of the mentioned stressors. Although each participant was given a survey to test their schizotypical potential and the ones who reported more schizotypy were at greater risk of giving erroneous answers, it never specified in the experiment whether the survey asked them when they started to display the tendencies. Since schizophrenic symptoms do not necessarily start from youth, it is most likely that the survey would have asked if they had experienced schizotypy fairly recently (within the past year or two), as that would be the most relevant time period. Yet with the age group being primarily 19 year olds, they still could be said to have developed the symptoms as a result of their undergraduate life.

Concerning the conclusion drawn from the results, I have some disagreements with it. The experimenter states that by understanding the mechanics of these false perceptions psychologists will be better able to catch schizophrenia in its early stages and

...