'Cause your hot then your cold

by kevin chan 2007-47565

In a nutshell, the aforementioned study is about determining at what heat intensity does a subject feel the change in temperature.

After reading the title, “Thermal Perception Thresholds Recording Using Method of Limits Change Over Brief Time Intervals”, the first thing that entered my mind was the ethical constrains the experimenters were faced with (dorky but yes 4 years in psychology will do that to you).

Of course, studying thermal perception is no easy feat. One would have to induce a certain amount of heat to a subject for subjects to feel a warm sensation or conversely, the lack thereof for a cold sensation.

Indeed, subjects were exposed to pain (whether brought about by a hot or a cold stimulus). They were then asked to say at what level is the pain noticeable or manageable. As my initial reaction to the title of the study, ethical dilemmas did arise.

To sum up the methodology and materials, 24 healthy women were placed in an isolated room. A Thermal Sensory Analyzer[TSA] was placed on the thenar eminence of their dominant hand. The TSA was used to both apply thermal stimuli and record

subjects responses using a method of limits algorithm. A rate of 5^O C/s was applied. The subjects went through the following groups in random order: cold sensation (were to press a button as soon as they felt a change in temperature), warm sensation (similarly, had to press a button as soon as they felt a change in temperature), cold pain (were to press a button until it becomes painful) and hot pain (similarly, were to press a button until it becomes painful). Pressing the button stopped the stimulus and returned the thermode to the baseline. The thresholds of each sensation was tested three times with a 6-8 s rest period. Separate two-way ANOVAs was used to analyze the data.

It is important to note however that their methodology was approved by The Queen Margaret University College Ethics committee. Even so, any experiment involving pain was, is still and will forever raise serious question. Introducing pain in a study has detrimental ramification that needed to be addressed.

For example, it is commonplace that people who participate in experiments involving pain are paid after doing so. After reading the experimenters methodology, it seems that the subjects did not get a token for their participation. What did they get in return? Yes they signed an informed consent but what did that consent say? Were they free to back out of the experiment at any point? Were they bound by the consent to finish the study? I am personally in the service of the discipline of psychology but at what lengths would psychology to through for new knowledge.

Emphasis here on new knowledge. The researchers submit to the fact that many a man, or researcher for that matter, has already studied thermal perception threshold. Their only rationale is that past studies all involve studying it over a long time interval. The research at hand, however, studies thermal perception threshold at a brief time interval. I personally think that the researchers failed to explain if there is such a leap from long time intervals (past studies had approximately up to 7-8 days) to their brief time interval methodology (of 6-8 seconds). I was disappointed to see an elaborate explanation explaining this in hopes to justity the need for another pain related experiment.

On a positive note, it is important to note that the journal seemed to not only cater to psychologist but to the general public as well. The researchers explained the concept of method of limits in the literature obviously aimed at readers who do not have a background in psychology. I would honestly not know the concept of the methods of limits if I did not take an undergraduate course in psych (hi sir diwa!).

Indeed, the general public will be able to understand such highfaluting concepts. But then again, who reads journals such as these anyway? Wouldn’t it be psychologist themselves? Or maybe the brainiac aliens from another galaxy? Hence why the need for such explanation? I don’t think the average Juan would read Somatosensory and Motor Research, the journal where the study was obtained.

For a psychologist reading the study (or a student in psychology for that matter). The study is very much complete up to the last detail. The review of related literature is concise yet adequate. There were no stray paragraphs that were off topic to the study. The methodology was meticulous in describing the instruments, procedures, variables and statistical measures (they used ANOVAs). The results are complete with graphs and figures which are comprehendible through visual inspection. The only drawback is that there was not sufficient recommendations said for future replications.

The only recommendation was found in the abstract. In the abstract, I did not feel the need for the statement, “In research trials exclusion of a control group would be a fundamental flaw.” I feel that though it seems the paper appeals to the laymen, this statement is pretty obvious that it should not be included in the abstract. The way that it was stated makes it sound so preachy, as if a professor was lecturing to his class. Such a statement could be more appropriate for the discussion or conclusion but ultimately not in the abstract (or in the review of literature as what the researchers did). This is probably the researcher’s recommendation but I feel that it is lost. It did not seem like a recommendation since it was shown in the abstract and in the review of literature.

Another good point of the study was that it related all its findings with past studies. This gives the reader a good sense of comparison with past studies.

On a final note, the study does have positive and negative points. The study caters both to psychologist and the general public a like. It was able to address some of my issue (pain dilemma, etc) but I still have issue that seemed unresolved (such as the recommendations, etc).

Source: Palmer, S. & Martin, D. (2005). Thermal Perception Thresholds Recorded Using Method of Limits Change Over Brief Time Intervals. Somatosensory and Motor Research. 22(4): 327-334