Psychiatry & Psychology--General/Sensation and Perception-thresholds
Hello! This is an introductory psychology question about sensation and perception. In order for a person to detect a stimulus, it must go over the absolute threshold for that sense. Also, in order for a person to notice the difference between two similar stimuli--for example, between a bell at 12 decibels and one at 14 decibels-- the stimuli must exceed a difference threshold. My question is, is it possible for an individual to increase these thresholds? Thanks.
I think you're asking if you could learn to perceive a stimulus that was below the ab. thresh. (or a "jnd" that was under the diff. thresh.) Interesting question in the realm of psychophysics.
The simple answer is that insofar as the thresholds are physiological, no. As an example, our eyes perceive a certain range of visual wavelengths because our photoreceptors respond chemically within that range only. No amount of training, diet supplements, hypnosis, motivation, etc., can change the physics of your retina.
However, suppose "thresh" is defined in practical as opposed to physiological terms. Let's suppose at 100 lbs the diff thresh, as measured on a calibration sample is 5 lbs. A blindfolded circus acrobat holds a 100-lb partner on his shoulders. If someone throws a 4-lb hoop to the partner, maybe the acrobat would be able to perceive this sub-threshold added weight through training, attention, ancillary cues, and expectation.
Another complication may involve interpretation, especially if the stimulus is at an upper level. For instance, the touch threshold is the lowest level of touch-stimulus you can perceive. But how about the pain thresh? When does feeling a touch change to feeling pain? Here, many psychological factors can come into play. And if we study, say, pain tolerance, there are still more.
Hope I've answered your query; if not, feel free to send a follow-up.