Psychology 2115A/B Lecture Notes - Lecture 2: Absolute Threshold, Psychophysics, Perseveration

• School: Western University
• Department: Psychology
• Course: Psychology 2115A/B
• Professor: Prof

Document Summary

What is the minimum amount of intensity that the stimulus needs to have until you can sense the stimulus- detection: this is called the absolute threshold. Minimum difference needed to perceive two different stimulus- Discrimination: the just noticeable difference, the jnd . Able to test for the absolute threshold by graphing the probability that you will react to a stimulus given, the probability will stay zero until you react to the stimulus, thus crossing the absolute threshold. Fechner came up with two ideas: 1. The method of limits: you take a stimulus, weak intensity- subject will most likely say that they have not perceived it. Over time slightly increase the stimulus until the subject perceives that stimulus (crossed the absolute threshold) Always alternate series, starting from hearing the stimulus until you cant, and then starting from not being able to hear the stimulus until you can. Errors of perseveration: will say no or yes longer then they should (keeps going)