PSYCH 100 Lecture Notes - Lecture 5: Retina, Action Potential, Hot Tub

• School: UMASS-Amherst
• Department: Psychology & Brain Sciences
• Course: PSYCH 100
• Professor: Tammy Rahhal

Document Summary

Converting the physical world into a mental representation (transduction) Variations of air pressure ---> experience of sound. The study of the relationship between physical characteristics of stimuli (energy) and our psychological experience of them. Light ---> brightness, sound ---> volume, pressure ---> weight, taste ---> sweetness/bitterness. Absolute thresholds: smallest magnitude of a stimulus that can be reliably discriminated from no stimulus at least 50% of the time. Difference threshold: minimum difference between 2 stimuli that a person can detect at least 50% of the time (just noticeable difference) Signal detection theory: predicts how and when we will detect the presence of a stimulus amidst background stimulation. Complex decision mechanisms are involved to determine if a stimulus exists. Our experiences - expectations, motivation, level of fatigue. Sounds in my house vs. sounds outside (expected a murdered vs. it"s just background noise) Absolute thresholds and difference thresholds are not fixed. Our sensitivity to a stimulus varies based on experiences.