PSYCH 100 Lecture Notes - Lecture 9: Basilar Membrane, Detection Theory, Absolute Threshold

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

Document Summary

Converting the physical world into a mental representation (transduction) And relaying that info to the brain (conduction) Variations of air pressure experience of sound. We distinguish black from white in a picture. Smallest magnitude of a stimulus that can be reliably discriminated from no stimulus at lease. Physical characteristics of stimuli (energy) and our psychological experience of them. Ex: being able to smell a drop of perfume. Minimum difference between two stimuli that a person can detect at least 50% of the time. 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. Based on both: stimulus strength, our experiences: expectations, motivations, level of fatigue. Sounds in my house (we hear when we"re alone) Point: absolute threshold and just noticeable differences are not fixed. Our sensitivity to a stimulus varies based on experiences. Factors that affect absolute & difference thresholds: chance variation.