310 likes | 913 Views
Sensory Processing. Bottom-Up (Data-Based):Analysis that begins with the sense receptors and works up to the brain's integration of sensory information.Top-Down (Knowledge-Based):Information processing guided by higher-level mental processes, as when we construct perceptions drawing on our exp
E N D
1. The Perceptual Process
2. Sensory Processing Bottom-Up (Data-Based):
Analysis that begins with the sense receptors and works up to the brain’s integration of sensory information.
Top-Down (Knowledge-Based):
Information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experiences and expectations.
3. Sensation and Perception
4. Three Steps in the Sensation and Perception of a Stimulus
5. Sensory Reception
6. A Variety of Sensory Receptors
7. Some Animals are Able to Sense Stimuli that Humans Cannot
8. A Sensory Transducer
9. Generator Potential
10. Sensory Adaptation Adaptation:
A reduction in response caused by prior or continuing stimulation
11. Coding
12. Stimulus Intensity Coding
13. Stimulus Type Coding
14. StimulusLocation Coding
15. Sensory Stimuli Summation Across Levels
16. Early Philosophy of Perception Heraclitus (540–480 BC):
“You can never step into the same river twice.”
One of the first notions of perception.
Everything is always changing
Idea that perceiver cannot perceive the same event in exactly the same manner each time
Perception depends also on the qualities of the observer.
17. Early Philosophy of Perception Democritus (460–370 BC):
The world is made up of atoms that collide with one another, and the sensations caused by these make contact with our sense organs
Perception is the result of the physical interaction between the world and our bodies – So it should be trusted
He had an almost complete trust in the senses.
Idea of primary qualities and secondary qualities
Weight and texture (low level)
All others (higher level)
18. Nativism and Empiricism Nativism: The idea that the mind produces ideas that are not derived from external sources – certain mental abilities must be innate.
Empiricism: The idea that experience from the senses is the only source of knowledge – senses drive human nature.
19. Nativism and Empiricism Descartes (1596–1650):
dualist view of the world:
both mind and body exist
Mind–Body Dualism: Originated by Descartes, the idea positing the existence of two distinct principles of being in the universe: spirit/soul and matter/body
Monism: The idea that the mind and matter are formed from, or reducible to, a single ultimate substance or principle of being
20. Nativism and Empiricism Hobbes (1588–1678):
believed that everything that could ever be known or even imagined had to be learned through the senses
Materialism: The idea that physical matter is the only reality, and everything including the mind can be explained in terms of matter and physical phenomena.
21. Nativism and Empiricism Locke (1632–1704):
sought to explain how all thoughts, even complex ones, could be constructed from experience with a collection of sensations
22. Nativism and Empiricism studied ways in which perception is limited by the information available to us through our eyes
Concluded that all of our knowledge about the world must come from experience, no matter how limited perception may be
23. The Dawn of Psychophysics Weber (1795–1878):
discovered that the smallest change in a stimulus, such as the weight of an object, that can be detected (Weber Fraction) is a constant proportion of the stimulus level—“Weber’s Law”
Two-Point Threshold: The minimum distance at which two stimuli (e.g., two simultaneous touches) can be distinguished
JND (Just Noticeable Difference)/Difference Threshold: The smallest detectable difference between two stimuli, or the minimum change in a stimulus that can be correctly judged as different from a reference stimulus. Also known as difference threshold
24. The Dawn of Psychophysics Fechner (1801–1887):
invented Psychophysics: The science of defining quantitative relationships between physical and psychological (subjective) events
Pioneering work relating changes in the physical world to changes in our psychological experiences
25. Fechner’s Law A principle describing the relationship between stimulus magnitude and resulting sensation magnitude.
States that the magnitude of subjective sensation increases proportionally to the logarithm of the stimulus intensity (S = k log R).
Suggests that your psychological experience of an energy increases less quickly than the actual physical stimulus.
26. Signal Detection Theory A theory stating that the detection of a stimulus depends both on the participant’s sensitivity to the stimulus and on the participant’s response criterion.
27. Methods of Measuring Sensation: Method of Constant Stimuli
28. Methods of Measuring Sensation: Method of Limits
29. Methods of Measuring Sensation: Method of Adjustment
Similar to method of limits but in this case, the subject steadily increases or decreases the intensity of the stimulus until they detect or fail to detect the stimulus.
30. Methods of Measuring Sensation: Magnitude Estimation