ggapp5 - Sensation I Introduction 1 Sensation Process that...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Sensation I. Introduction 1. Sensation - Process that helps us to detect physical energy from the environment and encode it as neural signals 2. Perception – a process where we select, organize and interpret our sensations 3. Bottom-up processing - sensory analysis at the entry level 4. top-down processing - constructing perceptions drawing both on sensations coming bottom-up to the brain and on our experience and expectations 5. prosopagnosia – losing a temporal lobe area essential to recognizing faces II. Sensing the world: Some Basic Principles A. Thresholds 1. psychophysics - the study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them 2. Absolute thresholds 3. Awareness of faint stimuli 4. The minimum stimulation necessary to detect a particular stimulus (light, sound, pressure, taste, odor) 5. signal detection theory – predicts when we will detect weak signals, measured as our ratio of “hits” to “false alarms” 6. absolute thresholds vary 7. different people respond differently to different stimuli based on experience, expectation, motivation and alertness 8. subliminal stimulation 9. below one’s absolute threshold for conscious awareness 10. most people do perceive such stimuli 11. does not effect one’s belief in them, although 12. difference threshold 13. the minimum difference between two stimuli required for detection 50 percent of the time 14. aka the just noticeable difference 15. difference threshold increases with the magnitude of the stimulus 16. Weber’s law - the principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage 17. Weber’s principle - our thresholds for detecting differences are a roughly constant proportion of the size of the original stimulus B. Sensory Adaptations our diminishing sensitivity to an unchanging stimulus if our eyes were not constantly in motion, the stimulus would fade and we would see nothing II. Vision 1. Transduction – the process by which our sensory systems convert stimulus into neural messages 2. The Stimulus Input : Light Energy 3. wavelength - the distance from one wave peak to the next 4. hue – the amount of energy in light waves (determined by wave’s amplitude, or height) A. The Eye 1. light enters through the cornea 2. passes through the pupil - the adjustable opening in the center of the eye through which light enters 3. iris – a color muscle surrounding the pupil, that regulates the amount of light entering the eye
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
4. lens - behind the pupil – focuses the incoming rays into an image on the eye’s light-sensitive back surface 5. accommodation – process which changes light’s curvature 6. retina – the eyeball’s light sensitive surface on which rays focus 7. acuity - sharpness of vision is affected by small distortions in the shape of the eye 8. nearsightedness – a condition in which nearby objects are seen more clearly than distant objects
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 6

ggapp5 - Sensation I Introduction 1 Sensation Process that...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online