PSYCH TEST2 study guide

PSYCH TEST2 study guide - Chapter5Sensation...

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Chapter 5- Sensation How do we construct our representations of the external world? Sensation : we detect physical energy (a stimulus) from the environment and convert it into neural symbols Perception : the process of organizing and interpreting sensory info, enabling us to recognize meaningful objecs Bottom-up Processing - Analysis of the stimulus begins with the sense receptors and works up to the level of the brain and mind Top-Down Processing - Info processing in guided by higher- level mental processes as we construct perceptions, drawing on our experience and expectations. Making Sense of Complexity - Our sensory and perceptual processes work together to help us sort out complex images Sensing the World Senses are nature’s gift that suit an organism’s needs. - we as human beings are sensitive to sound frequencies that represent the range of human voice. - We also can have damage to our specialized detectors Prospagnosia and the fusiform face area Exploring the Senses Psychophysics - A study of the relationship between physical characteristics of stimuli and our psychological experience with them (Light Brightness, Sound Volume, Pressure Weight, Sugar Sleep) Absolute Threshold - Minimum stimulation needed to detect a particular stimulus 50% of the time Subliminal Threshold - When stimuli are below one’s absolute threshold for conscious awareness Difference Threshold - Minimum difference between two stimuli required for detection 50% of the time, also called just noticiceable difference (JND) Weber’s Law - 2 stimuli must differ by a constant min percentage (rather than a constant amount), to be perceived as different Signal Detection Theory (SDT)- Predicts how and when we detect the presence of a faint stimulus ( signal ) amid background noise (other stimulation). SDT assumes that there is no single absolute threshold and detection depends on: Person’s experience, Expectations, Motivation, Level of fatigue Sensory Adaptation- Diminished sensitivity as a consequence of constant stimulation (put a band aid on your arm and after awhile you don’t sense it) Now you see, now you don’t Saccades - eye jiggle, so you don’t adapt… (taste, smell, hearing, too) Transduction- In sensation, the transformation of stimulus energy into neural impulses Phototransduction - Conversion of light energy into neural impulses that the brain can understand The Stimulus Input: Light Energy Light Characteristics- Wavelength (hue/color), Intensity (brightness), Saturation (purity) Intensity (Brightness) Color Solid - represents all three characteristics of light stimulus on this model The Eye Parts of the eye- Cornea - Transparent tissue where light enters the eye Iris - Muscle that expands and contracts to change the size of the opening (pupil) for light Lens - Focuses the light rays on the retina Retina - Contains sensory receptors that process visual information and sends it to the brain INSERT DIAGRAM OF EYE The Lens Nearsightedness
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This note was uploaded on 04/29/2009 for the course PGS 11653 taught by Professor Kate during the Spring '09 term at ASU.

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PSYCH TEST2 study guide - Chapter5Sensation...

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