Psychology ch.3
Perceptual Constancies
Acquired through experience; creates stability - Size Constancy - Color Constancy - Brightness Constancy - Shape Constanc
Optic Nerve
Axons of ganglion neurons form optic nerve - Conducts sensory input to brain (occipital lobe)
inner ear
Cochlea • Basilar membrane • Organ of Corti
Complementary Colors
Colors across from one another on color wheel - Mix complementary colors = gray
prostagandis
Facilitate transmission of pain message - Heighten circulation to injured area (inflammation) - Pain-relieving drugs inhibit production of prostaglandins - Emotional response and response to stress affect degree of pain
outer ear
Funnels sound waves to the eardrum
loudness
Height (amplitude) of sound waves - Expressed in decibels (dB)
Retina
Light Sensitive Surface,Photoreceptors - Rods, Cones, Bipolar and ganglion cell
locating sounds
Loudness and sequence in which sounds reach the ear provide cues - May turn head to clarify information
Just noticeable difference (JND)
Minimum difference a person can detect
Difference Threshold
Minimum difference in magnitude of two stimuli required to tell them apart - Detected 50% of the time
Desensitization
Negative adaptation - Process by which we become less sensitive to stimuli that remains the same
Sensitive areas of the body
Nerve endings are more densely packed - More sensory cortex is devoted to perception of sensations in those areas
gate theory of pain
Nervous system can only process a limited amount of stimulation - Rubbing the pained area competes for neural attention - Closes the "gate" on pain messages to the brain
pain
Nociceptors in skin are stimulated - Pain is usually sharpest where nerve endings are densely packed - Pain can be felt deep within body - No nerve endings for pain in the brain
Trichromat
Normal color vision
smell
Odors trigger receptor neurons in olfactory membrane
Subliminal Stimulation
Sensory stimulation that is below a person's absolute threshold for conscious perception - Visual stimuli flashed too briefly to be processed - Auditory stimuli played a volume too low to consciously hear or played backward
- Active touching
Skin sensory receptors fire when skin surface is touched
Sound
Sound waves require a medium; air or water • Sound waves compress and expand molecules of the medium, creating vibrations - A single cycle of compression and expansion is one wave of sound
Weber's constant
Standard of difference
Signal-Detection Theory
Stimulus characteristics and psychological factors interact to influence whether a stimulus is detected.
taste
Taste is sensed through taste cells - Receptor neurons on taste buds
Opponent-Process Theory
Three types of color receptors • Respond to red or green, blue or yellow, or light or dark • Cannot respond to both at simultaneously
Perception of Motion
Visual perception of motion is based on change of position relative to other objects
Absolute Threshold
Weakest amount of a stimulus that can be distinguished from no stimulus at all - Detected 50% of the time
Spectrum of electromagnetic energy
Within visible light, color is determined by wavelength • The height of a wave gives us it's intensity (brightness). • The length of the wave gives us it's hue (color). • ROY G BIV • The longer the wave the more red. • The shorter the wavelength the more violet.
the human ear
is sensitive to sound waves with frequencies of 20 to 20,000 cycles per second
Iris
muscle; colored part of the eye
Pupil
opening in the iris • Sensitive to light and emotion
Perception
process by which sensations are organized and interpreted to form an inner representation of the world.
odors
sample molecules of substances in the air
sensation
stimulation of sensory receptors and transmission of sensory information to the central nervous system.
Cornea
transparent eye cover
Gestalt Rules of Perceptual Organization (6)
• Figure-Ground • Proximity • Similarity • Continuity • Closure • Common Fate
Sensation/perception
• Sensation is a mechanical process • Perception is an active process - Involves knowledge, expectations, and motivations
Lens
- Changes in thickness for focusing - Image is projected onto retina
Sensorineural deafness
- Damage to inner ear or auditory nerve
conduct deafness
- Damage to middle ear - Hearing aids can help
middle ear
- Eardrum, hammer, anvil and stirrup - Acts as an amplifier - Oval window - Round window
pitch
- Frequency (# of cycles per second) - Expressed in hertz (Hz) - Pitch of women's voice is higher than men's
Müller-Lyer Illusion
- Interpret length of lines based on experience
Cones
- Most densely packed in center of retina (fovea) - Provide color vision
Dichromat
- Partial color blindness - Difficulty in discriminating between two colors - More common in males (sex linked trait)
Monocular Cues
- Perspective - Relative size - Clearness - Overlapping - Shadows - Texture gradient - Motion parallax
volley principle
- Pitch is discriminated through alternate firing of neurons
Illusions of movement
- Stroboscopic motion
four primary taste quality
- Sweet, sour, salty and bitter - Umami (fifth basic taste) - savory
Trichromatic Theory
- Three types of cones • Respond to red, green, or blue
Monochromat
- Totally color blind
the ear
- capture sound waves - vibrate in sympathy with them - transmit auditory information to the brain
phantom limb pain
2 out of 3 combat veterans with amputated limbs report phantom limb pain - May involve activation of nerves in the stump of missing limb - May also involve reorganization of motor and somatosensory cortex
Hering-Helmholtz Illusion
Perceive drawing as three-dimensional
Afterimage
Persistent sensations of color are followed by perception of the complementary color when the first color is removed
• Light is the source of all colors
Pigments reflect and absorb light selectively
place theory
Pitch is sensed according to place that vibrates
frequency theory
Pitch perceived on stimulation of impulses that match the frequency of the sound
Sensitization
Positive adaptation - Process by which we become more sensitive to stimuli of low magnitude
Adaptation to bright light
Process occurs within a minute or so
Dark adaptation
Process of adjusting to lower lighting • Cones reach maximum adaptation in about 10 minutes • Rods continue to adapt up to 45 minutes
Visual Perception
Process used to organize sensory impressions caused by the light that strikes our eyes
Rods
Provide vision in black and white - More sensitive to dim light than cones
temperature
Receptors are located just beneath the skin - Skin temperature increases - receptors for warmth fire - Skin temperature decreases - receptors for cold fire
perception of loudness
Related to number of receptor neurons on the organ of Corti - Sounds are perceived as louder when more sensory neurons fire
Binocular Cues
Retinal disparity - Convergence
Kinesthesis
Sense that informs you about the position and motion of your body - Sensory information is sent to the brain from sensory organs in joints, tendons and muscles • Housed mainly in semicircular canals in your ears • Monitor your body's motion and position in relation to gravit