Unit V & VI Notes:
Unit V: Sensation and Perception:
Sensation: your window to the world.
Bottom up Processing: analysis that begins with the sense receptors and works up to the brains integration of sensory information.
Top down Processing: information processing guided by higher level mental processes. As when we construct perceptions drawing on our experiences and expectations.
Perception: interpreting what comes in your window. the process of organizing and interpreting information. Enabling us to recognize meaningful objects and events.
Visual Capture: the tendency for vision to dominate the other senses.
Gestalt Psychology: (gestalt means an organized whole) these psychologists emphasize our tendency to integrate pieces of information into meaningful wholes.
Gestalt Philosophy: the whole is greater than the sum of its parts.
Figure Ground Relationships: the organization of the visual field into objects (figures) that stand out from their surroundings(ground).
Groupings: the perceptual tendency to organize stimuli into groups that we understand.
1. Proximity- group nearby figures together.
2. Similarity- group items that are similar together.
3. Continuity- continuos patterns
4. Connectedness- uniform and linked together.
Depth Perception: the ability to see objects in three dimensions litho ugh the images that strike the retina are two dimensional. Allows us to judge distance.
How do we transfer two dimensional objects to three dimensional objects:
Binocular Cues: depth cues that depend on two eyes.
Monocular Cues; depth cues that depend on one eye.
Retinal Disparity: a binocular cue for seeing depth. The closer an object comes to you the greater the disparity is between the two images.
Interposition: if something is blocking our view, we perceived it as closer.
Relative Size: I we know that two objects are similar in size the one that looks smaller is farther away.
Relative Clarity: we assume hazy objects are farther away.
Texture Gradient: the coarser it looks the closer it is.
Relative Height: things higher in our field of vision, they look farther away.
Relative Motion; things that are closer appear to move more quickly.
Liner Perspective: parallel lines seem to converge with distance.
Light and Shadow: dimmer objects appear farther away because they reflect less light.
Phi Phenomenon: an illusion of movement created when two or more adjacent lights blink on and off in succession.
Perceptual Consistency: perceiving objects as unchanging even as illumination and retinal images changes.
Transduction: transforming signals into neural impulses. Information goes from the retna to the thalamus then to various areas in the brain.
Sensory Adaptation: decreased responsiveness to stimuli due to constant stimulation.
Sensory interaction: the principle that one sense may influence another.
Taste and smell are chemical senses:
Papillae: those bumps on your tongue. Helps you grip food while your teeth are chewing. They contain your taste buds.
Sweet: it is sensed when our sensitive taste buds come into contact with sugar. Found on the tip of your tongue.
Salty: sensed when our salty taste buds come in contact with salt.
Sour: sensed when our sour taste buds come in contact with an acid
Bitter: sensed when our bitter taste buds come in contact with alkaline chemical. Base of the tongue.
Spicy: Sensed when the nerve receptors in our mouth come into contact sigh a chemical that irritates them.
Cocktail Party Phenomenon: the cocktail party effect describes the ability to focus ones listening attention on a single talker among a mixture of conservations and background noises, ignoring other conservations. Form of selective attempt.
Energy vs. Chemical Senses:
Vision: our most dominating sense. Visual capture.
Phase One: gathering light
The height of a wave (brightness) gives us its intensity.
The length of the wave (color) gives us its hue.
The longer the wave the more red
The shorter the wavelength the more violent.
Phase Two: getting the light in the eye:
Phase Four: in the brain:
Goes to visual cortex located in the occipital love of the cerebral cortex. Features detectors. Parallel Processing
Color Vision:
1. Trichromatic Theory: three types of cones. Red. Blue. Green.
These three types of cones can make millions of combinations of colors. Does not explain afterimage a or colorblindness well.
2. Opponent Processing Theory: the sensory receptors come in pairs. Red and green. Yellow and blue. Black and white. If one color is stimulated, the other is inhibited.
Hearings:
our auditory sense.
We hear sound waves. The height of the wave gives us the amplitude of the sound.
The frequency of the waves gives us the pitch of the sound
Transduction in the ear: sound waves hit the eardrum then anvil and then hammer then stirrup then oval window.
Then the cochlea vibrates.
The cochlea is lined with the mucus called the basilar membrane.
In basilar membrane there are hair cells.
When hair cells vibrate they turn vibrations into neural impulses which are called organ of Corti.
Sent then to thalamus up auditory nerve.
Pitch theories:
Place Theory: different hairs vibrate in the cochlea when they feel different pitches. So some hairs vibrate when they hear high and other vibrate when they hear low pitches.
Frequency Theory: all the hairs vibrate but at different speeds.
Deafness:
Conduction deafness: something goes wrong with the souf and the vibration on the way to the cochlea. You can replace the bones or get a hearing aid to help.
Nerve (sensorineural) Deafness: the hair cells in he cochlea gets damaged. Loud noises can cause this type of deafness. No way to replace the hair. Cochlea implant is possible.
Frequency: # of complete wavelengths that pass through point at a given time. This determines the pitch of a sound.
Short wavelength= high frequency
Long wavelength= low frequency
Amplitude: how loud a sound is. The higher the crest of the wave is the louder the sound is. Measured in decibels.
Absolute Threshold: the minimum stimulation needed to detect a stimulus 50% of the time.
Difference Threshold: the minimum difference that a person can detect between two stimulus. Also known as Just Noticeable Difference.
Webers Law: the idea that to perceive a difference between two stimuli they must differ by a constant percentage not a constant amount.
Signal Detection Theory: predicts how we detect a stimulus amid other stimuli. Assumes that we do not have an absolute threshold. We detect stuff based on our experiences motivations and fatigue level.
Subliminal Stimulation: below ones absolute threshold for conscious awareness.
Intensity: The amount of energy in a light wave determined but the height of the wave the higher the wave the more intensity.
Parallel Processing: the processing of several aspects of a problem simultaneously (color motion form)
Color Blindness:
caused by: 1. Genetics 2. Exposure to chemicals.
Rods facilitate black and white vision
Cones facilitate color vision.
