Unit Two (Sensation + Perspective) Flashcards
Sensation
Process of receiving a stimulus from the external environment that activates a receptor-how one gathers info
Perception
Our interpretation of sensation
Psychophysics
Study of the relationship between sensory experiences and physical stimuli that cause them
Transduction
How stimulus info is transformed into electrochemical energy-info sent to appropriate area in the cerebral cortex
Sensory Adaptation
Loss of responsiveness in receptor cells after stimulation has remained constant
Stimulus
An aspect of change in the environment that a person reacts to
Bottom-up Processing
Sensory analysis that begins at the entry level, with information flowing from the sensory receptors to the brain
Top-down Processing
Information processing by when we construct perceptions by filtering information through our experiences and expectations
Threshold
What is the least amount of stimulus needed to create a reaction?
Absolute Threshold
Weakest amount of stimulus that can be detected half of the time
Difference Threshold
Smallest difference in stimulation that can be detected between two stimuli 50% of the time
Weber’s Law
Size of JND (just noticeable difference) is proportional to the intensity of the stimulus
Signal Detection Theory (SDT)
Predicts how and when we detect the presence of a faint stimulus (signal) among background stimulation (noise)
Selective Attention
Focusing on a specific aspect of your experience while ignoring others
Cocktail Party Effect
Picking out familiar voices
Pre-attentive Process
Unconsciously obtaining info from our environment, our brain filters out what “isn’t important”
Attentive Process
Focusing on a certain stimuli purposefully and processing that info
Subliminal Messages
Stimuli below the absolute threshold
Path of Light Into the Eye
Enters through the cornea, passes through the pupil, iris controls the amount of light that passes into the eye, then the image is inverted on your retina
Path of Light Into the Eye Part 2
Axons of the ganglion cells that make up the optic nerve send info to the thalamus, optic nerve is divided in two
Optic Chiasma
Where the optic nerves cross
Trichromatic Theory
Three types of cones for blue, red, and green which combined create all colors
Dichromatic Color Blindness
Cannot perceive red green or blue yellow shades
Dichromats
People with two types of cones and color blindness
Trichromats
People with three cones and normal vision
Opponent Process Theory
Sensory receptors (bipolar/ganglion cells) arranged in the retina come in pairs: red/green, yellow/blue, black/white pairs, if one fires, the other won’t
Prosopagnosia
Can’t recognize faces or facial expressions
Organ of Corti
Neurons activated by movement of hair cells, that transmit impulses to the brain through the auditory nerve
Volley Principle
For high frequency sounds a cluster of neurons can produce a volley of impulses that exceed the individual limit
Place Theory
Theory of hearing, our perception of sound depends on where each component frequency produces vibrations along the basilar membrane
Conduction Deafness
Blocking of waves to the eardrum
Sensorineural Deafness
Damage to the auditory nerve
Smell (Olfaction)
Not routed to the thalamus, but directly to the olfactory bulb (via olfactory nerve) in the brain
Olfactory Epithelium
In the roof of the nasal cavity, receptor cells for smell
Pheromones
Allow animals to mark areas, signal sexual receptivity, danger boundaries and food sources
Taste (Gustation)
Aided by papillae, the bumps on the tongue which contain taste buds, perceived in the gustatory cortex of the frontal lobe
Supertasters
Born with more taste buds for bitter tastes
Touch (Pressure)
Skin senses are connected to the somatosensory cortex in the parietal lobes
Temperature
Thermoreceptors allow us to determine temperature – two types, one for hot and one for cold
Pathways of Pain
Pain receptors spread widely around the body, fast myelinated fibers deliver most info to the brain, slow unmyelinated fibers for nagging and throbbing pain
Gate Control Theory of Pain
Spinal column has a neural gate that can be opened and closed to stop pain
Vestibular Sense
Provides info on body position, motion, and posture in relation to gravity
Semicircular Canals
Three tubes in the inner ear that detect head motion and help us keep balance
Kinesthetic Sense
Keeps track of body parts in relation to each other
Feature Detectors
Cells in the cortex that specialize in extracting certain features of stimuli
Perceptual Constancy
Recognition that objects stay the same even if we change position or lighting etc.
Depth Perception
Our ability to judge distance
Binocular Depth Cues
Depends on both eyes
Convergence
Eyes turn inward to see close objects
Retinal Disparity
The change in the image between our two eyes
Linear Perspective
How roads and tracks seem to converge in the distance
Interposition
When two objects overlap, the one we see completely is closer
Atmospheric Perspective
Fewer perceivable details with greater distances
Relative Motion/Motion Parallax
Nearby objects seem to be moving toward you (faster), but the distant objects seem to be moving your direction (slower)
Figure Ground Relationship
Being able to tell the difference between an item and its background
Gestalt
Experience gained from organization of bits of info into meaningful wholes, greater than the sum of each part
Closure
Seeing incomplete figures as wholes by supplying missing segments, filling in the gaps, and making inferences about potentially hidden objects
Laws of Perceptual Grouping
Explain how the brain organizes stimuli elements together
Perceptual Set
Predisposition or readiness to perceive something in a particular way
Apparent Motion
Perception that a stationary object is moving
Stroboscopic Motion
Illusion of rapid movement when different parts of the retina are stimulated (ie movies)
Movement After Effects
Illusion created when watching continuous movement and looking at a stationary object which then appears to move
