Chapter 6 Module Flashcards
Absolute Threshold
Smallest amount of sensory stimulation that can be reliably detectected 50% of the time.
Signal Detection Theory
A theory predicting how and when we detect the presence of a faint stimulus amid background stimulation.
Assumes that there is no absolute threshold and that detection depends on context.
Hit Stimulus: Present and detected
Miss Stimulus: Present and missed
False Alarm: Absent and detected
Correct Detection: Absent and missed
Difference Threshold
Minimum difference between two stimuli required for detection 50% of the time.
Weber’s Law.
More stimulus: less detection in difference changes.
Weber’s Law
For a difference to be perceptible, two stimuli must differ by a constant proportion rather than amount.
The Influence of Stimuli Below Absolute Threshold
Stimuli below the absolute threshold still may influence perception, even if it is undetected.
Subliminal Persuasion
May produce a fleeting & subtle effect on behaviour.
Discounts effectiveness of subliminal advertising & self-improvement.
Subliminal Stimuli
Too weak to detect 50% of the time.
Subliminal Sensations
Too fleeting to enable exploitation with subliminal messages.
Sensation
Process by which sensory receptors & nervous system receive & represents stimulus energies from our environment.
Perception
Process of organizing & interpreting sensory information, enabling us to recognize meaningful objects & events.
Transduction
Conversion of one form of energy into another.
Transforming sights, sounds, and smells into neural impulses that our brain can interpret.
Psychophysics
A study of the relationship between physical characteristics of stimuli and our psychological experience with them.
Ex. Physical world: light. Psychological world: Brightness.
Bottom-Up Processing
Analysis begins with sensory receptors relaying information to the brain and then works up to higher levels of processing.
Top-Down Processing
Constructs perceptions from sensory input by drawing on past experiences and expectations.
Perceptual Constancy
Perceiving objects as unchanging even as illumination and retinal images change.
Colour and brightness constancy
Shape and size constancies
Shape and Size Constancies
We perceive the form of familiar objects as constant even while our retinal images of it changes.
Size Distance Constancies
Knowing that things are the same size, eventhough they adjust size based on distance.
Relative Luminance
The relative brightness of any point in a colorspace.
Can lead to optical illusions.
Vision
Transforms light energy into neural signals.
Represents objects in the environment in terms of shape, size, colour, and location
Parts of the Eye
Iris
Pupil
Lens
Cornea
Retina
Fovea (Point of central focus)
Blind Spot
Optic Nerve to brain’s Visual Cortex
Retina
Contains receptor rods, cones, and layers of neurons (bipolar and ganglion cells).
Rods
Function in dim light
Detect black & white vision, but not colours
Necessary for peripheral and twighlight vision
Owls
Cones
Near center of retina (fovea)
Function in bright or day light
Detect fine deatil
Enable colour perception
Young-Helmholtz Trichromatic (3-Colour) Theory
3 types of colour receptor cones: red, green and blue
All colours we perceive are created by combinations of these cones.
Opponent-Process Theory
Neural processing of things based on 3 sets of opponent colours:
Red vs. green
Yellow vs. Blue
White vs. Black
Dual Process Theory of Colour Processing
- Retina’s red, green, blue cones respond in varying degrees
- The cones’ responses are then processed by opponent-process cells
The two theories are complementary
Colour-Deficient Vision
People missing red or green cones have trouble differentiating red from green.
Feature Detection
Ganglion cells in the eye send signals directly to visual cortex in response to certian features.
Edges, lines, angles, and movements.
Supercells integrate these feature signals to recognize more complex forms.
Taste Sensations
1.Sweet
2.Sour
3.Umami
4.Bitter
5.Salty
Supertasters
Twice as many taste buds as regular tasters.
Tend to dislike taste of alcohol and bitter tastes.
Identified with PTC.
Categories of Tasters
Non-tasters
Regular tasters
Supertasters
Sensory Interaction
When one sense affects another sense.
Ex. the taste of strawberry interacts with its smell and texture on the tongue to produce flavour.
McGurk Effect
Visual information received from mouth movement does not correspond to auditory information received from spoken sounds.
The brain makes a best guess by perceiving a third sound.
Sensory Adaptation
Diminishing sensitivity to an unchanging stimulus.
We perceive the world not as it acutally is, but as it is useful for us to perceive it.
Freedom to focus on informative changes.
Four Components of Touch
Warmth
Pressure
Cold
Pain
Gate Control Theory
Dorsal horns of the spinal column act like a gate.
Intense stimulation “opens the gate” and pain information is transmitted.
Thoughts, emotions, beliefs influence our experience of pain.
Phantom Limb Sensations
Brain can also create pain.
Experience sensations after a limb has been amputated.
Mirror Box Therapy
Biological Influences to Pain
Activity in spinal cord’s large and small fibers.
Genetic differences in endorphin production
The brain’s interpretations of CNS activity.
Psychological Influences to Pain
Attention to pain
Learning based on experience
Expectations
Social-Cultural Influences On Pain
Presence of others
Empathy for others’ pain
Cultural expectations
Sensory Receptors
Sensory nerve endings that respond to stimuli.
Subliminal
Below one’s absolute threshold for conscious awareness.
Perceptual Set
A mental predisposition to perceive one thing and not another.
Involves top-down processing.
Light Wavelength
The distance from one wave peak to the next.
Determine hue.
Hue
The color we experience
Light Intensity
Determined by light wave’s amplitude (height).
Influences brightness.
Accommodation
The process by which the eye’s lens changes shape to focus near or far objects on the retina.
Gestalt
An organized whole. Filling in the gaps to create an organized whole.
Gestalt psychologists emphasized our tendency to integrate pieces of information into meaningful wholes.
Figure-Ground
The organization of the visual field into objects that stand out from their surroundings.
Depth Perception
The ability to see objects in three dimensions although the images that strike the retinaare two-dimensional; allows us to judge distance.
Visual Cliff
A lab device for testing dpeth perception in infants and young animales.
Binocular Cues
A depth cue, such as retinal disparity, that depends on the use of two eyes.
Retinal Disparity
Binocular cue for perceiving depth.
By comparing retinal images from teh two eyes, the brain computes distance - the greater the disparity between the two images, the closer the object.
Monocular Cues
A depth cue, such as interposition or linear perspective available to either eye alone.
Phi Phenomenon
Illusion of movement created when two or more adjacent lights blink on and off in quick succession.
Perceptual Adaptation
The ability to adjust to changed sensory input, including an artificially displaced or even inverted visual field.
Audition
The sense or act of hearing.
Auditory Frequency
The number of complete wavelengths that pass a point in a given time.
Determines pitch.
Decibels
How we measure sound intensity.
0 decibels is the absolute threshold for heaing.
Outer Ear
Auditory canal.
Middle Ear/Inner Ear
Hammer
Anvil
Eardrum
Stirrup (staples)
Oval Window
Cochlea
Basilar Membrane
Protruding Hair Cells
Nerve Fibers to Auditory Nerve
Auditory Nerve
Inner Ear
Semicircular Canals
Bone
Auditory Nerve
Cochlea
Piston
Hammer
Anvil
Stirrup
Sensorineural Hearing Loss
Most common form of hearing loss.
Caused by damage to the cohclea’s receptor cells or to the auditory nerve.
Nerve deafness
Conduction Hearing Loss
A less common form of hearing loss.
Caused by damage to the mechanical system that conducts sound waves to the cochlea.
Cochlear Implant
A device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea.
Place Theory
The theory that links the pitch we hear with the places where the cochlea’s membrane is stimulated.
Frequency Theory
The theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch.
Low pitch sounds.
Temporal Coding.
Social Influence Theory
Contends that hypnosis is a by-product of normal social and mental processes.
Dissociation Theory
Proposes that hypnosis is a special dual-processing state of dissociation.
Dissociation
A split between different levels of consciousness.
Posthypnotic Suggestion
A suggestion, made during a hypnosis session, to be carried out after the subject is no longer hypnotized.
Used by some clinicians to help control undesired symptoms and behaviors.
Gustation
Our sense of taste
Survival Functions of Basic Tastes
Sweet - Energy Source
Salty - Sodium essential to physiological processes
Sour - Potentially toxic acid
Bitter - Potential Poisons
Umami - Proteins to grow and repair tissue
Olfaction
Our sense of smell
Kinesthesia
Our movement sense.
Our system for sensing the position and movement of individual body parts.
Vestibular Sense
Our balance sense.
Our sense of body movement and position that enables our sense of balance.
Embodied Cognition
The influence of bodily sensations, gestures, and other states on cognitive preference and judgments.
Synesthesia
Where the stimulation of one sense triggers an experience of another.
Extrasensory Perception (ESP)
The contraversial claim that perception can occur apart from sensory input.
Includes telepathy, clairvoyance, and precognition.
Telepathy
Mind-to-mind communication.
Clairvoyance
Perceiving remote events, such as a house on fire across the country.
Precognition
Perceiving future events, such as an unexpected death in the next month.
Parapsychology
The study of paranormal phenomena.
