Unit 3 Flashcards
Sensation and Perception
Sensation
Information you take in. Sensory receptors (eyes, ears…) and the nervous system receive stimuli from the environment.
Senses
Sense organs transform physical stimulation into neural impulses that give us sensations. Light waves give us light and dark sensations.
Bottom-Up Processing
Body response. See, smell, touch, hear. Analysis that emphasizes the characteristics of the stimuli rather than our concepts or expectations.
Perception
How you interpret the information (sensation). Process of organizing and interpreting sensory information.
Top-Down Processing
Emotional response. Looks pretty/ugly, smells gross, feels rough, sounds loud. Analysis the emphasizes the perceiver’s expectations, concept memories, and other cognitive factors, rather than individual characteristics.
Psychophysics
Relationship between physical stimuli and our psychological experiences to them.
Absolute Threshold
Weakest amount of a stimulus required to produce a sensation.
Difference Threshold
Smallest difference in stimulation that can be detected. A just noticeable difference.
Weber’s Law
The noticeable difference of the stimulus is large when the intensity is high and vice versa.
Sensory Adaptation
Getting used to a level of stimulus. Sense organs are change detectors. Diminishing responsiveness of our sensory systems to prolonged stimulation. Unless it is intense or painful, stimulation that persists without change shifts to the background of our awareness.
Signal Detection Theory
The detection of a stimulus depends on the intensity of the stimulus and the physical and psychological state of the individual.
Sesory Overload
Over stimulating the senses.
Selective Attention
Focusing attention on selected aspects of the environment.
Divided Attention
Focusing attention on several aspects of the environment.
Cocktail Party Effect
You can hear your name across the room in another conversation.
Transduction
Process of stimuli changing from physical to neural. Converts energy such as light into neural messages. Begins with sensory neurons detecting physical stimuli. When stimuli reaches sense organ, activates receptors. Receptors convert excitation into a nerve signal.
Cornea
Protective outer layer.
Iris
Colored part of the eye. Muscle that constricts pupil.
Pupil
Opening in the iris. Changes shape in light and dark.
Lens
Changes shape to send best image to back of the eye. Flips the image upside down. Is an “accessory structure” in the body- modifies stimulus before transduction.
Retina
Back of the eye. Contains rods and cones. Transduction occurs here.
Photoreceptors
Light sensitive cells (neurons) that convert light energy to neural energy. Rods- black and white (125 mil/eye) vision. Cones- color vision (7 mil/eye)
Fovea
Area of sharpest vision. Highest concentration of cones.
Distal and Proximal Stimuli
Distal: what you see- exists in the real world
Proximal: inverted image the retina sends to the brain- image formed in the mind
Optic Nerve
Carries impulses from the retina to the brain. Bundles of neurons/fibers.
Blind Spot
Area in the retina (called the optic disk) without photoreceptors- where the optic nerve exits the eye. Any stimulus in this area cannot be seen.
Visual Cortex
Brain region where neural impluses are transformed into visual sensations of color, form, boundary, and movement. Through parallel processing- the simultaneous processing of several aspects of a stimulus.
Feature Detectors
Specific cells that see lines, motion, curves, and other features. Work of Hubel and Wiesel- cats have special feature detectors for edges. Evolutionarily helpful to see objects and other critters.
Light Energy, Wavelength, and Intensity
Light energy: visible spectrum.
Wavelength: distance from the peak of one light wave to the peak of the next (the distance determines the hue (color) that we perceive). Short- blues. Long- reds.
Intensity: Amount of energy in a light wave. Determined by height of the wave (amplitude). The higher the wave, the more intense the light.
Color Blindness
True color blindness: see only black and white. Must have a color deficiency.
Inherited: most common in males, worsens over time.
Partial: affects some colors- trouble distinguishing between some colors.
Trichromatic Theory
Realized any color can be created by combining the light waves of 3 primary colors- red, green, and blue. Guessed that there are three types of receptor cells in our eyes. Together they pick up 7 million color variations. Most color-blind people lack cone receptor cells for one or more of these primary colors.
Depth Perception: Binocular Fusion and Monocular Cues
The ability to see objects in three dimensions although the images that strike the retina are two dimensional. Allows us to judge distance.
Retinal Disparity
Differences between images you see in each eye.
Accommodation
Tension of the muscle that changes the focal length of the lens of the eye. Brings into focus objects at different distances. This depth cue is weak- effective only at short viewing distances.
Relative Height
Objects that are higher in the field of vision (closer to the horizon line), are further away.
Linear Perspective
Parallel lines converge with distance (at the horizon line).
Interposition
On a series of overlapping images, the closer image is on top.
Relative Motion
Objects that are closer appear to move more quickly.
Relative Clarity
Assume hazy objects are farther away.
Texture-Density Gradient
More detail in close objects.
Shape Constancy
An object keeps its form despite changes in orientation.
Light and Brightness Constancy
An object keeps the same color even when the light changes.
After Images and Opponent Process Theory
Light sensitive cells become less responsive to certain colors of light. Different colors show through after you get used to a certain level of color and light.
Change Blindness
Failure to notice a change.
In-Attentional Blindness
Failure to notice an unexpected stimuli.
Prosopagnosia
Face blindness.
Perceptual Adaptation
The ability to adjust an inverted visual field.
Illusions: Hermann Grid and Phi Phenomenon
Misrepresented stimuli. Mind playing a trick on you. Hermann Grid- Stare at the center of the grid and dark fuzzy spots start to appear at the intersections of the white bars. But if you focus on the intersections, there are no spots. This happens because while most cones have a direct neural pathway to the brain, rods do not and have to share with many other neurons. Not all can send their information at the same time, so we are left with mini “blind spots”.
Phi Phenomenon: An illusion of momentum created when two or more adjacent lights blink on and off in succession.
Law of Figure Ground
You see the main object first, you see the surrounding objects second.
Law of Good Figure (Pragnanz)
When presented with a set of complex objects, your brain will make them appear as simple as possible.
Law of Closure
Our brain fills in the missing parts that it wants to perceive. Our brain “closes” the image.
Law of Proximity
Tendency to group stimuli that are close together as part of the same object.
Law of Similarity
Tendency to group stimuli that are similar together as part of the same object.
Law of Continuity
Points connected by lines are seen in a way that follows the smoothest path.
Law of Common Fate
Tendency to group similar objects that share a common motion or destination.
Set
Our mental predisposition to see what we want to see.
Stroop Effect
Disposition to read the words first.
Context Effects
Form of perceptual set. You do not hear a word, but you can guess it based on the context in which it was stated.
Phantom Limb
Sensation that an amputated or missing limb is still attached to the body and is moving appropriately with other body parts.
Synesthesia
Stimulation of one sensory pathway leads to automatic involuntary experiences in a second sensory pathway.
Subliminal Messaging
Everything underneath the absolute threshold.
Priming
Exposure to a stimulus influences your response.
Hearing: Frequency and Amplitude
Vibrational energy of vibrating objects, transfer the surrounding air as the vibrating objects push molecules back and forth.
Frequency: number of cycles of complete wavelengths in a given amount of time determines pitch.
Amplitude: how loud the sound is- the higher the crest of the wave, the louder the sound.
Pinna
The outside structure of the ear. This is the “accessory structure” that modifies stimuli. Shape collects sound waves.
Cochlea
Where transduction occurs.
Eardrum
Get sound waves and send to best place.
Hammer, Anvil, Stirrup, Oval Window (Inner Ear)
Stirrup vibrates and transmits the sound waves through the oval window. Vibrations hit the cochlea’s membrane. This causes ripples in the basilar membrane (hair cells). Transduction in cochlea. The movement of cells triggers impulses from nearby nerve fibers which form the auditory nerve that connects via the thalamus to the temporal lobe.
Process of Hearing (Order of Middle Ear and Inner Ear)
Middle ear transmits vibrations (sound waves). They hit the eardrum -> hammer -> anvil -> stirrup.
Place Theory
Different hairs vibrate in the cochlea when they interpret different pitches. Some hairs vibrate when they hear high pitches and others vibrate when they hear low pitches.
Frequency Theory
The rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch. All the hairs vibrate, but at different speeds.
Deafness
Conduction: an inability to hear, resulting from damage to the structures of the middle or inner ear.
Nerve (sensorineural): an inability to hear, linked in a deficit in the body’s ability to transmit impulses from the cochlea to the brain. The hair cells in the cochlea get damaged. Loud noises can cause this type of deafness.
McGurk Effect
Interaction of hearing and vision.
Sensory Interaction
The senses work together. Smell works with taste.
Taste
Sense of taste is gustation. Specialized nerves carry nothing but taste messages to the brain. Taste is realized in a specialized region of the parietal lobe’s somatosensory cortex.
Papillae
The bumps on our tongue. Helps grip food while your teeth are chewing. Also contain your taste buds.
Types of Taste
4 main: sweet, sour, bitter, salty.
Umami- savory; like meats.
Astringent- drying; like an apple.
Olfaction/Smell
Nose is an “accessory structure”. Odors first interact with the receptor proteins associated with hairs in the nose. The hairs convey information to the brain’s olfactory bulbs- skip the thalamus. In humans, olfaction has a close connection with memory. They can evoke emotional memories.
Pheromone Theory
How pheromones induce a sexual response: 1) glands in our armpits, genital regions, and navals secrete a clear liquid that contains pheromones. 2) our pheromone scent reaches the noses of women. 3) the olfactory system (starting with the nose) bypasses the rational brain. 4) this information is fed directly to the behavior center in a woman’s brain. 5) If the information communicated by our pheromone scent is positive (this guy is healthy, fit, and fertile), then a sexual response may be observed.
Touch
Receptors located in our skin. Skin is an “accessory structure”.
Gate Control Theory
The spinal cord contains a neurological “gate” that either blocks pain signals or allows them to continue to the brain. Pain is sensed by two different sensory pathways- one moving fast, one moving slow. Pain signals routed to anterior cingulate cortex- located along the fissure separating the frontal lobes.
Pain Receptors
A-Delta fibers: fast pain nerve messages.
C Fibers: slow pain nerve messages.
Anterior cingulate cortex in the brain processes pain.
Analgesia
Inability to feel pain. Can still feel touch. From birth or from injury of spinal cord.
Vestibular Sense
Controls balance. Otoliths- small particles in the ear; sense gravity. Semicircular canals- tubes of the inner ear that sense motion with fluid. Vestibular ocular reflexes- reflex eye movement that stimulates the vestibular system.
Kinesthesia
Ability to be aware of the motion of your own body parts in relation to one another.
Proprioception
Ability to be aware of the location of your own body parts in relation to one another.
Semicircular Canals
Tubes of the inner ear that sense motion with fluid.
