Set 4: Sensation Flashcards
To represent the world, we must detect physical energy (a stimulus) from the environment and convert it into neural signals. This is a process called
sensation
We we select, organize, and interpret our sensations, the process is called
perception
A message is sent from your senses to your brain.
Bottom-Up Processing
Your brain telling your senses what was just experienced
Top-Down Processing
are sensory nerve endings that respond to stimuli.
Sensory Receptors
A study of the relationships between physical characteristics of stimuli and our psychological experience with them.
Psychophysics
Minimum stimulation needed to detect a particular stimulus at least 50% of the time.
Whether you can detect a the ticking of a clock in a quiet room
Absolute Threshold
When stimuli are below one’s absolute threshold for conscious awareness.
Rome Cheese Ellen
Subliminal Threshold
Minimum difference between two stimuli required for detection 50% of the time, also called just noticeable difference.
Car radio being turned up
Difference Threshold
Two stimuli must differ by a constant minimum percentage (rather than a constant amount), to be perceived as different.
a person is much more likely to react to a quiet commercial that suddenly doubles in volume than a commercial that only slightly increases in volume
Weber’s Law
A person’s absolute threshold can change depending on the situation they are in.
Signal Detection Theory
Diminished sensitivity as a consequence of constant stimulation. Colonge
Sensory Adaptation
Transduction
In sensation, the transformation of stimulus energy into neural impulses.
Phototransduction
Conversion of light energy into neural impulses that the brain can understand.
How the brain understands images
Wavelength
Short wavelength = high frequency
(bluish colors and high pitched sounds)
is the distance from the peak of one wave to the peak of the next.
Hue (color)
Long wavelength = low pitched sounds
(reddish colors and low pitched sounds)
is the dimension of color determined by the wavelength of the light.
Intensity
Amount of energy in a wave determined by the amplitude. It is related to perceived brightness.
Cornea
Transparent tissue where light enters the eye.
Iris
Muscle that expands and contracts to change the size of the opening (pupil) for light.
Lens
Focuses the light rays on the retina.
Retina
Contains sensory receptors that process visual information and sends it to the brain.
Accommodation
The process by which the eyes lens changes shape to help focus near or far objects on the retina. (Not to be confused with schemes)
Nearsighted
A condition in which nearby objects are seen more clearly than distant objects.
Farsighted
A condition in which faraway objects are seen more clearly than near objects.
Optic nerve:
Carries neural impulses from the eye to the brain. This creates a blind spot.
Fovea
Central point in the retina around which the eye’s cones cluster.
Blind Spot
Point where the optic nerve leaves the eye because there are no receptor cells located there.
Photoreceptors
-Rods/Cones are photoreceptors that transduce light to color and brightness.
-You have more rods than cones.
-Cones in the center of the retina, rods in the periphery.
-Cones see in color, Rods don’t
Rods see in the dark, Cones don’t
The Visual Process
Cornea —-> Iris/Pupil —-> Lens —-> Retina (Rods & Cones) —-> Bipolar Cells —-> Ganglion Cells —-> Optic Nerve (Blindspot) —-> Optic Chiasm ——-> Thalamus —-> Occipital Lobe
Feature Detectors
Nerve cells in the visual cortex respond to specific features, such as edges, angles, and movement.
Shape Detectors
Specific combinations of temporal lobe activity occur as people look at different important objects.
Fusiform Face Area
Area of the Temporal Lobe dedicated to recognizing face.
Prosopagnosia
The inability to perceive faces.
Parallel processing
Processing of several aspects of the stimulus simultaneously is called _______ ____________.
The brain divides a visual scene into sub-divisions such as color, depth, form, and movement.
Trichromatic theory
Also known as Young-Helmholtz Theory. States that there are cones for: blue, green, and red. Every other color you can see is a combination of those.
Subtraction of Colors (Art)
Paints/Pigments
Three primary colors: Red, Blue, Yellow
When you combine paints you subtract wavelength, so you end up with black.
Addition of Colors
When dealing with light the three primary colors are: Blue, Red, and Green. When you mix light you add wavelength so when all are mixed together you end up with white.
Color Vision Deficiency (Color Blindness)
Genetic disorder in which people are blind to green or red colors. This supports the Trichromatic Theory.
Dichromatism
Inability to distinguish between red/green or blue/yellow
Monochromatism
Inability to perceive color
Opponent Process Theory
Hering proposed that we process that four colors are seen by the ganglion cells combined in pairs of red-green, blue-yellow, and black-white.
Sound waves
are composed of compression and rarefaction of air molecules
Acoustical transduction
Conversion of sound waves into neural impulses in the hair cells of the inner ear.
Wavelength
Wavelength: The distance from the peak of one wave to the peak of the next determines the pitch.
Intensity (Loudness):
Intensity (Loudness): Amount of energy in a wave, determined by the amplitude, relates to the perceived loudness. The taller the wave the louder the sound.
Outer Ear:
Outer Ear: Pinna–>Auditory Canal–> Eardrum
Middle Ear
Ossicles (Three tiny bones: Hammer, Anvil, Stirrup)–>Oval Window
Inner Ear
Cochlea–>Basilar Membrane (Hair Cells = Transduction)–>Auditory Nerve–>Thalamus –>Temporal Lobe
Cochlea
Coiled, bony, snail-like fluid-filled tube in the inner ear that transforms sound vibrations to auditory signals.
How do we detect loud sounds?
Louder sounds activate more hair cells than soft sounds.
Place Theory
There are hair cells for high pitches and hair cells for low pitches, it depends where the stimulation happens.
Frequency Theory
All hair cells can hear all pitches, it just depends on how fast the hair cells are stimulated that allow one to hear different pitches.
Volley Theory
For really high frequencies multiple areas of the basilar membrane alternate back and forth to achieve a combine high frequency sound.
Localization of Sounds
Because we have two ears, sounds that reach one ear faster than the other ear cause us to localize the sound.
- Intensity differences (One ear hears it louder)
- Time differences (One ear hears it sooner)
Conduction Hearing Loss
Hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea (heading aids)
Sensorineural Hearing Loss
Hearing loss caused by damage to the cochlea’s receptor cells or to the auditory nerve, also called nerve deafness (cochlear implants)
Cochlear implants
are electronic devices that enable the brain to hear sounds
The sense of touch is a mix of four distinct skin senses
pressure, warmth, cold, and pain
Pain
tells the body that something has gone wrong. Usually pain results from damage to the skin and other tissues. A rare disease exists in which the afflicted person feels no pain.
Phantom Limb Sensation
occurs to some people who have lost a limb. They can still feel sensation in the missing limb, often it manifests as pain.
Gate-Control Theory
Melzak and Wall (1965, 1983) proposed that there is a gate on our spinal cord that when open sends pain, but when shut blocks pain.
Pain Control
Pain can be controlled by a number of therapies including: drugs, surgery, acupuncture, exercise, hypnosis, and even thought distraction.
Chemical Senses
Your two chemical senses are taste and smell. They are called chemical senses because chemical messages are sent through the tongue and nose for us to experience taste and smell.
Taste = _________ System
6 types of tastes are:
Gustatory
6 types of tastes are: Sweet, Sour, Salty, Bitter, Umami (savory), and Oleogustus (oily, fat).
How strong can you taste?
Scientists have separated people into Supertasters, Medium Tasters, and Non Tasters based on how strong their sense of taste is.
Sensory Interaction
Synesthesia
When one sense affects another sense, sensory interaction takes place. So, the taste of strawberry interacts with its smell and its texture on the tongue to produce flavor.
Synesthesia occurs when a person has senses that interact in unusual ways.
Smell
Known as the olfactory system. Many unique smell sensations. Bypasses the Thalamus and goes right to the Temporal Lobe. Pheromones are chemical messages from people or animals that give them a distinct smell.
Age with Smell
Smell declines with age. Women are better at detecting odors than men.
Smell and Memories
The Brain region for smell and the brain region for memory are located close together. Therefore your sense of smell is highly connected to your memories.
Kinetheisis
Vestibular Sense
Knowing how your body is positioned in space and senses it’s movement is called kinesthesis. The vestibular sense located behind the ear is in control of your balance and your head’s position. It is controlled by your semicircular canals and your vestibular sacs in your inner ear.
Embodied Cognition
Embodied Cognition sometimes allows our senses to affect our thinking. (Ex: A hard chair might make a teacher more strict. )
