Test 2 Flashcards
Absolute Threshold
The Absolute Threshold: The distance between not being able to sense a stimulus and being just barely able to sense it.
Absolute Threshold for the 5 senses
Vision: A Candle flame 30 miles away
Hearing: A watch ticking 20 feet away.
Taste: 1 teaspoon of sugar dissolved in two gallons of water.
Smell: 1 drop of perfume in an average sized three room house
Touch: A bee’s wing falling a distance of 1 cm onto the cheek.
Difference Threshold
The smallest increase or decrease in a stimulus for you to notice a difference.
eg. 5 pound weight < 5.1 pounds noticing no difference, 5 lbs to 10 lbs then you notice a difference
Transduction
When our senses accept stimuli and change it into neural impulses. (everything that happens to us is because of neural transmitters)
Sensory Adaptation
Adapting to stimuli in your environment
Anatomy of Sensory Organs
Diagram of eye
Cornea is the soft protective layer of your eye
Pupil is meant to control the amount of light that goes in your eye.
Iris is the colored part of the eye, it is a type of striated muscle. Responsible for closing and opening the pupil
Lens focuses the light that comes in your eye (sends it to a particular area of the retina)
Retina is a small patch at the back of the eye where transduction takes place.
Rods: Shades of grey
Cones: Responsible for color
Fovea: blind spot, there are no nerves.
Optic nerve goes to thalamus then goes to occipital lobe then to the perception area.
The Ear
Stimulus: sound waves
We measure sound in Hertz (Hz). Hertz is frequency how high or low something is. Amplitude is how loud something is (Decibels, Db) . Timbre is the unique quality of sound (eg. Trumpet and Violin)
Pinna: Captures and isolates the sound.
Auditory Canal is where the sound enters
It hits the ear drum (cartilage that looks like a drum)
Hammer, Anvil and Sturup (they are the Ossicles) part of the middle ear.
Cochlea is where transduction takes place
Fluid filled structure with hair cells that align inner area.
There is as much brain activity during auditory hallucinations as if you were actually hearing it.
Smell
The only sense that does not go through the thalamus it goes directly to the olfactory bulb then to the olfactory cortex. The olfactory cortex sends the message to other parts of the brain.
Olfactory epithelium is the nasal cavity
olfactory bulb
when you smell something, an image from the occipital lobe is usually associated with the smell.
Taste
Papillae are the bumps on your tongue
taste buds are the crevices next to the papillae.
taste buds are where transductions take place.
also on roof of mouth, back of throat, bottom of tongue
genetically we’re certain types of tasters
there are super tasters
up two 4 times the amount of tastebuds genetically
non tasters
4 times less taste buds
Average tasters
normal number of tastebuds
Skin senses
different types of receptors found in the nerve endings in your skin
nerve endings for hot and cold specifically
nerve endings for pressure
nerve endings for texture
nerve endings for pain
they travel up the spinal cord through the brainstem and to the parietal love and the somatosensory cortex.
endorphins are the neurotransmitter for pain. They are released when we experience pain to ease it.
Gate Control Theory
belief is that there is a neural “gate” in your spinal cord that opens when you experience too much nerve stimulation.
the gate will shut if there is too much pain and you go into a numb state.
Vestibular sense
Detects movement and provides information about our body parts in space.
vestibular organs are located in our semicircular canals
they are fluid filled canals
depending on how the fluid moves it tells the brain where we are.
Kinesthetic Sense
provides information about your body parts in relation to each other.
the information comes from neurons in your joints, ligaments and muscles.
Where is Pain registered in the brain?
they travel up the spinal cord through the brainstem and to the parietal love and the somatosensory cortex.
How are hallucinations registered in the brain?
Know that they are registered in the exact same way as experiencing the stimuli.
Gestalt Principle of Figure and Ground
The whole is greater than the sum of its parts
How do people actually see the world.
They believe our sensory experiences organize into what they call figure and ground.
Believed that we need to focus on the figure (foreground) or the ground (background)
An innate part of human genetics
Binocular Convergence
Our eyes converge to focus on close objects and they release their convergence for close objects. (Convergence only starts 20 feet or closer)
The convergence of your eyes sends messages to optic nerve which sends messages to your brain.
Binocular disparity
Related to how the image falls on the retina tells us how close or how far it is.
Monocular (Learned Depth Cues)
Inter-positioned
When objects overlap it creates depth queues. When object blocks another object it is closer.
Linear Perspective
Parallel lines appear to grow closer together as they become more distant.
Relative Size
Larger appear closer and smaller objects appear farther away.
Texture Gradient
Closer objects have more defined texture.
Atmospheric Perspective
Blurry things appear farther away
Shadowing
Shadowing creates depth perception
Motion Parallax
While one moving, closer objects appear to move faster, father objects appear to move slower.
Gestalt Principles of Grouping
Similarity
Efficiency of information
Proximity
the closer things are together then we group then together.
Closure
We naturally close off naturally or unfinished objects to understand them as a whole.
You will only close and perceive known objects in your life.
Continuity
Says that we perceive figures or objects belonging together if they form a continuous pattern.
Perceptual Constancy
that we tend to see objects or people as maintaining the same size, shape, brightness and color regardless of our view.
Size Constancy
As objects move farther away they are perceived as being the same size.
Believed to be learned
Shape Constancy
We perceive shapes to be the same regardless of their angle.
Brightness Constancy
Brain keeps brightness of objects constant by comparing it against other objects.
Color Constancy
That Familiar objects are perceived to be the same color regardless of how bright the light.
