Psych #3 - Brain and Sensation Flashcards
What is the microstructure of the brain?
Neurons are the basic building blocks of the brain
What are dendrites?
They receive signals
What is the body?
It’s the machinery of the cell, nucleus etc.
What is the axon?
It’s the action. It sends the signal.
How do neurons “fire” messages?
Resting potential, action potential, and then refractory period
What is the resting potential?
It is when the negatively charged potassium ions inside, positively charged sodium ions outside. Axon is polarized.
What is the action potential?
A neural impulse; a brief electrical charge that travels down an axon. Positively charged ions flood in through the cell membrane. Axon depolarizes, propagates down axon.
What is the refractory period?
It is when the axon pumps the positively charged sodium ions back outside (repolarizes itelsef). Then it can fire again (is back.
What is the all or nothing response?
A neuron’s reaction of either firing (with a full-strength response) or not firing. No in-between.
What is the threshold?
If excitatory signals exceed inhibitory signals by a minimum, or threshold, this triggers an action potential.
What is the synapse?
Terminals don’t touch. “synaptic gap” It’s a chemical message where the axon releases and the dendrite picks up
What are the functions and malfunctions of the Acetylcholine?
Function: Enables muscle action, learning, and memory
Malfunctions: Undersupply, ach producing neurons deteriorate, marks alzheimers disease
What are functions and malfunctions of dopamine?
Function: influences movement, learning, attention, and emotion
Malfunction: Excess dopamine receptor activity linked to schizophrenia; starved of dopamine, the brain produces the tremors and decreased mobility of parkinson’s disease.
What are the functions and malfunctions of seratonin?
Function: Affects mood, hunger, sleep, and arousal
Malfunction: Undersupply linked to depression; prozac and some other antidepressant drugs raise serotonin levels.
What are the functions and malfunctions of norepinphrine?
Function: Helps control alertness and arousal
Malfunction: Undersupply can depress mood
What are the functions and malfunctions of GABA?
Function: A major inhibitory neurotransmitter
Malfunction: undersupply linked to seizures, tremors, and insomnia
What are the functions and malfunctions of Glutamate?
Function: A major excitatory neurotransmitter; involved in memory
Malfunction: Oversupply can overstimulate brain, producing migraines or seizures.
What are the three major regions of the brain?
Brain stem (basic life functions)
Limbic system (regulation, memory, emotion)
Cerebral Cortex (Sophisticated sensory/memory processing, “higher” mental functions)
What make up the limbic system?
Thalamus, hypothalamus, hippocampus, amygdala
What is the function of the thalamus (limbic)?
Point at which all sensory information enters the brain and it sends it to where it needs to go
What is the function of the hypothalamus (limbic)?
Regulates glands, autonomic nervous system, bodily temperature, basic functions
What is the function of the hippocampus (limbic)?
Memory formation
What is the function of the amygdala (limbic)?
Fear, anger, aggression
What is the general function of the limbic system?
Regulation.
What are the cerebral cortex lobes?
Front, temporal, parietal, occipital
What is the job of the frontal lobe?
Reasoning, movement, some speech. Central executive functioning (planning ahead, organizing)
What is the job of the temporal lobe?
Memory and hearing (right behind the ear)
What is the job of the occipital lobe?
Eyes in the back of your head.
What is the job of the parietal lobe?
It processes your sense of touch and assembles input from your other senses into a form you can use. It also is how you know where your limbs are and you know where you are in space.
What is the central nervous system?
The central nervous system is the brain and the spinal cord
What is the peripheral nervous system?
PNS is all the nerves going into and out of the spinal cord.
What is the somatic division of the PNS?
It controls voluntary movements of skeletal muscles.
What is the autonomic division of the PNS?
It controls self-regulated action of internal organs and glands.
What is the sympathetic of the autonomic?
Arousing
What is an example of the sympathetic?
Getting ready for a big game and all you adrenaline is pumping.
What is the parasympathetic?
It is calming
What is an example of the parasympathetic working?
It dumps all the adrenaline when you realize something is no longer a threat.
What is the absolute threshold?
The minimum stimulation necessary to detect a particular light, sound, pressure, taste, or odor 50 percent of the time
What is the difference threshold?
The minimum difference a person can detect between any two stimuli 50% of the time
What is webers law?
To be perceived as different, 2 stimuli must differ by a constant minimum %
What are the methods of studying brain functions?
Clinical Case studies: accidents
Brain-image techniques: PET, MRI, fMRI
Electrical Recording: EEG/ERP
Experimental interventions: Lesion in Animal’s brain
What is neuropsychology?
If there is damage to specific areas it causes specific patterns of losses and brain damage provides a set of clues to how the brain is organized and which parts perform which functions.
What is visual-spatial neglect?
It’s caused by right hemisphere damage (posterior parietal lobe)
Loss of “spatial awareness”
Pay attention to one side of space (usually the right side) ignore other side
What is neglect syndrome?
A patient with a stroke in the right hemisphere was asked to copy the model drawings.
The left side of the model is almost completely ignored.
What are two classic studies of the brain?
Brain asymmetry: split-brain patients.
Phineas Gage and more recent cases of frontal lobe damage.
What are some major questions about split brain patients?
Cortex has left and right hemispheres.
Are they equal and symmetrical with redundant functions? Or specialized? Is one side dominant?
Normally left and right hemispheres are always in communications (without brain damage)
What is the function of the Corpus Callosum?
Major (but not only) pathway between sides
Permits data received on one side to be processed in both hemispheres
Aids motor coordination of left and right side
What is the left brain more known for?
Sequential processing and language.
It is in charge of written language, number skills, reasoning, spoken language, scientific skills, right-hand control
What is the right brain known for?
Holistic processing (facial recognition)
Insight, 3D forms, art awareness, imagination, left-hand control, music awareness.
What is frontal lobe syndrome (Phineas Gage)?
Distractibility, difficulty concentraing, problems with organization and planning. They also suffer from perseveration: fail to stop inappropriate behavior. Changes to “affect”: emotional expression and control
What is an ambiguous figure?
If it has more than one thing you can see easily (duck and the rabbit)
What is perception?
It is the means by which information is acquired from the environment via the sense organs and is transformed into experiences of objects, events, sounds, tastes etc.
What is the nativist position?
It states that much of our knowledge is based on innately given characteristics from this perspective, sensation and perception should be “hard-wired”
What is the empiricist position?
We are born as blank slates thus we must learn to sense and perceive.
What is nature v. nurture?
Nature is the genes and it is innate.
Nurture is the experience, upbringing, and learning
What is taste?
Taste detects chemicals; bitter, sour, sweet, salty, umami
What is transduction?
Sense has to convert to physical stimuli (light, sound waves, pressure on hand) into electrical changes in nerve receptor cells
What is smell?
It’s a chemical sense where there is the mucous lining and the smell receptor and the olfactory bulb
What is touch?
It’s a mix of different sense, warmth, cold, pressure, and pain but there may not be specialized receptors for each of these sensations.
What is the somatosensory cortex?
The brain forms a map of our body and where things are
What is the general process of hearing?
Sound waves enter ear, causes eardrum to vibrate, vibration in a fluid cochlea, which then sends information to the nervous system.
What are rods?
Rods operate under low illumination and are achromatic - night time receptors
What are cones?
Cones operate under high illumination. Chromatic. Packed around fovea - daytime receptors.
What are the fundamental differences between rods and cones?
Cones allow us to see in bright light, see fine spatial detail, see different colors whereas
Rods allow us to see in dim light, can not see fine spatial detail, and can not see different colors, detect motion/peripheral vision
What is the trichromatic theory?
It’s 3 types of cones: red, green, and blue. Cannot account for afterimages.
What is the opponent process theory?
2 types of opponent cells: red-green, blue-yellow. It can account for afterimages
What is our current view on color vision?
The way we see color is based on both the trichromatic and opponent process theory
In the case of looking at a tree what would be the distal, proximal, and percept stimuli?
The distal stimulus is the actual object you are seeing in the real world in this case the tree.
The proximal stimulus is the energy that bounces off the tree and reaches our retina.
The percept stimuli is when you’ve processed the proximal stimulus and now what do you experience when you look at the tree.
What is a lack of correspondence in perception?
It is when a percept does not correspond to the distal stimulus (perceptual illusions)
What is a paradoxical correspondence in perception?
It is when a proximal stimulus does not correspond to the distal stimulus, but the percept still does. Our brains our correcting itself for missing or misleading information.
What is perceptual constancy?
Our perception of an object’s features remains constant even when our viewpoint (and the proximal stimulus) changes.
What does perception not change with?
Perception of size doesn’t change with distance.
Perception of shape doesn’t change with viewing angle.
Perception of darkness/color doesn’t change with light
What are the main takeaways from Adelson’s Checker-shadow illusion?
Perceptual constancy can lead to illusions - lack of correspondence.
In a bright room - or even outside with lots of sunlight - level of illumination is high. even dark objects reflect a lot of light
On the other hand, in a dimly lit room, even a white square on teh checkerboard is only relfecting back a small amount of light.
So our brains have to take into account the level of illuminaiton in a visual scene. In this case, that means taking into account shadows that fall on the checkerboard.
Percept differs from ____
Distal Stimulus
Proximal stimulus does not correspond to ___________but ____does?
distal stimulus; percept
Distal Stimulus is (the world)in _____
3D or the real world
Proximal stimulus (on retina) is in _______
2D
Perceptual experience is in _____
3D
What is the monocular cue?
Information available to one eye
What is a binocular cue?
It’s when you compare an image that is received by both eyes.
What is convergence relating to binocular cues?
A binocular cue such as convergence provides the direct information to the brain, helping you to interpret the world in three dimensions.
What is interposition?
Where things are in space and if they are being blocked by certain things
What is retinal disparity (binocular cue)?
When you look at something and close one eye you see a different thing from each eye. It moves around
What is an example of retinal disparity?
If you look at your finger with one eye closed and then switch to the other eye.
What is the main set up of the visual cliff?
It was a glass surface, with checkerboard underneath at different heights. Visual illusion of a cliff and the baby can’t fall.
What are the takeaways from the Visual Cliff?
They found that 6 months old avoid the “cliff” and in species like lambs, cats that walk on 1st day after birth also avoid the cliff
What did they notice in 2 month old babies in the visual cliff?
2 months old heart rate goes down on cliff side. They notice depth but are not afraid. They can sense depth they just don’t have experience falling yet?
Is depth perception innate?
There is evidence that depth perception is innate but there is also some that is learned.
What is the subminal?
When you’re affected by stimuli so weak that you don’t consciously notice them.
What is an example of the subminal?
As unnoticed image or word can reach your visual cortex and prime your next response.
What is the myelin sheath?
a fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next
What are neurotransmitters?
they interact with each other and their effects vary with the receptors they stimulate. a particular brain pathway may use only one or two neurotransmitters and they may affect specific behaviors and emotions
Reticular formation (brainstem)
a nerve network that travels through the brainstem into the thalamus; filters information and plays an important role in controlling arousal.
Medulla (brainstem)
controls heartbeat and breathing.
Pons (brainstem)
helps coordinate movement and control sleep.
Cerebellum (brainstem)
coordinates voluntary movement and balance, and supports skill learning and memories.
Motor Cortex
part of the cerebral cortex where nerve impulses initiate voluntary muscular activity
What are some examples of split brain studies?
Sperry and Gazzaniga.
corpus callous connecting the two hemispheres of the brain is severed. severed surgically to treat epilepsy
What is the contralateral and the ipsilateral?
- contralateral: pertaining to the other side.
stroke involving the right side of the brain may cause contralateral paralysis of the left leg - ipsilateral - pertaining to the same side
Kinesthetic system (touch)
system for perception of body movements
What is the cochlea?
a coiled, bony, fluid-filled, tube in the inner ear; sound waves traveling through the cochlear fluid trigger nerve impulses
Pitch perception (Place theory vs. Frequency Theory)
pitch is a tone’s experienced highness or lowness; depends on frequency.
Place Theory - perception of sound depends on where each component frequency produces vibrations along basilar membrane > 5,000hertz
vs.
Frequency Theory - wavelength/frequency determines pitch we experience < 5,000hertz
pitch=frequency
loudness=amplitude
higher frequency = higher pitch (vise versa)
Higher amplitude=higher loudness
Types of receptor cells for each sense
Hair cells - cochlea (hearing)
Rods & Cones - visual system
Fluid in Ears - vestibular
Retina
sensitive to light and tigers nerve impulses which are sent through the optic nerve to the brain to produce a vital image. there is no depth in the retina. distant stimulus - created by light bouncing off object
Ganglion cell
neuron located in the retina
Optic nerve
neuron that transmits electrical impulses from the eyes to the brain
Fovea
the central focal point in the retina, around which the eye’s cones cluster
Sensory adaptation
fatigue of a sensory system from constant exposure to the same stimulus
Muller-lyer illusion
effects of experience such as urban dwellers more likely to see certain visual illusions (lines with arrows pointing out and one in, both the same length but looks like one is bigger than the other)
What is linear perspective?
Looking down a hallway (small square in the middle)