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251 Mind & Brain
Chapter 4 (105-109, 117-120, 121 first paragraph)
Term | Definition |
---|---|
"Ability of the brain to change its neural pathways & connections over time because of behaviour changes, learning, memory, or in response to injury or degeneration; allows brain to develop new functions or regain functions lost due to injury or illness." | Plasticity |
"A term meaning "little man," often used to refer to the representation of the body within the brain, such as within the primary somatosensory or motor cortex." | Homunculus |
In the sensory and motor areas of the cortex, neighbouring _____ of _____ generally represent neighbouring parts of the ______. | populations, neurons, body |
Changes to a body plan, such as the loss of a limb, lead to massive _____ reorganization. | cortical |
"The process of removing or interrupting the incoming sensory information to a neuron; may occur in a deliberate experiment or during an accidental injury." | Deafferentation |
Following deafferentation, what happens to the sensory cortical areas? | They do not go unused. Instead, they are taken over by neighbors. |
"A limb that has been amputated or lost, but seems to still convey physical sensations; the perceived sensations may include touch, position, temperature, or pain." | Phantom limb |
What determines the magnitude of phantom limb pain? | Correlates with the extent of remodeling recorded in the cortex: the more changes, the more pain. |
"A persistant auditory ringing noise that is perceived even in the absence of an actual aufitory stimulus; this "ringing in the ears" may result from damage to auditory sensory structures or nerves, or from distressed emotional states." | Tinnitus |
Auditory phantom sensations | Musical and verbal hallucinations caused by cortical reorganization, in the event of progressive hearing loss. |
Temporary changes in sensory input (ex: losing a limb or simply having the nerves of an arm blocked pharmacologically) even within less than an hour cause ________. | cortical reorganization |
Cortical reorganization is proof of the brain's _____ and ______. | adaptability, plasticity |
"The idea that the brain will have a larger or smaller physical representation of a particular function or sensation, depending on the needs and experiences of the individual." | Adaptive coding |
"Form of therapy in which the more functional limb is restrained to force the patient to get better at using the injured or less functional limb (so that cortical areas don't take over neighboring functions of the injured part; rather, grow themselves." | Constraint therapy |
Adaptive coding takes place for ____ representation as well as ______ representation | sensory, motor |
"Learning to play the violin or learning to read braille both result in increased finger representations in cortical maps" is an example of what? | Adaptive coding |
"Idea that migrating axons make a connection with their target based on specific chemical signals released by the target - based on molecular cues, not based on external world interactions: Experience independent." | Chemoaffinity hypothesis |
Who came up with the Chemoaffinity hypothesis? | Sperry |
What did Sperry's chemoaffinity hypothesis allow us to learn about how the brain works? | Some general aspects of neural connectivity are prespecified and independent of experience. |
How will brain structures and learning abilities differ between rats raised in enriched environments vs deprived environments? | Rats raised in rich environments perform better at behavioural tasks and are found at autopsy to have lsuh, extensively branched dendritic trees. Rats raised in deproved environments are poor learners and have abnormally shrunked neurons. |
For humans at birth, the brain is remarkably unfinished, and ________ is necessary to complete it. | interaction with the world |
How is the brain's dependence on experience reflected through circadian rhythms? | The internal clock appears to run on a 24h cycle, but if deprived of cues to light (ex:in a cave) for several days, the circadian rhythms drift between 21-27h cycles. Proves that the brain builds a nonexact clock & pins its period on the solar cycle. |
The development of normal visual circuits depends on normal visual acitivty. It is said to be _____ _______. | experience dependent |
"Visual input that comes from both eyes, allowing depth perception." | Binocular |
Genetic instructions have ____ rather than ___roles in the detailed assembly of cortical connections. That is, neural networks require ________for their proper development. | general, specific, interaction with the world |
Explain competition at the neuromuscular junction. | Early in development, many axons innervate many muscle fibers. As the muscle matures, competition whittles down the playing field until each muscle fiber is driven by a single axon. |
"Regions or stripes within the primary visual cortex that receive input from just one eye, alternating with reigons that receive input from just the other eye." | Ocular dominance columns |
"A process in which the brain modifies or optimizes its neural circuitry by removing or withdrawing non-essential axonal connections, dendrites, or entire neurons." | Pruning |
Cells can die in which 2 ways? | 1.Necrosis 2.Apoptosis |
The general layout of brain circuitry is programmed through _____ mechanisms. _________ fine-tune these general circuits into more detailed programs. | genetic, real-world experiences |