Chapter 3 Flashcards
horizontal section
parallel to floor
coronal section
anterior/posterior
sagittal section
left/right
two parts of the nervous system
central nervous system
peripheral nervous system
central nervous system
- protected within bony encasements
- self repair more limited
- includes: brain and spinal cord
brain and meninges
- brain - enclosed in skull
- meninges (3 layers)
dura mater
tough double layer of tissue enclosing brain in loose sack
arachnoid membrane
very thin sheet of delicate tissue that follows brain contours
pia mater
moderately tough tissue that clings to brain surface
subarachnoid space
filled with CSF
spinal cord
encased in interlocking bony vertebrae
- spinal nerves do not directly control the target organs
- spinal cord is connected to a chain of autonomic control centers
brain’s blood supply
- two internal carotid arteries
- two vertebral arteries that enter the skull
- branch out into smaller arteries through brain stem and cerebellum
- ex: anterior cerebral artery (ACA), middle cerebral artery (MCA), posterior cerebral artery (PCA)
peripheral nervous system
- outside the bony protections
- more vulnerable to injury
- can renew themselves after injury by growing new axons and dendrites
stem cells
- originates in single, undifferentiated, neural stem cell, a germinal cell
- self renewing, multipotential neural stem cells give rise to different types of neurons and glia in nervous system
- in developing embryo, stem cells produce progenitor cells
progenitor cells
- produce two types of blasts:
- neuroblasts
- glioblasts
neuroblasts
differentiate into neurons
glioblasts
differentiate into glial cells
stem cell differentiation process
- stem cell divides into two stem cells
- once mature, one stem cell dies for every division to keep constant number of stem cells in brain
- stem cells produce progenitor cells
- progenitor cells produce blasts
- blasts differentiate to neurons and glial cells
vertebrate embryo
(fish, amphibian, reptile)
- prosencephalon
- mesencephalon
- rhombencephalon
prosencephalon
vertebrate embryo
- forebrain
- responsible for function
- includes: telencephalon, diencephalon
- anterior: develops to form cerebral hemisphere, the cortex, and related structures
- posterior: develops to form diencephalon
telencephalon
(prosencephalon)
endbrain
diencephalon
(prosencephalon)
between brain
develops into thalamus, hypothalamus, pineal body, third ventricle
metencephalon
(rhombencelphalon)
develops into cerebellum, pons, 4th ventricle
mylencephalon
(rhombencephalon)
spinal brain, lower region of brain stem
develops into medulla oblongata, 4th ventricle
mesencephalon
middle brain
vision and hearing
develops into tectum, tegmentum, cerebral aqueduct
rhombencephalon
hindbrain (including spinal cord)
movement and balance
sensory neurons
interneurons
stellate cells, pyramidal cells, purkinje cells
motor neurons
take signals from brain and sent to muscles
types of glial cells
- ependymal cells
- astroglia
- microglia
- schwann cells
ependymal cells
line the brain’s ventricle and make the cerebral spinal fluid, the CSF
astroglia
star-shaped glia, provide structural support and nutrition to neurons
microglia
fight infection and remove debris
schwann cells
- insulate sensory motor neurons in the PNS
- this insulation is called myelin
gray matter
- gray bc of capillaries in neural cell bodies
- cortex is made predominantly of layers of neurons
white matter
axons that extend from cell bodies to form connections with neurons in other brain areas
ventricles
4 permanent pockets of the hollow regions of the brain
lateral ventricles
(1 & 2)
form c-shaped legs underlying cerebral cortex
3rd and 4th ventricles
extend into the brainstem and spinal cord
cerebral aqueduct
connects the third and fourth ventricle
CSF
- produced by ependymal glial cells located adjacent to the ventricle
- flows from the lateral ventricles out through the fourth ventricle to drain into the circulatory system at the base of the brainstem
cranial nerves
- 12 pairs of cranial nerves convey sensory and motor signals to and from the head
- One set controls the left side of the head. The other set controls the right side.
- afferent functions as for sensory inputs to the brain from the eyes, ears, mouth, and nose
- efferent functions as for motor control of the facial muscle, tongue, and eyes
- Cranial nerves with sensory function interface with the posterior part of the brainstem, and those with motor function interface with the anterior part.
- Some cranial nerves have both sensory and motor function.
tracts in spinal cord
white matter tracts
outer cord consists of white matter tracts only
gray matter tracts
- composed largely of neural cell bodies, and has the shape of a butterfly
- interior of the cord consists of gray matter
spinal cord roots
posterior root
sensory
- Afferent fibers enter the posterior spinal cord to bring information in from the body’s sensory receptors.
- The spinal nerve fibers converge as they enter forming a strand of fibers referred to as a posterior root.
anterior root
motor
Efferent fibers exit the anterior spinal cord to carry information from the spinal cord out to the muscles forming a similar strand of spinal nerve fibers, an anterior root.
Bell-Magendie Law
principle that the dorsal or posterior roots in the spinal cord are sensory, and the ventral or anterior roots are motor
- enabled neurologists to distinguish sensory from motor impairments and to draw general conclusion about the location of neural damage to spinal cord segments on the basis of the symptoms displayed by the patient
- Bell (11 years earlier) suggested the opposite functions for each root basing his conclusions on anatomical information, and the results from somewhat inconclusive experiments on rabbits
Bell-Magendie Law
cutting dorsal roots
cutting ventral roots
- cutting dorsal roots
- caused loss of sensation
- cutting the ventral roots
- caused loss of movement
reflex
- spinal cord dependent movement caused by sensory stimulation
- specific movements elicited by specific forms of sensory stimulation
- each spinal segment: cervical, thoracic, lumbar or sacral, contributes to the simple behaviors in the body parts related to that segment
- Connections between the segments organize more complex movements that require the cooperation of many spinal segments
- ex: when one leg is withdrawn in response to a painful stimulus, the other leg must simultaneously extend to support the body’s weight
- different sensory fibers mediate different reflexes: stepping, posterior support and bladder control are examples
reflex
flexion
- flexion reflexes bring the limb inward
- If the stimulus is mild, only the distal part of the limb flexes in response. But with successively stronger stimuli, the science of the movement increases until the whole limb is drawn back.
reflex
extension
- extension reflexes extend the limb outward
- stimulation of fine touch and muscle receptors
autonomic nervous system
(peripheral nervous system)
- regulates internal organs and glands. Without our conscious awareness
- keep the heart beating, deliver releasing glucose, the pupil of the eyes adjusting to light and so much more
- includes: sympathetic and parasympathetic nervous system
sympathetic system
(ANS)
- arouses the body for action
- fight or flight response
- ex: stimulating the heart to beat faster and inhibiting digestion when we exert ourselves during exercise or time of stress
parasympathetic system
(ANS)
- calms the body down
- ex: slowing the heartbeat and stimulating digestion to allow us to rest and digest
sympathetic ganglia
function somewhat like a primitive brain to control the internal organs
brain stem
- begins where the spinal cord enters the skull and extends upward into the lower areas of the forebrain
- many cranial-nerve nuclei that converge at its core and send their axon to the head muscle
- brainstem core consists of those cranial-nerve nuclei and other nuclei that mediate a variety of regulatory functions
hypothalamus
22 small nuclei and fibers systems that pass through the hypothalamus take part in nearly all aspects of motivated behavior
epithalamus
(diencephalon)
- collection of nuclei located posteriorly in the diencephalon
- secretes the hormone melatonin which influences daily and seasonal body rhythms
thalamus
(diencephalon)
- largest structure in the diencephalon
- composed of 20 nuclei, each projecting to a specific area of the cerebral cortex
- Almost all the information the cortex receives is first relayed through the thalamus. It serves as a hub interconnecting many brain regions
midbrain
includes tegmentum and tectum
tectum
(midbrain)
- receives a massive amount of sensory information from the eyes and ears
- sits on top of the third ventricle and located anteriorly
bilaterally symmetrical nuclei in midbrain
two sets of bilaterally symmetrical nuclei
locating objects in surrounding space and orienting to those objects by visual or auditory modality
includes: superior and inferior colliculus
superior colliculus
receive projection from the retina of the eye`
inferior colliculus
receive projections from the ear
tegmentum
(midbrain)
motor function
includes: red nucleus, substantia nigra, PAG
red nucleus
(tegmentum)
controls limb movements
substantia nigra
(tegmentum)
substance connects to the forebrain, a connection important for rewarding behaviors such as approaching desired objects
periaqueductal gray (PAG)
(tegmentum)
made up of cell bodies that surround the cerebral aqueduct contains circuits for controlling species-typical behavior, including sexual behavior and for modulating pain responses
and which part
hindbrain
cerebellum
(hindbrain)
- motor coordination and motor learning and may participate in coordinating other mental processes
- evolved in size in parallel with the neocortex
- contains about four times more neurons than the cerebral cortex, but they are much more densely packed
reticular formation
(hindbrain)
- network that controls sleep/wake → general arousal/consciousness
- 1949 Moruzzi and Magoun
- stimulation produced a waking pattern of electrical activity in the cats’ cortices → reticular activating system
damage to reticular formation
results in permanent unnconsciousness
pons
(hindbrain)
Nuclei within the pons breach inputs from the cerebellum to the rest of the brain
medulla
(hindbrain)
regulate such vital functions as breathing and functioning of the cardiovascular system
damage to medulla
(hindbrain)
stops breathing and heart function and therefore can result in death
basal ganglia
- movement and learning functions
- have reciprocal connections within the midbrain, especially with the substantia nigra in the midbrain tegmentum
caudate nucleus
(basal ganglia)
- receives projections from all areas of the cortex
- its own projection to the putamen and the globus pallidus, through the thalamus, and from there, to frontal cortical areas
basal ganglia impairments list
- huntington’s disease
- tourette’s syndrome
- parkinson’s disease
huntington’s disease
- progressive loss of basal ganglia cells
- involuntary motor movements
tourette’s syndrome
- loss of basal ganglia cells
- involuntary motor tics, esp of the face and head and complex movements such as hitting, lunging, or jumping
- involuntary vocalization including curse words, and animal sounds
parkinson’s disease
- loss of connection from/to the basal ganglia
- especially connection from the substantia nigra of the midbrain
- rhythmic tremors of hands and legs
- difficulty in initiating movements, and muscular agility
limbic system
regulatory behaviors, including emotion, personal memory, spacial behavior, and social behavior
and entire thing
amygdala
(limbic system)
- located in the base of the temporal lobe
- emotion
hippocampus
(limbic system)
- lying in the anterior middle region temporal lobe
- personal memory and spacial navigation
cingulate cortex
(limbic system)
- three layer strip of limbic cortex that lies just above the corpus callosum along the medial walls of the cerebral hemisphere
- sexual behavior and social interactions
limbic lobe
- receives projections from the olfactory bulbs
- Experiments have yet to demonstrate precisely what olfactory function the limbic lobe serves, but it is not required, simply for identifying others
lateral fissure
separates the frontal and the temporal lobe
gyri, singular gyrus
ridges of the cerebral cortex
sulci, singular sulcus
clefts on the cerebral cortex
central sulcus
separating the frontal and the parietal lobe
primary areas
receive projections from the major sensory systems or send motor projections to the muscles
- Sensory information enters the primary areas and then it’s passed to the secondary areas. Each of which have sensory related functions.
- The tertiary area and the posterior neocortex receives projection from the secondary areas and forms more complex associations.
- This information is then passed on to frontal tertiary areas where it can be formulated into plans of actions then may then be performed by the frontal cortex secondary and primary areas, respectively.
secondary areas
interpret inputs or organize movements
usually adjacent to primary areas and interconnected with them are involved in elaborating information received from primary areas, or in the case of primary motor areas, sending commands to it
sensory vs motor cortex
layers
- layers 1 and 3
- integrity functions
- layers 4
- dedicated to sensory input or afferent signals
- thicker in sensory cortex
- layers 5 and 6
- dedicated to output to other parts of the brain or efferent signals
- thicker in motor cortex
what are the three ways to section a mouse brain?
midsagittal, coronal, horizontal
which describes the three different pairs of anatomical references used in neuroscience?
dorsal/ventral, rostral/caudal, lateral/medial
what are the two components of the PNS?
somatic and autonomic nervous systems
when someone scares you, how does your PNS react?
by decreasing digestion and increasing blood pressure
which of the following is CORRECT concerning gray and white matter?
- gray matter is characterized by myelination
- white matter contains electrically insulated axons
- gray matter contains dendrites but not cell bodies
- white matter contains unmyelinated axons
white matter contains electrically insulated axons
the cerebral hemispheres are derived from the…
telecephalon
the central sulcus is ___ to the occipitaal lope
anterior
the ___ is located immediately above the corpus callosum
cingulate cortex
describe
- shows that the two functions are double dissociated
- can identify neural substrates that are specific to the function but not the other
- independent from one another
- double dissociation
- more power
- wanna be as specific as possible
- key word: necessity
- Single does not separate if function X or Y are based in one brain region vs another whereas the double dissociation is able to demonstrate more conclusively that X and Y are functions that are based upon a certain region and are independent of each other..
describe
This set of diagrams illustrates why permanent lesions can support certain types of inferences about the necessity of particular brain regions to particular functions that temporary inactivations cannot. What we see is that temporary inactivation of region C leads to decreased performance on the task, which might lead us to conclude that Region C is crucial to that function. However, when Region C is permanently lesioned performance on the task recovers, suggesting Region C is not essential. On the other hand, a permanent lesion to Region B does cause long-term underperformance on the task, so Region B is crucial to the function in question. Only permanent lesions can support this kind of conclusion; temporary inactivations cannot. More generally, this figure draws attention to how different methods can lead to different conclusions about the necessity of a certain region.
describe
Overall, the image is emphasizing a multidisciplinary approach to the study of brain function. That each test affords its own pros/cons to better understand the brain, but it is the use of these three in congruence that lends itself to a more precise understanding of brain function. Individually these approaches allow the researcher to see a facet of the object, but it is their combined approach that facilitates the view of a more objective and whole diamond.
- protected within bony encasements
- self repair more limited
- includes: brain and spinal cord
central nervous system
tough double layer of tissue enclosing brain in loose sack
dura mater
very thin sheet of delicate tissue that follows brain contours
arachnoid membrane
moderately tough tissue that clings to brain surface
pia mater
filled with CSF
subarachnoid space
encased in interlocking bony vertebrae
- spinal nerves do not directly control the target organs
- spinal cord is connected to a chain of autonomic control centers
spinal cord
- outside the bony protections
- more vulnerable to injury
- can renew themselves after injury by growing new axons and dendrites
peripheral nervous system
- originates in single, undifferentiated, neural stem cell, a germinal cell
- self renewing, multipotential neural stem cells give rise to different types of neurons and glia in nervous system
- in developing embryo, stem cells produce progenitor cells
stem cells
- produce two types of blasts:
- neuroblasts
- glioblasts
progenitor cells
differentiate into neurons
neuroblasts
differentiate into glial cells
glioblasts
- prosencephalon
- mesencephalon
- rhombencephalon
vertebrate embryo
vertebrate embryo
- forebrain
- responsible for function
- includes: telencephalon, diencephalon
- anterior: develops to form cerebral hemisphere, the cortex, and related structures
- posterior: develops to form diencephalon
prosencephalon
(prosencephalon)
endbrain
telencephalon
(prosencephalon)
between brain
develops into thalamus, hypothalamus, pineal body, third ventricle
diencephalon
(rhombencelphalon)
develops into cerebellum, pons, 4th ventricle
metencephalon
(rhombencephalon)
spinal brain, lower region of brain stem
develops into medulla oblongata, 4th ventricle
mylencephalon
middle brain
vision and hearing
develops into tectum, tegmentum, cerebral aqueduct
mesencephalon
hindbrain (including spinal cord)
movement and balance
rhombencephalon
sensory neurons
stellate cells, pyramidal cells, purkinje cells
interneurons
take signals from brain and sent to muscles
motor neurons
- ependymal cells
- astroglia
- microglia
- schwann cells
types of glial cells
line the brain’s ventricle and make the cerebral spinal fluid, the CSF
ependymal cells
star-shaped glia, provide structural support and nutrition to neurons
astroglia
fight infection and remove debris. Oligodendroglia insulate neurons in the CNS
microglia
- insulate sensory motor neurons in the PNS
- this insulation is called myelin
schwann cells
- gray bc of capillaries in neural cell bodies
- cortex is made predominantly of layers of neurons
gray matter
axons that extend from cell bodies to form connections with neurons in other brain areas
white matter
4 permanent pockets of the hollow regions of the brain
ventricles
(1 & 2)
form c-shaped legs underlying cerebral cortex
lateral ventricles
extend into the brainstem and spinal cord
3rd and 4th ventricles
connects the third and fourth ventricle
cerebral aqueduct
- produced by ependymal glial cells located adjacent to the ventricle
- flows from the lateral ventricles out through the fourth ventricle to drain into the circulatory system at the base of the brainstem
CSF
- 12 pairs of cranial nerves convey sensory and motor signals to and from the head
- One set controls the left side of the head. The other set controls the right side.
- afferent functions as for sensory inputs to the brain from the eyes, ears, mouth, and nose
- efferent functions as for motor control of the facial muscle, tongue, and eyes
- Cranial nerves with sensory function interface with the posterior part of the brainstem, and those with motor function interface with the anterior part.
- Some cranial nerves have both sensory and motor function.
cranial nerves
- composed largely of neural cell bodies, and has the shape of a butterfly
- interior of the cord consists of gray matter
gray matter tracts
sensory
- Afferent fibers enter the posterior spinal cord to bring information in from the body’s sensory receptors.
- The spinal nerve fibers converge as they enter forming a strand of fibers referred to as a posterior root.
posterior root
motor
Efferent fibers exit the anterior spinal cord to carry information from the spinal cord out to the muscles forming a similar strand of spinal nerve fibers, an anterior root.
anterior root
principle that the dorsal or posterior roots in the spinal cord are sensory, and the ventral or anterior roots are motor
- enabled neurologists to distinguish sensory from motor impairments and to draw general conclusion about the location of neural damage to spinal cord segments on the basis of the symptoms displayed by the patient
- Bell (11 years earlier) suggested the opposite functions for each root basing his conclusions on anatomical information, and the results from somewhat inconclusive experiments on rabbits
Bell-Magendie Law
- spinal cord dependent movement caused by sensory stimulation
- specific movements elicited by specific forms of sensory stimulation
- each spinal segment: cervical, thoracic, lumbar or sacral, contributes to the simple behaviors in the body parts related to that segment
- Connections between the segments organize more complex movements that require the cooperation of many spinal segments
- ex: when one leg is withdrawn in response to a painful stimulus, the other leg must simultaneously extend to support the body’s weight
- different sensory fibers mediate different reflexes: stepping, posterior support and bladder control are examples
reflex
- bring the limb inward
- If the stimulus is mild, only the distal part of the limb flexes in response. But with successively stronger stimuli, the science of the movement increases until the whole limb is drawn back.
reflex
flexion
- extend the limb outward
- stimulation of fine touch and muscle receptors
reflex
extension
(peripheral nervous system)
- regulates internal organs and glands. Without our conscious awareness
- keep the heart beating, deliver releasing glucose, the pupil of the eyes adjusting to light and so much more
- includes: sympathetic and parasympathetic nervous system
autonomic nervous system
(ANS)
- arouses the body for action
- fight or flight response
- ex: stimulating the heart to beat faster and inhibiting digestion when we exert ourselves during exercise or time of stress
sympathetic system
(ANS)
- calms the body down
- ex: slowing the heartbeat and stimulating digestion to allow us to rest and digest
parasympathetic system
function somewhat like a primitive brain to control the internal organs
sympathetic ganglia
- begins where the spinal cord enters the skull and extends upward into the lower areas of the forebrain
- many cranial-nerve nuclei that converge at its core and send their axon to the head muscle
- brainstem core consists of those cranial-nerve nuclei and other nuclei that mediate a variety of regulatory functions
brain stem
22 small nuclei and fibers systems that pass through the hypothalamus take part in nearly all aspects of motivated behavior
hypothalamus
(diencephalon)
- collection of nuclei located posteriorly in the diencephalon
- secretes the hormone melatonin which influences daily and seasonal body rhythms
epithalamus
(diencephalon)
- largest structure in the diencephalon
- composed of 20 nuclei, each projecting to a specific area of the cerebral cortex
- Almost all the information the cortex receives is first relayed through the thalamus. It serves as a hub interconnecting many brain regions
thalamus
includes tegmentum and tectum
midbrain
(midbrain)
- receives a massive amount of sensory information from the eyes and ears
- sits on top of the third ventricle and located anteriorly
tectum
receive projection from the retina of the eye`
superior colliculus
receive projections from the ear
inferior colliculus
(midbrain)
motor function
includes: red nucleus, substantia nigra, PAG
tegmentum
(tegmentum)
controls limb movements
red nucleus
(tegmentum)
substance connects to the forebrain, a connection important for rewarding behaviors such as approaching desired objects
substantia nigra
(tegmentum)
made up of cell bodies that surround the cerebral aqueduct contains circuits for controlling species-typical behavior, including sexual behavior and for modulating pain responses
periaqueductal gray (PAG)
(hindbrain)
- motor coordination and motor learning and may participate in coordinating other mental processes
- evolved in size in parallel with the neocortex
- contains about four times more neurons than the cerebral cortex, but they are much more densely packed
- damage
- results in equilibrium problems, postural defects and impairment of skilled motor activities
cerebellum
(hindbrain)
- network that controls sleep/wake → general arousal/consciousness
- 1949 Moruzzi and Magoun
- stimulation produced a waking pattern of electrical activity in the cats’ cortices → reticular activating system
reticular formation
results in permanent unnconsciousness
damage to reticular formation
(hindbrain)
Nuclei breach inputs from the cerebellum to the rest of the brain
pons
(hindbrain)
regulate such vital functions as breathing and functioning of the cardiovascular system
medulla
(hindbrain)
stops breathing and heart function and therefore can result in death
damage to medulla
- movement and learning functions
- have reciprocal connections within the midbrain, especially with the substantia nigra in the midbrain tegmentum
basal ganglia
(basal ganglia)
- receives projections from all areas of the cortex
- its own projection to the putamen and the globus pallidus, through the thalamus, and from there, to frontal cortical areas
caudate nucleus
- huntington’s disease
- tourette’s syndrome
- parkinson’s disease
basal ganglia impairments list
- progressive loss of basal ganglia cells
- involuntary motor movements
huntington’s disease
- loss of basal ganglia cells
- involuntary motor tics, esp of the face and head and complex movements such as hitting, lunging, or jumping
- involuntary vocalization including curse words, and animal sounds
tourette’s syndrome
- loss of connection from/to the basal ganglia
- especially connection from the substantia nigra of the midbrain
- rhythmic tremors of hands and legs
- difficulty in initiating movements, and muscular agility
parkinson’s disease
regulatory behaviors, including emotion, personal memory, spacial behavior, and social behavior
limbic system
(limbic system)
- located in the base of the temporal lobe
- emotion
amygdala
(limbic system)
- lying in the anterior middle region temporal lobe
- personal memory and spacial navigation
hippocampus
(limbic system)
- three layer strip of limbic cortex that lies just above the corpus callosum along the medial walls of the cerebral hemisphere
- sexual behavior and social interactions
cingulate cortex
- receives projections from the olfactory bulbs
- Experiments have yet to demonstrate precisely what olfactory function the limbic lobe serves, but it is not required, simply for identifying others
limbic lobe
separates the frontal and the temporal lobe
lateral fissure
ridges of the cerebral cortex
gyri, singular gyrus
clefts on the cerebral cortex
sulci, singular sulcus
separating the frontal and the parietal lobe
central sulcus
receive projections from the major sensory systems or send motor projections to the muscles
- Sensory information enters the primary areas and then it’s passed to the secondary areas. Each of which have sensory related functions.
- The tertiary area and the posterior neocortex receives projection from the secondary areas and forms more complex associations.
- This information is then passed on to frontal tertiary areas where it can be formulated into plans of actions then may then be performed by the frontal cortex secondary and primary areas, respectively.
primary areas
interpret inputs or organize movements
usually adjacent to primary areas and interconnected with them are involved in elaborating information received from primary areas, or in the case of primary motor areas, sending commands to it
secondary areas
- layers 1 and 3
- integrity functions
- layers 4
- dedicated to sensory input or afferent signals
- thicker in sensory cortex
- layers 5 and 6
- dedicated to output to other parts of the brain or efferent signals
- thicker in motor cortex
sensory vs motor cortex
layers
single dissociation
can do one thing but not the other
A lesion to brain structure A disrupts function X but not function Y. Such a demonstration allows one to infer that function X and function Y are independent of each other in some way.
double dissociation
two related mental processes are shown to function independently of each other
If one manipulation affects the first variable and not the second, the other manipulation affects the second variable and not the first. If one can demonstrate that a lesion in brain structure A impairs function X but not Y, and further demonstrate that a lesion to brain structure B impairs function Y but spares function X, one can make more specific inferences about brain function and function localization.
can do one thing but not the other
A lesion to brain structure A disrupts function X but not function Y. Such a demonstration allows one to infer that function X and function Y are independent of each other in some way.
single dissociation
two related mental processes are shown to function independently of each other
If one manipulation affects the first variable and not the second, the other manipulation affects the second variable and not the first. If one can demonstrate that a lesion in brain structure A impairs function X but not Y, and further demonstrate that a lesion to brain structure B impairs function Y but spares function X, one can make more specific inferences about brain function and function localization.
double dissociation
ganglia vs nerves vs tracts
ganglia - cell clusters/bodies in PNS
nerves - cell clusters/bodies that enter and leave CNS
tracts - cell clusters/bodies in CNS
tertiary areas/association areas
modulate information between secondary areas
oligodendroglia cells
glial cell
Oligodendroglia insulate neurons in the CNS
insulate neurons in the CNS
oligodendroglia cells
cerebellum damage
results in equilibrium problems, postural defects and impairment of skilled motor activities
results in equilibrium problems, postural defects and impairment of skilled motor activities
cerebellum damage
