3.3 anatomy of the brain Flashcards
the brain
major control centre, for our behaviour and psychological experiences
subdivided into three parts: hind brain, mid brain and forebrain
divided into two cerebral hemispheres: left and right
the hindbrain
-midbrain
-pons
-cerebellum
-medulla
-spinal cord
(damage to this part is very lethal, b/c they are part of life substantial functions)
-form our functions without a need for us to be aware
ex.breath, hearts pumping
medulla
regulates breathing, heart rate, sneezing, salivating and vomiting
pons
contributes to our sleeping and waking cycle, and helps to control our balance, eye movements and swallowing
reticular activating system
important for alertness and contributes to everyday cycle of waking and sleeping
behind the spinal cord
Cerebellum
important for coordinating movements , maintaining balance, and also influences attention and emotional responses
midbrain
located behind hindbrain
serves as our transmission point for info for our senses
physical movement
midbrain:
superior colliculus
controls our orienting response to the sudden presence of a visual stimulus
midbrain:
inferior colliculus
responsible for orienting attention to the sudden occurrence of a sound
forebrain
ventricles are filled with cerebrospinal fluid
- lateral ventricle
- third ventricle
- fourth ventricle
- cerebral aqueduct
cerebrospinal fluid
performs important waste removal and nutrient providing functions
forebrain
basal ganglia:
responsible for engaging planned physical movements, learning motor skills, and integrating sensory info physical movement, and the reward system of the brain
- thamlya
- amygdala
disorders that originate from basal ganglia dysfunction include;
- parkinsons disease-uncontrollable motor function
- Huntington’s disease- cant control their muscles from twitching
- tourette’s syndrome
tourette’s syndrom
may be unable to control facial and muscle movement, their eyes from blinking, or from making grunting or snorting noises
Corprolalia-shouting offensive words is a rare symptom
the forebrain
nucleus accumbens
works with the basal ganglia to generate pleasurable experiences
forebrain
limbic system
-contains parts critical for memory and emotion amygdala hippocampus hypothalamus thalamus
amygdala
controls the creation of memory for emotional experiences and processing emotional content of stimuli
hippocampus
key structure for creating new memories
damage to this can cause catastrophic amnesia
hypothalamus
regulates body temperature and helps coordinate biological drives, such as sex and aggression, by controlling the release of hormones by the pituitary gland
-orgasms for both genders depend on signals originating from this structure
thalamus
relay station for receiving and transmitting sensory info from the eyes, ears, skin and tongue to higher brain areas
cerebral cortex
large and dense with neurons
serves as primary explanations for our mental advantages over other species
abilities to plan, make decisions , solve problems creatively, think deep thoughts and language, and our personalities
white matter(axons) , grey matter(neurons), ventricles(
neurons in cerebral cortex
mice - millions dogs -160m cats 300m chimpanzees 6 billion humans 19-23b
cerebral cortex lobes
frontal lobe
parietal lobe
occipital lobe
temporal lobe
occipital lobes
devoted to early processing of visual info with direct connections from the regions of the thalamus that relay inputs from the eyes to our brains
AKA primary visual cortex
Parietal lobes
receive info about the visual world from the occipital lobes and use it to provide us with info for visually guided action
-also contain the somatosensory cortex, which controls our sense of touch
temporal lobes
receive inputs from occipital cortex and use them to provide info about the identity and meaning of visual stimuli
top
-contains the area fro early processing of auditory info
AKA primary auditory cortex
-damage hear causing hearing impairments, cortical deafness
front
-essential for accessing general knowledge about the world
back
wernickes area- controls speech comprehension and written comprehension
frontal lobes
brocas area
involved in articulation spoken words
frontal lobes
-source of planning, initiating actions in support of those plans, creative problem-solving, language productions, and hosts our personalities
-control suppressing emotional responses when they are inappropriate for the context
back
primary motor cortex-controls voluntary movements
hemispheric specialition
right-art, creativity-music
left-language, logic and math
the idea of a division of labour b/w the hemispheres have some supportive evidence, but have also been highly exaggerated
corpus callosum
thick band of neural tissues which connects left and right
split brain patients
items presented to the right visual field can be verbally identified
- info presented from the left side of visual field gets sent to the right hemispheres of our brains and vise versa but in split brain this is not the case
- for most ppl, language production capacity originates exclusively from the left hemisphere, right cannot
neuroplasticity
the brains extraordinary capacity to change its structure as a consequence of experience and learning
- brain structure is not stable over time
- brain changes for our need
neuroscientific methods
lesioning
trans-cranial magnetic stimulation (TMS)
structural neuroimaging
lesioning
causing brain damage in non-human animals and the measuring what effect the damage has on their behaviour
trans-cranial magnetic stimulation (TMS)
directing a magnetic pulse at an area of a person’s brain and seeing what affect that has on their mental function
structural neuroimaging
non-invasive technologies that provide info about the state of brain structures
- computerized tomography (CT) scan
- magnetic resonance imaging (MRI)
- Disruption tensor imaging (DTI)
computerized tomography (CT) scan
a set of x-rays are taken of the brain by rotating a tube around the person’s head
magnetic resonance imaging (MRI)
a machine generates a magnetic field that brings hydrogen molecules in our brain into alignment
- radio waves then get sent through the skull to disrupt this alignment
- when the radio waves are turned off, energy absorbed from the radio waves are released when the H molecules become aligned by the magnetic field again
- diff types of brain matter and the ventricle release diff amounts of energy and alignment occurs at diff speed for diff types of brain matter
- computers then use this info to create a quite detailed image of the interior structure of the brain
Disruption tensor imaging (DTI)
provides a measure of white matter pathways
functional neuroimaging
tools for measuring changes in brain activity across time
- tools unable to provide researchers with an understanding of which brain areas are active during specific types of mental activity
- electroencephal ogram (EEG)
- Event related potentials
- functional magnetic resonance imaging
- positron emission tomography
- Magnetoenchephalography (MEG)
-electroencephal ogram (EEG)
involves attaching electrodes to a persons scalp and measuring the electrical activity generated by neurons sending messages to one another
event related potentials (ERPs)
EEF recordings that follow presentation of a stimulus
Magnetoenchephalography (MEG)
Provides a measure of the magnetic fields generated from neural activity
Positron emission tomography (PET)
involves injecting a radioactive substance into the bloodstream and then later using a scan to detect which parts of the brain contain more of the substance
Functional magnetic resonance imaging (fMRI)
involves placing a person’s head in a magnetic field and scanning for changes in the consumption of Oxygen by did parts of the brain
- areas that generate more deoxygenated blood, and that require more oxygenated blood to replace it are areas that are more active
- allows for the creation of images that identify the areas of the brain that identify the areas of the brain that are most active when someone is performing some mental function
Pros and Cons for each technique
EEG is fast and cheap but not very precise
MEG is more sensitive than EEG, but more expensive
PET is more expensive and slower than EEG and MEG, but also more precise at localizing brain activity
fMRI is the most expensive and not as fast as EEG and MEG, but it is faster and more precise than PET.
