Biopsychology Flashcards
What is Broca’s area?
An area in the frontal lobe of the brain, usually in the left hemisphere, related to speech production
What is localisation of function?
Refers to the belief that specific areas of the brain are associated with specific cognitive processes
What is the motor cortex?
A region of the brain responsible for the generation of voluntary motor movements
What is the somatosensory cortex?
A region of the brain that processes input from sensory receptors in the body that are sensitive to touch
What is Wernicke’s area?
An area in the temporal lobe of the brain important in the comprehension of language
When did interest in the localisation of function begin?
In the early nineteenth century there was a growth of interest in the theory
Where is the motor cortex located?
In the frontal lobe of the brain, along a bumpy region known as the precentral gyrus
Is the motor cortex found on both hemispheres?
Yes
The motor cortex on one side of the brain controls the muscles on the opposite side of the body
What do different parts of the motor cortex do?
Different parts of the motor cortex control different parts of the body
How are the parts of the motor cortex that control different parts of the body arranged?
The regions are arranged logically next to one another
e.g. the region that controls the actions of the foot is next to the region that controls the leg and so on
Where is the somatosensory cortex located?
In the parietal lobe of the brain, along a region known as the postcentral gyrus
What is the postcentral gyrus?
It is an area of the cortex dedicated to to processing of sensory info related to touch
What sensations does the somatosensory cortex produce and how?
It uses sensory info from the skin to produce the sensations of touch, pain, pressure and temperature
It then localises these to specific body regions
Is the somatosensory cortex found on both hemispheres?
Yes
The cortex on one side of the brain receives sensory info from the opposite side of the body
What are the two main language centres?
- Broca’s area
- Wernicke’s area
Who is Broca’s area named after?
Paul Broca
He was a French neurosurgeon who treated a patient who could only pronounce the syllable ‘Tan’
What was wrong with the patient that Broca studied?
He was able to understand spoken language, he was unable to speak or express his thoughts through writing
How many patients did Broca study, and what were they like?
8 more after the original patient who all had similar language deficits, along with lesions in their left frontal hemisphere
How did Broca discover that the ‘language centre’ was located in the posterior portion of the frontal lobe of the left hemisphere?
He studied patients with damaged right frontal hemispheres and they did not have the same language issues as the patients with a damaged left frontal hemisphere
What have scientists discovered in Broca’s area that is strange?
The area is believed to be critical for speech production, however scientists found evidence of activity in the same area when people performed cognitive tasks that have nothing to do with language
What were the two regions of Broca’s area that Fedorenko et al. found?
- One selectively involved in language
- Another involved in responding to demanding cognitive tasks
When was Wernicke’s area discovered?
Shortly after Broca’s area was discovered
Who discovered Wernicke’s area?
Carl Wernicke, a German neurologist discovered the area that was involved in understanding language
Where is Wernicke’s area located?
The posterior portion of the left temporal lobe
How were Wernicke’s patients different to Broca’s?
Broca’s patients could understand language but not speak
Wernicke’s patients couldn’t understand language but they could speak
What was Wernicke’s theory about language centres?
He proposed that language involves separate motor and sensory regions located in different cortical regions
The motor region, located in Broca’s area is close to which area of the brain?
The one that controls the mouth, tongue and vocal cords
The sensory region, located in Wernicke’s area is close to which regions of the brain?
The regions responsible for auditory and visual input
The input from theses regions is thought to be transferred to Wernicke’s area where it is recognised as language & associated with meaning
What runs between Broca’s area and Wernicke’s area?
A neural loop - it is named the arcuate fasciculus
At one end lies Broca’s area which is responsible for the production of language and at the other end lies Wernicke’s area which is responsible for the processing of spoken language
What is the name of the neural loop that runs between Broca’s area and Wernicke’s area?
Arcuate fasciculus
Where is the primary visual centre located in the brain?
It is located in the visual cortex in the occipital lobe of the brain
Where does visual processing begin?
In the retina, at the back of the eye, where light enters and strikes the photoreceptors (rods and cones)
Nerve impulses from retina are transmitted to the brain via optic nerve
Where do nerve impulses from the retina travel to?
Some travel to areas of brain involved in coordination of circadian rhythms
Majority terminate in the thalamus - acts as a relay station - passing on info to the visual cortex
Where is the visual cortex located?
It spans both hemispheres
Right hemisphere receives its input from the left-hand side of the visual field and vice versa
What do the different areas in the visual cortex do?
They process different types of info, i.e. colour, shape or movement
What is the role of the auditory centre in the brain?
It is concerned with hearing
Where is the auditory centre in the brain mainly located?
It mostly lies in the temporal lobes on both sides of the brain
Where we find the auditory cortex
What is the route of the auditory pathways in the brain?
They begin in the cochlea - in the inner ear
Pass through the brain stem
Then the thalamus
Finally reaches the auditory cortex
What is the role of the cochlea in the process of a sound reaching the brain?
It is located in the inner ear - sound waves are converted to nerve impulses
The impulses travel via the auditory nerve to the auditory cortex in the brain
What is the role of the brain stem in the process of a sound reaching the brain?
In the brain stem basic decoding takes place
i.e. the duration of a sound
What is the role of the thalamus in the process of a sound reaching the brain?
It acts as a relay station and carries out further processing of the auditory stimulus
What is the role of the auditory cortex in the process of a sound reaching the brain?
The sound has been largely decoded by this stage
In this stage it is recognised as may result in an appropriate response
What is hemispheric lateralisation?
Refers to the fact that some mental processes in the brain are mainly specialised to either the left or right hemisphere
What is split-brain research?
Research that studies individuals who have been subjected to the surgical separation of the two hemispheres of the brain as a result of severing the corpus callosum
What does the term brain lateralisation mean?
It refers to the fact that two halves of the human brain are not exactly alike
Each hemisphere has functional specialisations & some are localised primarily in one half of the brain
Give 2 examples of functions that are specialised to one side of the brain?
Left hemisphere is dominant in language & speech
Right hemisphere excels at visual-motor tasks
What did Broca discover about lateralisation in 1861?
He established that damage in a particular area of the left brain hemisphere led to language deficits
Yet damage in the same area of the right hemisphere did not have same concequences
If the main language centre is in the left hemisphere how do we process things that happen in the right hemisphere?
The two hemispheres are connected by the corpus callosum - allows info to be received by one hemisphere and sent to the other
What is the corpus callosum?
A bundle of nerve fibres which connect the two hemispheres of the brain and allow info to be passed from one side to the other
How did severe epilepsy help the research into hemispheric lateralisation?
It allowed researchers the chance to investigate the abilities of the two hemispheres
Due to a treatment for severe epilepsy - the bundle of nerve fibres that formed the corpus callosum were cut
What was the aim of cutting the corpus callosum in order to treat severe epilepsy?
To prevent the violent electrical activity the accompanies epileptic seizures from crossing one hemisphere to the other
What were patients that had their corpus callosum often referred to as?
‘split-brain’ patients
Who first studied split brain patients and when?
Roger Sperry and Michael Gazzaniga (1967)
How did Sperry and Gazzaniga test split-brain patients?
They were able to send visual info to just one hemisphere at a time in order to study what is known as hemispheric lateralisation
Because the corpus callosum is cut info presented in one hemisphere has no way of travelling to the other
What happens in a typical split-brain study?
The split-brain patient would fixate on a dot in the centre of a screen while info was presented to either left or right visual field
They were asked to make responses with either their left or right hand or verbally (controlled by left hemisphere) without being able to see what their hands were doing
What is Structural plasticity?
Growth - experience causes a change to brain structure
What is Functional plasticity?
Recovery - localised functions move from a damaged region to an undamaged region after an injury
What is plasticity?
The ability to change and adapt in response to experience
What are the brain that we are born with like?
They are small and incomplete
How do our brains develop as children?
Connections are made after new experiences
Happens very quickly in children
How do some connections in the brain grow thicker?
Connections that are used more will grow thicker & develop more branches
What happens to connections in the brain that aren’t used enough?
They are destroyed
How can plasticity help us?
It can help us recover from injury
What are the two types of plasticity?
- Structural plasticity
- Functional plasticity
What are the stages of neuroplasticity - growth and change?
1 - Synaptic pruning
2 - Neural unmasking
3 - Axonal sprouting
4 - Synapting connection
What is the purpose of neuroplasticity?
It is used for growth and change or functional recovery
What is synaptic pruning?
Axons that aren’t used will weaken and eventually be lost
What is neural unmasking?
A hormone; nerve growth factor (NGF) encourages growth
What is axonal sprouting?
Chemicals called neurotrophins sustain & encourage growth
What is synaptic connection?
The new connection makes its parent network stronger
What are the stages of neuroplasticity - functional recovery?
1 - Axon damage (axotomy)
2 - Axonal sprouting
3 - Blood vessels re-form (capillaries and glial cells)
4 - Recruitment of homologous (similar) areas
What is Axon damage (axotomy)?
Axon is severed by injury (dendrites would just re-grow)
What is axonal sprouting?
New axon/dendrite growth towards target
What happens in blood vessels re-forming (capillaries and glial cells)
Glial cells wrap around capillaries; support blood brain barrier
What is the recruitment of homologous (similar) areas?
Usually on the opposite hemisphere
What is plasticity a result of?
It is a result of life experience
How is the brain able to adapt to a changing environment?
By developing new connections and and pruning away weak ones, this makes the brain able to adapt to different environments
What was found in Boyke at al.’s study (2008)?`
Evidence of brain plasticity in 60 year old who were taught a new skill - juggling
Increases of grey matter found in visual cortex - however when practicing stopped the changes were reversed
What happens to cognitive function when age increases?
There is a natural decline in cognitive functions - can be attributed to changes in the brain
This has led to researchers to look for ways that new connections can be made to reverse this
What is an ultradian rhythm?
One that lasts less than one day (u = under)
What is an infradian rhythm?
One that lasts more than one day
What are the 5 sleep stages and what are you like during each of them?
- Gamma - Alert, learning, problem-solving
- Beta - Awake & aroused (excited/anxious)
- Alpha - Awake & relaxed
- Theta - Light sleep/dreaming/deep medetation
- Delta - Deep sleep/repair (glymphatic cycle)/dreamless
What sort of rhythmn is the sleep cycle?
Ultradian
Who theorised the Basic Rest Activity Cycle?
Kleitman (1969) - 90 mins day or night
When was the glymphatic system first described?
In 2015
What happens in the glymphatic system?
Cerebrospinal fluid (CSF) helps remove waste products from the brain in a convection process
Happens in pulses when awake, but much faster when asleep
What sort of rhythmn is the glymphatic system, and how long does it last?
It’s an ultradian rhythm - lasts 90 minutes
What can the glymphatic system be applied to in real life?
It can be applied to help us to understand Alzheimer’s development & may lead to treatments
What does oestrogen do?
Increases serotonin levels & the no. serotonin receptors
Changes the actions of endorphins (endogenous opioids) & protects nerves from damage
Can even stimulate nerve growth
What does progesterone do?
Increases amygdala activation & lowers its activation threashold
When it’s processed, one of its by-products binds to the GABA-a receptor (just like BZ drugs)
What are the symptoms of winter Seasonal Affective Disorder (SAD)?
- Overeating
- Unexplained weight gain
- Sleeping more than ususal
- Depression
What are the symptoms of summer Seasonal Affective Disorder (SAD)?
- Loss of appetite
- Unexplained weight loss
- Insomnia
- Irritability
Give some examples of 7 day rhythms (infradian)
- Testosterone cycle
- Blood pressure
- Heart rate
Give an example of a monthly rhythm in humans
The menstrual cycle
How long does the menstrual cycle last?
A month
Named this as mensis is latin for month
What is the average length of a menstrual cycle?
28 days
Some last only 23, while others can last up to 36 days (Refinetti, 2006)
How is the menstrual cycle regulated?
By hormones that either promote ovulation or stimulate the uterus for fertilsation
When does ovulation occur within the menstrual cycle?
Roughly halfway through the cycle, when oestrogen levels peak
Usually lasts for 16 to 32 hours
When do progesterone levels increase in the mestrual cycle?
After the ovulatory phase (which is halfway through)
These increase in preperation for the possible implantation of an embryo in the uterus
What sort of rhythm is Seasonal Affective Disorder (SAD)?
An annual rhythm
What are most annual rhythmns related to?
The seasons (e.g. migration in certain animals)
When do deaths and heart attacks tend to peak (annual rhythms)?
Deaths - January
Heart attacks - winter
Give two examples of ultradian rhythms found in humans
The sleep stages
Basic Rest Activity Cycle (BRAC)
What pattern does the human sleep cycle follow?
It follows patterns of REM (Rapid Eye Movement) and NREM (Non-Rapid Eye Movement) sleep
This cycle repeats every 90-100 minutes throughout the night
How do we know about the stages of the sleep cycle?
Through recording the electrical activited of the brain, with each stage showing a distinct EEG pattern
What happens when someone is in deep sleep?
Their brainwaves slow& their breathing & HR decreases
What happens during the fifth stage of the sleep cycle?
This is REM sleep (Rapid Eye Movement)
The EEG pattern resembles that of an awake person & this stage is where most dreaming occurs
What is the BRAC?
Basic Rest Activity Cycle
The 90-minute cycle found during sleep
However Kleitman also suggested the BRAC continues through the day
How is the BRAC different during the day than it is at night?
In the day, rather than moving through the sleep stages, we move from a state of alertness to a state of fatigue, every 90 mins
How long is the human body able to focus for?
(Relating to the daytime BRAC) It is said the human mind can only focus for 90 minutes
Towards the end of the end of the 90 minutes the body becomes fatigued, loss of concentration & hunger
What are biological rhythms?
Recurring patterns of behaviour in the body’s systems
e.g. endocrine syatem, immune system
What is a circadian rhythm?
A Latin term meaning a pattern/cycle that lasts around (circa) a day (dies)
How have circadian rhythms helped humans in the past?
In humans, evolutionary pressure on circadian rhythms included avoiding predators & repair/recovery/growth
How do circadian rhythms generally work in most animals?
(Ours inlcuded) the biological clock responds to sunlight
How long do circadian rhythms last?
A day (24 hrs)
