Biopsychology Flashcards
Define Central Nervous System
Made up of the brain and spinal cord
It’s 2 main functions are to control the behaviour and regulation of the body’s physiological processes
Cells in the NS are called neurons
- relay neurons are in the CNS
Nervous system
Made up of neurons that release neurotransmitters. Communicate via neurotransmitters
Sensory neurons pick up stimuli using the sensory receptor, sensory nreurons turn this into a nerve impulse, which travels down the axon of the sensory
Explain the breakdown of the CNS
CNS>PNS>SNS+ANS>(ANS)SNS+PNS
Central, Peripheral, somatic/autonomic, sympathetic/parasympathetic
Peripheral NS
Relays information via nerve impulses from the rest of the body back to the CNS
motor/sensory neurons are in both PNS + CNS
Somatic NS
controls muscle movement and receives information from sensory receptors
Autonomic NS
The part of the peripheral nervous system that controls our body’s involuntary movements, internal organs.
Features of sympathetic and parasympathetic NS
SNS: heartbeat accelerates, pupils dialate, inhibits salivation
PNS: heartbeat slows, pupils constrict, stimualtes salivation
[can remember as paramedic would help you to return to normal]
Process of synaptic transmission
nerve impulses arrive at pre-synaptic terminal
synaptic vesicles travel to the pre-synaptic membrane
the pre-synaptic membrane and synaptic vesicles fuse, releasing neurotransmitters
these diffuse from through the synaptic cleft
binding onto receptors on the post-synaptic terminal
neurotransmitters can be recycled and released back into the cleft, which are then re-uptaken by re-uptake proteins
what is summation
occurs when multiple nerve impulses occur in the pre-synaptic neuron
when multiple small changes in voltage add up together.
post-synaptic potentials
Excitatory neurotransmitters cause
positively charged particles to enter the post-synaptic neuron, and inhibitory neurotransmitters cause
negatively charged particles to enter the post-synaptic neuron.
Main function of the 3 different neurons
sensory
neurons, which pick up sensory information from sensory receptors, and transmit information towards the brain.
relay
neurons, which transform and process information.
motor
neurons, which carry information away from the brain, and tell our muscles to move.
Endocrine system
The ES is made up of glands which release hormones into the blood stream.
Communicate via
hormones
What is a gland
A cluster of cells that release hormones into the blood stream. They are part of the ES
Explain the difference between the NS and the ES
The cells in the ES group into clusters called glands. The ES communicates via glands which release hormones into the blood stream
Whereas the cells in the NS are called neurons. The NS communicates through electrical signals sent from one neuron to the next
Function of the glands in the brain
Receive electrical signals from neurons, and then send hormones.
Gland examples - Adrenal gland
Located above the kidneys, releases hormones in response to stress.
Inside is the adrenal medulla [adrenaline] and outside is the adrenal cortex [cortisol]
Pituitary gland (master gland)
Located in the brain
controls the release of hormones from all the glands in the body - releases ACTH
The pituitary gland receives electrical signals from neurons in the brain. In response, the pituitary gland releases hormones into the bloodstream.
ES communication (from stimulus)
A stimulus causes the gland to release a hormone into the bloodstream. Then the hormones travel around the bloodstream until they reach target cells. They bind to the receptors on the target cells. And this causes a response in the target cell.
Hypothalamus
Is part of the ES AND CNS
sits above the pituitary gland
Define fight or flight
The fight or flight response is a bodily reaction that occurs in response to stress and potential danger.
State 7 bodily reactions caused by the ForF response
pupil dialation
increased sweating
increased muscle tension
increased breathing
increased heart rate
decreased salivation
decreased digestion
Fight or flight process
Hypothalamus detects the stressor
Triggers the ANS into its sympathetic state
Pituitary gland releases ACTH
Causes the adrenal medulla to release adrenaline
Leading to bodily changes such as…
Fight or flight A03
Define brain localisation
Different functions are localised to different parts of the brain - localisation of function
Define hemispheric lateralisation
The idea that the two hemispheres perform different functions
Left hemisphere
Associated with language; understanding, speaking, reading
Right hemisphere
Spatial skills
Hemisphere communication
The 2 hemispheres work together to perform a task. This is done by sending nerve impulses to each other. Damage to either hemisphere would
Corpus callosum
A bundle of nerve axons that enables communication between the two hemispheres.
Both hemispheres involved in (examples of contralleral):
smell, taste and hearing are processed by both hemispheres
(movement + 5 senses)
examples of functions organised contralaterally
vision, touch, movement are organised contralaterally
processed in one hemisphere for the opposite side of the body (ie right hem controls left side of the body)
If a function is not hemispherically lateralised
The patient should be able to perform the function, regardless of whether the stimulus is presented to the right or left hemisphere.
If a function is hemispherically lateralised to the right hemisphere
The patient will only be able to perform the function if the stimulus is presented to the right hemisphere
Broca - Patient Tan
Had speech issues but the other parts of his brain were unaffected
Broca’s aphasia
Seizure
When someone has a brain abnormality that causes their brain to produce too much electrical activity
Split brain
Doctors may cut the corpus callosum of extreme seizure patients. This stops excess electrical activity from spreading to the other hemisphere, so that the seizure can be contained in one area. However they can now no longer communicate
Split brain research*friday worksheet
Patients are presented a stimulus, to one side to be processed by the opposite hemisphere.
Ask patient to respond to the stimulus
Split brain research: Sperry method
Presented images to either left/right hem.
1st study found that if patients were asked to point to one of four pictures to identify which matched the image, they could perform the task, whichever hem it was presented to.
2nd study found that if patients were asked to verbally describe the image, they could only perform this task if the image was presented to their left hem.
conc: language is hemispherically laterelised to the left hem
Split brain research A03
-rare procedure: split brain research only has a small number of ppts (unusual sample), findings may lack GENERALISABILITY. we cannot be sure other people’s brains work in the same way.
-seizure activity is a CONFOUNDING VARIABLE, seizures may have previously affected the way that their brain worked prior to the surgery.
-recent research shows results have not been REPLICATED as they have shown that not all aspects of language have been controlled by the left hem
label/explain brain regions
Motor cortex: controls body movement by sending nerve impulses to motor neurons (right side)
Somatosensory cortex: processes touch by receiving impulses from the sensory neurons (contralaterally controlled)
Auditory cortex: processes sound, there’s an auditory cortex in both hemispheres but is not contralaterally organised
Visual cortex: processes visiual info. receives nerve impulses from sensory neurons that talk to sensory receptors in your eyes
Brocas area: to produce language, left hemisphere
Wernickes area: to understand language, left hemisphere
A03 for brain localisation
+ Case studies using post-mortem, damaged brain areas consistently led to same abnormal behaviour
- over-simplified, because a complex function often requires more than one brain region/area (Dronkers study, scanned tan’s brain and found he had more damage)
- ignores the importance of communication between brain regions, axons branch to other brain regions,
Sperry research findings
Language is hemispherically lateralised to the left hemisphere
Brain plasticity definition
plasticity refers to the flexibility of something
research shows that the brain can adapt quickly to new situations, different life experiences can affect different parts of the brain
Brain Pl: Functional recovery
When a function is regained after other brain regions adapt and take over lost functions
Mechanisms of functional recovery - synapse strengthening
Synapses in near by brain areas become strengthened (nerve impulses being transmitted between two neurons increase) to take on the function of the damaged areas
Mechanisms of functional recovery - Rewiring
Neurons can form new connections and change which neurons they are connected to, rewiring is when new connections are formed between new synapses
Mechanisms of functional recovery - Neuronal Unmasking
when a silent synapse becomes active
silent synapse: synapse becomes inactive due to a lack of nerve impulses
How can synapses be strengthened
neurotransmitters released from the pre-synaptic terminal can be increased
the number of receptors available to receive the impulses can be increased
Brain plasticity types
Pruning: connections are lost due to a lack of use
Bridging: new connections are created due to use of a new stimulus
Maguire’s taxi driver study
Compared London taxi-drivers to a control group of non-taxi drivers and did and MRI
found that they have larger hippocampus volume this is due to the rewiring that there brains have, brain adapts as a result of experiences
Limitations of Maguire’s study
- it was quasi: meaning she couldn’t randomly assign them to an experimental group as they were either taxi drivers or not, cannot control participant variables
- could not establish cause and effect, maybe they already had a larger hippocampus, better memory and that made them want to be a taxi driver
BP: video games - improves neuroplasticity
Kuhn(2014): asked ppts to play super Mario for at least 30 mins for 2 months. They compared their brain development to a control group who didn’t play. They found significant differences in the grey matter
BP: meditation - improves neuroplasticity
Davidson et al (2004): studied Tibetan monks meditating vs a CG of non-meditators
Each group was asked to meditate, whilst fitted with electrical sensors to measure brain activity
The monk group showed higher levels of gamma wave activity
Ways of investigating the brain: fMRI
functional magnetic resonance imaging
Measures the blood flow in a persons brain, when patient is doing a task, by detecting changes in oxygen and flow that acts as a result of electrical activity in the brain
It produces 3D images to show which parts of the brain are active.
Difference between fMRI and MRI
MRI shows structural information whilst fMRI also shows brain activity. Both MRI and fMRI techniques are non-invasive.
fMRI A03
+ can investigate the relationship between brain activity and behaviour
-can’t establish a cause/effect rs
-assumes that changes in electrical activity is the only thing that affects blood flow
-time lag: may be too slow to pick up all changes and lack validity
Ways of investigating the brain: EEG
Electroencephalogram
Measures electrical activity via electrodes that are fixed into a skull cap. Picks up signals from the cortex, a signal can only be detected by the electrode if enough cells generate electrical activity.
EEG A03
+Allows us to measure actual neural activity in the brain directly.
+Allows us to detect certain types of events in the brain (synchronised activity)
-Cannot tell which neurons are generating the activity
-Cortex is only one brain region
-hard to interpret because the electrical signals are so small.
Ways of investigating the brain: ERP
Event related potentials
Isolates specific neural responses associated with specific events, the stimulus is presented to the patient over and over again, uses an EEG
ERP A03
+ can identify small electrical signals associated to a specific stimulus
- don’t know which neurons generate the ERP
- can only look at signals generated by the cortex
- stimulus has to be presented over and over, requires a very large number of trials to obtain meaningful data
Ways of investigating the brain: Post-mortem
A detailed examination of a person’s brain after-death to look for evidence of brain abnormalities.
Post-mortem A03
+ a person’s brain can be examined at a very high level of detail, to identify very small brain abnormalities
-no info about when the brain abnormality occurred making it difficult to establish a cause/effect relationship
- difficult to control confounding variables and extraneous variables ie. medication that may also affect brains
Circadian Rhythms
A biological rhythm that operates along a 24 hour cycle. It regulates a number of bodily processes such as the sleep/wake cycle
Circadian rhythm study
Duffy conducted a controlled obsevration on sleep/wake cycles. she found that we have different timings of our circadian rhythms (s/w and body temperature)
Define infradian rhythm and ultradian rhythm
Infradian: Biological rhythms that occur less than one cycle in 24 hours
Utradian: Biological rhythms that occur more than one cycle in 24 hours
Infradian and ultradian examples
Infra: menstural cycle, seasonal affective disorder (SAD)
Ultra: sleep cycle
Ultradian A03
Tucker et al conducted a controlled experiment where he observed their stages of sleep
Found that there was large individual differences in the length of the stages of sleep, mainly in stage 3/4 (deep sleep)
Endogenous Pacemaker + SCN
Internal body clock that regulates biological rhythms
SCN is a primary EP a tiny bundle of nerves in the hypothalamus which maintains circadian rhythms
Animal studies with SCN [2 studies]
DeCoursey et al (2000): destroyed SCN connections in 30 chipmunks. Returned them back to their natural habitats and monitored them for 80 days. Their sleep/wake cycle was destroyed and many were killed by predators
Ralph (1990): bred ‘mutant’ hamsters with a 20 hour s/w cycle. Transfered the SCN of the mutant hamsters to ‘normal’ hamsters. The s/w cycle also became 20 hours
Both studies highlight the role of the SCN in establishing and maintaining the s/w cycle
This gave him good evidence that the SCN is needed to control the sleep/wake cycle.
Pineal Gland and Melatonin
SCN passes info about the light and day length. During the night, the gland secretes melatonin and melatonin inhibits sleep by inhibiting brain mechanisms. It causes drowsiness and reduces body temp
Demonstrating that there is interactions between EZs and EPs
What are Exogenous Zeitgebers
Things outside the body which influence the biological rhythms
gives the body extra cues
Light, Noise, Social Interactions
Explain how light works as an EZ
Sensory neurons in the retina respond to light and send information directly to the SCN to influence melatonin release
EZ Siffre study
Isolated himself in a cave away from EZs for 6 months
to find the effect of light on the sleep wake cycle
He found that his sleep wake cycle got longer, light is need to regulate the sleep wake cycle
But it was a case study so it may lack generalisability
