Biopsychology Flashcards
What are neuronal cells?
cells that receive and transmit electrical signals
What are electrical impulses also called?
action potentials
How are neurones specialised?
For communication between other neurones to and from muscles or with other organs
How does communication happen between neurons?
through electrical impulses called an action potential
What does the cell body contain?
has a nucleus with genetic material
What are the four main components of the neuron?
dendrite, cell body, axon, and axon terminal
What is the axon?
a long extension from the cell body that has branches off it and covered with a myelin sheath
What is the function of the axon?
cries the impulses away from the cell body
What is the myelin sheath?
protector of the axon and helps increase the speed of impulse
What do Nodes of Ranvier do?
helps to speed up the impulse by forcing the impulse to ‘jump’ across the gaps along the axon
What are dendrites?
the protrude out from the cell body and connect towards other cells
What do dendrites do?
receive information
What do terminal buttons do?
send signals to an adjacent neuron or cell across the synapse
Where are nerve impulses triggered?
In the cell body of a neuron
When does a neuron generate a nerve impulse?
- there is a change in voltage at the cell body
- the change in voltage is large
How do nerve impulses travel?
Nerve impulses only travel in one direction, from the dendrite to axon terminal
What is the synapse?
A specialised gap that allows electrical messages from one neuron to transfer to another neuron
What is the definition of synaptic transmission?
the process through which nerve impulses are transmitted across the synapse
What is the presynaptic terminal?
The pre-synaptic terminal is the part of the axon terminal where a neuron forms a synapse with a second neuron.
What is the synaptic cleft?
What is the post synaptic neuron?
The post-synaptic terminal is the part of the dendrite where the second neuron forms a synapse with the first neuron.
What are synaptic vesicles?
The little round bags in the pre-synaptic terminal are called synaptic vesicles.
What are synaptic vesicles filled with?
neurotransmitters
What is Step 1 in synaptic transmission?
The nerve impulse arrives at the pre-synaptic terminal, causing the synaptic vesicles to travel down to the pre-synaptic membrane
What is Step 2 in synaptic transmission?
Synaptic vesicle and pre synaptic membrane fuse causing neurotransmitters to be released into the synaptic cleft
What is Step 3 in synaptic transmission?
Neurotransmitters diffuse across the synaptic cleft towards the post synaptic terminal
What is Step 4 in synaptic transmission?
The neurotransmitters bind to
receptors on the post synaptic membrane.
What is Step 5 in synaptic transmission?
receptors usually block positively charged particles from entering the post-synaptic neuron.
when neurotransmitters bind to post-synaptic receptors, the receptors change shape to allow flow into the post-synaptic terminal.
The more positively charged particles flow into the post-synaptic terminal…
the more likely it is that a nerve impulse is generated at the cell body.
When positively charged particles flow into the post-synaptic neuron, they cause
a small positive change in voltage.
What is the full process of synaptic transmission?
A nerve impulse (electrical impulse) travels down an axon, it arrives at the presynaptic terminals.
Electrical impulses (action potentials) trigger the release of neurotransmitters (from the synaptic vesicles) into the synapse.
Neurotransmitters diffuse across the synaptic cleft from vesicles.
Neurotransmitters combine with receptors on the postsynaptic membrane.
Stimulation of postsynaptic receptors by neurotransmitters result in either excitation (depolarisation) or inhibition (hyperpolarization) of the postsynaptic membrane
When is an action potential triggered In the cell body?
If the change in voltage is big enough
What happens after a neurotransmitter binds to the receptor on the post-synaptic membrane?
Positively charged particles flow into the post-synaptic membrane
What happens after positively charged particles flow into the post-synaptic membrane?
The neurotransmitter is released back into the synaptic cleft.
What is re-uptake?
process of removing neurotransmitters from the synaptic cleft.
What is responsible for the reuptake process?
The pre-synaptic terminal re-uptakes neurotransmitters.
What are Re-uptake proteins?
structures that suck up the neurotransmitters into the pre-synaptic terminal
What are the 5 steps of synaptic transmission?
The nerve impulse arrives at the pre-synaptic terminal, causing synaptic vesicles to travel to the pre-synaptic membrane. Step: 1
Synaptic vesicle and pre-synaptic membrane fuse, causing neurotransmitters to be released into the synaptic cleft. Step: 2
Neurotransmitters diffuse across the synaptic cleft towards the post-synaptic terminal. Step: 3
Neurotransmitters bind to receptors on the post-synaptic terminal, allowing particles to flow into it. Step: 4
Neurotransmitters are released into the synaptic cleft and are removed through the process of re-uptake. Step: 5
What is summation?
a process that makes it more likely a nerve impulse will be triggered when successive changes in voltage add up in the post-synaptic neuron.
When does summation occur?
occurs when multiple nerve impulses occur in the pre-synaptic neuron, in quick succession, multiple small changes in voltage add up together.
What do excitatory neurotransmitter do?
cause positively charged particles to enter the post-synaptic neuron
What do inhibitory neurotransmitter do?
inhibitory neurotransmitters cause negatively charged particles to enter the post-synaptic neuron.
What do excitatory neurotransmitters create?
excitatory post synaptic potentials
What do inhibitory neurotransmitters create?
lead to inhibitory post synaptic potentials
What neurotransmitter make a nerve impulse more likely to occur?
excitatory neurotransmitters
What are excitatory post-synaptic potentials?
A: Excitatory post-synaptic potentials are changes in the membrane potential of the post-synaptic neuron that make it more likely to generate an action potential.
What are inhibitory post-synaptic potentials?
A: Inhibitory post-synaptic potentials are changes in the membrane potential of the post-synaptic neuron that make it less likely to generate an action potential.
Can excitatory post-synaptic potentials and inhibitory post-synaptic potentials summate?
A: Yes, excitatory post-synaptic potentials and inhibitory post-synaptic potentials can summate (combine), but their effects can oppose each other.
How do inhibitory post-synaptic potentials affect excitatory post-synaptic potentials?
A: Inhibitory post-synaptic potentials can cancel out or negate the effects of excitatory post-synaptic potentials.
What determines whether a nerve impulse occurs?
A: Whether a nerve impulse occurs depends on the balance of excitatory and inhibitory neurotransmitters binding to post-synaptic receptors.
What is dopamine?
This can be both an excitatory and inhibitory neurotransmitter, and controls our responses to rewards.
What is serotonin?
This can be both an excitatory and inhibitory neurotransmitter, and controls our response to mood.
What is the function of sensory neurons?
Carry messages from the PNS to CNS
Sensory neurons pick up information from sensory receptors
Sensory neurons send information towards the brain
Where are sensory neurons located?
near our sensory receptors
The neurons that pick up sensory information from sensory receptors, and transmit information towards the brain, are called…
sensory neurons
What are the functions relay neurons?
Relay neurons can form synapses with both sensory and motor neurons
Relay neurons process and transform sensory information
Where are relay neurons positioned?
between sensory and motor neurons
What are the functions motor neurons?
carries messages from CNS to muscles and glands and cause them to contact
Where are motor neurons positioned?
Motor neurons are positioned next to muscles, and form synapses with them
What is the structure of sensory neurons?
long dendrites and short axons
What is the structure of relay neurons?
short dendrites and short or long axons
What is the structure of motor neurons?
they have short dendrites and long axons
When does a nerve impulse occur?
A nerve impulse occurs if multiple excitatory post-synaptic potentials summate in the post-synaptic neuron.
What and the two divisions of the human nervous stem?
Central nervous system and peripheral nervous system
What are the sub parts of the CNS?
The brain and spinal cord
What is the brains function in the human nervous system?
maintains life, involved in higher functions and psychological processes
What is the spinal cords function in the human nervous system?
receives and transmits information to and from the brain
What is the spinal cord?
the bunch of nerve axons that extends from the bottom of the brain down to the bottom of our back
What is the nervous system?
the network of all the neurons in the body
What is the peripheral nervous system?
All the parts of the nervous system that are outside the brain and spinal cord are part of the peripheral nervous system.
What are the two parts of peripheral nervous system?
Somantic and autonomic
What is the somantic nervous system?
transmits information to and from sense and to and from CNS
The activities of the somatic nervous system are usually unconscious.
Controls muscles movements
What is the autonomic nervous system?
transmits information to and from internal organs to sustain life processes - The activities of the autonomic nervous system are usually unconscious.
Governs vital functions in the body e.g. breathing
What are the two branches of the autonomic nervous system?
sympathetic and parasympathetic
What is sympathetic division of the autonomic nervous system?
The part that increases bodily activities - Fight or flight response
What is parasympathetic division of the autonomic nervous system?
The part that generally decreases bodily activities and maintenance - rested and saving energy
What is a discussion point of the nervous system?
Research into the nervous system has significantly contributed to the development of medications that address various psychological and neurological disorders.
How do glands communicate?
By releasing hormones
What are hormones?
chemical messengers released into the bloodstream and act as messages
How does the endocrine system communicate?
Through hormones released into the bloodstream
What are glands?
clusters of cells that release hormones
How do the glands in our brains communicate?
sending hormones into the bloodstream
What is the endocrine system?
A system of glands that release hormones into the bloodstream.
Hormones communicate messages to organs, influencing behavior.
What does the pituitary gland do?
Called the “master gland” because it controls other glands.
What does the thyroid gland control?
Releases thyroxine, affecting metabolism and growth rates.
What do adrenal glands do?
Release adrenaline in response to stress
How does the pineal gland affect sleep?
Releases melatonin.
Regulates the sleep-wake cycle.
What does the adrenal medulla release?
adrenaline in response to stress.
What does the adrenal cortex release?
cortisol in response to stress.
What is the adrenal cortex?
the outer bit of the adrenal gland.
What is the adrenal medulla?
the inner bit of the adrenal gland.
What can the piturarty gland do?
receive electrical signals from other neurons in the brain.
What is the pituitary gland?
The pituitary gland is a master gland, which controls the release of hormones from other glands in the body.
What does the pituitary gland release?
ACTH
What happens when a stimulus occurs in the body?
A stimulus causes a gland to release a hormone into the bloodstream.
How do hormones travel in the body?
Hormones travel around the bloodstream until they reach target cells.
What happens when hormones reach target cells?
Hormones bind to receptors on the target cells.
What is the result of hormones binding to receptors on target cells?
The binding causes a response in the target cell.
What is the fight or flight response?
The fight or flight response is a bodily reaction that occurs in response to stress and potential danger and is a reflex response
Where is the fight or flight response generated from?
The autonomic nervous system - sympathetic branch
What does the fight or flight response help an individual do?
react more quickly than normal and helps optimum functioning so that they can fight or run away
What are the 6 bodily reactions that occur while the sympathetic nervous system prepares the body for action?
Pupil dilation, increased sweating, increased heart rate, increased breathing, decreased salivation, and decreased food digestion.
What does heart rate increasing do to help the fight or flight response?
to speed up blood flow to vital organs and improve the speed of adrenaline around the body
What does pupil dilation do to help the fight or flight response?
improve vision
What does faster breathing rate do to help the fight or flight response?
increase oxygen intake
What does production of sweat do to help the fight or flight response?
to regulate temperature (cool the body down)
What does reduced functioning of the digestive system do to help the fight or flight response?
to save energy for running
What does reduced saliva do to help the fight or flight response?
digestion is inhibited
What role does the hypothalamus play in the fight or flight response?
The hypothalamus detects stress and triggers the fight-or-flight response.
It signals the adrenal glands to release adrenaline and other hormones.
To increase or decrease bodily activities, the hypothalamus sends electrical signals to the autonomic nervous system.
What is the chain of communication involved in the fight or flight response via the hypothalamus?
Signals from the autonomic or somatic nervous system and the somatic or autonomic nervous system reach the hypothalamus . This then releases chemicals called hormones that target the pituitary gland. This gland then releases hormones that target other glands, like the adrenal gland
What are the chain of event for the fight or flight response?
- immediate threat
2 hypothalamus, send electrical signal - sympathetic nervous system activates
- adrenal medulla released
- adrenaline
- bind to receptors of target cells
What is the chain of events for the slow response?
- Threat
- hypothalamus releases hormones
- pituitary gland released ACTH activating
- adrenal cortex releases
- cortisol
- binds to target cells
How does the body slow down after a fight or flight response?
to slow down the body, the hypothalamus sends electrical signals to the parasympathetic nervous system.
What happens in the body when stress is removed?
- The hypothalamus activates the parasympathetic nervous system.
- Bodily activities decrease
- The rest and digest response happens.
What is the response of the parasympathetic nervous system that maintains and conserved body energy?
pupils constrict to normal size
heart rate decreases
breathing back to normal
less sweat produced
digestion increases
saliva increases
What is a discussion point of the endocrine system?
The fight or flight response, which was essential for survival in our ancestors, is often triggered unnecessarily in modern society.
What is a limitation of fight or flight research?
A limitation of the fight or flight research is that it does not account for individual differences in how people respond to stress.
What is plasticity?
the apparent ability of the brain to change and adapt its structure and processes as a result of experience and new learning
What change happens to the brain during childhood?
goes through rapid growth in the number of synaptic connections
What happens to the connections were rarely use as we get older and what happens to the ones we use frequently?
the connection we rarely use are deleted, however connections frequently used are strengthened
TRUE OR FLASE: existing neural connections can change at any time in life. New neural connections can be formed due to learning and experience
TRUE
What is functional recovery?
When a function is regained after brain damage, because it is transferred from the damaged brain region to an undamaged brain region.
What changes happen in the brain during plasticity?
an increase in cell dendrites causing the number of synapses available increase in order to meet increased processing demands
What are structural changes?
changes in the size and number of synaptic connections between neurons
What is synapse strengthening?
when the likelihood of nerve impulses being transmitted between two neurons increases
What is rewiring neurons?
new neuron connections are formed between two neurons that aren’t already connected.
When do neurones rewire and reorganise itself?
during recovery, new synaptic connections are made
What are the 3 structural changes that can happen in the brain?
- Denervation supersensitivity
- recruitment of similar areas on the opposite side of the brain
- axonal sprouting
What is recruitment of similar areas on the opposite side of the brain?
This is for specific tasks, for example if Brocas area was damaged on the left side of the brain, the right sided equivalent would carry out its function. This could be temporary until functionality shift back to the original side
What is denervation supersensitivity?
this occurs when axons that do a similar job become aroused to a higher level to compensate for the ones that are lost
What is axonal sprouting?
the growth of new nerve endings which connect with other undamaged nerve cells to form new neural pathways
What is a silent synapse?
A synapse that becomes inactive due to a lack of nerve impulses.
What is brain plasticity?
The brain’s ability to change and adapt in response to new experiences
The brain’s ability to change and adapt in response to brain damage
What was the aim of Maguire et al. (2000) study on taxi drivers?
To investigate differences in the hippocampus between London taxi drivers and controls.
To explore the correlation between the length of taxi-driving experience and grey matter volume.
What was the IV of maguries study?
the persons job - taxi driving
What was the method used in Maguire et al.’s (2000) study?
16 right-handed adult male London taxi drivers (mean age 44), with an average of 14.3 years of experience.
50 right-handed adult male controls, matched on age.
MRI brain scans were used to compare grey matter volume in the hippocampus between the two groups.
What were the key results of the study?
Taxi drivers had greater grey matter volume in the posterior hippocampus than controls.
Controls had greater grey matter in the anterior hippocampus than taxi drivers. - Maguire found that taxi drivers have an increased brain volume in the hippocampus.
No difference in overall hippocampus size.
Positive correlation between right hippocampus volume and taxi-driving experience in the posterior hippocampus; negative correlation in the anterior hippocampus.
What did the conclusion of Maguire et al.’s (2000) study suggest?
There are differences in the hippocampi of taxi drivers and controls.
Taxi drivers have larger posterior hippocampus volume, while controls have larger anterior hippocampus volume.
Dependence on navigation skills is linked to changes in brain structure, supporting the idea of brain plasticity.
How does Maguire et al.’s (2000) research support brain plasticity?
The study shows that specific brain areas, like the hippocampus, can change in response to environmental stimuli, such as learning complex navigation routes.
MRI scans showed an increase in grey matter volume in the posterior hippocampus of taxi drivers, demonstrating brain adaptability.
What is the first strength of plasticity and functional recovery after trauma?
A strength of plasticity is its role in functional recovery after trauma, with evidence showing that it continues throughout the lifespan.
What is the first limitation of plasticity and functional recovery after trauma - Maguire study?
One limitation of Maguire’s study is that she could not directly manipulate the independent variable, which was already a personal characteristic of the participants.
What are biological rhythms?
A change in body processes that conform to cyclical time periods/Processes in the body that follow a cycle
What is a cycle
A series of events that is continuously repeated in the same order
What influences biological rhythms?
Internal body clocks (endogenous pacemakers) and external changes to the environment (exogenous zeitgebers)
What are 3 biological rhythms?
Circadian rhythms
Infradian rhythms
Ultradian rhythms
What are circadian rhythms?
They are biological rhythms that repeat every 24 hours, a process in the body that take 24 hours to complete a full cycle
What are two examples of circadian rhythms?
Examples include the sleep-wake cycle and variations in body temperature.
What happens in a sleep wake cycle?
At 7 am, we wake up, At 11 am, we feel most alert, In the afternoon, we have a dip in alertness, At 11 pm, we fall asleep, At 2 am, we feel least alert
What are chronotheraputics?
Time therapy that was developed using knowledge of the circadian rhythm and allow people to take drugs which then aren’t effective until necessary, hours later.
Explain what Siffre did in his study
Siffre spent 2 months in the caves of Southern Alps and then 10 years later spent 6 months in a Texan cave and monitored his circadian rhythm. He has supplies of food and drink but no natural light.
What is the first strength of circadian rhythms?
A strength of circadian rhythms is their practical application in drug treatments, where the timing of drug administration can enhance the effectiveness of medications.
What is the first imitation of circadian rhythms?
A limitation of circadian rhythm research is that it reveals significant individual differences, which makes it difficult to apply universal findings to all individuals.
What is the second limitation of circadian rhythms?
A limitation of sleep/wake cycle research is the use of case studies or small sample sizes, which makes it difficult to generalise the findings beyond the studies.
What are infradian rhythms?
rhythms that last over 24 hours
What is an example of an infradian rhythm?
the menstrual cycle
What is the menstrual cycle?
monthly changes in hormone levels which regulate ovulation -
What does the cycle in the menstrual cycle refer to?
The time between the first table women’s period and the womb lining of shed to the day before the next period
Who conducted a study to support infradian rhythms?
Stern and McCkintock
What was Stern and McCkintock aim?
To investigate whether the menstrual cycle was affected by the factors other than internal endogenous pacemakers
What was Stern and McCkintock method?
They gathered samples of pheromones from nine women at different stages of the menstrual cycle via a cotton pad placed in their armpit the parts were worn for eight hours a day. The pads were been treated with alcohol and frozen to be rubbed on the upper lip of the other participants one day pads from the start of menstrual cycle replied to all 20 women. On day two they were all given a pad from the second day of the cycle and so on.
What was Stern and McCkintock findings?
68% of women experienced changes to their cycle which brought them closer to the cycle of their older donor. They study shows evidence of the external factors controlling your infradian rhythms.
What is another example of infradian rhythms?
SAD - seasonal affective disorder
What is SAD?
a depressive disorder which has seasonal pattern (yearly cycle)
How frequently does the cycle for seasonal affective disorder repeat?
Every year
What external factor contributes to SAD?
light
What is the first limitation on infradian rhythms?
A limitation of research on infradian rhythms is that synchronisation studies have produced mixed results, questioning the reliability of the findings.
What is the first strength of infradian rhythms?
A strength of infradian rhythm research is that it provides evidence for understanding conditions such as Seasonal Affective Disorder (SAD) and how external factors, like light, play a role in regulating mood.
what is the second limitation of infradian rhythms?
A limitation of research on infradian rhythms, particularly in relation to Seasonal Affective Disorder (SAD), is that it relies heavily on correlations rather than establishing a clear cause-and-effect relationship between external light and depression.
What are Ultradian rhythms?
rhythms that last less than 24 hours
What is an example of ultradian rhythms?
the sleep cycle
How many distinct stages are there in the sleep cycle?
5 distinct stages
How long does the sleep cycle last?
90 minutes
What are stages 1 and 2 of the sleep cycle?
light sleep where there person may be easily woken. At the beginning of sleep, brainwave patterns start ti become slower and more rhythmic
What are stages 3 and 4 in the sleep cycle?
Involves Delta waves which are slower still and have a greater amplitude than earlier wave patterns this is deep sleep or slow wave sleep and it is difficult to wake someone in the sleep
What are stages 5/REM sleep?
Random stands for rapid eye movement, which indicates the first movement of the eyes under the eyelids at this stage the body is paralysed resembling the awake brain researcher suggested the REM sleep correlates with experience of dreaming
Who conducted research to support the sleep cycle of ultradian rhythms?
Demet and Kleitman
What did Demet and Kleitman do?
Monitored sleep patterns of nine adult participants in a sleep lab brainwave activity was recorded on an EEG. REM activity during sleep was highly correlated with experience of dreaming brain activity varied according to how vivid dreams were and participants woke during dreaming. Reported very accurate recall of their dreams.
What is one strength of ultradian rhythms?
One strength of research into ultradian rhythms is that it has enhanced our understanding of age-related changes in sleep patterns and how these changes can impact health.
What is a limitation of ultradian rhythms?
One limitation of research into ultradian rhythms is that there is individual difference, making it difficult to define “normal” sleep patterns in any meaningful way.
What are endogenous pacemakers?
internal body clocks that regulate many of our biological rhythms
What is the SCN?
small bundle of nerve cells located in the hypothalamus in each hemisphere of the brain - in the hypothalamus that controls the pineal gland through nerve impulses.
What do we call parts of the brain that control the timing of the circadian rhythm?
pacemakers
What are pacemakers?
Structures in the body that control the timing of biological rhythms.
What is one of the main endogenous pacemakers in the brain?
SCN
What does the SCN influence?
Our sleep/wake cycle
What does the SCN do?
It receives information about light even when our eyes are closed enabling the biological clock to adjust to changing patterns of daylight whist we are asleep - The SCN tells the pineal gland when to release releasing melatonin.
The pineal gland controls our sleep/wake cycle by releasing melatonin into the bloodstream. The more melatonin in the bloodstream, the more sleepy we feel.
How does the pineal gland use melatonin to control when we sleep?
- It increases melatonin release at night to make us sleep.
- It reduces melatonin release in the day so that we feel awake and alert.
When does the pineal gland release the most melatonin?
At night - as melatonin induces sleep
What does the SCN pass to the pineal gland?
information on day length and light
Who conducted a study to support endogenous pacemakers influence on the sleep wake cycle?
DeCoursey
What was DeCourseys study?
Destroyed the SCN connections in the brains of 30 chipmunks who would then return to their natural habitat and observed for 80 days. The sleep wake cycle disappeared and many were killed by predators because they were awake and vulnerable when they should have been asleep. This shows that SCN is essential in our sleep cycle
What is a limitation of DeCoursey’s study - Endogenous pacemakers?
A limitation of DeCoursey’s study on endogenous pacemakers is that it was conducted on chipmunks, which may limit the generalisability of the findings to humans.
What is another limitation of the SCN as an endogenous pacemaker?
A limitation of research into endogenous pacemakers is that while the suprachiasmatic nucleus (SCN) plays a key role in regulating circadian rhythms, many peripheral clocks in different organs and cells can be influenced by external factors, complicating the understanding of how these rhythms are regulated.
What is endogenous?
producing from the inside
What is exogenous?
everything outside, producing from the outside
What are exogenous zeitgebers?
External cues that may affect our biological rhythms
What is a zeitgeber in humans?
light is an exogenous zeitgeber
Why is light an exogenous zeitgeber?
as it plays a role in the maintenance of the sleep/wake cycle
How does light influence the sleep/wake cycle?
sensory receptors in our eyes detect light can send information directly to the SCN to influence melatonin release
What are the three exogenous zeitgebers for the sleep/wake cycle?
light, noise and social customs
What are social customs?
Possible factors that control the circadian rhythm that are external and influence times in the day
Who conducted a study for light as an exogenous zeitgebers?
Campbell and Murphy
What was Campbell and Murphys aim?
To demonstrate the light may be detected by skin receptor sites on the body even in the same information is not received by the eyes
What was Campbell and Murphys method?
15 participants were woken at various times and a light pad was shown on the back of their knees. It was possible to produce a deviation of their usual sleep cycle for up to 3 hours.
What was Campbell and Murphys conclusion?
They suggest that light is a powerful exogenous zeitgeber that not necessarily rely on the eyes to influence the brain
What type of study was Siffre’s research into the role of light as an exogenous zeitgeber?
a case study
How did Siffre conduct his cave study - about exogenous zeitgebers
Siffre conducted a case study
Siffre lived in a cave for 6 months with no access to natural light.
What were the results of Siffre’s study?
Siffre’s sleep/wake cycle increased to a 25-30 hour cycle without access to light.
What is one limitation of exogenous zeitgebers?
A limitation of exogenous pacemakers is that the influence of exogenous zeitgebers, such as light, may be overstated.
What are the four methods to study the brain?
- post-mortem examination
- EEG’
- ERPs
- fMRI scan
What is a post morten examination?
when a person’s brain is examined in detail after-death to look for evidence of brain abnormalities.
What are invasive methods of studying the brain?
post morterns - not used unless the person needs brains surgery
What is a limitation of non-invasive methods in brain research?
Non-invasive methods can relate brain activity to behavior, but they do not manipulate the brain, meaning they cannot directly test cause and effect.
What is an advantage of using invasive methods in brain research?
Invasive methods allow us to directly test cause and effect relationships between the brain and behavior.
What is a post-mortem technique in psychological research
A post-mortem technique involves assessing the brain of a deceased patient, typically those with rare disorders or unusual deficits, to examine areas of damage and determine the likely cause of the deficits.
How was Broca’s area discovered?
Broca’s area (responsible for speech) was discovered using a post-mortem examination of a patient’s brain, revealing damage in a specific area linked to speech deficits. - Tan
What is one strength of post-mortem examinations?
In a post-mortem examination, a person’s brain can be examined at a very high level of detail, to identify very small brain abnormalities.
What is one limitation of post-mortem examinations?
A limitation of post-mortem examinations is that the degree of damage in the brain cannot be controlled, which can affect the accuracy of cause and effect about brain function.
What is fMRI?
functional magnetic resoancne imaging
What is the basic function of fMRI?
fMRI measures changes in blood oxygenation and flow in the brain to detect neural activity.
How does fMRI work?
fMRI detects changes in blood flow as active brain areas require more oxygen, producing a detailed image of brain structures.
What happens to protons during an fMRI scan?
The magnetic field tilts the protons in hydrogen atoms, and as they realign, oxygen levels can be measured.
What does fMRI measure in the brain?
fMRI measures changes in blood oxygenation and blood flow that occur due to neural activity.
What does fMRI measure?
changes in brain activity across the brain.
What is a strength of fMRI?
A strength of fMRI is that it allows researchers to investigate the relationship between brain activity and behaviour more easily and directly than post-mortem examinations.
What is a limitation of fMRI?
A limitation of fMRI is that it is too slow to pick up all neural activity in the brain, leading to inaccurate measurements. = blood flow
How does EEG work?
- EEG picks up electrical signals from the cortex.
- EEG uses electrodes placed on the scalp to pick up electrical activity of neurons located under the electrodes.
What do EEG patterns show?
EEG patterns show brain wave activity, which helps identify neurological issues like epilepsy, sleep problems, or tumours.
What does EEG measure?
EEG measures electrical activity in the brain’s cortex by detecting the signals from neurons.
Where are the electrodes placed in an EEG?
Electrodes are placed on the scalp to record electrical activity from the brain’s cortex.
What type of brain activity does EEG detect?
EEG detects electrical activity when brain regions become active, with signals produced by groups of neurons.
What is the first strength of EEG’s?
A strength of EEGs is that they allow us to measure actual neural activity directly in the brain.
What is the second strength of EEG’s?
A strength of EEG is that it is excellent at detecting synchronised brain activity, which is especially useful for studying sleep patterns or identifying seizures.
What is the first limtiation of EEG’s?
A limitation of EEG is that the electrodes are not sensitive enough to detect the activity of individual neurons.
What are ERP’s?
are small electrical signals recorded using EEG that occur in response to the presentation of a stimulus.
What is the key difference between ERP’s and EEG’s?
that a stimulus is presented such as a picture of a sound and the researcher looks for activity directly related to that stimulus
How are ERP’s measured?
by presenting the same stimulus across hundreds of trials.
What is a strength of ERP’s?
A strength of ERPs is that they allow us to measure changes in electrical signals in response to a specific stimulus.
What is a limitation of ERP’s?
A limitation of ERPs is that we can only measure signals generated by the cortex.
What is localisation of function?
The idea/theory that different areas of the brain are responsible for different processes and functions.
What type of theory is the localisation of function?
reductionist theory
According to the localisation of function theory, what happens if a certain area of the brain becomes damaged?
The function associated with that area will also be affected
Who conducted a study to support localisation of function of the brain?
Phineas Gage - case study
What was Phineas Gages study?
Whilst working in New England (US) 25-year old Gage was preparing to blast a section of rock using explosives to create a new railway line.
An explosion hurled the metre length iron pole through his left cheek behind the eye and out of his skull and brain from the top.
He survived, but his personality had changed from someone who was kind and reserved, to rude, quick tempered, boisterous and blasphemous (swear).
How does Phineas Gages study support localisation of function?
Gage’s case supported the idea that specific areas of the brain control certain behaviours
The frontal lobe is involved in reasoning, higher cognitive functioning, impulse control, social interaction, emotional regulation, and interpreting emotions in others
This case shows one specific brain area is responsible for certain aspects of personality
Similar to Tan (Broca’s area for speech production) and HM (hippocampus for memory), it highlights the localisation of function in the brain
How did researchers examine localisation of the brain?
When patients died, researchers performed post-mortem examination to see which parts of the brain were damaged.
From post mortems, researchers found that damage to specific brain areas consistently led to the same symptoms
How many lobes is each hemisphere divided into?
4
What does the Motor Cortex (motor area) control?
Controls body movement
Tensing muscles
Walking
Voluntary movements
What does the motor cortex in the left hemisphere control?
the right side of the body (vice versa)
Where is the motor area located?
in the frontal lobe
What does the Somatosensory cortex(area) control?
Processes the feeling of touch
Sensations from the skin and muscles
Detects heat, cold, touch, pain
Helps with our sense of movement
How does the Somatosensory area process touch?
by receiving nerve impulses from neurons, which are next to the sensory receptors on the skin.
What does organised contralaterally mean?
It refers to how the brain controls the opposite side of the body.
For example, the left hemisphere of the brain controls the right side of the body and vice versa.
What lobe is the Somatosensory cortex(area) located?
the parietal lobe
What does the auditory cortex(area) control?
Part of the brain that processes sound
Analyses speech information
Where is the auditory cortex(area) located?
temporal lobe
What happens if the auditory cortex gets damaged?
may produce partial hearing loss
What does the visual cortex do?
processes visual information
True or false both hemispheres are involved in processing vision.
TRUE
How does the visual cortex work?
by receiving nerve impulses from sensory neurons that talk to sensory receptors in your eyes.
What happens if you damage your visual cortex?
If you damage the left visual cortex, you lose the ability to process vision and see things on your right side.
If you damage the right visual cortex, you lose the ability to process vision and see things on your left side.
Where is the visual area located?
occipital lobe
What is Brocas area?
Part of the brain that enables us to produce language
Allows us to choose the right words when talking or writing
Involved in producing meaningful speech
How did Brocas study the function of this area?
Broca gave his patient a nickname based on the only word he could say: “Tan”
This patient’s case helped Broca discover that this area is involved in producing language.
What hemisphere is language hemispherically lateralised to?
left hemisphere
What is Brocas area located?
situated in the left frontal lobe
What could happen if the Brocas area is damaged?
aphasia - which causes slow speech and lacks fluency
What is Wernickes area?
understand language, responsible for language comprehension- struggle to understand the meaning
If we know that Wernicke’s area is dedicated to processing language, where is Wernicke’s area?
left hemisphere - frontal lobe
What can damage to Wernickes area cause?
unable/ have serve difficulties understanding language produced
What is aphasia?
Aphasia is when people lose the ability to understand or use language
What is the first limitation of localisation of the brain?
A limitation of the localisation theory of brain function is that it may be over-simplified.
What is the first strength of localisation of the brain?
A strength of the localisation theory of brain function is there is evidence from brain scans to support the validity
What is the second limitation of localisation of the brain?
A limitation of the localisation theory of brain function is the evidence from animal studies, which challenge the idea that specific functions are confined to particular areas of the brain.
What are the two cerebral hemispheres involved in?
Higher cognitive functions such as vision, memory, and thinking (intelligence)
What is the cerebral cortex, and what does it cover?
The outer layer of both hemispheres
It covers the inner parts of the brain
About 3mm thick
Why is the human cortex different from other animals?
The human cortex is much more developed, which separates us from other animals
What higher-level processes are associated with the cerebral cortex?
Consciousness
Thought
Emotion
Reasoning
Language
Memory
How are the left and right hemispheres connected?
They are joined in the middle by the corpus callosum, which enables communication between the two sides of the brain
What hemisphere is Language is hemispherically lateralised to?
left hemispehre
What hemisphere is spatial skills is hemispherically lateralised to?
right hemisphere
What is lateralisation of function?
The right hemisphere controls the left side of the body, and the left hemisphere controls the right side
What us the left hemisphere dominant for?
language, logic, and analysis
What us the right hemisphere dominant for?
emotion, music, and face recognition
Where are the main centres for language located in the brain?
Broca’s area is in the left frontal lobe
Wernicke’s area is in the left temporal lobe
Which functions are not lateralised?
Vision, motor, and somatosensory areas appear in both hemispheres
How does vision work across both hemispheres?
Items presented in the left visual field (LVF) are connected to the right hemisphere
Items presented in the right visual field (RVF) are connected to the left hemisphere
Who conducted research for lateralisation of function?
Sperry
What is a strength of lateralisation of function?
A strength of the theory of lateralisation of brain function comes from Sperry’s research, which showed that the two hemispheres are responsible for different tasks.
What is the first limitation of lateralisation of function?
A limitation of the theory of lateralisation is that modern neuroscientists argue the distinction between the two hemispheres is not as clear-cut as initially believed.
What is the second limitation of lateralisation of function?
A further limitation of the localisation theory is the concept of brain plasticity, which suggests that if one hemisphere is damaged, the other hemisphere can sometimes take over the lost functions.
How do the two hemispheres communicate with each other?
By sending nerve impulses to each other via synapses
What is the corpus callosum?
A bundle of nerve axons that allow communication between the two hemispheres
What does hemispherically lateralised mean?
functions that are only processed by one hemisphere
Who conducted split brain research?
Sperry
What is a split-brain individual?
A person who has undergone a surgery, where the corpus callosum is cut to control severe epilepsy.
Why did Sperry study split-brain patients?
To investigate the extent to which the two hemispheres are specialised for certain functions.
What happens when the corpus callosum is removed?
The two hemispheres cannot communicate, creating a split-brain patient.
How were images or words presented to patients in the study?
They were projected to either the right visual field (processed by the left hemisphere) or the left visual field (processed by the right hemisphere).
Why couldn’t split-brain patients transfer information between hemispheres?
Because their corpus callosum had been cut, preventing communication between the hemispheres.
What happened when a picture was shown in the right visual field?
The patient could describe what they saw because the left hemisphere controls language.
What happened when a picture was shown in the left visual field?
The patient could not describe it and reported seeing nothing, as the right hemisphere lacks language ability.
Could patients identify objects shown to the left visual field?
Not verbally, but they could use their left hand to select a matching object from a grab-bag.
What does split brain research reveal about the right hemisphere?
It can understand objects but lacks verbal communication abilities.
What happened when two words were presented simultaneously, one in each visual field?
The patient would say the word shown in the right visual field (processed by the left hemisphere) and write the word from the left visual field (processed by the right hemisphere) using their left hand.
Which hemisphere is dominant for facial recognition?
The right hemisphere.
What happened when a composite face was shown to both hemispheres?
The left hemisphere dominated verbal description, while the right hemisphere dominated in selecting a matching picture.
What do Sperry’s findings suggest about brain lateralisation?
The left hemisphere is specialised for language, while the right hemisphere is specialised for spatial and facial recognition.
What did Sperry’s research demonstrate about split-brain patients?
Each hemisphere functions independently, highlighting the brain’s division of labor.
What is the method used in split-brain research?
- The researcher presents a stimulus to either the patient’s left, or their right hemisphere.
- Patients are asked to respond to a stimulus that has been presented to them, by pointing at the stimulus that matches the one they were just shown.
- Patients are asked to describe a stimulus that has been presented to them.
What is one strength of split brain lateralisation?
One strength of split-brain research is that it has been conducted in highly controlled conditions with standardised procedures.
What is one limitation of split brain lateralisation?
A key limitation of split-brain research is that its findings may lack generalisability due to the small and unusual sample used.
What is a second limitation of split brain lateralisation?
Another limitation of split-brain research is the presence of confounding variables, which may affect the validity of the findings.
