Psychology-Biopsychology Flashcards
What is brain plasticity?
It refers to the brain’s ability to modify its own structure and function as a result of experience
What is functional recovery?
It refers to the recovery of abilities and mental processes that have been compromised as a result of brain injury or disease
What factors are known to affect plasticity?
Life experience, playing video games and meditation
How can life experience affect plasticity?
New experiences mean nerve pathways that are frequently used develop stronger connections, whereas neurones that are rarely or never used eventually die, eg Maguire (posterior hippocampus), Rosenzweig and Bennet (cerebral cortex), Perry (cerebral cortex), and Boyke (teaching 60 year olds to juggle)
How can playing video games affect plasticity?
It makes many different complex cognitive and motor demands. Kuhn found that playing video games for 30 minutes a day for two months had increased grey matter in brain areas including the cortex, hippocampus and cerebellum as the games led to new synaptic connections
How can meditation affect plasticity?
Davidson et al compared Tibetan meditation practitioners and volunteers with no meditation experience. Whilst meditating, the monks had much greater activation of gamma rays (coordinate neurone activity), whilst the volunteers only had a slight increase. Meditation has short and long term affects on brain workings
What are three evaluation points on plasticity?
Implications for real life (Boyke), application of research (support studies), and methodology eg animal studies
What are two mechanisms for functional recovery after trauma?
Neuronal unmasking and stem cells
What is neuronal unmasking?
Wall identified dormant synapses in the brain which are not active, but can be activated when the neural input increases due to a surrounding brain area becoming damaged or unmasked. Unmasking dormant synapses can open connections to regions of the brain which are not normally active, creating a lateral spread of activation which, in time, can give way to the development of new structures
When was the localisation of brain function discovered?
In the 19th century
What is the definition of localisation?
Theory that specific areas of the brain are associated with particular physical and psychological functions
How is the brain divided?
Into two hemispheres (left and right) and each is responsible for specific functions
What is the general rule for the hemispheres?
Activity on the left hand side of the body is controlled by the right hemisphere. Activity on right hand side of the body is controlled by the left hemisphere
What is cerebral cortex?
The outer layer of both hemisphere, about 3mm thick, It is what separates humans from other animals because the human cortex is much more developed
What are the six parts of the brain looked at in this section?
The motor cortex, the somatosensory cortex, Wenicke’s area, the visual cortex, the auditory cortex, and Broca’s area
What parts of the brain are used for movement and touch?
The motor cortex and the somatosensory cortex
What is the motor cortex responsible for?
The generation of voluntary motor movements (not reflexes)
Where is the motor cortex located?
In the frontal lobe, in area called the pre-central gyrus
Which hemisphere have a motor cortex?
Both hemispheres. One side of the motor cortex controls the opposite side of the body
How are the regions attached?
Logically. The area which controls the foot is next to the area which controls the leg etc
What is the somatosensory cortex responsible for?
Detecting sensory events related to touch from different regions of the brain
Where is the somatosensory cortex located?
In the parietal lobe, in an area called the post-central gyrus
Which hemisphere has a somatosensory cortex?
Both-one side of the somatosensory cortex receives sensory information for the opposite side of the body
What somatosensory cortex produce?
Sensations of touch, pressure, pain and temperature which are localised to specific body regions
What parts of the brain are used for sight and sound?
The visual cortex and the auditory cortex
What does the visual cortex do?
It has several different areas, with each of the areas processing different types of visual information, such as colour, shape or movement
Where is the visual cortex located?
In the occipital lobe, in an area called the visual cortex ?
Which hemisphere contains the visual cortex?
Both-one side of the visual cortex receives information from the visual field from the opposite side of the body
How does visual information travel to the visual cortex?
Nerve impulse from retina to the optic nerve to the brain, to the thalamus, to the visual cortex
What is the auditory cortex responsible for?
Sound and producing an appropriate response
Where is the auditory cortex located?
In the temporal lobe in the auditory cortex?
Which hemisphere has a auditory cortex?
Both however information doesn’t swap hemispheres in a clear cut manner
How does auditory travel to the auditory cortex?
Sound waves to nerve impulses, to auditory nerve, to brain stem for decoding, to thalamus for processing, to the auditory cortex
What parts of the brain are used language?
Broca’s area and Wernicke’s area
What is Broca’s area responsible for?
Speech production-both verbally and internally (affecting expression thoughts in area)
Where is Broca’s area located?
In the frontal lobe of the left hemisphere in an area known as the Broca’s area?
Why is it called Broca’s area?
After Paul Broca who studied Tan in 1861-called ‘tan’ as that was the only syllable he could express, but could understand spoken language
Since 2012 psychologists also believe what about Broca’s area?
Parts of it is also used in demanding cognitive tasks
What is damage Broca’s area is know as?
Broca’s aphasia
What is Wernicke’s area responsible for?
Comprehending language-speech is typically fluent but is empty of content in Wernicke’s aphasia
Where is Wernicke’s area located?
In the left posterior temporal lobe, in an area known as Wernicke’s area?
What did Carl Wernicke study?
Aphasia 1874
What has also been found out about Wernicke’s area?
It is close to regions of the brain responsible for auditory and visual input-where information should be recognised with language and associated with meaning
What are the strengths of localised function theory?
There is support for language centres from aphasia studies (expressive aphasia-Broca’s aphasia, and receptive aphasia-Wernicke’s aphasia)
What are the limitations of localised function theory?
Conflicting theory (equipotentiality-Lashley), communication between brain areas may be more important than localisation (Dejerine), Individual differences in language areas (Bavelier et al), and Language production may not be confined to Broca’s area alone (Dronkers et al)
What is hemispheric lateralisation?
Some mental processes in the brain are mainly specialised to either the right or left hemisphere
What are examples of hemispheric lateralisation?
Language is in the left hemisphere, and facial recognition is in the right hemisphere
What is the corpus callosum?
A bunch of nerve fibres that join the two lobes of the brain, so that, for example, you can see something in your left eye, have it register in your left hemisphere, and then talk about it from the left hemisphere
What is a split brain patient?
Some patients with epilepsy have the nerve fibres cut, to stop the seizures passing between hemispheres
What experiment did Sperry and Gazzniga conduct?
They placed different objects in one visual field at a time and asked the participant what they saw. If a dog was placed in the right visual field it would be picked up by the left hemisphere, if a cat was placed in the left visual field it would be picked up by the right hemisphere
What did Sperry and Gazzniga find?
If the dog was placed in the right visual field then participants could say that they could see a dog, but if a cat was in the left visual field, a split brain patient would not be able to say that they could see it
Why did Sperry and Gazzniga find the results that they did?
Because language is in the left hemisphere and so when a cat is seen in the left visual field, it goes to the right hemisphere and cannot move to the left (where language is) as their corpus callosum has been cut
What are the strengths of lateralisation and split brain research?
Language may not be restricted to the left hemisphere (Gazzniga-JW damaged left hemisphere bit can speak about information in both sides of the brain), and methodological evaluation (Sperry’s research was wee designed, had standardised procedures, control and it was replicable)
What are the weaknesses of lateralisation and split brain research?
Theoretical evaluation(growing amount of pop-psychology literature concerning the functional distinction between hemispheres, oversimplifies and over emphasises the differences), lateralisation changes with age (lateralised patterns switch to bilateral patterns in older adults in many types of tasks and brain areas) and methodological evaluation (Andrewes-only small amounts of split brain patients exist and so studies are very small, where participants may have a confounding physical disorder)
What are biological rhythms?
Cyclical changes in the way biological systems behave
What are three biological rhythms?
Circadium (24 hours), ultradian (more than once every 24 hours) and infradian (less than one every 24 hours)
What is a circadian rhythm?
Comes from latin (circa=about and dies=a day). It is also known as the ‘body clock’. Circadian rhythms are drived by our body clocks, found in all of the cells of the body, which are synchronised by the master circadian pacemaker-the suprachiasmatic nucleus, which is found in the hypothalamus. This pacemaker must constantly be rest to be in synchrony with the outside world
What is the nature of circadian rhythms?
Light proves primary input, light sensitive cells in eyes are brightness detectors, send messages about light levels to suprachiasmatic nucleus (SCN), SCN uses this information to co-ordinate activity of the entire circadian system, body clock is set to correct time “photoentrainment”
What are sleep and wakefulness determined by?
Circadian rhythms and homeostatic control
How do circadian rhythms affect the sleep and wake cycle?
Light and darkness are the external signals that determine when we should be sleeping or feeling awake. There are also dips and rises at different times of the day, ie our strongest sleep drive is between 2-4am and 1-3pm. This sleepiness is less intense if we have had sufficient sleep, and vice versa
How does homeostatic control affect the sleep and wake cycle?
When we have been awake for a long time, homeostasis tells us that the need for sleep is increasing due to decreased energy. This homeostatic drive for sleep increases gradually through the day, reaching its maximum in the evening when most people fall asleep. This homeostatic system tends to make us sleepier as time goes on, irrespective of it being night or day
The internal circadian ‘clock’ maintains a cycle of about what?
24-25 hours, even in the absence of external cues, however it is intolerant of any circadian rhythm sleep disorders, either intrinsic eg jet-lag and shift work sleep disorder, or extrinsic eg delayed sleep phase syndrome (common amongst teens who habitually sleep in late
What is a case study for circadian rhythms?
Michel Siffre-he lived underground in a cave to study his circadian rhythms. First stay was 61 days until September 17th but he thought it was August 20th. Then stayed for six months and his natural circadian rhythm was just over 24 hours. He stayed again at 60 years old to see the effects of ageing, and his circadian rhythm was about 48 hours
What are two other circadian rhythms?
Core body temperature and hormone production
Explain core body temperature as a circadian rhythm
Body temperature is lowest at 3:30am and highest at 6pm. Sleep occurs when core body temp begins to drop. It starts to rise during the last hours of sleep, prompting alertness. There is also a small drop at 2-4pm which explains afternoon tiredness
Explain hormone production as a circadian rhythm
Melatonin is a hormone produced by the pineal gland and controls sleep and wake cycles. In darkness the body produces more melatonin which signals to the body to prepare for sleep. In light melatonin drops and the person wakes
What is research support for the importance of light?
Hughes-tested circadian hormone release in 4 participants at an Antarctic Station. At end of Antarctic summer, cortisol levels followed the familiar pattern (highest point=woke and lowest point=sleep) After 3months of continuous darkness, this pattern changed peak levels of cortisol at noon rather than when waking up. Suggests extremes of daylight in polar regions may be responsible for variations in circadian hormone release. However other research in the Arctic who found similar prolonged winter darkness found no disruption in cortisol release patterns
What are the evaluation points for circadian rhythms?
Practical applications to shift work (leads to desynchronisation of circadian rhythms which can lead to accidents and heart disease due to stress so research has economic implications in terms of maintaining productivity and preventing accidents ), Real life applications: Chronotherapeutics (can determine best time to administer drug treatments eg risk of heart attack is greatest in early mornings so drugs can be taken at night and released in the morning, increasing efficiency ), issues with case study evidence (Siffre study was one individual, hard to generalise especially with age research ), and poor control in studies (Cave studies still had artificial lights that weren’t controlled which can influence circadian rhythms so original studies lack validity )
When do ultradian rhythm cycles occur?
More than once a day, so its a period is less than 24 hours
What is an example of an ultradian rhythm?
Sleep
How stages of sleep are there?
Five
What is stage 1 sleep?
2-5% of sleep cycle. Light sleep. Muscle activity slows down. Occasional muscle twitching
What is stage 2 sleep?
45-55% of sleep. Breathing pattern and heart rate slows. Slight decrease in body temperature
What is stage 3 sleep?
4-6% of sleep cycle. Deep sleep begins. Brain begins to generate slow delta waves
What is stage 4 sleep?
12-15% of sleep cycle. Rhythmic breathing. Limited muscle activity. Brain produces delta waves
What is stage 5 sleep?
20-25% of sleep cycle. Rapid eye movement. Brain waves speed up and dreaming occurs. Muscles relax and heart rate increases. Breathing is rapid and shallow
What is supporting research for the sleep cycle?
Dement and Kleitman-studied 9 sleeping participants for 61 nights in a lap. They monitored the EEG record during sleep and woke participants during each of the different stages of sleep, then asked them to report their experiences and emotions
What did Dement and Kleitman find?
People awakened during REM sleep reported dreams 80-90% of the time in great detail and involved elaborate visual image but only 7%recall in nonREM sleep. This shows stage 5 dreaming and that delta waves make dreams less accessible. This was also shown by the fact that in deep sleep participants reported confusion and though they’d been dreaming but couldn’t describe them
What are strengths of Dement and Kleitmans research?
The use of EEG is an objective measurement and so it is factual meaning everyone should find the same thing. Also later replications of the study have found similar things, showing the research was replicable which increases it’s reliability
What are limitiations of Dement and Kleitmans research?
It was a lab study and so lacked mundane realism meaning sleep may have been different to if participants were at home asleep
What did Kleitman call the 90 minute cycle found during sleep?
The basic rest activity cycle (BRAC) and suggested however that this 90 minute ultradian rhythm continues through the day, even when we are awake, but instead of sleep stages we move to stages of alertness and physiological fatigue every 90 minutes
