Biopsychology Flashcards
Outline the fight or flight response
The amygdala in the limbic system sends a stress signal to the hypothalamus which activates the SAM pathway. The sympathetic system can the stimulate the adrenal medulla to release adrenaline and noradrenaline.
Adrenaline kick starts the fight or flight response, temporarily stopping bodily functions which aren’t essential for survival so more energy can be given to those that are. Breathing rate, heart rate and blood pressure all increase.
When perceived or real danger/threat is removed the parasympathetic system can begin restoring the body to its previous rested state.
Outline brain plasticity
The brain’s ability to change its structure and function. This can happen in response to internal and external stimuli, such as injuries, learning experiences, and environmental inputs.
Synaptic pruning: neural connections which are frequently used are strengthened whereas connections which aren’t used often become weaker.
Outline functional recovery
Functional recovery is a form of plasticity that describes when healthy regions of the brain compensate for damaged areas of the brain typically after the brain has undergone some form of trauma or damage.
This can involve several things
Axonal sprouting: when new neural pathways are formed via the growth of new nerve endings.
Reformation of blood vessels.
Recruitment of homologous areas to the opposite side of the brain to perform specific functions.
Spontaneous recovery- functional recovery happens quickly after trauma and then slows down after several weeks. Then rehabilitative therapy may be required.
Evaluate the strengths of functional recovery and brain plasticity.
There is lots of research to support the concept of functional recovery and brain plasticity making it more reliable and credible.
Maguire et al:
Used fMRI scanners to compare the posteriori hippocampi of London taxi drivers to a control group. The size of the hippocampus was significantly larger in those of taxi drivers than the control group. Moreover, the volume of their hippocampus was directly proportional to the length of time the individual had worked as a taxi driver. The hippocampus has a crucial role is forming and storing memories as well as spatial navigation. Its increase in size suggests it adapted to the taxi drivers’ jobs requiring good navigational skills.
Research used reliable, objective methodologies, providing credible evidence that the brain adapts to help carry out certain functions.
However, correlation does not prove causation.
Kuhn et al:
The amount of grey matter was compared between the brains of participants in a control group and participants who were told to play 30 mins of Mario kart a day.
They found a significant increase in grey matter in the experimental group, including regions of the brain associated with spatial navigation and motor performance. As this difference was not seen in the control group, these findings support the idea of brain plasticity and how it was able to adapt its structure when demands cause it to do so, such as how playing a motor sports video game demands more navigational skills.
These findings demonstrated the plasticity of the brain and how it can adapt its structure when demands cause it to do so, such as how playing a motor sport video game demands more navigational skills.
Real life application:
The understanding of brain plasticity has contributed to the field of neurorehabilitation. Research into spontaneous recovery shows recovery tends to slow down after a few weeks. This shows that even though the brain has the ability to heal itself to a certain point, further intervention is also required for it to be completely successful.
This knowledge has led to treatments such as movement therapy and electrical stimulation of the brain which can help counter any deficits in cognitive and/or motor functioning that may be experienced following brain trauma.
This research has helped identify ways in which recovery can be maintained and improved and thus can enable patients following trauma a better quality of life.
Evaluate the weaknesses of brain plasticity and functional recovery.
Individual differences: despite supporting evidence for functional recovery, alternative research suggests level of recovery differs between people. Therefore, we must consider individual differences when assessing the likelihood of functional recovery in the brain after trauma.
Ebert et al concluded that the capacity for neural reorganisation is much greater in children than in adults, meaning that neural regeneration is less effective in older brains. This may explain why adults find change more demanding than do young people.
Mathias conducted a metanalysis which demonstrated IQ and educational background are positively correlated with better outcomes after traumatic brain injury, suggesting certain individuals have better cognitive reserve which helps in the process of recovery. ), stated that education level and IQ will effect how well the brain copes and changes with trauma
Outline localisation of function in the brain
Localisation of function is the idea that certain functions (e.g. language, memory, etc.) have certain locations or areas within the brain.
Motor cortex: located in the frontal lobe the motor cortex controls voluntary movement in the opposite side of the body. Damage to this area leads to loss of control over fine motor movements.
Somatosensory cortex: this region is located in the parietal lobe and Detects sensory events from different regions in the body and produces sensations such as touch and pain from receptors.
Auditory area is located in the temporal lobe and analyses and processes acoustic information.
Visual area: located at the back of the occipital lobe the visual area receives and processes visual info. With the right visual cortex processing information from the left eye and the left visual cortex processing information from the right eye.
Broca’s area: located in the left frontal lobe and known to be responsible for the motor control used in speech production.
Wernicke’s area: located in the left temporal lobe and is involved in the comprehension of written and spoken language.
Evaluate localisation of function in the brain
Supporting case studies:
Phineas Gage’s frontal lobe was impaled with a pole. The damage to his brain left a mark on his personality from a calm to quick-tempered individual. This suggested that the frontal lobe may be responsible for regulating mood.
Neuroimaging support: Peterson et al used brain scans to demonstrate how Wernicke’s area was active during a listening task and Broca’s area was active during a reading task, suggesting that areas of the brain have different functions.
Counter evidence:
The Holistic Theory of brain function undermines that localisation of function occurs. Lashley conducted an animal study involving rats and found that there was not specific areas involved in memory but instead memory was stored all over the brain. This undermines the idea that specific parts of the brain perform functions and is potentially invalid.
Lashley’s study:
50 rats run and re-run a course of a maze after having regions of their cortex destroyed. Lashley found that their ability to successfully re-run the route was impacted not by which regions of the cortex were destroyed but rather the amount that was damaged. This suggested that higher cognitive brain processes such as learning and memory weren’t localised but distributed across the brain.
Outline the role of exogenous zeitgebers and endogenous pacemakers.
Endogenous pacemakers are the body’s internal body clocks which help govern biological rhythms.
The suprachiasmatic nucleus is an example of an important endogenous pacemaker which has an important role in maintaining and governing the body’s sleep-wake cycle. However, its function is also dependent on external factors.
The SCN contains receptors that are sensitive to light, when low light levels are detected the SCN sends signals to the pineal gland, which leads to an increase in the production of melatonin at night, helping to induce sleep. The SCN and pineal glands work together as endogenous pacemakers; however, their activity is responsive to the external cue of light.
Exogenous zeitgebers are external, environmental factors which influence the function of the body’s internal body clocks. Examples include natural factors such as sunlight, temperature changes, and social cues such as meal times and daily routines.
Evaluate research into biological rhythms:
Research support:
Siffre - found that the absence of external cues significantly altered his circadian rhythm: When he returned from an underground stay with no clocks or light, he believed the date to be a month earlier than it was.
Menaker: bred a strain of hamsters with an abnormal sleep /wake cycle (20 hours) and transplanted SCN neurons into hamsters with a normal cycle. Their circadian rhythm changed to 20 hours, highlighting the importance of the SCN.
Real life applications:
Chronotheraputics - the study of how timing can effect drug timings.
