Biopsychology Flashcards
What is the Central Nervous System (CNS)?
This system comprises of the brain and spinal cord, concerned with all life functions and psychological processes.
What is the function of the brain?
Maintains life, involved in higher functions and psychological processes.
What is the function of the spinal cord?
Receives and transmits information to and from the brain
What is the peripheral nervous system (PNS)?
This system transmits information to and from the central nervous system, comprised of the somatic and autonomic nervous systems.
What is the function of the somatic nervous system?
Transmits information to and from senses and to and from the central nervous system.
What is the autonomic nervous system?
Comprised of the sympathetic and parasympathetic nervous systems. Transmits information to and from the internal organs to sustain life processes.
What is the function of a sensory neuron?
Transmits information from the senses to the central nervous system.
What is the function of a relay neuron?
Transmits information to and from the central nervous system.
What is the function of a motor neuron?
Transmits information from the central nervous system to muscles, glands and organs.
What are the electrical impulses that travel through neutrons called?
Action potentials.
What is synaptic transmission?
When an action potential reaches the presynaptic terminal, vesicles containing neurotransmitters fuse with the presynaptic membrane expelling the neurotransmitters into the synaptic cleft and bind to the receptor sites on the surface of the postsynaptic neuron.
What are excitatory potentials?
As an excitatory neurotransmitter (e.g - noradrenaline) binds to receptor sites on the postsynaptic neurone, Positively charged sodium ions will flood inside the postsynaptic neuron resulting in a higher probability of firing an action potential.
What are inhibitory potentials?
As an inhibitory neurotransmitter (e.g-GABA) binds to receptor sites on the postsynaptic neurone, Negatively charged chloride ions will flood inside the postsynaptic neurone.This decreases the chance of new action potentials to be sent along the postsynaptic neuron.
What is the likelihood of a neuron firing?
The chance of a neuron firing is dependent on the summation of excitatory and inhibitory potentials.
What happens to the neurotransmitters after they have fulfilled their role?
They are broken down by enzymes and pumped back into the presynaptic terminal in a process called reuptake.
What is the endocrine system?
Network of glands that provide hormones by secreting them into the bloodstream.
What are hormones?
Chemicals secreted by the endocrine system into the blood that target specific tissues to have a different effect on the body.
What is the hypothalamus?
A part of the brain which is located in the centre of the brain and deals with basic survival functions.
What is the adrenal gland?
The gland in the endocrine system that releases adrenaline.
What is the adrenal medulla?
The central part of the adrenal gland.
What is the function of the sympathetic nervous system ?
Increases bodily activities
What is the function of the parasympathetic nervous system?
Maintains or decreases bodily activities
Outline the fight or flight response
The hypothalamus activates the sympatho-medullary pathway. This causes the adrenal medulla to secrete adrenaline into the bloodstream and detected by adrenergic receptors in target cells. As a result, pupils dialate, heart rate increases and the spleen produces more red blood cells. At the same time, there is reduced activity in non-Essential systems such as the digestive system.
Define localisation
The part of the brain in which a function is carried out
Define hemispheric lateralisation
When one hemisphere carries out a particular function
Define contralateral
Where the right hemisphere controls the left side of the body and left hemisphere controls the right side of the body
What are the four lobes of the brain?
Frontal lobe
Parietal lobe
Temporal lobe
Occipital lobe
What is the primary motor cortex?
The part of the brain which send messages to the muscles via the brain stem and spinal cord. It is located in the frontal lobe
What is the somatosensory cortex?
Part of the brain that perceived touch and other sensations of the body. It is located in the parietal lobe.
What is the primary visual cortex?
The part of the brain that deals with visual information. Located in the occipital lobe.
What is the primary auditory cortex?
The part of the brain that deals with auditory (sound) information. It is located in the temporal lobes.
What functions resides only within the left hemisphere?
Language - Broca’s area is where speech is produced, Wernicke’s area is where speech is processed.
What functions reside in the right hemisphere only?
Recognition and spatial relationships
What is a split brain patient?
A person that has a severed corpus callosum and therefore their hemispheres do not communicate
What unique ability do split brain patients have?
If an object is shown to the left visual field then the right hemisphere can see it, but the left hemisphere cannot articulate the object as the left hemisphere is responsible for speech and did not see it. The right hemisphere did see the object and therefore the patient is able to draw the object with their left hand because their right hemisphere controls the left side of the body.
Who has researched split brain patients and what did they find?
Sperry et al. Found that certain unfamiliar functions such as stringing beads onto a piece of thread cannot be performed, yet familiar actions such as tying shoelaces can still be done
What is the strengths of split brain research?
Useful in understanding the role of each hemisphere and the extent to which they are lateralised.
What are the weaknesses of split brain research?
The extent to which the split brains were indicative of normal functioning prior to surgery is problematic as the surgery was used to treat a problem within the brain
Define neural plasticity
The ability of the brain to adapt its connections as it experiences, this includes replacing functions lost by anatomical damage.
How does the brain adapt its networks?
Axon sprouting
Neuronal unmasking
Stem cells (neurogenesis)
How does neuronal unmasking recover function?
‘dormant’ synapses (which have not received enough input to be active), open connections to compensate for a damaged area of the brain.
How does axon sprouting recover function?
When an axon is damaged it’s connection with other neurones is lost. Other axons that already connect with that neurone form extra connections to replace the damaged one. This can only compensate if the axons have similar functions, but if not the connections can be maladaptive.
How do stem cells recover function?
Stem cells unspecialised cells which can become specialised to carry out different types of task and therefore replace damaged neurones and carry out their function
What was the case study of EB by Danelli?
EB was a boy who had his left hemisphere removed due to a large benign tumour at the age of 2.He had lost his ability to speak because language is lateralised to the left hemisphere. He underwent intensive rehabilitation and regained his ability to speak without problems by the age 17. Danelli found that the right hemisphere had compensated following the intensive rehabilitation.
How does age affect recovery?
There is a deterioration of the brain in old age and therefore, affects the extent and speed of recovery. At a young age, children have an abundance of neurones and so as they undergo ‘synaptic pruning’ the ability to recover function decreases
How does gender affect recovery?
Research suggests Women recover better than men from brain injury as their brain is less lateralised (concentrated in one hemisphere).
What did Schneider find about higher education affecting recovery from brain trauma?
People who have remained in education for longer have a greater ‘cognitive reserve’ which means they are more likely to maintain function in spite of damage because they have a more active, well-connected brain.
What is functional magnetic resonance imaging (fMRI)?
A technique of brain scanning that uses a magnetic field and radio signals to monitor blood flow in the brain. Areas of the brain that are involved in activities done by the person during scanning have a greater blood oxygenation and flow, so specific brain areas can be linked to specific cognitive abilities.
What are the strengths of fMRI?
Accurate spatial resolution 1-2mm of the brain
Good temporal resolution up to 6 seconds delay and so patterns of brain activity can be established
What are the weaknesses of fMRI?
Expensive machines
Sample sizes are small due to limited availability and funding and therefore difficult to generalise
Cannot observe individual neurones
Cannot show brain activity in real time and therefore cannot measure speed of cognitive processes
Define circadian rhythms
Biological rhythms that occur every 24 hours
Give an example of a circadian rhythm
Sleep/wake cycle
Outline the role of the suprachiasmatic nucleus (SCN) and pineal gland in the sleep/wake cycle
Neurones project from the SCN to the pineal gland which releases melatonin to induce sleepiness.
What are endogenous pacemakers?
Internal ‘body clocks’ that regulate biological rhythms such as the suprachiasmatic nucleus and pineal gland
What are exogenous zeitgebers?
External stimuli such as light and social cues which influence biological rhythms
What research supports the role of endogenous pacemakers?
Ralph et al. Removed the SCN out of hamsters with a circadian cycle of 20hrs and placed them in rats which had a 24hr cycle. Following the transplant the circadian rhythms of the rats had shortened to 20hrs
What are infradian rhythms?
Biological rhythms that occur more than once a day
Give an example of an infradian rhythm
The menstrual cycle
Hibernation in certain animals
What are ultradian rhythms?
Biological rhythms that occur less than once a day
Give an example of ultradian rhythms
Sleep cycle (five stages)
What research supports the ultradian rhythms?
Dement & kleitman used EEG’s on pps and found that everyone had periods of REM sleep every night, and that the stages of sleep follow a typical pattern throughout the night, and that dreams mostly occur in REM sleep.
What research supports the role of endogenous zeitgebers?
Research by Siffre (1975), in which he isolated himself in a cave away from natural light, found the human sleep-wake cycle to actually be around 24-25 hours.
