Biopsychology Flashcards
What is the nervous system?
A complex network of nerve cells called neurons, it is divided into two main sub systems: the central nervous system nd the peripheral nervous system.
What is the CNS and PNS?
CNS - recieves info from the senses and controls the body’s responses. It includes the brain and spinal cord.
The PNS - carries sensory and motor info to and from the CNS. Branches into the somatic NS (controls voluntary movement) and the Autonomic NS (controls involuntary activity of non-skeletal muscles and internal body systems, it is self regulating). The autonomic ns branches off into the sympathetic NS and the parasympathetic NS.
What is the role of the spine in the CNS?
Main function is to relay info between the brain and the rest of the body - consists of 31 pairs of spinal nerves, each nerve is divided into 2 roots - one root contains sensory neurons enabling the transmission of sensory info to the brain and the other contains motor neurons which are involved in the transmission of motor signals to skeletal muscles. Also enables us to perform simple reflexes.
How is the brain split up?
The main areas are the cerebrum (each lobe has a different function), cerebellum (involved in motor skills), diencephalon (which includes the thalamus and hypothalamus - includes body regulation and acts as link between the endocrine system and the nervous system) and the brain stem (which as the midbrain, pons and medulla oblongata - this regulates automatic functions). The cerebrum is split into 4 lobes: the parietal, temporal, frontal and occipital,
What are the different types of neurons?
Sensory neurons - mostly unipolar. carries sensory information from the body’s sensory receptors to the CNS. These impulses travel to the brain and are translated into sensations so we can respond appropriately.
Motor neurons - mostly multipolar, carries motor commands from the CNS to skeletal muscles, control contractions and when stimulated neurotransmitters are released triggering a response.
Relay neurons - mostly multipolar, surrounded by dendrites, interconnect different parts of the CNS, they pass messages and allow the sensory and motor neurons to communicate with each other.
Explain synaptic transmission.
Transmission of chemical messenger across the synapse, takes a fraction of a second, stored at the end of the axon are sacs containing neurotransmitters (synaptic vesticles), as the nerve impulse (action potential) travels down the axon to the axon terminal it stimulates the vesticles to release the neurotransmitter molecules.
What are excitatory and inhibitory neurotransmitters?
Excitatory - increases likelihood that an excitatory signal is send to the post synaptic, which makes it more likely to fire.
Inhibitory - decrease the likelihood of the neuron firing.
What is localisation of function? Give examples of the areas involved.
Refers to the belief that specific areas of the brain are associated with different functions e.g. language, memory, hearing etc… It is also known as cortical specialisation.
What is hemispheric lateralisation?
Refers to the fact that some mental processes in the brain are mainly specialised in either the left or right hemisphere. e.g. the left hemisphere is dominant for language where as the right is for visual motor functions.
Evaluate localisation of function.
Support - brain scan evidence - Petersen et al used brain scans to demonstrate how Wernicke’s area was active during a listening task and Broca’s area was active during reading, areas have different functions. Long term memory studied by Tulving revealed by semantic and episodic memories reside in different parts of the pre-frontal cortex.
Equipotentiality - the belief that basic motor and sensory functions are localised but high mental functions are not. Researchers have claimed that intact areas of the cortex could take responsibility for specific cognitive functions following injury to the area that is usually involved in it. Therefore, tje effects of damage to the brain (according to this view) are determined by extent of damage rather than location.
How are the two hemispheres connected in the brain?
Connected via the bundle of nerve fibres called the corpus callosum, it allows the two hemispheres to communicate with each other.
What is split brain research and give an example?
Sperry THE DIVIDED FIELD EXPERIMENT- a split brain patient (who had undergone a commissurotomy which is the splitting of the corpus callosum, usually because of epilepsy) asked to report any word he or she saw (having been shown for 200ms), a word flashed in the RVF was immediately reported but they were unaware of a word flashing up in the LVF. RVF goes to left hemisphere, LVF goes to right hemisphere which has no language system therefore they cannot talk about it, so can only report on what the left hemisphere has seen. He would then show in the LVF a word like glass, then ask the left hand to select something from a range of objects, they always picked glass but could not explain why.
Evaluate split brain research.
- very few patients, so a very small sample size AND the sample was an extremely varied group as they differ in age, when they developed epilepsy, gender, handedness and the age when they had the operation..
- The operations which they had were not always comparable as there are smaller pathways connecting the two hemispheres, one being the anterior commissure, in some cases this was kept intact which could allow for communication.
What are the ways of studying the brain?
Post mortem examinations - after death, if it is suspected a persons behaviour has been caused by brain damage is allows us to look for possible causes.
fMRI’s - measures changes in blood flow and levels of oxygen, indicating an increase in activity in specific areas of the brain. It is useful for identifying areas if the brain used for specific tasks.
EEG - measures electrical activity in the brain by using electrodes on the scalp, people with epilepsy show spikes of electrical activity.
ERP’s - more detailed that EEG because they allow a way to study specific responses to certain stimuli, it will detect small voltage changes. There are two types: sensory ERPs and cognitive ERPs.
What is the sympathetic and parasympathetic ns?
Sympathetic - produces arousal preparing the body for rapid action, contains fight or flight response e.g. rapid heart rate and slowed digestion.
Parasympathetic - reduces arousal, conserves energy and digestion, returns the body to a state of normality e.g. slowed heart rate and glucose is stored.
