Role of the Brain Flashcards
What does the mind-versus-body topic debate?
whether the mind is a separate entity from the brain and the body
Dualism
- the mind and body are two distinct systems but there is an interaction between the two
What did Rene Descartes support?
Dualism:
- he believed that our non-material mind (or soul) constructs our reality and causes us to ‘exist’, rather than our physical body. He believed that the body was controlled by the soul, and that only exists in humans. He believed that the nature of the mind is different from the body and therefore it is possible for one to exist without the other
Monism
- there is no distinction between the mental (mind) and the physical (body)
- more of a biological perspective on the debate and views consciousness (the mind) as a result of complex physical interactions between neurons
- we are simply ‘complicated physiological organisms’ governed by biological processes of our nervous systems
What did Claudius Galen support?
Monism
Who developed phrenology?
Franz Gall
What was Phrenology the study of?
- bumps and indentations on the skull to determine a person’s character, intelligence and a range of other behaviours and functions
- Gall believed that mental abilities and personality functions were controlled by specific brain organs located on the surface of the brain, reflected in the shape of the skull
- although Gall was incorrect, phrenology led to the concept of localisation and lateralisation of fuction -> the idea that specific brain regions control specific functions
What did Pierre Flourens discover?
- he found that removing different areas of the brain resulted in loss of function e.g. removal of the cerebellum meant loss of coordinate movements
- his experiments showed that a loss of brain tissue resulted in a loss of function, Flourens believed that the brain was composed of areas of specific function, but specific areas interacted and worked as a whole
- from his work with animals he could provide evidence that there were main areas of the brain responsible for different functions that the brain regions worked together for higher order function. This also provided evidence for localisation and lateralisation of function
Describe Wilder Penfield’s experiments
- he mapped the brain and its functions while performing surgeries on people with epilepsy
- he electrically stimulated different areas of the exposed brain and asked patients to tell him what they experienced
- for example, whilst probing the temporal lobe he was able to stimulate memory and summon a past experience
- his work further provided evidence that there were areas of the brain responsible for different functions and localisation and lateralisation of function
- he was able to map the primary motor and somatosensory cortices and show which areas are responsible for movement and sensation
What do Magnetic Resonance Imaging (MRI) do and how?
- uses a strong magnetic field, radio frequency pulses and computers to produce a detailed structural image of the brain
- different tissue types emit different signals, which allow imaging
- to create 3D picture of the brain and allows the detection of tumours and other structural abnormalities
What do Positron Emission Tomography (PET) do and how?
- they are based on the glucose consumption of the brain as higher glucose levels reflect higher brain activity
- identify various brain problems, such as epilepsy, brain tumours and blood clots
- provide information about areas of the brain that can be linked to a particular activity e.g. solving mathematical problems
What do Functional Magnetic Imaging (fMRI) do and how?
- MRI is used to measure the activity of the brain when neurons are consuming oxygen, therefore, measuring function
- higher levels of oxygen indicates higher brain activity
- correlates of different types of behaviour
What does Electroencephalography (EEG) do and how?
- measures brain waves or electrical activity in the brain
- different patterns of brain waves are used to correlate behaviour and levels of consciousness and can indicate problems such as epilepsy or tumours
Central nervous system (CNS) and…
Peripheral nervous system (PNS)
CNS…
is the control centre and is comprised of the brain and spinal cord
PNS…
is comprised of all the nerves (axons) and ganglia (cell bodies) outside of the brain and spinal cord
Autonomic nervous system and…
Somatic nervous system
Sympathetic nervous system and…
Parasympathetic nervous system
Sympathetic
stress - responsible for fight or flight response
Parasympathetic
peaceful - rest and digest response
Dendrites —>
Cell body
Cell body —>
Axon
Axon —>
Myelin sheath