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
Myelin sheath —>
Axon terminal
Identify the structure that contains the nucleus and keeps the entire cell alive and functioning.
Cell body
Identify the structure of the neuron that receives messages from other neurons.
Dendrite
Identify the structure of the neuron that carries messages to other cells.
Axon
When we receive signals and then transmit signals, different neuron structures in the brain activate. In what order do these neuron structures activate?
dendrites, soma (cell body), axon, axon terminals
What is space between two neurons called?
synapse
The __________ look like branches coming off the soma and are responsible for receiving information from other neurons.
dendrites
Motor neurons (multipolar neurons)
communicates messages from the central nervous system to the body’s muscles
- aka efferent neurons (E for Existing)
You will be able to move the muscles in your hand and fingers to answer this question through the specific action of your
motor neurons
Neurons that carry messages from organs and muscles to the central nervous system are called
sensory or afferent neurons
Interneurons
primary function is integration and carry sensory information and regulate motor activity
- aka multi-polar neurons
What are the major divisions of the brain?
Hindbrain, midbrain, and forebrain
Hindbrain
most primitive part
responsible for basic survival function e.g. coordination of movement and balance
Midbrain
connects the hindbrain and forebrain and controls arousal levels, attention, consciousness and coordinates movement
Forebrain
most ‘advanced’ part
responsible for higher order thinking processes and behaviours
What are the lobes of the brain?
Frontal, temporal, and parietal
Frontal lobe
planning judgement problem-solving aspects of personality and emotions
Temporal lobe
processes auditory information
important for higher order visual processing and memory
Parietal lobe
allows a person to perceive their own body and where things are located in the immediate environment
contains the primary somatosensory cortex
Occipital lobe
processes visual information
Someone with damage to the right occipital lobe might experience…
difficulty interpreting visual stimulus from the left eye (visual field).
If your temporal lobes were electrically stimulated, you would probably
hear sounds
The area of the brain that, if injured, is more likely to adversely affect mental abilities such as symbolic thinking, planning and decision making, is the
forebrain
Which part of the brain is the most highly developed and is the largest part of it?
Forebrain
Broca’s area (left hemisphere) is…
responsible for production of fluent and grammatically correct speech (language)
Where is Broca’s area found?
left frontal lobe
Broca’s aphasia
nonfluent conversational speech and slow, halting speech (language) production
the patient is typically aware of the deficit and feels frustrated about it
Wernicke’s area (left hemisphere) is involved in
receiving and interpreting language
Where is Wernicke’s area found?
left temporal lobe
Wernicke’s aphasia
fluent speech that lacks sense
comprehension is impaired
reading and writing are often severly impaired
Geschwind’s territory (left hemisphere)…
provides a connection between Broca’s area and Wernicke’s area
Where is Geschwind’s territory found?
left parietal lobe
Jeremy well dance bear in the house underneath the bath, well, I mean, the trees.
The speech pattern above may be indicative of damage to which brain area?
Wernicke’s area
Elijah was working on a building when his ladder broke. Elijah fell several meters and suffered an injury to the left frontal lobe of his brain. Prior to his fall, Elijah was fluent in English and Hungarian. Based on the information provided, identify what may be a plausible result of Elijah’s injury.
an inability or difficulty producing speech
Geschwind’s territory was vital in understanding how humans were able to develop higher order thinking. The reason for this is
Geschwind’s territory was found in an area that has highly multimodal neurons that can process a range of stimuli
