Week 6 Flashcards
What is experimental ablation and how does it work?
Experimental ablation involves creating a brain lesion (stroke) that targets a specific area of the brain to study the effects on behavior. (destroying a specific part of the brain)
What are target mutations?
Target mutations genetically knock out a specific region of the brain or neurotransmitter receptor type, to study its effect.
What is neural plasticity?
The brain changing in response to learning and/or injury
How do we study intact brains and describe each?
We study intact brains with the use of CT scans that use X-rays. PET scans that use radioactive dyes (substances that are injected into the body to enhance the visibility of internal structures in imaging techniques) to measure glucose/energy and MRI scans that use magnetic fields to study the structure of the brain.
What type of blood do working areas of the brain use?
Oxygenated blood
How can the brain’s electrochemical signals be measured and why is it used?
They are measured using sensitive electrodes, placing them all around the head to detect what parts of the brain are active during different kinds of activities.
What is a functional MRI scan(fMRI)?
Functional MRI scans are like MRI scans except they can observe and record the blood flow within the brain, allowing another view of the brain’s activity.
What is an electroencephalography (EEG)?
Electroencephalography (EEG) uses electrodes to measure electrical activity
What is diffuse optical imaging?
Diffuse optical imaging detects changes in blood oxygen levels.
What is electromyography (EMG)?
EMG measures the electrical signals generated by muscles during contraction.
Which scans would you use to look at the brain structures involved in specific activities?
fMRI and PET
What is temporal resolution?
Temporal resolution describes a techniques ability to show you exactly when the activation of mental processes is happening.
What is spatial resolution?
Spatial resolution refers to the capacity a technique has in showing you exactly which area of the brain is active.
In the context of temporal and spacial resolution how good are the EEG, fMRI and PET?
EEG- Excellent temporal, limited spatial
fMRI- Moderate temporal, good spatial
PET- Poor temporal, good spatial
How to choose your scan?
Risk to the patient (radioactive dye), what are you measuring (location, activity, coordination between different areas) and cost (EEG-cheap, fMRI- expensive)
What is transcranial magnetic stimulation?
Transcranial magnetic stimulation uses magnetic waves to trigger an electric current in the brain. This is particularly valuable because it can be used on healthy, conscious human participants who can then report what they felt or thought.
What is transcranial direct stimulation?
Transcranial direct stimulation uses electrodes for a direct electrical current.
What are the two major problems with transcranial magnetic stimulation and transcranial direct stimulation?
When applied to humans, they are almost always correlational meaning true causality is hard to know because the brain is highly inter-connected, so it is very rare to find only one area of the brain that is responsible for a particular behavior. There are specific parts of the brain that have a specific function, but overall behavior is the result of many areas of the brain working together.
What does the nervous system consist of?
The central nervous system- the brain and the spinal cord and also the peripheral nervous system- nerves, ganglia and sensory receptors.
What do motor nerves do?
Motor nerves send signals out to muscles, causing movement
What is the function of the sympathetic nervous system?
The sympathetic nervous system prepares the body for fight or flight by shutting off unnecessary systems (digestion) while ramping up important systems
What is the function of the parasympathetic division?
The parasympathetic division is responsible for calming the body from the fight or flight response to a more energetically efficient state (lowers heart rate and sugar use). It also promotes digestion and the growth and repair of the bodily tissues.
What do afferent neurons do?
Afferent neurons carry information from sensory receptors to the CNS (brain and spinal cord)
What do efferent neurons do?
Efferent neurons carry information from the CNS to muscles causing movement.
What divisions can the brain be split into and what do they mean?
The brain can be split into sub-cortical and cortical. The Sub-cortical is underneath what we can see (inside) and the cortical is what we can see (outside).