Lecture 10 - Interfering with brain function Flashcards
(38 cards)
What does TMS stand for?
Transcranial magnetic stimulation
What does tDCS stand for?
Transcranial direct current stimulation
What is brain stimulation?
Non invasive technique using a magnetic coil to induce a voltage or electrodes to induce current into brain tissue
What is brain stimulation used for?
To investigate the causal function of a target brain area
See how behaviour changes if we interfere with a brain function, rather than just measuring it.
What is TMS?
a non-invasive procedure that uses magnetic fields to stimulate the brain
What is the control condition for TMS?
Sham condition
Where a fake pulse is emitted or a different brain region is affected
What are virtual lesions?
Created by TMS
Brain regions become temporarily impaired or disconnected
Allows us to study the causal involvement in certain brain functions in behaviour.
How do we test the causal contributions?
Combine TMS technique with carefully designed behavioural experiments
If the brain region is causally involves in a certain function, TMS will …
cause difference in performance (errors) and speed (reaction times) compared to a control condition
What are the benefits of TMS?
Brain research
Medical research
How does TMS help with brain research?
- Precise localisation of brain regions
can also be used in combination with eeg or fmri - Temporary brain impairment without long term consequences
saving lives of test animals
study brain function disruption in the same person
How does TMS hep with medical research?
Many therapeutic benefits of TMS for conditions including:
- depression
- addiction
- stroke rehabilitation
- parkinsons
- chronic pain
What is tCDS? How does it work?
Non invasive painless brain stimulation treatment that uses direct electrical currents to stimulate specific parts of the brain
Constant low intensity current is passed through two electrodes placed over the head which modulates neural activity
What are the two types of stimulation with tDCS?
Anodal stimulation - acts to excite neuronal activity
Cathodal stimulation - inhibits or reduces neuronal activity
What are the advantages of tDCS?
- cheap, non invasive, painless
- easy to administer and portable equipment
- minimal side effects
- valuable for treatment of neuropsychiatric conditions such as depression, anxiety, parkinsons, chronic pain, brain injury, and relieving symptoms of language and movement disorders
- cognitive improvement
What are the disadvantages of tDCS?
- too easy and too promising
- prone for abuse
- long term cognitive consequences not clear
How do painkillers work?
- depress nervous system, making it harder for pain signals to reach the brain
- attaching to opiate receptors to block pain signals coming from the body
What are NSAIDS and how do they work?
E.g. Aspirin and ibuprofen
Block an enzyme used by injured cells to make prostaglandins (pain messengers).
How does paracetamol work?
Treats pain by blocking the enzyme receptors in the brain, meaning the pain is there but your mind does not receive the message.
What are beta blockers?
Block the effects of stress hormones such as adrenaline and noradrenaline to reduce physical signs of anxiety like decreasing heart rate
e.g propranolol
Disadvantages of beta blockers (propanolol)
Can also supress positive stress which can result in loss of libido, erectile dysfunction and depression
What are the cognitive effects of beta blockers?
can impact perception and motor function, may improve complex task performance
What are examples of widely socially acceptable stimulants?
Caffeine and Nicotine
How does caffeine work?
Mimics adenosine (neurotransmitter that causes drowsiness) and attaches to adenosine receptors in the brain. Caffeine blocks receptors making us feel more alert
