Week Two - Questions & Approaches In Cognitive & Behavioural Neuroscience Flashcards
Who is Jose Delgado?
Claimed that electrical stimulation of caudate nucleus could tame aggressive behaviour
Why use non-human subjects?
Simpler brains
simple behaviour
comparative approach
fewer ethical restrictions
Why use human subjects?
Can follow instructions
able to provide subjective reports
less expensive
What are some lab based tests used to understand human function?
Reaction time tasks
- simple (with or without warning signal)
- choice
- cued
What are some tests used to try and diagnose brain damage?
Single test, standardised test battery, customised test battery
Define simple reaction time tasks
green dot appears, P responds by pressing button
can include warning signal
Define Choice Reaction Time Test
Choosing to respond with either left hand or right hand
Change where the signal appears on screen
There is uncertainty about stimulus and response due to two possible stimuli and two possible responses
Explain congruent trials
Congruent trial = if it appears on the right/respond with right hand
Explain incongruent trials
Incongruent trial = if it appears on the right/respond with left hand
Explain Inhibitory Control
Stop Signal Task
Green light turning red
Occurs around 22-33% of trials
Stop signal delay (long pause after green light turns red)
Often requires a choice (CRT)
Explain Perceptual Decision Making
Random dot stimuli
Strength of motion signal (ratio of signal dots to noise dots)
Can embed stop signal cue
Explain the process of Letter Matching
Physical representations are activated first, then phonetic representations, and category last.
What can be tested with defensive burying?
Antianxiety drugs can be tested to see if the behaviour are affected or the amount of defensive burying is reduced
What is an electromyography?
It is an indirect measure of output from the motor cortex.
It is non invasive, cheap and easy to use.
The single trial analysis is powerful
What are the 2 ways of recording human psychophysiological activity?
Skin conductance
cardiovascular activity
How can we use Skin Conductance to measure human psychophysiological activity?
It Measures electrodermal activity
Techniques include measurement of skin conductance level (SCL) and skin conductance response (SCR)
How can we use Cardiovascular activity to measure human psychophysiological activity?
Often used to link physiological changes with emotional state
Measures include heart rate, blood pressure, and blood volume
What is the problem with X-rays?
Cannot see the density of the brain
What are contrast X-rays?
Inject something that absorbs X Rays less or more than surrounding tissue
What is a CT?
A procedure that results in cross-sections or slices and provides a 3-D representation of the brain.
It is computer assisted.
What is an MRI?
It measures the waves emitted by hydrogen atoms.
When identifying subcortical structures, what is better?
Bigger as we get a clearer image.
What does a Diffusion Tensor Imaging (DTI) do?
Makes use of the properties of water molecules, and how they diffuse along white matter tracts in the brain
What is a PET scan?
A measure of function/activity within the brain. It highlights brain activity via a injection of a radioactive tracer.
How does an fMRI work?
By blood carrying the oxygen which binds to the haemoglobin. From this the image can detect which areas of the brain are active.
How is an EEG conducted?
Electrodes are attached to the subjects scalp, and the device records the patterns of brain waves.
What are event related potentials (ERP’s)?
Momentary changes in electrical activity of the brain when a particular stimulus is presented to the subject.
What is a Magnetoencephalography (MEG)?
A measure of neural activity. It measures changes in magnetic fields on the surface of the scalp. It has fast temporal resolution.
What is TMS?
A magnetic stimulation/current used to activate the brain
Non-invasive
Temporal specificity- excellent
Spatial specificity – average (intensity dependent)
Can be used in conjunction with motor tasks/cognitive tasks to actually explore the neural mechanisms of behaviour
What are the 3 uses of TMS?
Assessment
Disruption
Modulation
What is tDCS?
Induction of LTP-like or LTD-like plasticity through
1) shifts in the membrane potential of underlying tissue
2) changes in synaptic activity that mimic LTP and LTD processes
What is a key concept of tDCS?
It can only be used to induce neuroplasticity, It does not measure excitability or inhibition in regions or circuits.
What do you need TMS for in regards to tDCS?
You need TMS to assess the physiological outcomes of tDCS or look at the behavioural effects of tDCS.
What is Stereotaxic Surgery?
It is a lesion method using radio frequency lesions via knife cuts and cryogenic blocks.
What is the magnitude limit?
1500
What is a limitation of lesion methods in animals?
You cannot be assured with only stimulating one type of cell within the brain
What is a solution of this limitation?
To specifically stimulate or inhibit particular neurons within particular brain regions
What are Optogenetics?
A technique that involves inserting photosensitive proteins into the neural membrane through the use of light.
What colour causes excitation
Blue
What colour causes inhibition?
Yellow
