NEURO2020 week 1

WEEK 1

Brain structure

• Tells us about the morphology or form of things 

• CT scan may show brain structure and indicate a tumour that may be causing some observable behaviour

Brain Function

• Tells us about activity 

• EEG may show abnormal brain activity that is indicative of a seizure   

• Superior =

• Inferior =

above, below

• Rostral =

• Caudal =

towards the head, towards the tail

• Contralateral =

• Ipsilateral =

other side, same side

• Bilateral

• Unilateral

both sides, one side

• Proximal

• Distal

close to main body, far from main body

yellow?

dorsal

red?

posterior

purple?

anterior

green?

ventral

blue?

medial

pink?

lateral

bottom?

frontal plane?

bottom?

cross section

highest?

sagittal plane

middle?

horizontal plane

CAT SCAN

Computer assists in reconstructing 3-D structure of brain from many individual 'slices' 

Positron Emission Tomography (PET) 

• Somewhat invasive  

• Inject or inhale radioactive isotope – then image brain after task. 

• Program accumulates intersections of collisions to build a map if where highest activity occurs 

Magnetic Resonance Imaging (MRI) 

Detects waves emitted from hydrogen atoms when in a magnetic field  

Functional Magnetic Resonance Imaging (fMRI) 

• Captures area of increased oxygenated blood flow in the brain 

• More active areas take up more oxygenated blood 

• Oxygenated blood has magnetic properties 

• Non-invasive 

• High spatial resolution 

• Poor temporal resolution 

Transcranial Magnetic Stimulation 

• Single magnetic pulses are applied to specific locations on scale during/prior to task 

• Magnetic activity disrupts activity in targeted structures by inducing an electrical current 

• Cognitive or behavioural consequences are observed 

• Allows causal inference 

Electroencephalography (EEG) 

• Gives you waveforms that reflect different brain states 

• Beta/alpha/delta waves etc.  

• Individual signals are noisy, the average is informative 

Invasive recording methods 1

Invasive recording methods 2

spatial resolution

• How blurry/sharp is the image? 

• How precisely can we locate a structure or region from a given method? 

• High resolution is on the order of micrometres or the sub-cellular level. 

temporal resolution

• How precisely can we determine the timing of neural events from a given method? 

• Highest resolution is on the order of microseconds 

 

Causation in Brain activity

• Can be inferred by observing the consequences of stimulating/disrupting activity in specific brain region on associated behaviours.  

 

detection threshold

Faintest stimulation a person can detect 

discrimination threshold

What is the smallest detectable difference between two stimuli