Lecture 4 - Brain Scans

How does a brain scan identify the relationship between cognitive events and brain events

Insight, maps of brain activity, relate brain events to cognititve events, analyze patterns

How does differences in brain activity (as measured by fMRI) may not actually correspond to cognitive differences

Colors show difference maps relative to the stimuli used. Colors are not brain activity

Describe the basic properties of the Tongue Display Unit (TDU)

device used for blind people, placed in one’s mouth and would gather information of surroundings by sending vibrations to grooves/pixels on device on the tongue and then sending this info as signals to the brain so images from the world are put onto a camera in which the blind person can then see

What does a tongue display unit brain scan tell us about its use?

uses motor cortex area

Describe in general terms the method of reading the mind of someone who adds or subtracts numbers

MRI scan is used where person decides to either add or subtract, given 2 numbers they add or subtract based on end choice, deduce their choice and then predict it.

What are the limitations to mind reading someone who adds or subtracts numbers

person could choose to multiply then causing the adding or subtracting to be useless

Describe in general terms the method of thought reconstruction

Technology uses computer image to occipital lobe to computer to projection. Reproduces an originally shown image, if shown the letter A, the letter A will be generated again. Fewer errors occur in lower brain regions. Shows neurophysiological differences between cognitive events, CAN be measured by tech.

What are the limits of all the brain scan mind reading techniques

as the number of possible images increases, it becomes harder to reconstruct, too much data. Voxels give different responses just by change, difficult to compare across subjects, blurring makes difficult, fissures create blur, cog events faster, only measure brain, does not manipulate.

Describe in general terms the difficulties with statistics in brain scans

Easy to do them incorrectly, some data from salmon, even purely random noise will cause statistically different findings, moving around in MRI machine can also cause issues, problems can be reduced but not eliminated

Dendrite

received inputs (touch on the skin)

Axon

output of information, passes info to other neurons, travels through system

Soma

integrate, transfers proteins through axons and dendrites

Myelin Sheath

insulates by wrapping around neuron, also exists in the brain, allows imaging in the human brain connectome