From the figure individuals with alzheimers have

From the figure, individuals with Alzheimer’s
have significantly less brain activities in areas
related to memory system than healthy people
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People use this technique to figure what’s going on
in brains to understand processes eg. Memories in
this case
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However, PET scan is not frequently used because
it involves injection of external substance into the
body
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Another common technique is Functional Magnetic Resonance Imaging (FMRI)
which relies on the fact that brains contain magnetic elements such as iron which can
be measured via magnets
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By using a giant magnet, we can measure oxygen content in the blood flowing through
each brain region which gives us accurate picture of brains from moment to moment
activity
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An example of FMRI is conducted by Calvert where
participants are asked to read talker’s lips from assigned videos
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The researchers were able to show when a person is doing this,
the same part of the brain responsible for allowing us to hear auditory
stimuli (auditory cortex) is activated even though there is no auditory
information presented to them
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In the figure, blue region is the area activated when hearing only
speech while the purple area is activated when seeing visual lips. The
yellow region is activated when people hear and see moving lips
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This experiment shows how we can use visual information to
help us understand language
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Another method to measure brain activity is known as EEG (electroencephalograph)
which can be used to look at broad rhythms in brain activities
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This method works because our brain is consisted of trillions of neurons
communicating with each other using chemical signals (One neuron releases signal
while the other neuron receives)
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This message needs to be transmitted to brain by electric pulse in brain
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Measuring electric signals can allow us to record voltage changes throughout skull

giving broad activity in wave-like pattern
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We can also see how brain responds in
shorter time scales during specific events
such as when a stimulus is presented but
measuring before and after to see changes
in wave pattern
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Brain has distinct pattern depending on
kind of activity eg. Deep sleep vs. awake
resting with different waves
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Scientists can examine the waves to see
how brain respond to certain stimuli
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The most recent technique is called transcranial magnetic stimulation (TMS) which
strong magnetic pulses are at specific areas of brains temporarily to disrupt brain
activity in that area allowing to see what functions are compromised when certain areas
are targeted (noninvasively to see how brain controls cognitive functions)
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Eg. By disrupting visual cortex, the ability to see faces is interfered or by disrupting
motor cortex, ability to perform action is interfered. Also, ability to compute, speak
can be interfered etc.
Computational approaches to cognition:
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Scientists try to create models to approximate ability of human brains so models can
be created by all kinds of neuro processes to understand cognition
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