From the figure individuals with Alzheimers have significantly less brain

From the figure individuals with alzheimers have

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From the figure, individuals with Alzheimer’s have significantly less brain activities in areas related to memory system than healthy people lPeople use this technique to figure what’s going on in brains to understand processes eg. Memories in this case lHowever, PET scan is not frequently used because it involves injection of external substance into the body lAnother 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 lBy 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 lAn example of FMRI is conducted by Calvert where participants are asked to read talker’s lips from assigned videos lThe 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 lIn 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 lThis experiment shows how we can use visual information to help us understand language lAnother method to measure brain activity is known asEEG (electroencephalograph)which can be used to look at broad rhythms in brain activities lThis 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) lThis message needs to be transmitted to brain by electric pulse in brain lMeasuring electric signals can allow us to record voltage changes throughout skull
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giving broad activity in wave-like pattern l 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 l Brain has distinct pattern depending on kind of activity eg. Deep sleep vs. awake resting with different waves l Scientists can examine the waves to see how brain respond to certain stimuli l 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) l 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: l 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 l
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