PSY 345 Lecture Notes - Lecture 14: Social Isolation, Prosopagnosia, Soltyrei
Thursday, December 7, 2017
Social Neuroscience
Social Neuroscience
- Neuroscience examines the physiological makeup and function of the nervous system.
When neuroscience is used with psychology, social psychologists are interested in seeing
what process occurs primarily in the brain that influence affect, cognition, and behavior
o What neural mechanisms control social cognition (if there is a dedicated location
in the brain for these processes at all)?
o Are there dedicated sections of the brain that function to control stereotyping,
decision-making, aggression, prosocial behavior, attitude, etc. (like breathing or
blinking)?
o An even weirder question is how do we know the ability to know ourselves (in
other words, the brain has evolved over millions of years to talk about itself)?
- Neuroscience started off shaky in the early 20th century. Phrenology was the popular way
to explain different personality differences and cognitive abilities – all of which was
based on the shape of a person’s skull
- This “science” was no better at explaining a person’s behavior than a horoscope or a
fortuneteller. It was largely abandoned over time, since it didn’t deserve a practical
function… but more importantly, those interested in knowing what was going on in the
brain were not actually looking in the brain
- However, just because early psychologists could not look into the functions of the brain
does not mean they couldn’t interfere what neurological processes were occurring
- Individuals with damage to specific areas of the head or damage to different parts of the
brain had previously demonstrated evidence that the brain had specific functions that
could be affected by lesions/damage in certain areas
- A man named Phineas Gage had an iron bar shot through his head through his cheek and
into his brain while working on a railroad. Miraculously, he seemed unaffected at the
time of his accident, speaking clearly and possessing memory of the accident…
- Despite that fact the Gage’s injuries did not hinder his memory, verbal fluency,
quantitative ability… those around him reported drastic personality and social deficits
o Aggression
o Inappropriate, dysfunctional social behavior
o This suggested that damage to the area of the brain could affect one aspect of a
person’s personality and social function while NOT affecting other areas. There
were localized areas of the brain that controlled specific functions… this was
clear without looking inside the brain (only observing damage from outside the
brain)
o Even earlier in psychology’s history is the study of brain trauma leading to
amnesia. Édouard Claparède conducted experiments in the late 19th century on a
woman who had experienced head trauma and could not form new memories
(although she could recall old memories and had basic cognitive skills)
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o Claparède interacted with the women every day, each time shaking her hand.
Each new day she could not remember him or the previous encounter the day
before. After a number of meetings, he hid a pin in his hand when he shook her
hand, which obviously caused her a lot of pain. Interestingly, she could not
remember him on following days, but eventually would not shake his hand stating
that “sometimes people hide pins in their hands as a practical joke” (Reisberg, p.
221)
o This early research showed that a person could have memory dysfunction in one
area of the brain (from an injury) while maintaining memory of events in a
different area of the brain…
o Other research showed that the more tissue removed from rats’ brain, the worse
their resulting cognitive ability and behavior (i.e. navigating through a maze).
However, even the smallest amount of tissue removed from a specific region of
rats’ brains (hippocampus and amygdala) significantly affect their ability to
remember, and use direction (to get through a maze)
Technological Explosion
- In the 1970s and 1980s, Magnetic Resonance Imaging (MRI) was created, which
allowed researchers to see structures of the brain within a person for the first time. This
allowed expert neuroscientists the possibility to explain how the brain localizes different
centers and theorize how these centers appear to be working to produce different
cognitive abilities
- Quickly followed by functional MRI’s (fMRI), researchers where able to see how the
structure of the brain appeared and see the process/activity within these structures as
people performed activities. This measures changes in blood and oxygen throughout the
brain using magnetic sensitive materials
- Positron Emissions Tomography (PET) allows researchers to see where blood is
moving in the body by injecting mildly radioactive solution into a person and then
measuring them with a machine that can detect the emissions of radioactive particles
from within the body
- This allows researchers to see where blood is going when participants are
performing certain mental/physical tasks
- In addition, Transcranial Magnetic Stimulation (TMS) is an amazing technology that
has been developed to stop brain activity in certain regions of the brain, with little to no
side effects. Using electromagnetic pulses to halt blood flow, this technology allows
researchers to disable functioning in the brain (much like your hand falling asleep) and
measure its’ effects on behavior
- In fact there was an amazing study where participants were “blinded” continuously for
two weeks (they wore an apparatus that blocked all light from entering their eyes). In
this time, they were taught how to read Braille. While this occurred, their brain was
measured using fMRI to see what was occurring inside…
- At the start of the trial, the activity in the visual cortex was almost nothing (which had
previously been used to process information from the eyes). However, after about two
weeks, the visual cortex began to light up again… when people were reading Braille
- Amazingly, the brain started using an area it was no longer using anymore to control how
participants were reading in Braille
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- Even more shocking, the participants who had learned to read Braille had TMS applied to
their visual cortex and they were unable to read Braille
- They learned this while “blinded” … the brain had started using the visual cortex to read
in Braille, and TMS took this away. Even freakier is when they used TMS on people
who had been blind since birth. Magnetic stimulation to the visual cortex took these
people’s ability to read Braille away also, even though their eyes had never processes
information in the visual cortex in the first place
- This demonstrates how the brain may not localize function of individual abilities in
specific areas. This suggests that the brain is able to “re-wire itself” and adapts its
functionality to the environment. This is known as plasticity
- But measuring the functions of the brain is not as easy as just turning on a switch. The
process behind MRI, fMRI, PET, and TMS scanning is far more complex and intricate
than you think
- These machines attempt to measure specific signals given off by the brain…
o 1. Electric/Magnetic Activity – these can be used to understand the timing of
brain activity or how quickly the brain is sending out signals (temporal
resolution)
▪ The disadvantage of using this method of collecting data from the brain is
that finding where in the brain the source of activity is coming from is
difficult
o 2. Blood Flow – determining where neural activity is occurring (spatial
resolution) is sometimes more important than determining the speed of neural
activity. However, since blood moves much slower than electromagnetic
impulses, the temporal resolution of this method of collecting data from the brain
is poor
Electroencephalography (EEG)
- This method allows researchers to measure the TOTAL amount of electric impulses
transmitted from the brain during various activities
o Electrodes on various locations of the scalp measure specific locations where
electric pulses from the brain are released
o Specific locations of activity are not known (just the TOTAL amount of activity
measured from the brain)
Event Related Potentials (ERP)
- These are “very small voltages generated in the brain structures in response to specific
events or stimuli” (Blackwood and Muir, 1990)
- They are multiple EEG measurements that are combined to form a “wave” or graphical
interpretation which describes how intense and how lasting different electromagnetic
pulses from the brain last
- This examples comes from a study, which measured the ERPs of native and secondary
language speakers. The electromagnetic waves of each person’s brain were recorded
when participants heard and saw different words in the language, as well as different
versions of gender specific words
- This method allows research to see the differences in wave form patterns over thousands
of milliseconds (and how and when these signals activate)
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Document Summary
Neuroscience examines the physiological makeup and function of the nervous system. Neuroscience started off shaky in the early 20th century. Phrenology was the popular way to explain different personality differences and cognitive abilities all of which was based on the shape of a person"s skull. This science was no better at explaining a person"s behavior than a horoscope or a fortuneteller. It was largely abandoned over time, since it didn"t deserve a practical function but more importantly, those interested in knowing what was going on in the brain were not actually looking in the brain. However, just because early psychologists could not look into the functions of the brain does not mean they couldn"t interfere what neurological processes were occurring. Individuals with damage to specific areas of the head or damage to different parts of the brain had previously demonstrated evidence that the brain had specific functions that could be affected by lesions/damage in certain areas.
