PSYC100 Study Guide - Final Guide: Synaptic Pruning, Neuroplasticity, Lip Reading
14 May 2018
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Department
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Professor
HUMAN DEVELOPMENT: INFANCY & ATTACHMENT
• How is the nature vs. nurture debate relevant to the study of human development?
• Critical/Sensitive periods
o Key ideas regarding plasticity
❖ Brain plasticity- compensation for loss and normative development process (in response
to environmental input)
➢ Which of the following is true regarding brain plasticity?
■ The length and amount of plasticity for an individual can be changed
based on environmental input
❖ Core ideas within developmental psychology
➢ Nature-nurture dichotomy and beyond
■ How do they become the person they are today: understanding biology
and environment interact
➢ “Embeddedness”= any individual behavior it is embedded within a context
(biological, social, and cultural factors); anyone one person sits within multiple
context
➢ Plasticity= part of who we are we are biologically prepared for the world and how
the world shapes our biological
• TED Talk clip by David Lewkowicz – How babies come to acquire knowledge
o Biological development of an organism as “multiple hierarchically organized systems”
o “Embeddedness”
❖ Doctor Lewkowicz Ted Talk eye tracking studies: at first 4 months of age (lots of
plasticity) babies are looking primary at the eyes, at 8-10 months babies look primary at
the mouth and lip read and imitate new way to manipulate their mouth and babble, at 12
months babies are shifting focus back to eyes because adults do that, and these babies
develop their expertise for their native language, at about 1 year babies become experts
and have perceptual broadening, adults predominately look at each others eyes when
speaking, eye gaze tells info about relationships
➢ When english native babies are exposed to new language everything is same
until 12 months they continue to lip read and become more familiar with this new
language, monolingual babies look a lot more at mouths because they are really
unsure of the language, even for spanish sounds adults look at the eyes but also
mouth
➢ Bilinguals babies are doing a great deal of lip reading and do this for longer
period of time relative to monolinguals, spending more time separating the two
sounds
➢ Knowledge emerges from developmental experience
❖ Development and Evolution: “Embeddedness”- have to understand all the persons
layers and interaction of context or can’t understand their behaviors or them
➢ (Inner circle) DNA, Cell, Tissue, organ, system, organism, environment (outer
circle)
■ DNA: only encodes for proteins
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■ Arrows between layers are bidirectional influences (work in two
directions)
■ Within an organism- If we have issues with a system, then the issues with
the larger system level impact downward towards your DNA and back out
■ Environment
● You (inner circle)
● Caregivers
● neighborhood/community
● Institutions- government
● Cultural context (outer circle)
❖ As a human we are made up of hierarchy structure
❖ We are shaped by openness and different environments
❖ Caregivers context are most important in the first few years of life
➢ Brain most plastic in early years and grows quickly
■ When your an infant how you see depends on your caregiver= visual
input
■ Social relationships- in early years of life you were modeled that kind of
social relationship which sets the stone for your later years
• Early brain development
o Neurogenesis
o Myelination
o Synaptogenesis “burst”
o Synaptic pruning
o Further synaptogenesis and strengthening of connections
■ Neurogenesis- by time you are born you will have all neurons for most
part you will have for rest of the life; assume typical development=
biologically and genetically driven process
■ Myelination- as you get older, this process is rapid, and is where the
myelin sheath is wrapped around the axon (important for speed of
electrical transmission), important for how the cells in brain communicate
and how you process information from the world, process becomes better
overtime; across cultures the process is the same, biological and genetic
process; part of body system that prepares you for the world;
speeding=more efficient=more cognitive processing; severe malnutrition
impacts this process
■ Synaptogenesis “burst”- over production of creation of synapses, basis for
production of synapse and most plastic period of your life; preparing to
receive environmental inputs-weak synapses
■ Pruning- extremely dependent on environmental inputs; lose weak
synaptic connections are trimmed and the things that we need are
strengthened; developmentally normative process; trim things we don’t
need to be efficient in the things we do need; do not need to be able to
hear all language sounds; Ex: picture of two 2 yr old brains- 1st brain in
typical environment, vs. brain that has experienced extreme neglect
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(much smaller, less developed, ventricles are much larger- less brain
matter), ready for experience but experience is not happening so the
neurons are trimmed away because they are not being used
■ Further synaptogenesis and strengthening of connections-extremely
dependent on environmental inputs; things you becomes expert in is
strengthened
❖ Review questions
➢ This early brain development process is thought to help us understand why
plasticity lessens over time. And which part of the neuron is affected by this
process?
■ Pruning- synapse (synaptic connection across the brain) is being trimmed
away
➢ Some researchers have argued that the focus on memorizing definitions and
vocab words is coming at a cost of the ability for students to solve problems
when replaced in new situation. Students are not developing…
■ Fluid intelligence
• How might early brain development processes be the basis for critical periods?
o Brain plasticity
■ Critical periods thought to map onto the periods of synaptogenesis “burst”
and pruning
■ Graph: birth, sensory, motor/language, higher cognition are peaks;
plasticity versus development
■ Peaks eventually close out due to pruning and plasticity close out, making
learning new languages more difficult
■ During period of language- exposed to multiple language sounds-
extends outward/lengthens bc of amount of environmental influence being
given to the child, or shorten if not exposed to multiple language sounds
■ Video: younger babies (under 6 months) can tell the difference between
the different faces of the lemur, babies 9 months and older were still
bored because they couldn't tell the difference- dishabituation
➢ Clicker questions:
■ In the video, it describes babies as being able to distinguish between all
faces when they are very young. Which process of the developing brain is
thought to be basis of this ability?
● Synaptic gentiss burst- most plastic period of development, takes
in so much, part of taking environmental input is looking at it
■ Also in the video it describes somewhat older babies as being unable to
distinguish between all faces. Which process of the developing brain is
thought to be the basis of why this change occurs?
● Synaptic pruning - babies get better at human faces because they
typically see them often but prune away ability to see lemur faces
• Perceptual narrowing vs. perceptual broadening
o Examples of each?
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Human development: infancy & attachment: how is the nature vs. nurture debate relevant to the study of human development, critical/sensitive periods, key ideas regarding plasticity. Brain plasticity- compensation for loss and normative development process (in response to environmental input) The length and amount of plasticity for an individual can be changed based on environmental input. How do they become the person they are today: understanding biology and environment interact. Embeddedness = any individual behavior it is embedded within a context (biological, social, and cultural factors); anyone one person sits within multiple context. Bilinguals babies are doing a great deal of lip reading and do this for longer period of time relative to monolinguals, spending more time separating the two sounds. Development and evolution: embeddedness - have to understand all the persons. (inner circle) dna, cell, tissue, organ, system, organism, environment (outer layers and interaction of context or can"t understand their behaviors or them circle)
