8. Explain the
concept of experience-dependent plasticity in the brain. Provide a
hypothetical example of how this might occur in a young child.
Experience-dependent plasticity refers
to the study of how the brain responds to its environment; as well as
how environmental changes impacts the biological organization of the brain.
Research supports the idea
that we have neurons that respond to specific
types of stimuli; this way we know when something is vertical, horizontal, obliquus,
etc. Research suggests that complex variations in the environment (and
therefore the individual’s experience) affect brain structure and function.
This experience-dependent plasticity is observed in numerous cell types,
brain regions, and circuits and can contribute significantly to stress
regulation,
mood, cognition, addiction, etc. A good hypothetical example of how this might occur
in a young child
would be exposing a child to only one way to build a house
with blocks rather than letting him do it his way; he’ll probably attempt
to build the house the way he sees it in real life, four vertical walls
with a horizontal
roof. Their concept of the house will be always the same
so they will find it difficult to break their schemas and create a
different model using a different architectural technique.
9. Why are
memories represented in the brain differently than sensory stimuli? Give an
example comparing
how the brain would process a visual stimulus and a memory,
and explain your reasoning.
Memories should be seen as virtual
recreations of the real world, and the way we retrieve them is by
bringing
our brain to the exact configuration of the moment we received the
stimulus. This explain why we
remember things when we recreate factors that
are consistent with the moment at which we created the
memory. For example,
we might not remember the name of the hotel we stayed in during our last
vacations, but we do remember we had a delicious specific food plate at
that place. We’ll probably remember the
name of the hotel once we try that
specific food plate again. We make use of our senses to receive stimuli,
perceive them, and consolidate it in our short or long memory. In
psychology, memory refers to the process of storing information, how it is retrieved and
encoded, whereas the perception is defined as the process of interpreting information
as well as recognizing the sensory stimulus. Memory is different from
perception
and so is their neural representation. Making use of techniques
such as MRI we can literally define the areas that show more activity when
responding to specific stimuli, such as occipital activity upon visual
stimuli, or temporal activity upon auditory stimuli. We cannot do the same
with memories since we cannot trace their exact location.
Sensory memory in psychology is
the memory process that stores information taken in by the senses.
These
sensory impressions are stored very briefly when compared to other types of
memory. Although
humans rely on sensory information to create memories and
increase understanding, they do not
necessarily have to retain impressions
of sensory input long-term in order to maintain memory stores or
sort
through information. Research has shown that memory is stored in neural
networks in different parts
of the brain, which are associated with
different types of memory, including short-term memory, sensory
memory, and
long-term memory. Memory traces, or engrams, are physiological neural
changes associated with memories. Scientists have learned about these
neuronal codes from studies on neuroplasticity. The
encoding of episodic
memory involves permanent changes in molecular structures, which alter
communication between neurons. Recent functional-imaging studies have
detected working-memory
signals in the medial temporal lobe and prefrontal
cortex. The frontal lobe and prefrontal cortex are both associated with
long- and short-term memory, suggesting a strong link between these two
types of memory.
10. Explain the
difference between functional connectivity and structural connectivity.
Provide an example to support your thinking.
When
applied to the brain, the term connectivity refers to several different and
interrelated aspects of brain organization. The human brain is
characterized by structural and functional connectivity within and between
regions. As the name implies, structural connectivity refers to the
anatomical organization of the brain with its structure’s connectivity via
fiber (neural) tracts. Recent advances in magnetic resonance imaging (MRI) and
image processing show various means to quantify structural connectivity in
a non-invasive way using short-range local measures and/or long-range
tract tracing procedures, which is called diffusion tractography. On the
other hand, functional connectivity refers to the connection of different
brain areas based on a specific function. As the class video mentions, functional
connectivity measures the synchrony or correlation of brain activity
between two or more regions. Common methods include seed connectivity,
independent components analysis, and voxel-wise connectivity. Seed-based
connectivity measures functional connectivity from a predefined region of
interest (ROI, or seed, shown in green) and the rest of the gray matter.
Regions of positive or negative functional connectivity are shown as red
and blue regions. Independent components analysis is mathematical modeling
technique that parcellates the brain into independent spatial components or
networks.
