2. When it comes to the brain the most fascinating thing, to me, is getting insight on what
happens to the human subjective experience when higher order functions of the brain are lost,
when some element of our internal subjective interpretation of the world is changed in some
way, what the clinic would call agnosias (agnosia = loss of knowledge). The reason I’m
fascinated with such cases is because they shape our understanding of how the brain works to
eventually bring about our perceptions, thoughts and feelings.
I am going to mention three examples in this paper, all of them taken from a course on the
brain by The Teaching Company, taught by teacher and neuroscientist Jeanette Norden. I have
watched the whole course at least three times (that’s how great it is) and there is one particular
lecture called Agnosias (lecture 16) that is where I have heard about these clinical cases for the
first time.
So, agnosias are caused by lesions to higher order processing cortex, and by higher order it is
meant cortex that does not interpret first hand input from the senses (like eyes, ears, skin…), but
cortex that is further up in the system, interpreting the information that already got to us. Here
are the three examples:
1. Motion agnosia – caused by a lesion in part of the junction between the occipital and
temporal lobes. A person with this type of lesion would lose the ability to perceive motion and
would only see the world as composed of still frames, certainly a challenging condition and very
difficult for us to even imagine.
2. Contralateral neglect – caused be a lesion to brodmann’s areas 5 and 7 of the right
hemisphere. This type of lesion would cause a person to ignore the left side of the world and of
their body as if they weren’t there, as if they didn’t exist. A lesion to the left hemisphere would
not cause contralateral neglect and it is believed that this is because the right hemisphere is
interpreting both sides of the world, while the left hemisphere only interprets the right side of the
world.
3. Color agnosia – brought about by a lesion to brodmann’s area 4. This type of lesion would
cause a person to lose the ability of interpreting different light frequencies, resulting in a loss of
color perception, even though they would still perceive the difference in light frequencies but
this would only be seen as different shades of grey.
3. There are many more types of agnosias, and, as professor Norden put it, there is no function
that cannot be lost with the right brain lesion (or maybe the wrong brain lesion?) so we should
never take for granted anything that we experience.
Now, about how learning about the brain has changed the way I look at the world, and mostly
the way I look at other people, is truly huge and really did make a difference. Professor’s Mason
course gave me great insight into brain anatomy, and even though I’m more interested in the
conceptual interpretation of the brain the anatomy is the foundation of this interpretation so I
certainly enjoyed the whole experience. I want to make three points at this point in my paper:
1. By learning more about the anatomy of the basal ganglia I am now more able to appreciate
my father’s personal experience after a stroke in the left hemisphere that mostly affected his
putamen, that is a nucleus in the striatum, and I am also compelled to try to explain all this to my
mother who is somewhat interpreting the slight changes in my father’s behavior at a personal
level.
2. After learning a lot about the brain I am now interpreting psychological disorders very
differently, I am more understanding of people, more tolerant and more willing to accept very
different interpretations of the world that other people might have. I think this is a very important
point and that by introducing neuroscience into the educational system there is a lot to gain
precisely in this direction of making people more understanding towards each other.
3. I have always wondered what intelligence is and just how precisely it is measured by the
tests that seem to be invading our lives and, by learning about the brain, and more exactly about
neuroplasticity, I am now fairly confident that we should stop measuring intelligence and
classifying people in this way. I do not think that some people are more or less intelligent than
others. I think we all just have our personal interpretation of the world, an interpretation that is
dynamic (it might be that is is more dynamic in some people than in others, but the point is that
it is not fixed) and unique and that our lives would be enriched if we just open our minds and try
to learn from each other instead of judging and classifying and categorizing…
Now to end my project I must mention my favorite part of professor Mason’s course and that
is most of the week 8 that had to deal with motor function and, more precisely, with the
cerebellum. I am fascinated with the cerebellum and in love with the Purkinje cells (they look
like a work of art). I enjoyed finding out about the vestibulo-ocular reflex and I always think
about it every time I read a book while riding the bus (which is fairly often). And I always have
4. to mention how greatly moved I was to find out about the lateral geniculate nucleus, which is the
first brain nucleus to get input from the retina, but that it always get input from area 17 (the
primary visual cortex) that is a loop which underlies our expectations of what the world should
look like built on our previous experiences.
Thank you professor Mason, and thank all neuroscientists out there who learn about these
things and are willing and, in fact, compelled to share their findings and their insights into the
human brain!
