Latest / Professor Peterson’s Psychology Classroom / Neurons to Nuance: How the Brain Builds the Mind

Transcript

Neurons to Nuance: How the Brain Builds the Mind · Professor Peterson’s Psychology Classroom

• 0:00
  Welcome to this edition of Psychology Explained by Dr.
• 0:04
  Curtis Peterson, who is trying to bring psychology
• 0:07
  alive for us all. Right here
• 0:11
  with the basic cell of the system, the nerve cell,
• 0:15
  which we approximately have around 86
• 0:19
  billion, uh, by the time we're around the age
• 0:23
  of 6. And as I said,
• 0:26
  uh, when we introduced this little guy,
• 0:29
  Um, it's kind of a lose it or use it type of deal.
• 0:33
  These cells do not regenerate,
• 0:36
  unlike the other cells in our body.
• 0:40
  And so they rely on these other guys
• 0:43
  that we call, uh, glial cells,
• 0:47
  which nourish it, protect it, clean it,
• 0:51
  all of those things. And we had mentioned that it
• 0:56
  is actually the reduction of these cells that
• 1:00
  actually predict cognitive decline as
• 1:04
  we age. However, when we talked
• 1:08
  about things like dementia, those type
• 1:12
  of attacks occur directly on the neuron itself.
• 1:18
  And then we went through the myelin process.
• 1:22
  We talked about the different neurotransmitters that,
• 1:35
  that are associated with these different— specifically
• 1:39
  within the area of psychology. So we talked about dopamine,
• 1:43
  serotonin, glutamate,
• 1:46
  norepinephrine. Uh, in those, which we
• 1:51
  will get to, and how they really kind of, uh,
• 1:55
  uh, impact the system when we get to the overall system
• 1:59
  this coming Wednesday. And then
• 2:03
  where we ended last Wednesday was a talk about the limbic
• 2:08
  system and the brainstem area,
• 2:11
  where most species who have a brain They
• 2:16
  definitely have the limbic system, but as they increasingly evolve,
• 2:20
  they, uh, brainstem, excuse me.
• 2:25
  Um, but they definitely have a limbic system as
• 2:28
  well as it evolves larger and larger.
• 2:32
  Okay, so where we are today is
• 2:36
  what sets on top of that limbic system
• 2:40
  that gives us some of the specialized things that
• 2:44
  make us human. Um,
• 2:48
  if you remember in the beginning
• 2:52
  lecture, I said that the brain size was important in
• 2:56
  proportion of the body mass of
• 2:59
  the species. We defy that
• 3:03
  a little bit because we actually have oversized brains for
• 3:08
  our body mass. So we kind of, uh,
• 3:11
  break that law or that rule.
• 3:15
  However, when we look at the cerebral
• 3:18
  cortex, whatever the species
• 3:22
  is specialized in will
• 3:26
  determine the size of their cortical area.
• 3:30
  Okay, so if we look at this as a basic human brain
• 3:34
  right here, We have areas that are associated
• 3:38
  with auditory language. We have the
• 3:42
  occipital lobe, which deals with
• 3:46
  sight and vision. We have the parietal
• 3:50
  lobe, which is associated with things like depth
• 3:54
  and integration of information. And what's missing here
• 3:58
  on the graph is the
• 4:02
  somatosensory strip and the motor sensory
• 4:06
  strip, which lies between the parietal
• 4:10
  lobe and the frontal lobe,
• 4:13
  which integrates, uh, sensory input
• 4:18
  with motor output. Okay,
• 4:22
  and then we have the frontal lobe, which is this area right here,
• 4:27
  which gives rise to decision-making,
• 4:32
  voluntary movement, Uh, this,
• 4:35
  uh, identity, social interaction,
• 4:39
  um, and, and impulse control.
• 4:43
  Okay, so it's kind of the executor of
• 4:47
  the cerebral cortex.
• 4:50
  Now I had mentioned that species-wide,
• 4:54
  species-wise, um, these areas
• 4:58
  tend to shift between species.
• 5:03
  So for example, a bird of prey or a bird that
• 5:08
  relies heavily on visual acuity
• 5:14
  have a larger occipital lobe
• 5:17
  and parietal lobe in proportion to what we
• 5:21
  have. When we look at dogs and
• 5:25
  mice Dogs have smaller
• 5:30
  visual acuity, but they have a
• 5:34
  larger amount of olfactory and
• 5:39
  auditory systems. So their areas
• 5:43
  of the brain are much larger than,
• 5:47
  than in proportion what ours would be.
• 5:50
  Okay.
• 5:53
  What humans tend to have a larger
• 5:57
  area of tends to be this prefrontal
• 6:01
  area that does the
• 6:05
  executive and social learning and social integration
• 6:11
  than these other areas do. Okay,
• 6:16
  the other thing that we should note, and I'll go ahead and put
• 6:21
  this on present,
• 6:27
  is that when we develop, we develop from
• 6:30
  the, the back forward.
• 6:34
  So the temporal lobe,
• 6:38
  which is at the bottom, develops first,
• 6:43
  and then these other areas of the lobe develop
• 6:47
  in sequence. An example of
• 6:52
  this is, uh, an infant that is prenatal—
• 6:56
  they're in mom's stomach— they start to hear
• 7:00
  before they're even born. And mostly
• 7:05
  what they're hearing is a sequence of mom's voice because
• 7:10
  it can be transmitted through the skeletal
• 7:14
  muscle system of the mother to the infant.
• 7:18
  Hence, when they're born, the first voice
• 7:22
  that they recognize usually is the mother's voice.
• 7:27
  We're born with pretty poor parietal
• 7:32
  and occipital acuity.
• 7:36
  We see, uh, we see at about
• 7:40
  a 20/400 rate Which
• 7:44
  we'll get into in developmental psychology.
• 7:47
  Uh, me— but basically what that means is we can see
• 7:51
  about 12 to 18 inches in front
• 7:56
  of us when we're born. And this is what,
• 7:59
  uh, when we get into developmental psychology,
• 8:03
  is what we think is why the female
• 8:06
  breast is located where it's at. Because a
• 8:11
  female breast is located about
• 8:15
  12 to 18 inches from
• 8:19
  the female's face. So when breastfeeding
• 8:23
  is taking place, the infant actually can clearly
• 8:27
  see mother's face and start
• 8:31
  to associate it with her voice.
• 8:35
  And so that's what theoretically the
• 8:39
  explanation of where, why the female
• 8:43
  breast is located where it's located. The second
• 8:48
  thing we start to develop, uh, at an early
• 8:52
  age is where we are in time and space,
• 8:57
  which is what the somatosensory cortex
• 9:01
  does. Is it locates us where
• 9:05
  we are in a place and at a
• 9:08
  time. And then what starts
• 9:13
  to develop is our ability to connect our sensory
• 9:17
  experiences with our motor experiences.
• 9:21
  So if you think about this as a child now being able to
• 9:26
  stand up and walk within a certain location.
• 9:31
  This is because this area of the brain that's represented right
• 9:36
  here starts to connect with each
• 9:40
  other, the motor area and the sensory
• 9:43
  area. The last area of the brain
• 9:47
  that develops is the frontal lobe,
• 9:51
  which a large portion right here deals
• 9:54
  with social dynamics. So this is where we're going
• 9:58
  to learn to give in to the demands of authority figures,
• 10:02
  to do things like potty training,
• 10:06
  uh, to be quiet at certain points but
• 10:11
  be active at other points due to social situations
• 10:16
  and social demands. And then right here
• 10:20
  in the prefrontal cortex, which it's often count called
• 10:24
  is the last stage of development, uh, which theoretically—
• 10:30
  there's been some debate, uh, that it develops anywhere
• 10:35
  between the age of 21 to about the
• 10:39
  age of 34. But we'll get into that
• 10:43
  debate when we get into the developmental section.
• 10:46
  But this is where we're able to start doing things like
• 10:50
  planning. And in developmental psychology,
• 10:54
  we'll talk about the analogy that is often used when
• 10:58
  we see this part of your brain come online,
• 11:03
  which is the purchase, um,
• 11:07
  uh, analogy. And I'll just take you through this
• 11:10
  really quick, but we'll get into it more specifically when
• 11:14
  we get into developmental psychology.
• 11:18
  This is where, let's say you have $50
• 11:23
  in your checking account.
• 11:26
  It's Friday and you go to the mall
• 11:30
  or you go on Amazon and there's a shirt
• 11:34
  that you've wanted that is on sale for
• 11:39
  $50, but it will only be on sale until
• 11:44
  the end of Friday.
• 11:47
  But what complexes this situation is
• 11:51
  that you also have an electric bill that
• 11:56
  is $50, and it's due on Monday,
• 11:59
  and you're not gonna get another paycheck till the following Friday.
• 12:06
  Okay, what we find is when
• 12:10
  we measure the frontal cortical area or
• 12:14
  we measure, measure age is it's not
• 12:18
  until about the age of 26 on average
• 12:24
  that a person makes the right decision to delay gratification,
• 12:30
  not purchase the shirt, pay their electric
• 12:34
  bill. And then go on before
• 12:38
  the age of 26. On average,
• 12:42
  they choose to buy the shirt and they'll
• 12:46
  figure out the electric bill sometime else.
• 12:50
  Okay, now on average, again,
• 12:53
  this is what complicates the frontal cortical area.
• 12:58
  There's a gender difference currently.
• 13:01
  And what makes the overall average 26
• 13:05
  to 27 is this, is that
• 13:09
  on average, those individuals who
• 13:13
  are identified as female tend
• 13:18
  to have disability at 21. And on
• 13:22
  average, individuals that are identified as
• 13:25
  male don't have this ability
• 13:29
  until they're 34 on average,
• 13:32
  meaning 50%. Okay,
• 13:36
  so this area, we are very
• 13:40
  clear that it does not develop until
• 13:44
  emerging adulthood into young adulthood.
• 13:49
  And so that's the developmental sequence. Thank you for
• 13:54
  joining us for this Psychology Explained. I hope you'll join us
• 13:57
  in later episodes where we can— we'll continue to
• 14:01
  investigate the human mind and psychology.