Brain & Behavior – Lectures
CHAPTER 1
1. What is the brain?
the brain is an organ
it consists of nervous tissue and within this tissue there are nerve cells (neurons/glial cells)
the glial cells “glue” the neurons together and support them
2. What is behavior?
behavior consists of patterns in time
ex. movement, speech, attitude, blushing, thinking
more practical definition: behavior is any form of observable action or reaction of a person or
animal in response to external or internal stimuli
- if you can observe it, you can measure it
most behaviors consist of a mix of inherited and learned actions
ex. sucking reflex in newborns = inherited
ex. eating later in life = strongly influenced by external sources (learning and culture)
the mixture varies considerably from species to species:
the more complex the behavior, the bigger the capability of learning
3. The mind-body problem (not needed for the exam)
consciousness (having a soul) is not discussed in this course
dualistic versus monistic philosophical views
spiritualistic versus materialistic views
the fact that we are conscious is a byproduct of our brain activity
nobody knows what the connection is
atypical behavior = alterations – refers to brain damage
4. A brief history of humankind
we do not descend from chimpanzees – men and chimps do share a common Hominin ancestor
- we are the last surviving Hominin species
men and chimps only differ by around 1% in their DNA
, walked upright
it is not certain whether homo habilis used tools
homo erectus for sure used tools
the brain weight tripled – more sophisticated behavior
the brain volume is pretty large in comparison to our ancestors
encephalization quotient (EQ)
= actual brain size/ expected brain size (relative to body weight)
examples:
cat = average domestic animal – EQ 1
Australopithecus – EQ 2.5
Homo sapiens – EQ 7.0
our brain weight – tripled in 4 million years time
humans have the largest brain size relative to body weight (explains complex behavior)
how did our brain get so big?
1) lifestyle adjustments
- social group size (around 150) – hunter-gatherer
- eating patterns (fruits) – more difficult than eating grass
- use of fire (cooking) – more time for social interaction (the most plausible explanation) ; cooking
pre-digests the food
2) efficient brain cooling system
- circulating blood functions as a radiator (like a car engine)
- enabled homo sapiens to maintain high metabolism (= more horsepower)
70% glucose is used, 25% oxygen, 2% weight
3) neoteny
- retention of juvenile features in the adult animal
- lack of development in specific features
- it has to do with inheritance (ex. less facial hair which is passed onto the successive lineage)
- our head is relatively big compared to our body
- our brain is wrinkled up in the skull because otherwise it would not fit
- because our skull size is enlarged, there is more space for a bigger brain
, - adult humans closely resemble the infants of gorillas and chimps (large head relative to body
size)
is a larger brain also a better brain? (within species)
- within species: NO
ex. Einstein’s brain weighed only 1.2 kg which is less than average adult male brain
ex. men have more brain volume than women but are not more intelligent
ex. perhaps it is the number of connections between brain cells that matters
- default mode network – high intelligence shows a more connected brain (more interconnected
brain structure)
most of our behavior is not innate but acquired during life and is culturally determined
CHAPTER 2 (PART 1)
֎ describes the basic structure and function of the brain
֎ although the brain has structure, the brain is not a static organ – we are not born with a brain that
remains unchanged for the rest of our lives
֎ the brain is a plastic organ – the neural tissue has the ability to adapt to the world around us –
neural plasticity required in learning
֎ brain-body orientation
- everything that is located upward is dorsally located
- ventral structure points towards the belly
֎ spatial orientation
caudal – the spinal cord
, dorsal structure in the spinal cord is located in the back
rostrally - located towards the front
caudally – towards the tail
dorsal = superior
ventral = inferior
֎ anatomic orientation
sections/ views must be known
dorsal/ventral view for the horizontal section
the name of the view tells us something about the viewed structure
the last one is a lateral view
medial is located towards the inner structures
ventral –from the bottom towards the top
֎ brain protection – meninges and cerebrospinal fluid (CSF)
- meninges – three layer coverage
1) dura mater = tough matter / a double-layered membrane/ sensitive/ blood vessels/ sensitive
receptors
CHAPTER 1
1. What is the brain?
the brain is an organ
it consists of nervous tissue and within this tissue there are nerve cells (neurons/glial cells)
the glial cells “glue” the neurons together and support them
2. What is behavior?
behavior consists of patterns in time
ex. movement, speech, attitude, blushing, thinking
more practical definition: behavior is any form of observable action or reaction of a person or
animal in response to external or internal stimuli
- if you can observe it, you can measure it
most behaviors consist of a mix of inherited and learned actions
ex. sucking reflex in newborns = inherited
ex. eating later in life = strongly influenced by external sources (learning and culture)
the mixture varies considerably from species to species:
the more complex the behavior, the bigger the capability of learning
3. The mind-body problem (not needed for the exam)
consciousness (having a soul) is not discussed in this course
dualistic versus monistic philosophical views
spiritualistic versus materialistic views
the fact that we are conscious is a byproduct of our brain activity
nobody knows what the connection is
atypical behavior = alterations – refers to brain damage
4. A brief history of humankind
we do not descend from chimpanzees – men and chimps do share a common Hominin ancestor
- we are the last surviving Hominin species
men and chimps only differ by around 1% in their DNA
, walked upright
it is not certain whether homo habilis used tools
homo erectus for sure used tools
the brain weight tripled – more sophisticated behavior
the brain volume is pretty large in comparison to our ancestors
encephalization quotient (EQ)
= actual brain size/ expected brain size (relative to body weight)
examples:
cat = average domestic animal – EQ 1
Australopithecus – EQ 2.5
Homo sapiens – EQ 7.0
our brain weight – tripled in 4 million years time
humans have the largest brain size relative to body weight (explains complex behavior)
how did our brain get so big?
1) lifestyle adjustments
- social group size (around 150) – hunter-gatherer
- eating patterns (fruits) – more difficult than eating grass
- use of fire (cooking) – more time for social interaction (the most plausible explanation) ; cooking
pre-digests the food
2) efficient brain cooling system
- circulating blood functions as a radiator (like a car engine)
- enabled homo sapiens to maintain high metabolism (= more horsepower)
70% glucose is used, 25% oxygen, 2% weight
3) neoteny
- retention of juvenile features in the adult animal
- lack of development in specific features
- it has to do with inheritance (ex. less facial hair which is passed onto the successive lineage)
- our head is relatively big compared to our body
- our brain is wrinkled up in the skull because otherwise it would not fit
- because our skull size is enlarged, there is more space for a bigger brain
, - adult humans closely resemble the infants of gorillas and chimps (large head relative to body
size)
is a larger brain also a better brain? (within species)
- within species: NO
ex. Einstein’s brain weighed only 1.2 kg which is less than average adult male brain
ex. men have more brain volume than women but are not more intelligent
ex. perhaps it is the number of connections between brain cells that matters
- default mode network – high intelligence shows a more connected brain (more interconnected
brain structure)
most of our behavior is not innate but acquired during life and is culturally determined
CHAPTER 2 (PART 1)
֎ describes the basic structure and function of the brain
֎ although the brain has structure, the brain is not a static organ – we are not born with a brain that
remains unchanged for the rest of our lives
֎ the brain is a plastic organ – the neural tissue has the ability to adapt to the world around us –
neural plasticity required in learning
֎ brain-body orientation
- everything that is located upward is dorsally located
- ventral structure points towards the belly
֎ spatial orientation
caudal – the spinal cord
, dorsal structure in the spinal cord is located in the back
rostrally - located towards the front
caudally – towards the tail
dorsal = superior
ventral = inferior
֎ anatomic orientation
sections/ views must be known
dorsal/ventral view for the horizontal section
the name of the view tells us something about the viewed structure
the last one is a lateral view
medial is located towards the inner structures
ventral –from the bottom towards the top
֎ brain protection – meninges and cerebrospinal fluid (CSF)
- meninges – three layer coverage
1) dura mater = tough matter / a double-layered membrane/ sensitive/ blood vessels/ sensitive
receptors
