Summary Brain & Behaviour Lecture
Chapter 1
What is the Brain?
The brain is an organ
It consists of nervous tissue
The cells within this tissue are called nerve cells (neurons and glial cells)
What is Behaviour?
Definition used in the book:
Behavior consist of patterns in time
Examples:long dendrites
Movement, speech, attitude, blushing, thinking
More practical definition:
Any form of observable action or reaction of a person or animal in response to external or internal stimuli
Behaviour
Most behaviors consist of a mix of inherited and learned actions.
Examples: Sucking reflex in newborns = inherited
Eating later in life = strongly influenced by learning and culture
This mixture varies considerably from species to species:
▪ Smaller, simpler nervous system
→ narrower range of behaviors that depend mainly on heredity
▪ Larger, more complex nervous systems
→ more complex behavioral patterns that depend on learning
The mind-body problem
Dualistic versus monistic philosophical views
Spiritualistic versus materialistic views
TL;DR: Nobody knows
NB: extensively covered in other courses (philosophy)
Brain and Behviour for LAS
The brain is an organ, a physical object, living tissue
Behavior is action, not physical, but observable
This course is about the relationship between brain and behavior
based on evidence from:
1. Evolution of brain and behavior in diverse animal species
2. Brain-behavior relationship in typical people
3. How brain changes in people with brain damage/dysfunction
,A brief History of Humankind
We do not descend from chimpanzees!
Men and chimpanzees do share a common Hominid ancestor
Men and chimpanzees only differ ~1% (!) in their DNA
Hominids
▪ common ancestor originated ~ 5 million years ago
▪ primates who walked upright
▪ all hominids evolved from this ancestor
▪ humans only surviving hominid species
Some well-known ancestors
Australopithecus – “southern ape”
▪ originated ~ 4 million years ago in Africa (particularly south and east)
▪ brain size ~400 cm3 (0.4 kg)
▪ e.g.: australopithecus afarensis (Afar, Ethiopia): “Lucy”
Homo habilis – “handy man”
▪ ~2.5 – 1.5 million years ago, Africa
▪ larger brain volume than australopithecus: ~800 cm3 (0.8 kg)
▪ used simple stone tools
▪ ate animal food
Homo erectus – “upright man”
▪ ~1.5 million years ago
▪ larger brain (900-1200 cm3 – 0.89-1.18 kg), better tools than homo habilis
▪ migrated to Europe (Neanderthal) and Asia
Homo sapiens = “knowing man”
▪ ~120,000 years ago, originated in Africa
▪ ~100.000 years ago, migrated to Europe (Cro-Magnon, SW France)
▪ perhaps responsible for extinction of Neanderthal
▪ cave art, the oldest are aged ~30,000 years
▪ brain volume about 1500 cm3 (1.48 kg)
Evolution of the brain size
Encephalization quotient’ (EQ)
= actual brain size / expected brain size (relative to body weight)
cat = average domestic animal → EQ 1
Australopithecus → EQ 2.5
Homo sapiens → EQ 7.0
Our brain weight ~tripled in 4 million years’ time!
,What is do special about the human brain?
▪ Modern humans have the largest brain size relative to body weight
How did our brain get so big?
Lifestyle adjustments
• social group size (~150) hunter-gatherer
• eating fruit (more difficult than e.g. grass)
• use of fire (cooking) more time for social interaction
Efficient brain cooling
• circulating blood functions as a radiator (like in a car engine)
• enabled homo sapiens to maintain high metabolism (= more horsepower)
• 2% weight, 25% oxygen, 70% glucose
Neoteny
• retention of juvenile features in the adult animal
• adult humans closely resemble the infants of gorillas and chimpanzees
• (e.g. large head relative to body size)
Is a larger brain also better brain (within species)?
Answer: no
▪ Einstein's brain weighed only 1.2 kg, which is
less than the average adult male brain (~1.4 kg)
▪ Men have ~10% more brain volume than women,
but are not more intelligent
▪ Perhaps it is the (number of) connections
between brain cells that matters?
NB: Most behavior is not innate but acquired during life and culturally determined!
Chapter 2
What is the nervous system’s functional anatomy?
This chapter 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; neural tissue has the ability to adapt to the world → neural plasticity
Example: learning
, Navigating the brain- different orientation systems
Brain-Body Orientation
▪ illustrates brain structure location from the frame of reference of the
human face
Spatial Orientation
▪ illustrates brain structure location in relation to other body parts and
body orientation
Anatomic Orientation
▪ illustrates the direction of a cut or section through the human brain
from the perspective of a viewer
Brain protection
Blood supply of the brain
Chapter 1
What is the Brain?
The brain is an organ
It consists of nervous tissue
The cells within this tissue are called nerve cells (neurons and glial cells)
What is Behaviour?
Definition used in the book:
Behavior consist of patterns in time
Examples:long dendrites
Movement, speech, attitude, blushing, thinking
More practical definition:
Any form of observable action or reaction of a person or animal in response to external or internal stimuli
Behaviour
Most behaviors consist of a mix of inherited and learned actions.
Examples: Sucking reflex in newborns = inherited
Eating later in life = strongly influenced by learning and culture
This mixture varies considerably from species to species:
▪ Smaller, simpler nervous system
→ narrower range of behaviors that depend mainly on heredity
▪ Larger, more complex nervous systems
→ more complex behavioral patterns that depend on learning
The mind-body problem
Dualistic versus monistic philosophical views
Spiritualistic versus materialistic views
TL;DR: Nobody knows
NB: extensively covered in other courses (philosophy)
Brain and Behviour for LAS
The brain is an organ, a physical object, living tissue
Behavior is action, not physical, but observable
This course is about the relationship between brain and behavior
based on evidence from:
1. Evolution of brain and behavior in diverse animal species
2. Brain-behavior relationship in typical people
3. How brain changes in people with brain damage/dysfunction
,A brief History of Humankind
We do not descend from chimpanzees!
Men and chimpanzees do share a common Hominid ancestor
Men and chimpanzees only differ ~1% (!) in their DNA
Hominids
▪ common ancestor originated ~ 5 million years ago
▪ primates who walked upright
▪ all hominids evolved from this ancestor
▪ humans only surviving hominid species
Some well-known ancestors
Australopithecus – “southern ape”
▪ originated ~ 4 million years ago in Africa (particularly south and east)
▪ brain size ~400 cm3 (0.4 kg)
▪ e.g.: australopithecus afarensis (Afar, Ethiopia): “Lucy”
Homo habilis – “handy man”
▪ ~2.5 – 1.5 million years ago, Africa
▪ larger brain volume than australopithecus: ~800 cm3 (0.8 kg)
▪ used simple stone tools
▪ ate animal food
Homo erectus – “upright man”
▪ ~1.5 million years ago
▪ larger brain (900-1200 cm3 – 0.89-1.18 kg), better tools than homo habilis
▪ migrated to Europe (Neanderthal) and Asia
Homo sapiens = “knowing man”
▪ ~120,000 years ago, originated in Africa
▪ ~100.000 years ago, migrated to Europe (Cro-Magnon, SW France)
▪ perhaps responsible for extinction of Neanderthal
▪ cave art, the oldest are aged ~30,000 years
▪ brain volume about 1500 cm3 (1.48 kg)
Evolution of the brain size
Encephalization quotient’ (EQ)
= actual brain size / expected brain size (relative to body weight)
cat = average domestic animal → EQ 1
Australopithecus → EQ 2.5
Homo sapiens → EQ 7.0
Our brain weight ~tripled in 4 million years’ time!
,What is do special about the human brain?
▪ Modern humans have the largest brain size relative to body weight
How did our brain get so big?
Lifestyle adjustments
• social group size (~150) hunter-gatherer
• eating fruit (more difficult than e.g. grass)
• use of fire (cooking) more time for social interaction
Efficient brain cooling
• circulating blood functions as a radiator (like in a car engine)
• enabled homo sapiens to maintain high metabolism (= more horsepower)
• 2% weight, 25% oxygen, 70% glucose
Neoteny
• retention of juvenile features in the adult animal
• adult humans closely resemble the infants of gorillas and chimpanzees
• (e.g. large head relative to body size)
Is a larger brain also better brain (within species)?
Answer: no
▪ Einstein's brain weighed only 1.2 kg, which is
less than the average adult male brain (~1.4 kg)
▪ Men have ~10% more brain volume than women,
but are not more intelligent
▪ Perhaps it is the (number of) connections
between brain cells that matters?
NB: Most behavior is not innate but acquired during life and culturally determined!
Chapter 2
What is the nervous system’s functional anatomy?
This chapter 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; neural tissue has the ability to adapt to the world → neural plasticity
Example: learning
, Navigating the brain- different orientation systems
Brain-Body Orientation
▪ illustrates brain structure location from the frame of reference of the
human face
Spatial Orientation
▪ illustrates brain structure location in relation to other body parts and
body orientation
Anatomic Orientation
▪ illustrates the direction of a cut or section through the human brain
from the perspective of a viewer
Brain protection
Blood supply of the brain
