Hersenen en gedrag – Samenvatting “An Introduction to Brain and Behavior”
“An Introduction to Brain and Behavior”
by Bryan Kolb, Ian Q. Whishaw & G.
Campbell Teskey
1 | What Are the Origins of Brain and Behavior?
1.1 | The Brain in the Twenty-First Century
CNS: brain & spinal cord
Peripheral NS (PNS): processes beyond CNS
Major parts brain
1. Cerebrum/forebrain (grote hersenen): conscious behavior
2. Brainstem: unconscious behavior
3. Cerebellum (kleine hersenen): learning + coordination
Jacobson: “we always make subliminal (onbewuste) movements related to our
thoughts, even if motionless”
Embodied behavior (theory): movements we make and perceive are central to
communication
Locked-in syndrome: patient is aware and awake but completely paralysed,
except for eyes
Minimally conscious state (MCS): unconscious but can display some basic
behaviors (e.g. uttering words)
Persistent vegetative state (PVS): alive but completely unconscious and
unfunctional
Deep brain stimulation (DBS): neurosurgery, electrodes in brain stimulate
targeted area to facilitate behavior
Magnetic resonance imaging (MRI): measures brain function in terms of
oxygen use
1.2 | Perspectives on Brain and Behavior
Mentalism (Aristoteles)
: behavior is a function of the nonmaterial mind
- “The psyche is nonmaterial, responsible for life and death, consciousness,
perceptions and emotions”
Dualism (Descartes)
: both nonmaterial mind and material body contribute to behavior
- Mind-body problem: difficulty of explaining the interaction of a
nonmaterial mind and a material body
Materialism (Darwin)
: behavior is a function of the nervous system without recourse to the mind
- Natural selection (theory): preferable traits survive through generations
- All animal brains and brain cells are related
- All animal behavior is related
- Brains and behaviors of complex animals evolved from simpler one’s
- Eliminative materialism: mental explanation should be eliminated if
behavior can be described without recourse to the
mind
,Hersenen en gedrag – Samenvatting “An Introduction to Brain and Behavior”
Contemporary perspectives
- Hebb: “learning because of neurons forming new connections to form a cell
assembly, which is a memory”
1.3 | Evolution of Brains and of Behavior
Chordates: animal with brain and spinal cord
Cladogram: phylogenetic tree suggesting taxonomy of organisms, based on time
sequence
Evolution NS
1. Neurons & muscles
2. Nerve net (simple NS without a center but its neurons receive sensory info
and connect to other neurons which move muscles)
3. Bilateral symmetry (organs and parts of body are symmetrical)
4. Segmentation (similarly organized body segments, e.g. vertebrates)
5. Ganglia (collection of nerve cells that function kind of like a brain)
6. Spinal cord
7. Brain
1.4 | Evolution of the Human Brain and Behavior
Primate order: subcategory of mammals including apes and humans
Hominids: primates that walk upright
Topographic maps: represent different functional areas of CNS
Connectome maps: represent all pathways connecting regions of CNS
Humans most closely related to chimpanzees.
1. Australopithecus africanus
2. Homo habilis (handy human)
3. Homo erectus (upright man)
4. Homo neanderthalensis
5. Homo sapiens
Encephalization quotient (EQ)
: quantitative measure of brain size, obtained from ratio actual-expected
brain size
- Trend line = expected brain size according to principle of mass and body
size
- The lower an animal’s brain falls relative to the trend line, the smaller its
EQ
- Critique: complex behavior also depends on neuron’s packing density
Hypotheses about brain enlargement
- Drastic climate changes drove adaptation by hominids, requiring more
complex behavior
- The primate lifestyle favors an increasingly complex NS
- Blood flowing to the brain adapts a more effective cooling system, which
makes brain size increase (radiator hypothesis)
- A changed rate of maturation favors larger brains
Heterochrony: study of processes regulating onset and end-of-life stages and
their developmental speed and duration
Neoteny:delayed maturation compared to ancestors
1.5 | Modern Human Brain Size and Intelligence
Species-typical behavior: behavior characteristic for a species
,Hersenen en gedrag – Samenvatting “An Introduction to Brain and Behavior”
2 | What Is the Nervous System’s Functional
Anatomy?
2.1 | Overview of Brain Function and Structure
Neuroplasticity: NS’s potential to physically or chemically modify itself to adapt
to changes
Phenotypic plasticity: individual’s capacity to develop into range of phenotypes
PNS nerves carry sensory info into CNS & carry motor instructions from CNS to
muscles and tissues.
NS
↓ ↓
CNS
PNS
(mediates
behavior)
↓ ↓ ↓ ↓
Somatic NS Autonomic NS Enteric
NS
Spinal (transmits (balances internal functions)
Brain
cord sensation, (controls
produces gut)
movement)
↓ ↓ ↓ ↓
Cranial Spinal Sympatheti Parasympat
nerves nerves c division hetic
division
(arousing;
fight-or- (calming;
flight) rest-or-
digest)
Afferent = incoming; efferent = outgoing
Meninges
Outer → inner:
1. Dura mater (tough, encloses brain & spinal cord as a loose sac)
2. Arachnoid layer (ultrathin sheet, delicate connective tissue, follows
brain’s contours)
~cerebrospinal fluid (CSF): cushions brain~
3. Pia mater (moderately tough membrane, connective tissue, clings to
brain’s surface)
Meningitis: infection in layers of meninges (particularly between
arachnoid layer & pia mater); body’s immune reaction to infection
increases the pressure within the cranium → affects brain’s
functioning
Symptoms: severe headache, stiff neck, head retraction/tilting
Encephalitis: infection of brain
Hemispherectomy: surgical removal of entire affected hemisphere
Cerebral cortex
: outer layer of brain, consists of folded and layered tissue
, Hersenen en gedrag – Samenvatting “An Introduction to Brain and Behavior”
- Temporal lobe: visual, auditory, gustatory; language, musicality, facial
recognition, emotional processing
~lateral fissure~
- Frontal lobe: executive functions (e.g. decision making, voluntary
movement)
~central sulcus~
- Parietal lobe: tactile; directing movements toward a goal or task
performing
- Occipital lobe: visual
Gyri: ‘bumps’ of cortex
Sulci: ‘cracks’ in cortex (fissures = really deep sulci)
Longitudinal fissure separates hemispheres.
Circulation
Stroke: severely reduced blood flow → neurological symptoms
Major arteries:
- Anterior cerebral artery (bij longitudinal fissure)
- Middle cerebral artery (aan buitenkant, rond lateral fissure
- Posterior cerebral artery (aan buiten- en binnenkant, bij onderste
gedeelte tot aan hoogte van occipital lobe)
Cerebral ventricles
: produce and secrete CSF
Lateral ventricles: 2 wing-shaped cavaties
Third & fourth ventricle: (on brain’s midline)
Gray matter: darker regions; cell bodies + capillary blood vessels; collecting &
modifying info before sending it out
White matter: lighter regions; nerve fibers covered with myelin; forms
longer-distance connections between brain’s neurons
Corpus callosum: contains nerve fibers, joined hemispheres together and allows
communication
Subcortical regions: make ‘wederzijdse’ connections with (sensory,
perceptual, cognitive and motor) cortical areas
Planum temporale: understanding speech (larger in left hemisphere for right-
handed people)
Heschl’s gyrus: analyzing music (larger in right hemisphere for right-handed
people)
Pineal gland lies within both hemispheres.
Neurons: communicative and info processing functions
Glial cells: aiding and modulating neurons’ activities
Tract: collection of nerve fibers in CNS
Nerves: collection of nerve fibers outside CNS
2.2 | The Conserved Pattern of Nervous System Development
Mammalian embryo Fully developed human brain
