Unit 1 Flashcards
Anatomical and Functional Organisation of the Nervous System
What is the definition of Psychobiology?
Aims to understand the biological basis of behaviour: it seeks to explain behaviour in terms of biological mechanisms
What is all behavior?
a reflection of activity in the nervous system
Is the brain the center of behavior? Why?
No. Behavior and interactions with the environment can also affect the brain
How do the brain, behavior and the environment relate to each other?
it is a circular system
-> environment provides input, brain processes the input and produces output, which in turn influences environment
What is the black box?
the analogy used to describe how the nervous system works
What influences the blackbox and what happens then?
Causal Elements influence the Black Box: Genes and Environment
The Brain (Neurochemistry & Neurocircuitry)
Brain creates Behaviors
What are the different levels of psychobiological analysis?
- study large brains and see how they relate to behavior
- how groups of neurons relate to behavior
- how individual neurons relate to behavior
Who was René Descartes and what did he believe regarding psychobiology?
A philosopher with important theories in the study of psychobiology
-> believed behavior occurs automatically and involuntary (everything is reflexive)
Is there behavior which doesn’t require the mind?
Yes, they are called reflexes
What is Cartesian dualism? Who invented it?
Réne Descartes
mind and body do somehow interact (even tho he saw mind and body as separate entities)
Who disproved Descartes theory that the mind sends “animal spirits” down hollow tubes in oder to move muscles and tendons?
Luigi Galvani
What did Luigi Galvani discover?
the electrical nature of neural conduction (stimulating frogs nerve caused contractions of muscle - EVEN when detached to body)
How do nerves work?
by sending electrical impulses
Does the brain produce movement in muscles?
no, the neurons do
-> muscle contractions are produced by the nerves and muscles themselves
How does the brain ‘produce’ movement?
by initiating a chain of commands, in the form of electrical nerve impulses
Who was Johannes Purkinje and what was he first to describe?
a nerve cell in detail
- discovered large nerve cells in the cerebellum
What are the large cells in the cerebellum called and what are they important for?
Purkinje cells -> important for balance and movement
What did Theodor Schwann describe?
the myelin sheath wrapped around neurons
How can we imagine a myelin sheat in real life?
like the plastic tube around the metal in an electrical cable
What view did Joseph Gall present of the brain?
a view in which different areas are responsible for different functions
-> brain like a muscle, the more we use certain brain areas, the bigger it will get
-> would be measurable in skull (seen or felt)
What is the reading of bumps on the head called?
phrenology
What is cerebral localization?
The view that different brain areas are specialized for specific functions
What did John Baptiste Bouillaud consider the frontal lobes of the brain to be?
responsible for higher order mental functions (intelligence, inhibition, planning etc.)
Which case supported the concept of cerebral localization? What happened to him?
the rail worker Phineas Gage
- an iron rod projected through his skull, destroying part of his frontal lobe
-> before accident: hard-working, after accident: unreliable, heavy drinker, gambler
Does the frontal lobe influence our behavior?
yes
What did the neuroscientist Korbinian Brodmann divide the cerebral context in?
52 discrete areas, supporting the idea of cerebral localization
How did Brodmann divide the cerebral cortex into areas?
the areas were delineated based on cytoarchitecture - meaning the cells in each area had a similar cellular structure
What is the significance of the cellular structure in Brodmann areas?
the whole cortex is organized into layers of cells, and the thickness of these layers varies around the cortex
-> helping define different Brodmann areas
Do Brodmann areas correspond to specific functions? What is an example?
yes, most of them correspond with specific functions
e.g.: Brodmann Area 4: motor cortex, responsible for motor control
Who developed the silver staining technique and what is it?
Camillo Golgi
-> allowed the identification of single neurons among other body cells
What did Santiago Ramon and Cajal discover based on Golgi’s staining technique?
that neurons are discrete, unitary entities, rather then branches of a continuous network
What are synapses?
small gaps or junctions between neurons where they interact and communicate with each other
Who first identified and described synapses?
Charles Scott Sherrington
How do neurons communicate across synapses?
mostly by sending and receiving neurotransmitters
What are neurotransmitter and what is one of the first one that was discovered?
neurotransmitters are chemical substances
-> first one: acetylcholine
Who understood the advanced functions of the cerebral cortex and how?
Wilder Penfield, by removing malfunctioning brain tissue on epilepsy patients before neurosurgery
-> applied light electrical stimulation to different parts of the cortex to see which are healthy and which needed removing
What did the stimulation of the primary somatosensory cortex produce?
a tingling sensation in specific parts of the body
What did the stimulation of the temporal lobe cause some of Penfields patients?
to hear music, familiar voices or relive familiar events
What does invasive stimulation provide in Penfields work?
information on the functional organization of the cerebral cortex
What are some functions of the frontal lobe, precentral gyrus, central sulcus, postcentral gyrus, parietal lobe, occipital lobe, temporal lobe and where are they located?
- frontal lobe: planning of movements, recent memory, some aspects of emotion (front of brain)
- precentral gyrus: primary motor cortex (in back of front brain)
- central sulcus: middle of brain
- postcentral gyrus: primary somatosensory cortex (Middle to back of brain)
- parietal lobe: body sensations (upper back of brain)
- occipital lobe: vision (lower back of brain)
- temporal lobe: hearing, advanced visual processing (lower fore-middle brain)
What is the Frontal lobe for?
Planning of movements, recent memory, some aspects of emotions
What is the Precentral gyrus?
primary motor cortex
What is the Postcentral gyrus?
primary somatosensory cortex
What is the Parietal lobe for?
body sensations
What is the Occipital lobe for?
vision
What is the Temporal lobe for?
hearing, advanced visual processing
What was the case of patient HM about, Brenda Milner reported? What did the patient experience due to the removals?
patient had untreatable epilepsy and focus of his seizures was localized to medial temporal lobe of cortex
-> removed both medial temporal lobes and the hippocampus (to reduce seizures)
-> experienced anterograde amnesia (unable to form new memories)
Which process does the hippocampus play a role in?
the memory process
What did Hubel & Wiesel’s experiments on monkeys and cats showed?
that neurons in the visual cortex respond to different patterns of light projected on the retina
What do simple and complex cells best respond to?
simple cells: to stationary light in a particular orientation (e.g.: vertical line)
complex cells: to light in a specific orientation, that has a particular direction of movement (e.g.: vertical bar moving from left to right across the retina)
What does the responding of cells according to Hubel & Wiesel’s experiments show?
that neurons in the cerebral cortex respond to some patterns of stimulation of receptors but not others
What 2 things is the brain mainly made of?
Neurones and Glia
What changed the way we think about consciousness and free will?
Benjamin Libet’s recordings of the brain activity where participants had to make a random hand movement and hat to remember the time they made the conscious decision to move the hand
What were the findings of Benjamin Libet’s brain activity recording experiment?
the electrical brain activity was found in the form of a readiness potential (RP) 300 ms earlier than the perceived conscious decision
-> preceded by unconscious processes in the brain
What is the readiness potential (RP)?
a measure of neural activity that occurs in the brain before a conscious decision is made
Which part of the brain plays an important role in addiction?
nuecleus accumbens
What are the cells of the human body divided into? What are examples?
systems that perform particular functions
e.g.: urinary system = kidneys, ureters, bladder and urethra
e.g.: cardiovascular system = heart, blood vessels and blood
What does the nervous system consist of?
neurones and support cells called glia