Midterm1 Flashcards
Neuroscience definition
Study of the nervous system
Psychology definition
Study of the mind
Mentalism ‘Theory’
Aristotle
Human intellectual functions are produced by the psyche (mind), a nonmaterial entitity
The brain’s purpose was to cool the blood
Psyche - proposed to be the source of human behaviour
-independent of the body
Dualism ‘theory’
Descartes
Thought the mind and body must be linked to form a person (duo)
- Definition: behaviour is controlled by 2 (dual) entities: a nonmaterial mind and a material body
- Hypothesized that the mind resides in the pineal gland where it directs fluid flow through the ventricles and into the muscles to move the body
Materialism idea
Darwin
Position that behaviour can be explained as a function of the nervous system without recourse to the mind
- Argues for objective and measurable descriptions of behaviour that can be referenced to brain activity
- Nonmaterial entity for mind - this idea was thrown out the window
Modern brain theory is materialistic
Darwin, however, did not propose a mechanism through which genes were inherited
behavioural neuroscience
the field that relates behaviour to biological processes
- how the brain regulates behaviour
- also how behaviour and experience can affect the brain
- Biological Psychology = behavioural neuroscience
What are some tasks faced by all living things?
Avoid harm or damage
secure energy and essential nutrients
secure conditions for reproduction
Darwin’s idea of Natural Selection. 3 Facts and 1 Inference
- Idvls of a given species are not identical - that is there is variation among individuals
- Some of this variation can be inherited (passed on from parent to offspring)
- Not all offspring survive. Some idvls live while others don’t
Inference: Variation among individuals affects the probability that they will survive to reproduce and pass along their traits/genes while doing so.
Mendel
Defined the laws of inheritance
Genes come in pairs and are inherited in distinct units, one from each parents
Hugo de Vries
Described the mechanism of mutation that leads to new traits forming - ie difference in phenotypes
What is the Linnaeus system?
An organization of animals that is based on morphology. It may not correctly reflect evolutionary history
ex Kingdom, Phylum, Class, Order, Family, Genus, Species
What is modern taxonomy?
An organization of animals based on evolutionary history. Compares the DNA to sort out evolutionary lineages. Can predict how long ago two species diverged from a common ancestor based on spontaneous mutation rates.
We now use a combination of both the Linnaeus classification system and modern taxonomy.
How many years ago was the first simple nervous system found in the fossil record?
700 million years ago
250 million ya - first brain
3-4 million ya - first human-like brain
1- 200 000 years ago - modern human brain
The Neuron Doctrine
Nervous systems are made up of discrete, individual, polarized nerve cells that contact eachother at synaptic junctions and form the developmental, functional, structural and trophic units of nervous systems.
Development of the Neuron Doctrine
Leeuwenhoek - POstulasted that nerves are tubes containing fluids/spirit carrying sensations from and to the brain
Purkinje - Identified cells within the nervous system
Schwann- Enunciates cell theory (how cells work/form)
Waller - discovered concept of anterograde nerve degeneration
Gudden - Traced connections between the main centres of the brain. Discovered trophic support
Kolliker - Supplied proof that nerve fibres are continuous with nerve cells
What were some key advances that lead to the development of the neuron doctrine?
Advances in microscopy - invention of compound light microscope
Golgi stain - guy named Golgi invented a stain for neurons although it only stain about 20% of the neurons which led to underestimating the amount of neurons in the brain - Why golgi thought neurons formed a continuous network (not discrete cells)
Continuous network vs Discrete cells in the nervous system
Cajal - thought neurons were discrete cells (neuronistas) and that they were NOT physically connected
Golgi - thought neurons formed a continuous network (reticulum). This was largely because the stain for neurons he developed only stain about 20% of the neurons and caused him to inaccurately picture brain functionality
Unity of Transmission
Synaptic contacts between two cells can be either excitatory or inhibitory, but will always be of the same type (with a couple exceptions)
Dale’s Law
Each nerve terminal releases a single type of transmitter (with a couple of exceptions)
Who is the only one that has a ‘true brain’?
The phylum Chordata
All of the members have a brain and spinal cord
Brain complexity generally mirrors behavioural complexity (largely due to proportionally larger cerebral cortex)
What are the three subphyla of Chordata?
Vertebrata, Tunicata, Cephalochordata
What characteristics of the brain can vary between different mammalian brains?
Size (of brain areas, brain), size of olfactory bulb and size of cortex
Number of cells
Density of cells
What types of changes are there within neuroplasticity?
- chemical change
- structural change
- functional change
These changes occur in response to inputs from the environment and growth ie. learning, experiencing
Plasticity definition
the ability of one genotype to produce more than one phenotype when exposed to different environments
ie. can alter traits based on changes in the environment
behavioural plasticity - ex. tool use
Two approaches to studying evolution of the brain/ancestral brains
2 is beneficial because you can see the live behaviour of the animals and compare it to their brain structures/ relative size of parts of their brain etc.
- Endocasts -look at skull/fill skull with a model to visualize what brain looked like
- study the brains of organisms who have not changed much since ancient times (salamanders, opposums)
Cerebellum
- Part of the hind brain associated with motor control and sensory processing
- Not included in the brain stem
- Gets larger specifically in mammals and birds compared with other vertebrates (Birds and mammals have complex motion/ sensory processing and thus require larger brain areas for these functions)
encephalization factor
a concept implying an increase in brain size relative to body size
associated with the evolution of the brain and intelligence
- on a graph, the encephalization factor is the distance away from the line. The further the distance from the line, the larger the encephalization factor
Changes in size of mammalian brain parts with increase in body size
- Medulla takes up a smaller portion of the brain
- Cerebellum maintains the same proportion of the brain size
- IsoCortex takes up a larger portion in the brain
Brain areas dedicated to visual processing in different vertebrate groups
Lampreys - Midbrain
Amphibians/Reptiles - Midbrain and Tectum
Mammals - Midbrain and Tectum and Cortex
Sulci vs gyri
Sulci are grooves (U) while gyri are folds (n)
Forebrain
Consists of the telencephalon for sure and maybe the diencephalon
What makes up the telencephalon?
isocortex, basal ganglia, limbic system
What makes up the diencephalon?
Thalamus and hypothalamus. Connect the forebrain and midbrain
What makes up the midbrain?
Mesencephalon
2 pairs of bumps on the back of the brain stem
-superior colliculus
-inferior colliculus
Also includes:
- the substantia nigra (part of the basal ganglia)
- red nucleus - connected with motor neurons in spinal cord
- start of the reticular formation (sleep and arousal, temperature, motor control)
What makes up the hind brain?
The metencephalon and the myelencephalon
What structures make up the metencephalon?
Cerebellum, pons
What structures make up the myelencephalon?
medulla
What does the brain stem include?
The midbrain + hindbrain - the cerebellum
Connects the brain to the spinal cord