Cognitive Neuroscience Cognition: Variety of higher mental processes (thinking, perceiving,
imagining, speaking, acting, planning, etc.)
Neuroscience Biological investigations of the brain
Patient HM Case Study
Epileptic in 20s in 1953
Seizures from age 10, uncontrollable
Despite absence of epileptogenic activity, he received a bilateral medial temporal
lobectomy. This stopped his seizures, but made it so he was unable to form new long-term
memories. This is a selective memory deficit, not a perceptual/intellectual problem. He has
normal short term memory, but Anterograde Amnesia (cant remember anything past surgery)
HM does a tracing task: Draw a star while only looking at your hand in a mirror.
Even though he cannot make new memories, each day he does it, he gradually improves.
Procedural/Muscle memory is separate from memories of events in the past
Questions in Cognitive Neuroscience
How do biological systems work?
Can the brain learn, or does it have dedicated parts?
What happens when you take parts away?
Localization Vs Antilocalization How does the brain work?
Localization Parts of the brain are specific to certain functions
EEG measures brainwaves
fMRI Study activity in physical brain (topographic) in millimeter resolution
Early Conceptualizations of Mind
Aristotle (384-322 BC)
-Brain contains cooling fluid so it doesnt overheat
Descartes (1620) Dualism
-Pineal gland is where mind and body interact - Influences the body through ventricles
Spinoza (1650s) Mind and body are the same, the mind is just at a higher level
Dual aspect theory
Gall and Spurzheim (1810) Create true-to-life diagram of the brain
-35 areas with different functions
-Believed that brain grows to accomodate functions
-All sensations, all perceptions, and all volitions occupy the same seat in these cerebral
organs. The faculty of sensation, percept, and volition is then essentially one faculty. He tested
this by removing parts of birds brains, and then seeing them recover
-Aggregate Field (mass action of brain)
Mr. Leborgne has a stroke in his frontal cortex. After this, all he could say was Tan
(this is called aphasia). However, he could understand everything.
Showed the Language Production is localized in the frontal cortex
Patient can say things, but cannot understand. Produces Nonsense
Frisch and Hitzig
Electric stimulation in dog to produce movement
-Brodmann, Nissl, Von Bonin, Bailey, Von Economo
-Golgi, Cajal, Purkinje, Freud, von Helmholtz
They all agree on some form of localization Golgi, believing in mass action, develops a stain to see neurons. He does not notice the Synapses
Cajal saw the synapses, and shows that there is localization
Sensory and Motor Maps
Sir Henry Head sectioned branches of his own radial nerve (in the hand) and did
experiments on sensory loss.
Lashley: Mass Action
Maze Learning with Rats
Showed that lesions do not impair learning or performing tasks
20 Century: Localization
Penfield and Rasmussen studied those undergoing surgery for seizures. Delivered
electric shocks to the brain and showed that stimulating certain regions (the motor cortex)
produces specific responses in the body
Complex behaviors include many different areas
Smaller processes are localized
Psychology story the black box
-Goal is to measure behavior and study the mind
Empiricists vs. Rationalists
Rationalists meaning of life through right thinking about happiness/public good/etc.
Empiricists knowledge/meaning through sensory experience
Behaviorists try to understand the mind using stimuli/responses
Demise of behaviorism
Some behavior property of mind alone responds differently to the same output, I.E.
optical illusions/apparent motion
-Emphasis on built-in properties (mental events)
-Internal representations, mental maps, and models
-Newell and Simon
-Chomsky states that language is formed in the brain
-How cerebral cortex is organized and functions -Hubel and Wiesel
-Marr: Multiple levels of analysis, algorithm, implementation, and computation
-requires appeal to biology: how everything is wired
MRI created, cognitive neuroscience rises
Cajals Neuron Doctrine
-Brain contains individual cells with small gaps between them
-Connectional specificity: there are specific pathways that cells attach to to perform
-Dynamic polarization parts of neuron made to send information, parts made to receive
Neurons: Like other cells, but some specific properties
Glia: Non-neural cells playing supportive function
100-1,000 billion neurons in the brain each makes ~1000 connections on average
What do neurons do with this information?
1. Receive information/collect information
2. Process information
3. Produce output
4. Transmit information over a distance
Metabolic Machinery: Nucleus, ribosomes, mitochondria, Golgi apparatus.
Enclosed in membrane, suspended in cytoplasm
-Receives input from neurons at synapses (postsynaptic)
-Treelike may be large arbors (Purkinje) or small (thalamus)
-Before synapse (presynaptic)
-communicates output of neuron
-connects to the soma at the Axon-Hillock
-Insulated with myelin sheaths