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1. The story of HM2. Types of
memories3. How memories
are stored
Learning and Memory
Do Now
Where is long term memory created in the brain?• It is stored in the hippocampus.It is stored in the hippocampus.
And where is this part of the brain located?(What lobe?)
• In the Temporal LobeIn the Temporal Lobe
Hippocampus
The hippocampus belongs to the limbic system limbic system and plays important roles in the consolidation of information from short-term memory short-term memory to long-long-term memory term memory and spatial navigationspatial navigation. – Humans and other mammals have two hippocampi, one in
each side of the brain.
The story of H.M.
H.M. had epilepsy So he had parts of his medial temporal
lobe removed He could then no longer form long-term
memories of his experiences– http://www.youtube.com/watch?v=LBsW5qz5sDU– http://www.youtube.com/watch?v=hqi1xo658NE
Review
H.M. had parts of what lobe removed?
•What structures that are in this lobe were removed?
•What happened because these structures were removed?
medial temporal lobe
Hippocampus & parahippocampal region
Unable to convert short term to long term memory
TYPES OF MEMORY
Types of Memories
Declarative – conscious memory of facts/events– First enters as working memory (WM)
(transient) The prefrontal cortex can combine info in WM
with other relevant info
– Executive functions – selection, rehearsal, etc.
Can help put info from WM into long-term storage
Prefrontal Cortex
The prefrontal cortex is responsible for working memory.– Combines sensory information into
memories.Prefrontal cortex is activated in humans
when memories are manipulated.
Delayed Non-Match to Sample
Striatum & Procedural Memory;Prefrontal Cortex & Working Memory
Types of Declarative Memories
Semantic – data and facts– There are different zones for different types
of data Episodic – experiences and events
– Parts of the parahippocampal region help process the “what/when/where” of events
What is the capital of Washington
Olympia: This was an example of__________
memory.
semantic
Where did you learn the capitals of the states? Who taught them to you?
This was an example of__________ memory.
episodic
Types of Memories
Nondeclarative memories – remembering how to do something, or memories you have no conscious recollection of– Requires processing by basal ganglia and
cerebellum. Why?
The Basal Ganglia play an important role in planning and coordinating motor movements and posture.
Types of Memories
EXAMPLE OF Nondeclarative memories –– For example, when an amnesic patient
was stuck by a pin when she tried to shake hands with a physician, she later refused to shake hands although she had no memory of ever having met the doctor before. When asked why she refused to shake, she answered that she didn't really know, but that sometimes people hid pins in their hands.
http://brainmind.com/Amnesia.html
Emotion in Memory
The amygdala plays an important role in the emotional aspects of memory.
The hypothalamus and the sympathetic nervous system support emotional reactions and feelings
– For example, the movie Titanic.
Review
What is the knowledge of how to do a skill? Nondeclarative knowledge What is another word for nondeclarative
knowledge? Procedural memory What parts of the brain play an important role in
emotional memory? Amygdala, hypothalamus, and the sympathetic
nervous system.
More Review
What is declarative memory?
What is semantic memory?
What is episodic memory?
What is working memory?
What is nondeclarative memory?
Conscious memory of facts and events
Type of declarative memory for facts and data
Type of declarative memory of events
Working with information. Reason, comprehend and manipulate transient information.Remembering how to do something
How are memories stored?
Involves changes in synapses between two neurons
LTP (long-term potentiation) – long-lasting increase in the strength of a synapse
Long-term potentiation (LTP)
As a long-lasting enhancement in signal transmission between two neurons that results from stimulating them synchronously.
It is one of several phenomena underlying synaptic plasticity, the ability of synapses to change their strength.
LTP (more than you need to know for your quiz)
What do you remember about glutamate and the 2 different glutamate receptors?
– NMDA receptor (cation channel) is blocked by Mg2+ at resting membrane potential.
– To unblock the channel, the postsynaptic cell must be depolarized.
Glutamate is an Excitatory NT, and has NMDA and AMPA receptors
LTP
Involves NMDA receptors, which allow calcium ions to enter.
Once calcium enters…
LTP (more than you need to know for your quiz)
SO, NMDA cannot be utilized unless the cell has already received a signal to cause depolarization.
Therefore, the NMDA receptor functions as a "molecular coincidence detector".
LTP (more than you need to know for your quiz)
Its ion channel opens only when the following two conditions are met simultaneously: – Glutamate is bound to the receptor, and the
postsynaptic cell is depolarized (which removes the Mg2+ blocking the channel).
– This property of the NMDA receptor explains many aspects of long-term potentiation (LTP) and synaptic plasticity
LTP
Glutamate binds to postsynaptic AMPARs and another glutamate receptor, the NMDAR.
Ligand binding causes the AMPARs to open, and Na+ flows into the postsynaptic cell, resulting in a depolarization.
NMDARs, on the other hand, do not open directly at resting membrane potential they are blocked Mg2+ ions.
LTP
NMDARs can open only when a depolarization from the AMPAR activation leads to repulsion of the Mg2+ cation out into the extracellular space, allowing the pore to pass current.
Unlike AMPARs, however, NMDARs are permeable to both Na+ and Ca2+.
The Ca2+ that enters the cell triggers the upregulation of AMPARs to the membrane, which results in a long-lasting increase in EPSP size underlying LTP.
Model for LTP Induction
Question Time!
Describe LTP
This causes long-lasting increase in the strength of a synapse
Videos to watch
http://www.youtube.com/watch?v=euINCrDbbD4
Language & the Brain
Neural Basis for Language is ComplexNeural Basis for Language is Complex
• What is language?– spoken, written, nonverbal communication
• What senses do you need?– vision, hearing– proprioception
• What processes occur?– Motor processes– Memory processes (long-term, short-term / working
memory)– Higher order / abstract reasoning (symbolism)
Aphasia = Impaired Language AbilityBroca’s Aphasia Wernicke’s Aphasia
Damage to left frontal lobe*** Damage to left temporal lobe***
Impaired Speech ProductionSlow halting speech
Speech requires effortIntact Comprehension
Impaired ComprehensionNormal fluency and speed;
Errors in sound and word selection (gibberish)
http://commons.wikimedia.org/wiki/File:Brain_Surface_Gyri.SVG
Speech production(Broca’s area)
Understanding speech(Wernicke’s area)
***In some people, the right hemisphere is the dominant hemisphere for language. For this group of people, Broca’s area and Wernicke’s area will be located in the right hemisphere.
Guess the type of aphasia!
Guess the type of aphasia!
Answers• First clip = Wernicke’s Aphasia
– Nonsense speech, but is spoken at a normal speed and some complex words are used
• Second clip = Broca’s Aphasia– Meaning of words used correctly, but it’s hard to
get the words out
Word deafness
• Cause by damage to the superior temporal lobes in both hemispheres
• Inability to comprehend any auditory speech
Language throughout the brain
http://en.wikipedia.org/wiki/File:BrainLobesLabelled.jpg
Middle and Inferior Temporal Lobe:Accessing the meaning of words
Anterior temporal lobe:Sentence-level comprehension
Frontal lobe and posterior temporal lobe (left):Speech production
Left Posterior Temporal Lobe:Sensory-motor circuit; supports verbal short-term memory
Genetics
• Inherited disorders can impede the development of fluent speech and language.– For example, rare mutations of a
gene called FOXP2• impede learning to make sequences of
mouth and jaw movements that are involved in speech, accompanied by difficulties that affect both spoken and written language.
Genetics
• The FOXP2 gene codes for a special type of protein that switches other genes on and off in particular parts of the brain. – Changes in the sequence of this gene may have
been important in human evolution.