1. The story of HM 2. Types of memories 3. How memories are stored Learning and Memory.

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Transcript of 1. The story of HM 2. Types of memories 3. How memories are stored Learning and Memory.

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.