Presentation on theme: "1. The story of HM 2. Types of memories 3. How memories are stored Learning and Memory."— Presentation transcript:
1. The story of HM 2. Types of memories 3. 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 Lobe In the Temporal Lobe
Hippocampus limbic system short-term memory long-term memory spatial navigation The hippocampus belongs to the limbic system and plays important roles in the consolidation of information from short-term memory to long-term memory and spatial 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=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 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.
Striatu m & Proced ural Memo ry; Prefro ntal Cortex & Worki ng Memo ry
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 Mg 2+ 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 Mg 2+ 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 Mg 2+ ions.
LTP NMDARs can open only when a depolarization from the AMPAR activation leads to repulsion of the Mg 2+ cation out into the extracellular space, allowing the pore to pass current. Unlike AMPARs, however, NMDARs are permeable to both Na + and Ca 2+. The Ca 2+ that enters the cell triggers the upregulation of AMPARs to the membrane, which results in a long- lasting increase in EPSP size underlying LTP.
Neural 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 Ability Broca’s AphasiaWernicke’s Aphasia Damage to left frontal lobe***Damage to left temporal lobe*** Impaired Speech Production Slow halting speech Speech requires effort Intact Comprehension Impaired Comprehension Normal 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.
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:BrainL obesLabelled.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.