Exam 1: Chapter 1-2 Flashcards
Define learning and memory.
Learning is a set of processes intiated by experience. Memory is a product of that process.
What are the 2 goals of psychology?
- Derive a set of principles that describe how experience influences behavior
- Provide a theorectical account that can explain the observed facts
What were the 2 methods Ebbinghause used to study memory?
- Memorization Phase Repetition: number of times & how the list was presented
- Test phase trial spacing: Interval between the learning and test phase
What is the difference between the single trace theory and the dual trace theory of forgetting curves?
Single trace theory proposes that the forgetting curve reflects the natural decay of the underlying memory trace. In contrast the dual trace theory proposes that the forgetting results from the decay of two memory traces. One decays rapidly; the other much slower.
Why does the pyschological approach only study memory at a single level of analysis?
Psychologists study only the relationship between experience and behavior, without manipulating or measuring brain processes.
What does the neurobiological approach study?
Nuerobiologists study brain systems, synapses, and molecules, as well as behavior by manipulating the brain and measuring the brain’s response to experiences and drugs.
What is Ribot’s Law?
Old memories are more resistant to disease/disruption than new memories.
What did Serge Korsakoff propose about amnesia?
Amnesia can be due to either storage failure or retrieval failure.
Korsakoff’s Syndrome is characterized by anterograde amnesia.
What is anterograde amnesia?
The inability to acquire new memories.
In the late stages of Korsakoff’s Syndrome there is retrograde amnesia.
What is retrograde amnesia?
The loss of memories acquired before the onset of the disease.
What is plasticity?
The brain changing in response to experiences.
Proposed by William James
What are the 3 stages that memories emerge in?
- An after image is supported by a very short-lasting trace
- The after image is replaced by a primary memory trace that also decays
- Secondary memory is viewed as the reservoir of enduring memory traces that with a retrieval cue can be recalled.
Proposed by Santiage Ramon y Cajal
What is the Neuron Doctrine?
The idea that brain is made up of discrete cells called nerve cells, that are contiguous with each other.
Proposed by Stantiago Ramon y Cajal
What is the Synaptic Plasticity hypothesis?
The idea the strength of a synaptic connection can be modified by experience.
Prior to the Neuron Doctrine, there was the Reticulum theory.
What is the Reticulum Theory?
Proposed by Camillo Golgi.
The cells of the brain are fused into a giant network, the neuron was not an independent unit.
What were Cajal’s 3 major contributions?
- The neuron is an independent unit
- Brain’s wiring diagram where axons terminate at specefic locations among fields of dendrites
- The synapse
Why is the neuron an anatomical unit?
It is the fundamental structural and functional unit of the nervous system.
What are the 3 parts of a neuron?
- Cell body
- Dendrites
- Axon(s)
Why is the neuron a physiological unit?
Electrical activity flows through the neuron in one direction.
Proposed by Santiago Ramon y Cajal.
What is the synaptic plasticity hypothesis?
The strength of a synaptic connection can be modified by experience.
What did Ivan Pavlov develop?
Developed the fundamental methodolgy for studying associative learning in animals.
(What comes before the behavior)
In Ivan Pavlov’s associative learning
What is the importance of the conditioned response?
It provides a behavioral measure of a learned association.
What did Edward Thorndike develop?
Developed instrumental conditioning which demonstrates how we learn about the consequences of our actions.
(What comes after the behavior)
In Edward Thorndike’s instrumental conditioning
What is the Law of Effect?
The correct behavior was learned because the consequences of a sucsessful outcome strengthend connections between the stimulus and the correct response.
Consequence of unsucsessful responses weaken the wrong stimulus and response connections.
What did Ebbinghaus’s forgetting curve reflect?
Memory declines rapidly over the first hour, but remains stable thereafter
Describe Lashley’s experiment and what he learned.
Lashley trained mice to complete a maze and recorded the number of errors made after cutting different sections of the brain. He showed that memory could be spread out across different brain regions.
What did Donald Hebb propose?
Hebb proposed that cell assemblies of neurons could provide a substrate for memories.
Neurons that fire together, wire together.
What is the hippocampus essential for?
Episodic memory
How is the neuron a representation device?
Stores information about past synaptic experiences as changes in synaptic strength.
Describe the Sodium-Potassium pump.
What is it stimulated by? What ions are exchanged?
Stimulated by intracellular increases in Na+. 3Na+ out, 2K+ in.
Understanding Field Potentials
Why are intracellular and extracellular recordings mirror images of each other?
The intracellular electrode detecs positive ions flowing into the neuron, indicating synaptic depolarization. This draws the positive ions away from the extracellular electrode causing hyperpolarization.
Understanding Field Potentials
What does the slope mean?
The slope reflects positive Na+ ions moving away from the electrode into the neuron, ie. the strength of the synapse.
A field potential is a measure of the strength of a population of synapses.
What is the strength of a synapse defined by?
The strength of a synapse is defined by the change in transmembrane potential resulting from activation of the postsynaptic neurotransmitter receptors.
Describe the long-term potentiation methodology.
- Test stimulus: used to establish a baseline synaptic activity
- Inducing stimulus: a high frequency stimulus that induces LTP
- If the experiment is sucsessful, the test stimulus evokes a larger fESPS after
Why is synaptic plasticity bidirectional?
What is LTD?
Experience can weaken synaptic strength.
Long-term depression occurs when a low frequency stimulus induces a lower fESPS than baseline.
What are the 2 functions of postsynaptic density?
A major feature of excitatory synapses is a thickening of the postsynaptic membrane termed the PSD.
- Localizes glutamate receptors and adhesion molecules
- Positioning of other signaling molecules needed to modify synapses near glutamate receptors so that they can be rapidly activated.
Signaling Cascades
What are first messengers?
First messengers target receptors on the post synaptic membrane.
Signaling Cascades
What are second messengers?
Second messengers are molecules that relay signals from receptors on the cell surface to target molecules inside the cell. They amplify the effect of first messengers.
Second messengers are not proteins so they can rapidly increase.
What are kinases?
Proteins that can change the function of exsisting proteins via phosphorylation.
What are phosphatases?
Proteins that remove phosphate groups via dephosphorylation.
How is a kinase activated?
When a second messenger binds to the kinase the inhibitory unit is dissociated and the kinase is in the active state.
What determines the duration of LTP?
The number of theta-burst stimuli determines the duration of the LTP.
Describe the in vitro LTP preparation.
Requires dissecting a thin tissue slice from the hippocampus and sustaining its function by placing the sample in a chemical cocktail. A stimulating electrode is positioned to stimulate axons, and a recording electrode is positioned to record the field potential.
Why is the resting membrane potential negative?
There are more negatively charged ions inside the neuron.
What are the 3 functions of phosphorylation?
1) Change a protein’s location
2) Change a protein’s ability to associate with other proteins
3) Change a protein’s enzymatic activity
Initial change in the strength of synapses depends on ______; however, enduring changes require __________.
post-translation processes; new protein (transcription and translation processes)
The performant path connects the entorhinal cortex to _________
Dentate gyrus
Axons projecting from the dentate gyrus to CA3 are called _________
mossy fibers
Shaffer collaterals terminate onto ________
CA1 neurons
What is the order of memory loss according to Ribot?
- Recent
- Autobiographical/Personal
- Habits/Emotional memory
What is an excitatory synapse?
A synapse with a postsynaptic component that has dendritic spines containing glutamate receptors.
Where would you place the extracellular recording electrode to measure the field potential if you stimulated mossy fibers?
in the CA3 region
