Neuroscience: Inhibitory Signals and Action Potential

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Questions and Answers

What is the threshold value at which a neuron fires?

-40 mV

-55 mV (correct)

-60 mV

-70 mV

What must happen for a neuron to fire in relation to excitatory and inhibitory signals?

Excitatory signals must be weaker than inhibitory signals.

Excitatory signals must be equal to inhibitory signals.

Inhibitory signals must be at least 15mV weaker than excitatory signals.

Excitatory signals must be at least 15mV stronger than inhibitory signals. (correct)

What is the resting membrane potential of a neuron before any signals arrive?

-55 mV

-40 mV

-70 mV (correct)

0 mV

Which ions are crucial for sending signals down an axon?

Potassium and Sodium Signup and view all the answers

What process occurs at the axon hillock when signals arrive?

Summation Signup and view all the answers

How do charged particles move across the cell membrane?

Through ion channels Signup and view all the answers

What keeps the concentration of potassium ions stable inside and outside the cell?

Concentration gradients and electrical gradients Signup and view all the answers

What is the resting membrane potential of a neuron primarily due to?

Higher concentration of K+ inside the cell Signup and view all the answers

What is the approximate capacity of short term memory as described by George Miller?

Seven items plus or minus two Signup and view all the answers

What technique can increase the capacity of short term memory according to the content?

Chunking information into meaningful groups Signup and view all the answers

According to Chase and Ericsson's research, what did participants improve in after extensive practice?

Their digit span by using meaningful chunks Signup and view all the answers

What initiates the action potential by triggering sodium channels to open?

-55mV voltage Signup and view all the answers

Which of the following is NOT a function of emotions?

Enhance cognitive dissonance Signup and view all the answers

What did Chase and Simon's study reveal about expert and novice chess players?

Experts excel at remembering spatial arrangements relevant to their domain Signup and view all the answers

What occurs immediately after sodium ions (Na+) enter the cell?

Potassium ions (K+) rush out Signup and view all the answers

Which category of emotions includes feelings such as jealousy and awe?

Blended categories Signup and view all the answers

In Baddeley and Hitch's working memory model, which component is responsible for the auditory store?

Phonological loop Signup and view all the answers

What is the primary purpose of the Na+/K+ pump during the refractory period?

To restore resting membrane potential Signup and view all the answers

What is the term used for the process by which the action potential travels more rapidly in myelinated neurons?

Saltatory conduction Signup and view all the answers

According to Ekman, which of the following is NOT a characteristic that defines a basic emotion?

Subjective emotional ambiguity Signup and view all the answers

What does the levels of processing theory suggest affects memory strength?

The type of encoding used Signup and view all the answers

In dimensional models of emotion, which of the following describes the motivation behind emotions?

Motivation; approach/withdraw Signup and view all the answers

What was demonstrated in Peterson and Peterson's (1969) research on short-term memory?

Short-term memory fades quickly without rehearsal Signup and view all the answers

Which ion primarily moves out of the cell during the process of repolarization?

Potassium (K+) Signup and view all the answers

Which component of the working memory model serves as a mental workspace for integrating information?

Episodic buffer Signup and view all the answers

How much more energy-efficient is saltatory conduction compared to continuous conduction?

100x less movement of ions Signup and view all the answers

What is one conclusion of Darwin's perspective on emotions?

Survival emotions have evolved over time. Signup and view all the answers

What is the result of K+ continuing to move outside of the cell after depolarization?

Restoration of the resting membrane potential Signup and view all the answers

What is the main function of neurotransmitters in neuronal communication?

To facilitate synaptic transmission Signup and view all the answers

What is the primary purpose of encoding in memory construction?

To incorporate new information into existing memory Signup and view all the answers

What does deep processing enhance in the context of memory encoding?

Long-term retention of information Signup and view all the answers

Which of the following represents a bound morpheme?

Cats Signup and view all the answers

What type of words do content morphemes represent?

Words that carry semantic meaning Signup and view all the answers

How does Broca's aphasia primarily affect language processing?

Inability to process syntax effectively Signup and view all the answers

Which statement about phonemes is accurate?

Phonemic differences indicate differences in meaning. Signup and view all the answers

What cognitive strategy involves studying various topics together?

Interleaving Signup and view all the answers

Which of the following is considered a salient non-consistent event in a story?

An event that does not align with the audience's expectations Signup and view all the answers

Which process involves the reactivation of stored memories along with current scripts or schemas?

Retrieval Signup and view all the answers

What role do grammatical function morphemes play in language?

They serve to connect and organize content words. Signup and view all the answers

Study Notes

Inhibitory Signals

Inhibitory signals make a cell less likely to fire.
Summation occurs at the axon hillock, where all incoming signals are added together.
The neuron fires when the sum of excitatory signals is 15 mV stronger than inhibitory signals.
The threshold value for firing is -55 mV.
The neuron's resting potential is -70 mV.

Resting Membrane Potential

The inside of the cell is more negatively charged than the outside.
This is due to the concentration of ions inside and outside the cell.
Key ions include positively charged sodium (Na+) and potassium (K+).
Ion channels in the cell membrane control the movement of ions.
Concentration gradients and electrical gradients drive ion movement.

Action Potential

An action potential is a sudden change in voltage across the cell membrane.
It occurs at one section of the cell at a time, creating a chain reaction.
Sodium channels open when the membrane potential reaches -55 mV, causing Na+ to rush into the cell.
This depolarizes the cell, making it more positive inside.
Potassium channels then open, allowing K+ to move out of the cell, repolarizing it.

Refractory Period

The Na+/K+ pump actively moves 3 Na+ ions out of the cell and 2 K+ ions in.
This helps restore the resting membrane potential.
It requires energy and is not passive diffusion.

Myelinated Axons

In myelinated axons, the action potential jumps from one node of Ranvier to the next, called saltatory conduction.
Saltatory conduction increases the speed of signal transmission.
It is energy efficient as fewer ions need to move.

Synaptic Transmission

Cells in the nervous system communicate through synaptic transmission.
Neurotransmitters are released from the presynaptic neuron and bind to receptors on the postsynaptic neuron.
Neurotransmitters can be excitatory or inhibitory.
Receptors are ligand-gated ion channels.
Reuptake removes neurotransmitters from the synapse.

Short-Term Memory

George Miller described the capacity of short-term memory as 7 plus or minus 2 items.
Chunking information into meaningful units can increase short-term memory capacity.
Chase and Ericsson's research demonstrated that digit span could be increased with practice.
This increase in capacity is due to chunking, not a fundamental change in short-term memory.

Working Memory Model

Baddeley and Hitch proposed a model with three components:
- Central executive: controls the flow of information.
- Phonological loop: processes auditory information.
- Visuo-spatial sketchpad: processes visual information.
Episodic buffer: holds together different parts of our current perception or thought.

Memory Encoding

The depth of processing influences memory strength.
Deeper processing, such as semantic processing, leads to better encoding.
Craik and Lockhart's levels of processing theory emphasizes the importance of elaborative rehearsal.

Memory Retrieval

Retrieval involves reactivation of encoded information and associated schemas.
Each retrieval can revise memory based on current schemas.

Effective Study Strategies

Minimize distractions and multi-tasking.
Actively engage and take notes during lectures.
Link new knowledge to existing knowledge.
Organize information.
Generate your own study materials.
Space learning episodes and use interleaving.
Create retrieval cues.
Practice retrieval.

Language Hierarchy

Language is organized hierarchically, with phonemes, morphemes, syntax, and semantics.

Phonemes

Basic units of sound that carry meaning.
Languages differ in their sets of phonemes.
Changing a phoneme can change the meaning of a word.

Morphemes

Smallest units of language carrying meaning.
Include words, prefixes, and suffixes.
Content morphemes carry semantic information.
Function morphemes have a grammatical role.

Syntax

The structure of language.
Rules for ordering words are learned implicitly.
Cued by word order and function words.

Semantics

The meaning of language.
Relies on content words.
Involves mapping words onto mental concepts.

Broca's Aphasia

Characterized by difficulty processing syntax.
Damage to Broca's area, located in the left hemisphere, especially the frontal lobe.

Emotions

Discrete models categorize emotions into basic, blended, social, intellectual, and homeostatic categories.
Dimensional models describe emotions based on valence, arousal, and motivation.

Basic Emotion Theories

Darwin suggested that basic emotions are evolutionarily preserved and adaptive.
Ekman's definition of basic emotions includes:
- Distinctive universal signals.
- Distinctive physiology.
- Distinctive subjective experience.
- Automatic appraisal.
- Distinctive universal triggers.
- Presence in other primates.
- Presence in infants.

Psychological Constructionist Theories

Emotions emerge from our interpretations of events and our physiological responses.
Emotions are not pre-defined but constructed based on experiences and context.

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Description

Explore the mechanisms behind inhibitory signals and action potentials in neurons. This quiz covers topics such as resting membrane potential, ion movement, and the thresholds for neuronal firing. Test your knowledge and understanding of these fundamental concepts in neuroscience.