Neuroscience Key Concepts: MRI, Neurons, and Coding Methods

Depolarization

A change in membrane potential that makes it less negative.

Distributed representation

A way of encoding information in which multiple neurons are activated by a single stimulus.

Excitatory response

A response that increases the likelihood of a neuron firing an action potential.

Falling phase of the action potential

The phase where the membrane potential returns to a more negative value after depolarization.

Functional connectivity

The temporal correlation between spatially remote brain regions.

Functional magnetic resonance imaging

A neuroimaging technique that measures brain activity by detecting changes associated with blood flow.

Grandmother cell

A hypothetical neuron that represents a complex but specific concept or object.

Hyperpolarization

An increase in membrane potential that makes it more negative.

Inhibitory response

A response that decreases the likelihood of a neuron firing an action potential.

Ions

Atoms or molecules with a net electric charge due to the loss or gain of one or more electrons.

Magnetic resonance imaging

A medical imaging technique used to visualize internal structures of the body.

Mind-body problem

The philosophical question of how the mind relates to the body and the physical world.

Modularity

The idea that the brain is composed of distinct modules that perform specific functions.

Module

A specialized unit within the brain that performs a specific function.

Nerve fiber

An axon or a bundle of axons in the nervous system.

Neurons

The basic building blocks of the nervous system that transmit information through electrical and chemical signals.

Neuropsychology

The study of the relationship between brain function and behavior.

Neurotransmitters

Chemicals that transmit signals across a synapse from one neuron to another.

Permeability

The ability of a membrane to allow substances to pass through it.

Phrenology

The study of the shape and size of the skull as an indication of character and mental abilities.

Population coding

A neural coding scheme where information is represented by the collective activity of a group of neurons.

Propagated response

The transmission of an action potential along the length of an axon.

Receptor sites

Specific regions on a neuron that bind neurotransmitters.

Refractory period

The time following an action potential during which a neuron is unable to fire another action potential.

Resting potential

The electrical potential of a neuron when it is not actively transmitting signals.

Resting-state MRI

A type of MRI that measures brain activity by detecting changes in blood flow during rest.

Resting-state functional connectivity

The connectivity between brain regions during rest.

Rising phase of the action potential

The phase where the membrane potential becomes more positive due to the influx of sodium ions.

Seed location

A specific brain region used as a reference point for connectivity analysis.

Sensory coding

The process by which sensory information is represented in the nervous system.

Sparse coding

A coding scheme where information is represented by the activity of a small number of neurons.

Specificity coding

A neural coding scheme where individual neurons respond to specific stimuli.

Spontaneous activity

The intrinsic activity of neurons in the absence of external stimuli.

Structural connectivity

The physical connections between brain regions.

Synapse

The junction between two neurons where communication occurs.

Task-related fMRI

An fMRI technique that measures brain activity in response to specific tasks.

Test location

A specific area in the brain being studied or tested.

Wernicke's area

A region in the brain associated with language comprehension.