Cognitive Psychology: Neurons, Brain Structure, and Representation

Vocabulary flashcards covering cellular neuroscience, brain localization, sensory coding, and neural networks based on the Week 2 Goldstein text notes.

Levels of Analysis

The idea that a topic can be understood in multiple different ways, with each approach contributing to a broader understanding.

Nerve Net Theory

A 19th-century theory suggesting that the brain is a complex pathway for conducting signals uninterrupted through a continuous network.

Camillo Golgi

An Italian anatomist who in 1870 developed a staining technique using silver nitrate that made fewer than $1\%$ of brain cells visible.

Ramon y Cajal

Spanish psychologist who used Golgi's staining technique on newborn animal brains to discover that the nervous system is made of individual, non-continuous units.

Neuron Doctrine

The idea that individual cells, rather than a continuous network, transmit signals in the nervous system.

Synapse

The small gap between the end of a neuron's axon and the dendrites or cell body of another neuron.

Neural Circuits

Specific connections formed between groups of neurons rather than indiscriminate connections.

Receptors

Specialized neurons that pick up information from the environment, such as in the eyes, ears, or skin.

Cell Body

The metabolic center of the neuron containing mechanisms to keep the cell alive.

Dendrites

Branch-like structures that extend from the cell body to receive signals from other neurons.

Axons

Also called nerve fibers, these are long processes that transmit signals to other neurons.

Edgar Adrian

Scientist who in 1920 recorded electrical signals from single sensory neurons using microelectrodes, earning a Nobel Prize in 1932.

Microelectrodes

Small glass shafts or metal wires filled with conductive salt solution used to record electrical signals from neurons.

Resting Potential

The charge difference of $-70\,millivolts$ stayting the same as long as there are no signals in the neuron.

Action Potential

A nerve impulse where the charge inside the axon rises to $+40\,millivolts$ and lasts approximately $1\,millisecond$.

Neurotransmitter

A chemical released when signals reach the synapse that makes it possible to transmit the signal across the gap.

Principle of Neuronal Representation

The states that everything a person experiences is based on representations in that person's nervous system.

Feature Detectors

Neurons that respond to specific types of stimulation, such as orientation, movement, and length, discovered by Hubel and Wiesel.

Hierarchical Processing

The progression of neural processing from lower levels of the brain (simple shapes) to higher levels (complex stimuli like faces).

Specificity Coding

The unlikely idea that a specific object is represented by the firing of a single neuron that only responds to that object.

Population Coding

The representation of a particular object by the pattern of firing of a large number of neurons.

Sparse Coding

When a particular object is represented by a pattern of firing of only a small group of neurons, with the majority remaining silent.

Localisation of Function

The basic principle that specific functions are served by specific areas of the brain.

Cerebral Cortex

A $3\,mm$ thick layer of wrinkled tissue covering the brain where many cognitive functions are located.

Neuropsychology

The study of behavior in people who have suffered brain damage.

Cortical Equipotentiality

An 1800s theory suggesting the brain operates as an indivisible whole rather than having specialized areas.

Broca's Aphasia

Condition resulting from damage to the frontal lobe characterized by slow, labored, and grammatically incorrect speech.

Wernicke's Aphasia

Condition resulting from damage to the temporal lobe where speech is fluent and grammatical but incoherent and meaningless.

Occipital Lobe

The area containing the visual cortex; damage here can cause blindness.

Parietal Lobe

The brain region responsible for somatosensory (skin) sensations.

Frontal Lobe

The region that receives signals from all senses and coordinates higher-order functioning like thinking and problem-solving.

Prosopagnosia

The inability to recognize faces, caused by damage to the temporal lobe.

Double Dissociation

Occurs if damage to one brain area causes function A to be absent while B is present, and damage to another area causes B to be absent while A is present.

fMRI

Functional Magnetic Resonance Imaging; it measures brain activity by detecting changes in the magnetic properties of hemoglobin as neurons consume oxygen.

Voxels

Small cube-shaped units of analysis created by an fMRI scanner, measuring approximately $2-3\,mm$ on a side.

Fusiform Face Area (FFA)

An area in the fusiform gyrus on the underside of the temporal lobe specifically activated by faces.

Parahippocampal Place Area (PPA)

An area activated by indoor and outdoor scenes, specifically sensitive to spatial layout.

Extrastriate Body Area (EBA)

An area of the brain activated by pictures of bodies and body parts, but not faces.

Distributed Representation

The principle that most experiences are multidimensional and activate many different areas of the brain simultaneously.

Episodic Memory

Memories for specific events in a person's life.

Semantic Memory

Memories for facts.

Connectome

The term used to indicate the structural description of network elements and connections forming the human brain.

Functional Connectivity

Determined by the extent of correlation between the neural activity of two different brain areas.

Default Mode Network (DMN)

A large network that is active when the brain is at rest and not involved in a specific task, often associated with mind-wandering.

Track Weighted Imaging (TWI)

A technique used to determine structural connectivity based on how water diffuses along the length of nerve fibers.