exam 1

Comprehensive vocabulary flashcards generated directly from the lecture notes on sensation, perception, psychophysics, neural communication, eye anatomy, visual processing, and visual pathways.

Perception

The process of interpreting sensory information so we become aware of objects and events.

Sensation

The initial detection of information by the sensory systems.

Perceptual process

The series of steps that turns environmental information into perception, recognition, and action.

Distal stimulus

The actual object or event in the environment.

Proximal stimulus

The pattern of energy that reaches the sensory receptors.

Sensory receptors

Specialized cells that detect environmental energy.

Transduction

Converting physical energy into neural signals.

Neural processing

The nervous system's processing and transformation of sensory signals.

Recognition

Identifying what an object or event is.

Action

A behavior or response produced after perceiving something.

Knowledge

Information from previous experiences that influences perception.

Bottom-up processing

Perception that begins with incoming sensory information.

Top-down processing

Perception influenced by knowledge, expectations, and previous experience.

Categorize

To place something into a meaningful group or category.

Psychophysics

The study of relationships between physical stimuli and psychological experiences.

Absolute threshold

The smallest amount of stimulation that can be detected.

Difference threshold

The smallest difference between two stimuli that can be detected.

Thresholds

Levels of stimulation that determine whether something can be detected.

Classical psychophysical methods

Methods used to measure sensory thresholds.

Method of limits

A method in which stimulus intensity is gradually increased or decreased to find a threshold.

Method of constant stimuli

A method that presents different stimulus intensities in an unpredictable order.

Method of adjustment

A method in which the observer adjusts a stimulus until it reaches a particular level.

Magnitude estimation

Rating how strong a stimulus feels using numbers.

Perceived magnitude

How strong or intense a stimulus seems.

Reaction time

The time between a stimulus being presented and a response being made.

Phenomenological report

A person's description of their conscious experience.

Grating acuity

The ability to distinguish between closely spaced lines or patterns.

Oblique effect

Better ability to perceive horizontal and vertical orientations than tilted orientations.

Electromagnetic spectrum

The full range of electromagnetic radiation, including visible light.

Principle of representation

The idea that sensory information is represented in neural activity.

Principle of transformation

The idea that information changes as it moves through the nervous system.

Stimulus–behavior relationship

The relationship between physical stimulation and a person's behavioral response.

Stimulus–physiology relationship

The relationship between stimulation and neural activity.

Physiology–behavior relationship

The relationship between neural activity and behavior.

Visual form agnosia

Difficulty recognizing visually presented objects despite relatively intact basic vision.

Rat–man demonstration

A demonstration showing how previous knowledge can influence what we perceive.

Primary receiving area

The first major area of the cortex receiving information from a particular sense.

Neuron

A cell that communicates information within the nervous system.

Cell body

The main part of a neuron containing the nucleus.

Dendrites

Branch-like structures that receive information from other neurons.

Axon

A long neuron structure that carries signals away from the cell body.

Nerve fiber

Another name for an axon.

Action potential

An electrical signal that travels along an axon.

Resting potential

The electrical state of a neuron when it is not producing an action potential.

Rising phase of action potential

The part of an action potential when the neuron's electrical charge becomes more positive.

Falling phase of action potential

The part when the neuron's electrical charge returns toward its resting state.

Depolarization

A change in electrical charge that makes a neuron more likely to fire.

Hyperpolarization

A change that makes a neuron's electrical state more negative.

Ions

Charged particles that help create electrical signals in neurons.

Permeability

How easily substances can pass through a cell membrane.

Propagated response

An action potential traveling along an axon.

Refractory period

A brief period after an action potential when the neuron cannot immediately fire normally again.

Synapse

The junction where neurons communicate.

Neurotransmitters

Chemicals released by neurons to communicate with other cells.

Receptor sites

Places on a neuron where neurotransmitters attach.

Excitatory response

A response that makes a neuron more likely to fire.

Inhibitory response

A response that makes a neuron less likely to fire.

Spontaneous activity

Neural activity that occurs without a specific stimulus.

Sensory coding

The way sensory information is represented by neural activity.

Specificity coding

The idea that particular neurons respond to particular types of stimuli.

Sparse coding

Representing information using activity in a small number of neurons.

Population coding

Representing information through the combined activity of many neurons.

Grandmother cell

A hypothetical neuron that responds to one very specific object or person.

Distributed representation

Representation of information across multiple neurons or brain areas.

Brain imaging

Techniques used to study brain structure or activity.

MRI

A technique that produces detailed images of brain structure.

fMRI

A technique used to measure changes in brain activity.

Task-related fMRI

fMRI conducted while a person performs a particular task.

Resting-state fMRI

fMRI used while a person is not performing a specific task.

Functional connectivity

The relationship between activity in different brain areas.

Resting-state functional connectivity

Relationships between brain areas measured while a person is resting.

Structural connectivity

Physical connections between different brain areas.

Seed location

A selected brain location used as a starting point for examining connectivity.

Test location

Another brain location whose activity is compared with the seed location.

Modularity

The idea that different brain areas perform specialized functions.

Module

A brain area or system with a relatively specialized function.

Neuropsychology

The study of relationships between brain functioning and behavior.

Phrenology

An outdated theory that attempted to connect personality abilities to areas of the brain based on skull shape.

Mind–body problem

The question of how physical brain activity relates to mental experiences.

Broca's area

A brain area strongly associated with speech production.

Wernicke's area

A brain area strongly associated with understanding language.

Light

Electromagnetic energy that can be detected by the visual system.

Cornea

Transparent outer covering of the front of the eye that helps focus light.

Pupil

Opening through which light enters the eye.

Iris

Colored part of the eye that controls pupil size.

Lens

Structure that focuses light onto the retina.

Retina

Light-sensitive layer at the back of the eye.

Photoreceptors

Retinal cells that respond to light.

Rods

Photoreceptors especially sensitive to dim light.

Cones

Photoreceptors important for color and detailed vision.

Fovea

Small central area of the retina with high cone concentration and sharp vision.

Blind spot

Area where the optic nerve leaves the eye; it contains no photoreceptors.

Optic nerve

Bundle of nerve fibers carrying visual information from the retina to the brain.

Accommodation

Changing the shape of the lens to focus objects at different distances.

Refractive errors

Problems that prevent light from being properly focused on the retina.

Axial myopia

Nearsightedness caused by an eyeball that is too long.

Photoreceptor processes

Processes through which photoreceptors respond to light.

Visual pigment

Light-sensitive molecule found in photoreceptors.

Isomerization

Change in the structure of a visual pigment caused by absorbing light.

Dark adaptation

Increasing sensitivity to light after entering darkness.