Psyc 100

Sensation

The act of using sensory systems to detect environmental stimuli.

Perception

The conscious recognition and identification of a sensory stimulus.

Sensory Receptor Cells

Specialized cells that convert a specific form of environmental stimuli into neural impulses.

Sensory Transduction

The process of converting stimuli into a neural impulse that the brain can read.

Absolute Threshold

The smallest amount of stimulus that one can detect.

Difference Threshold

The minimal difference needed to notice a difference between two stimuli.

Signal Detection Theory

The theory that the response to a signal depends on the ability to differentiate between the signal and noise.

Sensory Adaptation

The process in which repeated stimulation of a sensory cell leads to a reduced response.

Bottom-up processing

Perception where environmental stimuli are transformed to neural impulses that move into more complex brain regions.

Top-down Processing

Perception process led by cognitive processes, such as memory or expectations.

Olfactory sense

The sense of smell, involving the detection of odorants.

Gustatory sense

The sense of taste.

Papillae

Bumps on the tongue that contain clusters of taste buds.

Taste buds

Clusters of sensory receptor cells that convert chemical signals from food into neural impulses.

Ageusia

Inability to taste.

Anosmia

Inability to detect odors.

Hyposmia

Reduced ability to smell.

Free nerve endings

Somatosensory receptors located near the surface of the skin, detecting touch, pressure, pain, and temperature.

Meissner’s corpuscles

Receptors located in fingertips, lips, and palms that transduce information about sensitive touch.

Ruffini’s end-organs

Receptors located deep in the skin that register heavy pressure and joint movement.

Pacinian corpuscles

Receptors located deep in the skin that respond to vibrations and heavy pressure.

Fast pathway of pain

Pathway that transmits sharp, localized pain quickly to the brain.

Slow pathway of pain

Pathway that transmits more diffuse, burning pain involving emotional processing.

Chronic pain

Most common abnormality in tactile senses.

Phantom limb sensations

Tactile hallucinations of touch, pressure, and pain in a body part that no longer exists.

Sound waves

Vibrations of air in the frequency of hearing.

Frequency

The number of cycles per second in a sound wave, measured in Hertz (Hz).

Amplitude

The magnitude or height of a sound wave, measured in decibels (dB).

Frequency Theory

The theory that different sound frequencies are converted into different rates of action potentials.

Place Theory

The theory that differences in sound frequency activate different regions of the basilar membrane.

Cocktail party effect

The brain's ability to pick up relevant sounds in noisy environments.

Deafness

Loss of hearing which can have various causes.

Tinnitus

A condition characterized by ringing in the ears.

Hue

The experience of colour based on the wavelength of light.

Saturation

The purity of color, how bright or vivid it is.

Brightness

How much light is reflected from an object.

Trichromatic theory

The theory that there are three different sensors for color, each responding to different ranges of wavelengths.

Opponent process theory

The theory that color pairs inhibit one another in the perception of color.

What pathway

The visual pathway that helps determine object identity.

Where pathway

The visual pathway responsible for locating objects in space.

Gestalt Laws of Perception

Principles explaining how we group objects based on proximity, similarity, continuity, closure, and figure-ground.

Binocular cues

Cues for depth perception obtained using both eyes.

Retinal Disparity

The difference in images cast on the retinas of each eye, aiding depth perception.

Perceptual constancy

The tendency to perceive objects as unchanging despite shifts in stimuli.

Size constancy

The perception of objects as the same size regardless of distance.

Shape constancy

The perception of an object as the same shape regardless of the viewing angle.

Visual impairment

Problems or conditions that affect vision, such as strabismus and amblyopia.

Kinesthetic sense

The sense that provides information about body motion and position.

Vestibular sense

The sense of balance and spatial orientation, located in the inner ear.

Associative Learning

Learning where connections are formed between two or more stimuli.

Habituation

The weakening of a response to a stimulus after repeated presentation.

Operant Conditioning

Learning where behavior is modified based on its consequences.

Reinforcer

An experience that increases the probability of a certain behavior.

Positive Reinforcement

A pleasant consequence following a behavior that increases the likelihood of its recurrence.

Negative Punishment

The removal of a pleasant stimulus as a consequence to decrease a behavior.

Continuous reinforcement

Reinforcement that occurs every time a behavior happens.

Shaping

The process of gradually reinforcing behaviors that are closer to the desired behavior.