Sensation & Perception: Key Concepts and Pathways in Psychology

Sensation

The simple stimulation of a sense organ.

Perception

The organization, identification, and interpretation of a sensation in order to form a mental representation.

Transduction

The process whereby sense receptors convert physical signals from the environment into neural signals that are sent to the central nervous system.

Sensory adaptation

The process whereby sensitivity to prolonged stimulation tends to decline over time as an organism adapts to current (& unchanging) conditions.

Absolute threshold

The minimal intensity needed to just barely detect a stimulus in 50% of trials.

Difference threshold / Just noticeable Difference

The smallest amount of stimulus needed to detect change.

Weber's law

For every sense domain, the change in a stimulus that is just noticeable is a constant proportion despite variation in intensities.

Vision Pathway

Cornea Pupil Lens Retina Optic Nerve.

Vision external stimuli

Gathering light - Light is reflected off an object and gathered into the eye.

Vision sensing organ

Light within the eye - Cornea, Pupil, Lens, Retina, & Optic Nerve.

Vision receptors

Transduction - Light energy is transduced into neural signals.

Vision essential brain regions

Light within the brain - Thalamus & Visual Cortex, Occipital lobe.

Audition Pathway

Pinna Auditory Canal Eardrum Ossicles Cochlea.

Audition external stimuli

Gathering sound - Outer ear: changes in sound waves are funneled into the outer ear via the Pinna.

Audition sensing organ

Sound within ear - Middle ear: Sound waves cause vibration of the eardrum; ossicles transmit vibrations to inner ear.

Audition receptors

Transduction - Inner ear: vibrations transduced into neural signal.

Audition essential brain regions

Sound within the brain - Thalamus, Auditory, Temporal lobe.

Psychophysics

Methods that systematically relate the physical characteristics of a stimulus to an observer's perception.

Sensitivity

How responsive we are to faint stimuli.

Acuity

How well we can distinguish two very similar stimuli.

Just Noticeable Difference (JND)

The minimal change in a stimulus that can just barely be detected.

Energy

Raw material.

Sensory Organ

Organs that gather sensory information.

Sensory Receptor Cells

Cells that detect stimuli and convert them into neural signals.

Pathway

Physical / Neural route through which sensory information travels.

Energy senses

Senses that gather energy from the outside world.

Chemical senses

Senses that gather chemicals from the outside world.

Body senses

Senses that gather information in the form of changes in pressure, temperature, and vibration.

Cornea

Protective outer covering of the eye that helps focus light.

Pupil

Opening behind the cornea, surrounded by the iris.

Lens

Focuses light and creates an inverted image.

Retina

Light sensitive photoreceptor cells containing cones and rods.

Cones

Photoreceptors that detect color, operate in daylight, and focus on fine detail.

Rods

Photoreceptors that detect black and white and are responsible for peripheral vision.

Optic Nerve

Bundle of nerve fibers allowing communication between the eyes and the brain.

Olfaction

Smell; the process where molecular structures of particles enter the nasal cavity and are processed as information.

Gustation

Taste; the process where taste buds detect the molecular structure of food chemicals.

Hepatic Senses

Receptor cells that detect pressure, temperature, pain, and itch.

Vestibular

Balance; related to the semicircular canals.

Kinesthetic

Body position in space.

Noise

All other energies that interfere with the process of sensation and perception.

Parallel processing

The brain's capacity to perform multiple activities at the same time.

Binding Problem

How the brain links features together to unify objects in our visual world.

Illusory conjunction

A perceptual mistake whereby the brain incorrectly combines features from multiple objects.

Attention

The active and conscious processing of particular information.