Chapter 2—Sensation and Perception Flashcards
Sensation
Provides the raw signal, communicating information, entering the nervous system through receptors in the Peripheral Nervous System
Information is sent to the Central Nervous System by action potentials and neurotransmitters
Perception
Processing of information obtained from sensation
Sensory Receptors
Neurons that trigger electrical signals in response to stimuli from the environment
Communicate modality (type of stimulus), location (where stimulus is coming from), intensity (frequency of action potentials), and duration (how long stimulus lasts) to the Central Nervous System
Divided into exteroceptors, which respond to stimuli from the outside world, and interoceptors, which respond to internal stimuli
Hair Cells
Sensory receptors that respond to movement of fluid in the inner ear
Function in hearing
Olfactory Receptors
Sensory receptors that respond to volatile compounds in the air
Function in smell
Osmoreceptors
Sensory receptors that respond to the osmolarity of blood in the body
Function in water homeostasis in the body
Nociceptors
Sensory receptors that respond to painful stimuli
Function in somatosensation (touch)
Photoreceptors
Sensory receptors that respond to the visible spectrum of the electromagnetic waves
Function in sight
Taste Receptors
Sensory receptors that respond to dissolved compounds in substances
Function in taste
Threshold
Minimum amount of stimulus required to deliver a difference in perception
Absolute Threshold
Minimum amount of stimulus energy that is needed to activate a sensory system
Threshold of sensation, not perception
Threshold of Conscious Perception
Minimum amount of stimulus energy that is needed for a signal to be sent to the Central Nervous System and perceived
Difference Threshold
Minimum difference in magnitude between two different stimuli before the difference can be perceived
Follows Weber’s Law—the change in magnitude of a stimulus that will make it noticeable is a constant ratio of the magnitude of the original stimulus
Cones
Photoreceptors of the eye that perceive color and fine detail
Rods
Photoreceptors of the eye that allow for the perception of light and dark
Have no involvement in color vision, but permit humans to see in reduced lighting
Macula
Central region of the retina
Contains a high concentration of cones
Fovea
Central point of the macula where vision is most clear and acute
Contains no rods
Optic Disk
Area where the optic nerve leaves the eye
Contains no photoreceptors (cones or rods), meaning it is a blind spot
Perception of Light—Pathway
Photoreceptors —> Synapse with Bipolar cells —> Synapse with Ganglion cells —> Optic Nerve —> Occipital Lobe
Parallel Processing
Ability to analyze and combine several pieces of information regarding color, motion, and shape simultaneously
How the brain is able to create a cohesive image of the world
Feature Detection Theory
Explains why different areas of the brain are activated when a person is looking at different things
Parvocellular Cells
Detect shape
Have high spatial resolution, allow us to see very fine detail of a stationary object; do not work with fast-moving objects because they have low temporal resolution
Allows for us to see the full three-dimensional shape of the object and differentiate it from its background (boundaries of the object are clearly seen)
Magnocellular Cells
Detect motion
Have high temporal resolution and low spatial resolution, meaning the detail of an object is lessened when it is in motion
