Topic 4: Sensation & Perception Flashcards
Define “perception.”
A process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.
How does sensation work?
A sense organ receptor cell is stimulated by energy. Information is carried via sensory neurons to the brain as a coded signal.
What is transduction?
Physical energy (like light or sound) is converted into an electrical charge.
Receptor cells are specialized. True or false?
True.
What are two types of sensation thresholds?
Absolute and difference.
What is Absolute Threshold?
Minimum amount of stimulation needed to detect a particular stimulus 50% of the time.
What is Difference Threshold?
Minimum difference between two stimuli required for detection 50% of the time. Just noticable difference. (JND).
What is Sensory Adaption?
Sensory receptors become less responsive to unchanging stimuli.
What are the components of the eye?
The retina, optic nerve, blindspot, cones, rods, iris, pupil, lens, fovea and cornia.
What does the cornea do?
Bends light waves so the image can be focused on the retina.
What does the iris do?
Its muscle controls the size of the pupil.
What does the pupil do?
Iris opening that changes size depending on the amount of light in the environment.
What does the lens do?
Changes shape to bring objects into focus.
What does the retina do?
Contains photoreceptor cells.
What does the fovea do?
Central area of retina, greatest density of photoreceptors.
What does the optic nerve do?
Sends visual information to the brain.
What is the blindspot?
Where the optic nerve leaves the eye. There are no photoreceptor cells here.
Describe the Retina.
Light sensitive, inner surface of the eye. Contains receptor rods, cones and layers of neurons that begins the processing of visual information.
Describe the light receptors.
Called rods, these are found on the retina. Detect black, white and gray. Work best in twilight or low light.
What are cones?
Receptor cells nears the center of the retina. Detects fine detail and color vision. Work best in daylight or well-lit conditions.
Describe Visual Information Processing.
Feature detectors in the brain that respond to specific features: shape, angle and movement. Made up of simple, complex and hypercomplex cells.
What is parallel processing?
Simultaneous processing of several aspects of a problem.
What is Audition (auditory systems)?
The sense of hearing.
What is frequency?
Measure in cycles per second (hertz). Includes pitch.
What is amplitude?
Height of a sound wave. Interpreted as volume.
What are the parts of the ear?
Outer ear, ear drum, hammer, anvil, stirrup, oval window, cochlea, inner ear, basiliar membrane, cilia.
What happens in the outer ear?
The outer ear acts as a funnel for sound waves. Travels to the ear drum (vibrates). Hammer, anvil, and stirrup strike each other which carries the sound to the oval windown on to the cochlea.
What happens in the inner ear?
Fluid in the cochlea moves which causes ripples in basilar membrane. Cilia in there stimulate receptor cell axons to send messages to auditory nerve to the temporal lobe’s auditory cortex.
What are the five taste gustations (senses).
Sweet, sour, salty, bitter, umami.
How to the taste receptors work?
Located on the taste buds, micovilli generate a nerve impulse interpreted in the brain as a particular taste. Saliva dissolves chemical substances in food in order to reach the taste buds.
Describe Smell.
Chemical scent like taste. Molecules travel to olfactory receptor sites. Closely linked to limbic system (scent and emotional memory linked).
What are the two types of decisions and what are they?
Endogenous (internal/ours), exogenous (not our decision).
What is inattentional blindness?
Failure to perceive a given stimulus.
What is change deafness and blindess?
Failure to detect auditory or visual changes.
What is pop-out stimuli?
Important or interesing stimuli “pop-out” at us.
What are the two theories of perception?
Visual system uses sensory info to draw conclusions about what we see. Brains want to create logic and order. Reason for optical illusions.
Describe the Perceptual organization gestalt principles.
Organized whole, tendency to integrate pieces of info into meaninful wholes.
What is field and ground?
Organization of the visual field into objects (figures) that stand out from their surroundings (ground).
What is grouping?
The perpetual tendency to organize stimuli into coherent groups.
What are the 5 grouping principles?
Proximity, similarity, continuity, closure and connectedness.
What is Proximity?
Group nearby figures together.
What is Similarity?
Group figures that are similar.
What is Continuity?
Percieve continuous patterns.
What is Closure?
Brain fills in the gaps.
What is Connectedness?
Spots, lines and areas are seen as unit when connected.
Define “sensation.”
A process by which our sensory receptors and nervous system recieve and represent stimulus energy.
What are three of the theories of Identification & Recognition Processes?
Top-Down Processing, Feature Integration Theory and Components Theory.
Describe Top-Down Processing.
A process in which expectations affect perception first.
Describe the Feature Integration Theory.
Combines ‘pop-out’ features of objects.
Describe the Components Theory.
Combines geons (simple 3D objects) into recognizable objects.
What are perpetual sets?
A component of Top-Down Processing.
Describe Perpetual Sets.
Readiness to detect a particular stimulus in a given context. Depends on expectations as well as properties of objects.
