Chapter 55: Sensation And Perception Flashcards
Name and give a brief description of our sensory systems
Visual system: allows us to see. Light activates visual receptors in eye where it’s converted into nerve impulses that send info to brain for interpretation in occipital cortex.
Auditory system allows us to hear. Sound waves are recieved by auditory receptors in ear and encoded being set along auditory pathway to brain which is interpreted in temporal lobe.
Proprioceptive system provide people with info about movement and orientation in space. Kinaesthetic info comes from muscles tendons and joints. Vestibular info comes from ear and provides info about head movements.
Somaesthetic system provides info about environment outside skin relating to touch pressure heat cold and pain.
Chemical system allows experience of taste and smell. receptors for taste found in taste buds on tongue for sweet sour bitter and salty. The sense of smell or olfactory sense depends on activation of receptors in nose by chemical in air. Olfactory nerve send info to olfactory bulb at base of brain.
What is sensation
It is the process of receiving sensory information and refers to sensory experience that occurs after sensory stimulus is detected.
What is perception
The process of interpreting and making meaning from sensory info is perception and refers to higher level of info processing.
What are receptors
Cells specifically adapted to receive info from environment which can differ in sensitivity.
What is the absolute threshold
It determines whether a stimulus is intense enough to lead to sensory experience.
If below threshold won’t generate a response and must act on receptor for certain time for activation.
What is the differencial threshold
The size of increase in intensity that results in a noticeable difference called just noticable difference.
What is transduction
The transformation of one form of energy to another.
What is a receptor potential
A resting potential in receptor cells.
What is a generator potential
Conversion of resting potential into action potential when stimulated and where receptor cells convert receptor potential.
What is an action potential
All or nothing event that’s a graded generator potential as energy comes from stimulus.
What is adaptation
The decrease in stimuli to prevent overstimulation.
What is monitoring
Refers to brains ability to process incoming info very rapidly and below level of awareness.
What are the indicators of orienting reaction OR
Bodily signs like increased muscle tone and movement of eyes head and body towards stimulus.
Vegetative signs are brief decreases in heart rate holding breath contraction of blood vessels in limbs decrease salivation and enlarge pupils
Sensory signs provided by increased sensory sensitivity
What is habituation
Is a basic form of learning and causes ignorance of stimulus that certain response can be stopped. It refers to disappearance of OR after repeated stimulation by event initially triggered them.
What is dishabituation
Is a form or OR that allows us to become aware of potentially important changes in environment that we have been accustomed to and response occurs before stimulus has been recognised and given meaning
What is perceptual organisation
The process of sensory info that ensures attention is given to relevant or important info.
What are the laws of perceptual organisation
Characteristics of stimulus: according to nature of stimulus some regarded as more important that influence way we perceive them
State of nervous system: nervous system has to be in state of readiness to perceive info.
Individual person characteristics and past experience: we interpret info received in terms of own experience.
What is figure and ground
When we perceive visual info we organise it into meaningful relevant info called figure against less meaningful info called ground.
The relevant information or figure is at higher level of awareness than less important ground so figure is first to be processed further.
They can be reversed but requires more cognitive effort and is applied to other kinds of sensory info.
Discuss contour closure and grouping
Contour refers to boundary or other features that seperate from figure and ground. The perception of contour depends on abrupt changes in brightness and colour which give contrast
Closure refers to tendency to complete something spontaneously so it had meaning. It depends on our experience in the world.
Perceptual grouping refers to tendency to group stimuli in a pattern or shape in a way that’s to help interpret them
What are the 4 types of perceptual grouping
Principle of proximity is the tendency to group elements that are close together as though they represent a figure.
Principle of similarity is tendency to group elements that are similar in colour shape or texture as though represent a figure
Principle of symmetry is tendency to group elements in a way that creates a symmetrical or balanced figure
Principle of continuity is tendency to perceive stimuli in a way that elements that are continuous form a figure.
What is spatial organisation
It explains why we see world in 3D height width and depth while image on retina is 2D width and height.
What is perceptual constancy
Seeing things as having a certain size shape colour and brightness irrespective of changing conditions.
Is a perception error in that perception aren’t same as retinal info but necessary for effective functioning because they provide our world with stability.
What are the 4 attributes of perceptual constancy
Constant size refers to fact that familiar objects are perceived as having constant size as long as there’s enough cues in environment to provide info a about distance and depth.
Constant shape or shape consistency depends on making a compromise between retinal image angle of objects and past experience.
Constant brightness means perception of brightness doesn’t change when conditions change.
Constant colour where our perception of Colour are constant despite changing conditions.
What are illusions
Object or stimulus exists but perceived because objects attributes are combined and perceived incorrectly. Are perceived spontaneously.
