Chapter 10: Book Flashcards
Sensation:
the neural activity triggered by a stimulus that activates a sensory receptor and results in sensory nerve impulses traveling the sensory nerve pathways to the brain
Perception:
a multistage process that takes place in the brain and includes selecting, processing, organizing, and integrating information received from the senses
Human movement is based on information about the ______ and one’s _____ or _____ in it.
- environment
- position
- location
_____ information and _____ information are highly integrated.
- sensory
- perceptual
What happens when sensory info and perceptual info contradict each other?
- we feel uncomfortable
- stagger, fall, feel sick
Individuals with normally functioning sensory receptors can attach different _____ to the same ______, and even the same individual can interpret a single _____ in different ways.
- meanings
- stimulus
- stimulus
Perception is the process whereby we attach _____ to _____ ____.
- meaning
- sensory stimuli
For individuals to move or act in an environment, they must _____ that environment.
perceive
The sensory-perceptual systems are _____ _____ constraints to movement.
individual structural
Acuity:
sharpness of sight
During the first month of life, the visual system provides the infant with functionally useful but unrefined vision at a level approximately ___% of eventual adult acuity, or _____ on the Snellen scale of visual acuity.
- 5%
- 20/400
The newborn’s resolution of detail is such that she can differentiate ____ ____ from a distance of ____ in.; beyond this, she probably cannot see objects clearly.
- facial features
- 20 in
At about 6 months, infants’ motor systems are ready to begin …
- self propelled locomotion
- their visual systems perceive adequate detail
From the ecological perspective, vision is…
another system that must develop to an adequate level to facilitate locomotion
5 year olds have visual acuity of about _____.
20/30
10 year olds have visual acuity of about ____.
20/20
It is likely that _____ _____ is necessary for the development of vision because _____ of vision during development is known to induce _____ errors in animals.
- visual experience
- deprivation
- refractive
What happens to a person’s vision as they age?
- changes occur naturally
- some conditions/diseases become more prevalent
- changes may affect the quality of visual info that reaches CNS
Any _____ errors resulting from imperfections in ____ ____ of the eye can be corrected with _____ or _____.
- refractive
- axial length
- glasses or contacts
Presbyopia:
- the gradual loss of accommodation power to focus on near objects
- accompanies advancing age
Presbyopia becomes clinically significant around age ____.
40
The resting _____ of the pupil also ______ with aging, typically reducing _____ _____:
- diameter
- decreases
- retinal illuminance: the amount of light reaching the retina
The lens ______ with age, further reducing the amount of _______ reaching the eye and making ____ a problem for older adults.
- yellows
- illuminance
- glare
Visual disturbances that are more prevalent in older adults include:
- cataracts
- glaucoma
- age-related maculopathy
Age-related maculopathy:
a disease affecting the central area of the retina that provides detailed vision
Certain signs that may indicate a visual problem:
- squinting
- under or overreaching for objects
- performing unusual head movements to align one’s gaze with a particular object
People depend heavily on _____ ____ in the performance of most skills.
visual perception
One of the fundamental perceptions is that of ____ ____ space.
three dimensional
What movements depend on 3D space perception?
- almost all movements
- reaching, grasping, locomotion, complex skills (driving, piloting)
Visual sensations are received by _____ ____ in the _____ in approximately a ____ ____ format.
- sensory receptors
- retina
- 2D
To perceive space in 3D, individuals must perceive ____ and _____.
- depth
- distance
Depth perception:
a person’s judgement of the distance from self to an object or place in space
Retinal disparity:
the difference in the images received by the 2 eyes as a result of their different locations
Depth perception is aided by good _____ _____ because a ____ picture from each eye provides more information for the ____.
- visual acuity
- sharper
- comparison
Motion parallax:
the change in optical location for objects at different distance during viewer motion
Objects in space change locations on our _____, and nearer objects _____ more distant objects as the head moves.
- retinas
- overlap
Optic flow:
- change in the pattern of optical texture
- a transformation of the optic array as a viewer moves forward or backward in a stable environment
Optic flow provides much information about ____ _____ nature of our environment.
3D
Optic flow likely guides _____, controls _____, and helps us _____ _____ with objects and surfaces.
- locomotion
- posture
- anticipate contact
Assumption of physical equality:
- used to judge depth
- when 2 like objects can be expected to have the same size but project different relative sizes on the retina, we assume that the object with the larger retinal size is closer to us
Cues about ____ and _____ in our environment are often deprived from the 2 eyes being in different _____ or from movement of the _____.
- depth
- distance
- locations
- head
Most older adults than younger adults fail ___ ____ tests, but thresholds for distinguishing _____ change little if at all.
- depth perception
- depth
Among the important attributes of objects are:
- size
- shape
- motion
The perception of ____ and _____ helps us extract an object or figure from the ____ environment.
- edges
- boundaries
- background
Figure-and-ground perception:
the ability to see an object of interest as distinct from the background
Whole-and-part perception:
the ability to discriminate parts of a picture or an object from the whole, yet integrate the parts into the whole, perceiving them simultaneously
Children improve in figure-and-ground perception tasks between _____ years of age and again between _____ years.
- 4-6
- 6-8
Very young children have difficulty _____ objects that form a ____.
- integrating
- whole
We must perceive that an object has ____ ____ even though it might vary in _____ from us.
- constant size
- distance
Size constancy:
the perception of actual object size despite the size of its image as projected on our retina