chapter 11 Perception and Action in Development

Role of Action in Perception Developmentalists suspect that movement is important to perceptual development. Movement is necessary for the coupling, or linking, of perception and movement.

Historical Views Perceptual-motor theories of the 1960s Identified perception as the precursor of movement and cognition. Speculated that learning disabilities could be remediated through perceptual-motor programs. Early evaluations were flawed. Little evidence exists that perceptual-motor programs improved classroom skills. (continued)

Historical Views (continued) Piaget Reality is constructed by relating action to sensory information. Children move through stages. Perception and action are not well organized in infancy.

Contemporary Views Perceptual-motor activities are important. They give children experience in performing skills based on perceptual information. They reinforce concepts such as shapes and directions. (continued)

Contemporary Views (continued) Motor and cognitive development are intertwined. Parts of prefrontal cortex and contralateral neocerebellum are coactivated. Prefrontal cortex might be involved in motor activity. Caudate nucleus and neurotransmitter dopamine are involved in neural circuits (in turn involved in motor and cognitive functions). (continued)

Contemporary Views (continued) Ecological views include the following: Reality does not need to be constructed. Perception of environment is ahead of purposeful movement. Perception–action loops guide movement (there is little research evidence of these loops).

Recent Research Perception develops ahead of movement skills. Movement skills are acquired with guidance from perceptual information. New actions make new information (perceptions) available. Exercise stimulates brain activity that facilitates learning and memory.

Implications If further research confirms that physical activity facilitates brain activity, what implications do you see for planning classroom instruction (for all ages)?

Self-Produced Locomotion Held and Hein (1963) –Placed kittens in a merry-go-round, one kitten in a gondola, the other able to walk. –Both had equivalent perceptions but only one was able to move. –Motor skill development in the passive kitten was hindered. Bertenthal, Campos, & Barrett (1984); Kermoian & Campos (1988) –Locomotor experience was provided to pre-walkers by baby walkers. –Locomotor experience, rather than age, was associated with response to heights. –Perception of spatial relationships was enhanced by locomotor experience. (continued)

Self-Produced Locomotion (continued) Lockman (1984); McKenzie & Bigelow (1986) –Study challenged infants to move around barriers. –Spatial perception improved with increased locomotor experience. Gibson et al. (1987) –Locomotor experience influenced perception of surfaces and slopes. –With increased experience, infants showed more sensitivity to surfaces and slopes.

Perception of Affordances Ecological view: It is the affordance that is perceived. –Affordances involve what the environment permits, given the capabilities of the performer. –They are perceived directly, without cognitive analysis of object characteristics. Example: Stairs afford climbing. –Warren (1984) related stair height to leg length. –No single model has been found to apply over the life span.

Affordances Incorporate Body Scale Body scale is an individual’s size relative to the environment. Body scales change over the life span. Scaling of sports equipment and environments allows individuals of various sizes to perform similar movements.

Using Body Scaling What are some ways in which youth sport programs scale dimensions and equipment for body size? What about physical education programs? If you visited an elementary school, how might you spot a kindergarten classroom?

Tool Use in First Year Infants use trial-and-error exploration. Infants relate objects to other objects and to surfaces. Affordances involve relationships between objects. Self-generated opportunity for perceptual learning exists (tool use facilitates perceptual development).

Accommodating Disabilities What challenges might infants with temporary or permanent physical disabilities face in experiencing normal perceptual development? What steps could parents or therapists take to compensate?

Movement Facilitates Perceptual Development: Summary Deprivation can put individuals at risk of deficient perceptual development. Movement experience might influence survival of synaptic connections in early development.

Posture and Balance: Perception–Action Ecosystem It involves visual, auditory, and kinesthetic input from proprioceptive and vestibular receptors. Posture and balance are maintained in various situations. –Stationary and moving –On various body parts and surfaces Posture and balance are specific to environmental and task constraints.

Balance in Childhood Balance improves throughout childhood and adolescence. Pattern of improvement is task specific. Trend is to rely more on kinesthetic information and less on visual information. Have you ever felt like you were moving when you were not (perhaps on a car, train, or bus)? What systems were in conflict?

Balance During Locomotion We use frames of reference. –Supporting surface –Gravity The challenge is to control the many degrees of freedom of movement at the various body joints. –We can stabilize our heads on our trunks. –We can stabilize head position in space.

Challenges to Balance Consider some surfaces that make balance difficult as you attempt to move across them. What strategies do you use to compensate and keep your balance? (Hint: Consider not only the surface’s covering but also its orientation and size.)

Assaiante Model Model identifies four time periods. –Birth to standing: cephalocaudal direction of muscle control –Standing to age 6 years: coordination of upper and lower body –Age 7 years through adolescence: refinement of head stabilization –Adulthood: refined control of degrees of freedom in the neck Task of childhood: Learn how different frames of reference complement each other during movement.

Balance Changes With Aging: Younger Adults Younger adults on a movable platform use ankle muscles to regain balance after small, slow perturbations. They use a hip strategy to regain balance after larger, faster perturbations.

Balance Changes With Aging: Older Adults Older adults take longer to initiate a response to perturbation. They sometimes use the opposite pattern of younger adults. What environmental and task constraints can threaten older adults’ balance but seem to present no problem for younger adults?

System Changes Contributing to Balance Difficulty in Older Adults Changes in sensory receptors Loss of strength Arthritic conditions in joints Slower nerve conduction speed

Balance Training for Older Adults Balance improves with practice in responding to perturbations. Exercise programs that stress strength and balance reduce falls. What exercise training equipment is used to practice balance? Can older adults use it?

Perception and Action as an Ecosystem: Summary Actions are coupled with perceptions. Movement experience is important to, and might facilitate, perceptual development. Perceptual system–environment interactions demonstrate interdependence of movement and perceptual development.

Assessment of Postural Control and Balance We can observe responses –on a force plate, –when balance is perturbed, –when perceptual information from one system conflicts with that from another system, and –when one source of information (such as vision) is taken away. Observation can involve electromyographs.