Control over one's motor behavior ranks among the infant's greatest achievements. Psychologists whostudy the acquisition of motor skills in children find it useful to distinguish between gross motordevelopment, that is, motor skills which help children to get around in their environment such as crawlingand walking, and fine motor development, which refers to smaller movement sequences like reaching andgrasping.
The development of motor skills has implications beyond simply learning how to perform new actions:motor skills can have profound effects on other areas of development. For example, researchers haveshown that infants with locomotor experience (experience moving around their environment) were lesslikely to make errors while searching for hidden objects. The ability to initiate movement around one'senvironment stimulates the development of, making hidden object tasks easier to solve. Psychologyprofessor Carolyn Rovee-Collier argues that the onset of independent locomotion at around nine monthsold marks an important transition in memory development. Children who can move about theenvironment develop an understanding of locations such as here and there. Because infant memory isinitially highly dependent on context that is, the similarity between the situations where information isencoded (stored in memory) and where it is recalled infants who have experience moving about theenvironment and who learn to spatially encode information become less dependent on context forsuccessful recall. These examples show that gross motor development has implications beyond theimmediately apparent benefits of crawling and walking.
Renowned psychologist Jean Piaget argued that the development of reaching and grasping was a keyaspect of development because it formed an important link between biological adaptation andintellectual adaptation. Reaching and grasping are voluntary actions under the infant's control, and as such,they open up exciting new possibilities in their ability to explore the environment. An infant who reachesfor and grasps an object so as to explore it pushes his development forward as he engages in processessuch as adapting his grip to the size and shape of the object. Piaget argued that these early processes drivecognitive development in the first two years of an infant's life.
The development of reaching begins early on in life. Newborn infants seated in an upright position willswipe and reach towards an object placed in front of them, a behavior labeled "prereaching." These poorlycoordinated behaviors start to decline around two months of age and are replaced by "directed reaching"which begins at about three months of age. At this time reaching becomes more coordinated and efficient,and improves in accuracy. According to research conducted by Clifton et al., the infant's reaching doesnot depend simply on the guidance of the hand and arm by the visual system but is controlled byproprioception, the sensation of movement and location based on the stimulation arising from bodilysources such as muscle contractions. By about nine months old, infants can adjust their reaching to takeinto account a moving object. However, nine month olds are far from expert reachers. A good deal of skillmust still develop.
Once infants begin reaching they also begin to grasp the objects that are the target of their reaches. Theulnar grasp is seen when infants first engage in directed reaching. The ulnar grasp is a primitive form ofgrasping in which the infant's fingers close against its palm. The fingers seem to act as a whole, requiringthe use of the palm in order to hold an object. Shortly after this accomplishment, when infants can situpright on their own, they can acquire the ability to transfer objects from hand to hand. Around the endof the first year, infants will have graduated to using the pincer grasp where they use their index fingerand thumb in an opposable manner (placing them opposite each other), resulting in a more coordinatedand finely tuned grip which allows for the exploration of very small objects or those objects which demandspecific actions for their operation, such as the knobs on a stereo system which require turning to the leftor right to adjust volume.
1. According to paragraph 1, the distinction between gross motor development and fine motor development isbased primarily on
A. how much control the infant has over the motor skills
B. when the motor skills are developed
C. the size of the movement sequences involved
D. the usefulness of the movement sequences involved
2. The word “onset” in the passage is closest in meaning to
3. The phrase “immediately” apparent in the passage is closest in meaning to
4. According to paragraph 2, why do infants with locomotor experience have less trouble locating hiddenobjects
A. Moving around their environment helps infants to develop a better memory for spatial locations.
B. Moving around their environment increases infants' ability to make use of context to identify objects.
C. Moving around their environment gives infants more opportunity to correct their errors when searchingfor objects.
D. Moving around their environment reduces the time infants have to spend spatially encoding information.
5. According to paragraph 2, as a result of developing an understanding of here and there, infants are betterable to
A. describe the locations of objects in space
B. feel comfortable in new and unfamiliar situations
C. use context as an aid to recalling previously encoded information
D. recall information in situations unlike the one in which it was originally encoded
6. The word “Renowned” in the passage is closest in meaning to
7. The phrase “engages in” in the passage is closest in meaning to
B. learns about
8. What can be inferred from paragraph 3 about the cognitive development of an infant in its first two yearsof life as described by Piaget
A. It is a sign of advanced development when an infant is able to control its urges to reach and grasp.
B. Repeated practice reaching for and grasping objects results in important biological adaptations.
C. Infants who spend large amounts of time in exciting environments have more difficulty in their intellectualdevelopment.
D. An infant's development will be slower if it is not given the opportunity to reach for and hold objects.
9. In paragraph 4, why does the author emphasize the point that nine month olds are far from expert reachers
A. To support the idea that nine-month-olds vary a great deal in their reaching abilities
B. To distinguish between the directed reaching and the non-directed reaching of infants
C. To stress that an infant's reaching skills continue to improve even after the first nine months
D. To call into question the accuracy of the results presented by Clifton et al