Chapter 5: Perceptual and Motor Development
- Sensory and perceptual processes are the means by which people receive, select, modify and organize stimulation from the world.
- Habituation - Novel stimuli - babies pay much attention. More familiar stimuli- pay less attention. This is used in studies of perception.
Smell, Taste and Touch
- Smell and touch help them recognize their mothers and make it much easier for them to learn to eat.
- Class Notes
Auditory Threshold - refers to the quietest sound that a person can hear.
- Adults can hear better than infants.
- Infants can differentiate vowels from consonant sounds, and by four and a half months, they can recognize their own names.
Visual Acuity - the smallest pattern that can be distinguished dependably.
Cones - in the retina, sensitive to wavelength light and detect them. This allows use to see in color.
Integrating Sensory Information
- Feeling and relating the feeling to what is used to be seen- rough or smooth.
- Amodal- can be presented in different senses- duration, rate and intensity. Seeing the mother clapping and understanding the beet of the music.
Inter-sensory Redundancy Theory - Bahrick and Lickliter, the infant’s perceptual system is particularly attuned to amodal information that is presented to multiple sensory modes.
- Perceptual Constancies - A challenge for infants is recognizing that an object is the same even though it may look different.
- Size constancy - the realization that an object’s actual size remains the same despite changes in the size of its retinal image.
- Brightness constancy
- Color constancy
- Depth - Determining position of an object. Cues are used to estimate distance and depth.
- Visual cliff - Elanor Gibson and Richard Walk, a glass-covered platform; on one side, a pattern appears directly under the glass, but on the other, it appears several feet below the glass. Most babies willingly crawl to their mothers when she stands on the shallow side of the platform. But virtually all babies refuse to cross the deep side, even when the mother calls the infant by name and tries to lure him or her with an attractive toy. Although young babies can detect a difference between the shallow and deep sides of the visual cliff, only older, crawling babies are actually afraid of the deep side. Even one-and-a-half month old notice that the deep side is different.
- Kinetic Cues - Motion is used to estimate depth.
- Visual Expansion - as an object moves closer , it fills an ever-greater proportion of the retina.
- Motion Parallax - Nearby moving objects move across our visual field faster than those at a distance.
- Retinal Disparity - the left and right eyes often see slightly different visions of the same scene. (4 months)
- Pictorial Cues - (7 months) arrangement of objects in the environment, cues that are used to convey depth such as shades.
- Texture Gradient - Close objects - Fine, Far objects - less distinct
- Interposition - Close objects partially obscure more distant objects
- Linear Perspective - Parallel lines come together at a single point in distance
- Relative Size - Nearby objects look larger than objects in distance
- Perceiving Faces
- The claim here is that some aspect of the face—perhaps three high-contrast blobs close together —constitutes a distinctive stimulus that is readily recognized, even by newborns.
The process by which we select information that will be processed further.
Orientating Response - when presented with a strong unfamiliar stimulus, a person startles, fixes the eyes on the stimulus and stimulus, and shows changes in heart rate and brain wave patterns. Collectively, these responses indicate that the infant is attending to this stimulus.
- Habituation indicates that attention is selective - A stimulus that once garnered attention no longer does.
- Maintaining focused attention is a demanding skill, one that emerges gradually during the preschool years and beyond.
Attention Deficit Hyperactivity Disorder
- Three symptoms of ADHD
- Inattention - Youngsters with ADHD skip from one task to another. They do not pay attention in class and seem unable to concentrate on schoolwork.
- Hyperactivity - Children with ADHD are unusually energetic, fidgety, and unable to keep still, especially in situations like school classrooms where they need to limit their activity.
- Impulsivity - Children with ADHD often act before thinking; they may run into a street before looking for traffic, or interrupt others who are speaking.
- Locomotion - Movement
- Mile stones - lecture notes
- Dynamic Systems Theory - motor development involves many distinct skills that are organized and reorganized over time to meet the demands of specific tasks.
- Posture and Balance - By a few months after birth, infants begin to use visual cues and an inner-ear mechanism to adjust their posture.
- Stepping - Children don’t step spontaneously until approximately 10 months because they must be able to stand upright to step.
- Environmental Cues - Infants soon discover that the environment offers a variety of surfaces, some more conducive to walking than others. If they cannot decide whether a surface is safe, they depend on an adult’s advice.
- Coordinating Skills - Each component skill must first be mastered alone and then integrated with the other skills. Differentiation- mastery of component skills. Integration- combining them in proper sequence into a coherent, working whole.
- Walking comes from imitation from parents.
- Fine-motor skills - grasping holding and manipulating objects.
- Reaching - Early reaches- 4 months but their arms and hands don’t move directly and smoothly to the desired object.
- Grasping - More difficult, combining the use of fingers and hands. Not until seven or eight months do most infants use their thumbs to hold objects.
- At about 6 months, finger food is given. They can pick up the food, but it is harder to put into mouth.
- At about the first birthday, youngsters are usually ready to try eating with a spoon. At the beginning it is just raising the spoon up and down without twisting the hand. But at the age of 2 the child is able to twist the wrist to scoop food and eat.
- By 3-4 years they are more independent, dressing with buttons and going to the washroom and taking off cloths.
- Development involves first mastering the separate elements and then assembling them to form a smoothly functioning whole.
- Handedness - Up until the first birthday, there is no preference for a certain hand over the other.
- Physical Fitness - Using motor skills promotes growth of muscles and bones, cardiovascular health and cognitive processes
Related notes you might be interested in
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