PSYCH CHAPTER 5 (Book)

Sensation is the detection of sensory stimulation, and perception is the interpretation of what is sensed.

Constructivists argue that the newborn must construct an understanding of the world through experience with sensory inputs. Thus, according to the constructivist perspective, nurture is the primary driver of the development of perception.

Nativists believe that each person is born with some innate understanding of how to interpret sensory information. Thus, according to the nativists, the origin of perception is largely nature.

Gibson’s ecological theory proposes that everything we need to understand the world around us is available in the environment itself. We are able to directly detect the affordances of objects—what they offer us in terms of how we might interact with them. In the ecological view, nature and nurture are integrally related.

Methods of studying infant perception include habituation, evoked potentials, preferential looking, and operant conditioning techniques.

The visual system is fairly well developed at birth. Infants younger than 2 months old discriminate brightness and colors and are attracted to contour, moderate complexity, and movement. Starting at 2 or 3 months, infants more clearly perceive whole patterns such as faces and seem to understand a good deal about objects and their properties, guided by intuitive theories of the physical world.

Spatial perception develops rapidly, and by about 7 months, after they begin to crawl, infants not only perceive drop-offs but also avoid, if not fear, them.

The auditory sense is well developed at birth. Young infants can recognize their mother’s voice and distinguish speech sounds that adults cannot discriminate.

The senses of taste and smell are also well developed at birth. In addition, newborns are sensitive to touch, temperature, and pain.

The early presence of sensory and perceptual abilities suggests that they are innate, but they are also clearly influenced by early experiences. Certain experiences may be necessary for normal visual perception to develop, suggesting a sensitive period for the visual system.

Infants actively seek out stimulation by exploring their environments, which typically provides them with the stimulation they need to develop normal sensory and perceptual skills.

Sensory skills undergo little change during childhood, although children learn better how to use the information coming in through their senses.

Coupling perception with action to walk is a major accomplishment of childhood made understandable by the dynamic systems theory.

Cross-modal perception, the ability to recognize through one sense what was learned by a different sense, originates in infancy but becomes more fully developed in childhood.

Learning to control attention is an important part of perceptual development during childhood. Infants and young children are selectively attentive to the world around them, but they have not fully taken charge of their attentional processes.

With age, children become more able to concentrate on a task for a long period, to focus on relevant information and ignore distractions, and to use their senses in purposeful and systematic ways to achieve goals.

Basic perceptual and attentional skills are perfected during adolescence. Adolescents are better than children at sustaining their attention and using it selectively and strategically to solve the problem at hand.

Teens often multitask, which can lead to less efficient learning of new information.

Time spent viewing digital screens can lead to eye strain, blurred vision, and difficulty focusing.

Exposure to loud noise can cause tinnitus or ringing sounds in the ear that can be temporary or permanent. Damage to the auditory system from exposure to loud noise can accumulate over time, leading eventually to hearing impairment.

Adolescents refine the connection between perception and action, most readily seen in highly skilled athletes who must perceive and act quickly under stress.

During adulthood, sensory and perceptual capacities gradually decline in most individuals, although many changes are minor and can be compensated for. Sensory thresholds—the amount of stimulation required for detection—rise, and perceptual processing of sensory information often declines. Moderate to severe declines that are not corrected can lead to declines in activities and quality of life among older adults.

Visual changes include cataracts (clouding of the lens), reduced ability of the pupil to change in response to changes in light, thickening of the lens leading to decreased acuity (presbyopia), and retinal changes such as age-related macular degeneration.

Presbycusis—changes in hearing associated with aging—affects many older adults and most commonly leads to trouble detecting high-pitched sounds. Older adults have more difficulty with speech perception, especially under noisy conditions, than younger adults. Hearing aids can significantly improve older adults’ abilities to detect sounds.

Many older people have difficulty recognizing or enjoying foods, largely because of declines in the sense of smell and taste; touch, temperature, and pain sensitivity also decrease slightly, but intense pain stimuli still hurt.