4.5: Sensory Capacities

Sensory Capacities

Throughout much of history, the newborn was considered a passive, disorganized mysterious little being who possessed minimal abilities Current research has demonstrated just the opposite, the newborn has very developed and well-organized sensory and perceptual abilities.

• Vision

The womb is a dark environment void of visual stimulation, and as a result vision is the most poorly developed sense at birth. Time is needed to build those neural pathways between the eye and the brain. Newborns typically cannot see further than 8 to 16 inches away from their faces, which is approximately the distance from the newborn's face to the mother/caregiver when an infant is breastfeeding or bottle-feeding). Within hours of birth an infant also shows a preference for the face of its own mother.

An infant's visual acuity is about 20/400, which means that an infant can see something at 20 feet that an adult with normal vision could see at 400 feet and the world may look quite blurry to young infant. Around 6 months of age, infants' visual acuity improves and approximates adult 20/25 acuity.

This weakness in early visual acuity means infants will look longer at a checkerboard with only a few large squares than one with many smaller squares. An infant's threshold for seeing a visual pattern is higher than an adults. Toys that are manufactured with black and white patterns rather than pastel colors offer a higher contrast, which makes the pattern more visible to the immature visual system.

Fig. 4.5. Infant looking at caregiver while bottle-feeding

Image Source: Infant Feeding by Ben_Kerckx on Pixabay

When looking at a person’s face, newborns do not look at the eyes the way adults do; rather, they tend to look at the chin—a less detailed part of the face. By 2 or 3 months, they will seek more detail when visually exploring a face or an object and begin showing preferences for:

• unusual images over familiar ones, for
• patterns over solids, for
• faces over patterns, and for
• three- dimensional objects over flat images.

Newborns have difficulty distinguishing between colors, but within a few months they can discriminate between colors as well as adults do. Sensitivity to binocular depth cues, which require inputs from both eyes, is evident by about 3 months and continues to develop during the first 6 months. By 6 months, the infant can perceive depth perception in pictures as well as their environment. Infants who have experience crawling and exploring will pay greater attention to visual cues of depth and modify their movement ad actions appropriately.

• Hearing

The ability of a fetus to hear is evident as soon as the 7th month of prenatal development. While in utero they will register specific information heard from their mother’s voice. Infants are born with a very keen sense of hearing. They prefer their mother’s voices over another female when speaking the same words, they can distinguish between a familiar and unfamiliar voice during their first few weeks, and between very similar sounds as early as one month after birth.

Infants are especially sensitive to the frequencies of sounds in human speech and prefer the exaggeration of infant-directed speech. Additionally, they are innately ready to respond to the sounds of any language, however some of this ability will be lost by 7 or 8 months of age as the infant becomes more familiar with the sounds of a specific language and less sensitive to sounds that are part of an unfamiliar language.

Fig 4.5.1. Newborn babies seem to recognize the language spoken by their mother.

Image Source: Fida Hussain/AFP/ Getty Images. Chen Ly. Babies may start to learn language before they are born. NewScientist.com. November 22, 2023.

• Taste and Smell

Studies of taste and smell demonstrate that babies respond with different facial expressions, suggesting that certain preferences are innate. Newborns can distinguish between sour, bitter, sweet, and salty flavors and show a preference for sweet flavors. Newborns also prefer the smell of their mothers. An infant only 6 days old is significantly more likely to turn toward its own mother’s breast pad than to the breast pad of another baby’s mother.

Fig. 4.5.1. Baby Responding to different tastes

Image Source: Created from images found in the article. Nine baby feeding faces every parent needs to know, and what they mean. Kidspot. news.com.au. April 24, 2019.

Source

• Lally, Martha and Suzanne Valentine-French. Lifespan Development: A Psychological Perspective. Licensed under CC BY-NC-SA 3.0.