Handbook of Language and Literacy Development - a Roadmap from 0 to 60 Months

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Developmental Milestones

Age

Skill / Category

Attributes

Birth to Six Months

Physiological Development

  • Visual pathways containing connections between the eye and the brain are in place but function with limited capacity.
  • Refinements occur in these pathways both in terms of speed of conduction (due to increased nerve myelination) and improved processing of information through increased neural connections.
  • As visual pathways develop they become more efficient and responsive leading to improved vision .
  • Visual functions develop rapidly as the infant receives and processes visual information usually within less than one month of age.
  • The basic focusing structures are present within the eye. However, the nerve cells of the sensitive retinal areas needed for fine vision are not fully developed compared to peripheral retinal areas that have a much coarser capacity for resolution.

Sensory Development

  • Infants are able to see outlines of objects but the ability to resolve details in objects (visual acuity) and the ability to detect contrast are only a fraction of what they are in adults. These functions however show rapid improvement shortly after birth.
  • By 2 months infants can distinguish their mother’s face from that of a stranger’s.
  • By 3 months, internal details of objects become more apparent, infants start to focus on facial details such as eyes.
  • Red/green colour discriminations emerge first.
  • By 6 months infants start to see with both eyes together allowing for the emergence of depth perception.
  • Colour vision is weak or absent, vision is close to black and white at birth. However the ability to discriminate a wide range of colours is present by 3 months.

Oculomotor Development

  • Accommodation (the ability to focus over a range of distances) is limited and almost fixed at birth.
  • Accommodation increases to adult-like ranges by 3 months, and accuracy by 6 months. (The improvement pertains primarily to the improvement in their spatial vision).
  • By 3 months of age infants can follow a moving object smoothly, similar to adults.

Visual Development

  • Between birth and 2 months infants clearly demonstrate an alert state, taking in information around them.
  • Improvements in spatial orientation and attending to objects are seen between 2 and 6 months from birth.
  • Beyond 5 or 6 months infants begin to pay attention to objects that interest them.

Seven to Sixty Months

Physiological Development

  • Specific modifications (some expansion, some refinement) to visual brain regions and the pathways that connect them to the eye correlate with a steady improvement in visual functions.
  • The eye itself continues to grow and the size, shape and distribution of cells in the retina lead to improvements in visual acuity.
  • As the eye grows errors of focus steadily decrease.

Sensory Development

  • As brain structures and pathways continue to develop so too vision continues to improve.
  • The development of these brain structures allows for spatial discrimination (visual acuity, contrast, colour), motion perception, and depth perception.
  • Visual performance is also increased due to maturation and refinement along the visual pathway where better connections are made through increased visual activity.
  • Visual acuity can be measured more accurately as a child’s cognitive and behavioural levels increase. A visual crowding effect is found where seeing a letter is harder when its surrounded by other letters or objects.

Development of Focus

  • ‘Normal’ vision in children is different from normal vision in adults.
  • Astigmatism (uneven focus) declines .
  • Farsightedness is still the norm in most children. Focus is often best and individual differences the least when children reach 5 to 6 years of age.

Visual Attention

  • Infants become able to shift attention from near to far distances and from one object to another, and from a whole object to fine details.
  • By 12 months of age, infants can pay attention to objects that are pointed out to them.
  • Attention in toddlers becomes wilful and effortful.
  • Preschoolers become proficient at selectively focusing on relevant information while ignoring irrelevant or conflicting information.