Related Experiment Videos
Human visual development over the first 6 months of life. A review and a hypothesis
Insights
Infant visual development shows early cortical function for orientation discrimination. However, subcortical control dominates early behaviors, with maturation of cortical-subcortical pathways enabling complex visual attention and binocularity by six months.
Area of Science:
- Neuroscience
- Developmental Psychology
- Ophthalmology
Background:
- Human visual development involves significant behavioral changes in the first six months.
- Understanding the neurophysiological underpinnings of these changes is crucial.
Purpose of the Study:
- To explore behavioral changes in infant visual development.
- To relate these changes to underlying neurophysiological mechanisms.
- To compare findings across species where relevant.
Main Methods:
- Review of recent data on infant visual discrimination capacities.
- Analysis of visual evoked potentials.
- Consideration of behavioral tasks assessing color discrimination, detection, and attention control.
Main Results:
- Orientation discrimination and cortical visual evoked potentials are present near birth.
- Subcortical control appears dominant for the first month, evidenced by color and attention data.
- Cortical binocular function emerges around three months postpartum.
- Maturation of cortical-subcortical pathways likely drives behavioral changes from two months onward.
Conclusions:
- Early visual development involves a shift from subcortical to cortical control.
- Maturation of pathways connecting the cortex to subcortical structures (pretectum, colliculus) is key.
- This maturation facilitates improved convergence, binocularity, and visual attention control.
Abstract:
The behavioural changes that occur in visual development in the first 6 months of human life are discussed in relation to the possible underlying changes in neurophysiological mechanisms, with inter-species comparisons being made when appropriate. Recent data on the developing infant's changing capacity to discriminate various stimulus attributes is considered. It appears that orientation discrimination and cortically related visual evoked potentials are present at, or soon after, birth. However, data on colour discrimination, field differences in detection tasks and control of visual attention suggest a subcortical site for control of behaviour for the first month of life. The improvements in spatial and temporal resolution depend on maturation of both peripheral and central structures in the visual pathway and so do not provide a clear distinction between cortical and subcortical function. There is clear evidence that binocular function in the cortex does not emerge until three months postnatally. A hypothesis is proposed that maturation of a number of pathways between cortex and subcortical structures underlies the observed behavioural changes starting at around 2 months of age. The initial immaturity of connections between cortex and pretectum may give rise to asymmetrical monocular OKN. Maturation of pathways from cortex to colliculus could account for improvements in convergence, allowing development of cortical binocularity, and for the developing ability to control shifts of visual attention.