Failure in developing high-level visual functions after occipitoparietal lesions at an early age: a case study

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Cognitive Neuroscience

Background:

• Functional magnetic resonance imaging (fMRI) studies have identified specialized regions in the ventral visual pathway for processing faces, words, and objects.
• The developmental origins of this functional selectivity remain largely unknown.

Observation:

• A pediatric patient with a left occipitoparietal lesion from a subdural hematoma in infancy was studied.
• Post-surgery, visual field deficits improved, with no apparent low-level vision deficits by age twelve.
• fMRI revealed normal activation in the left early visual cortex but absent selective responses in the left ventral temporal cortex.

Findings:

• The patient's left ventral temporal cortex did not exhibit selective responses to faces, words, or objects, unlike the intact right hemisphere.
• Early visual cortex activation in the affected hemisphere was comparable to the unaffected hemisphere.

Implications:

• This case suggests that the development of object selectivity in the ventral temporal cortex is dependent on early visual input from the early visual cortex.
• Findings highlight the critical period for visual experience in shaping specialized neural processing.