Representation of Contralateral Visual Space in the Human Hippocampus.

Area of Science:

• Neuroscience
• Visual System Organization

Background:

• Retinotopy, the mapping of visual space onto the brain, is a core principle in the primate visual system.
• Recent studies reveal retinotopic sensitivity extends beyond early visual areas to scene-selective regions like the parahippocampal cortex.
• The hippocampus, connected to scene-selective areas, was investigated for similar retinotopic biases.

Purpose of the Study:

• To test if the human hippocampus exhibits a biased representation of contralateral visual space.
• To determine the extent and location of retinotopic sensitivity within the hippocampus.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was employed to map population receptive fields (pRFs).
• Scene stimuli were used to probe retinotopic sensitivity in the hippocampus.
• Independent data from the Human Connectome Project (HCP) were used for validation.

Main Results:

• Bilateral hippocampus demonstrated significant biases for the contralateral visual field.
• Retinotopic sensitivity was more prominent in anterior medial portions of the hippocampus.
• Contralateral visual field bias in the hippocampus was confirmed in independent HCP data.

Conclusions:

• The hippocampus, considered a high-level visual processing area, exhibits significant contralateral visual field biases.
• This pervasive retinotopy has implications for understanding visual information within allocentric spatial representations.
• The findings underscore the widespread influence of retinotopic organization throughout the brain.