Visual System and Receptive Fields

What is a receptive field for a sensory neuron?

The specific region of the sensory surface that, when stimulated, leads to the activation of that sensory neuron.

How does lighting affect ganglion cells in the retina?

Ganglion cells respond to the edges between light and dark rather than constant illumination.

What do on-center and off-center bipolar cells indicate?

On-center bipolar cells activate in the presence of light in the center and inhibit in the surround; off-center bipolar cells do the opposite.

What is the function of intrinsically photosensitive retinal ganglion cells?

They help in detecting light for circadian rhythms, rather than visual details.

What is the role of the lateral geniculate nucleus (LGN) in the visual system?

It's the thalamic relay station that processes visual information coming from the retina and separates it based on whether it is from rods or cones and left or right eyes.

How does the visual field relate to ganglion cell activity?

The left visual field is processed by the right hemisphere of the brain, and vice versa, through the optic chiasm where nasal ganglion cell axons cross.

What happens when light hits only the center of a ganglion cell's receptive field?

It increases the action potentials from that ganglion cell.

What is Meyer's loop?

The pathway where optic nerve axons loop around the lateral geniculate nucleus before reaching the primary visual cortex.

How do the receptive fields of ganglion cells contribute to edge detection in vision?

Ganglion cells that only respond to light at specific spots help identify borders between light and dark, essential for contrast detection.

What is the significance of the 'blind spot' in vision?

The blind spot is where the optic nerve exits the retina, lacking photoreceptors, leading to a gap in visual perception that is usually filled in by the brain.