Receptive Fields

7 flashcards · Biology · by lakesare

1. What's a receptive field?

   The area of the visual field that changes the response of the cell being studied (increases or decreases the number of spikes). This concept of receptive fields can be extended further up the nervous system; if many sensory receptors all form synapses with a single cell further up, they collectively form the receptive field of that cell. For example, the receptive field of a ganglion cell in the retina of the eye is composed of input from all of the photoreceptors which synapse with it, and a g…

2. Name 2 types of receptive fields.

   On-center Off-center

3. What's on-center receptive field?

   Firing rate increases when light hits the center.

4. What's off-center receptive field?

   Firing rate decreases when light hits the center.

5. What's the relationship between size of ganglion receptive field and distance from fovea?

   Size of ganglion cell receptive fields increases as you move away from center of retina and out into periphery

6. What will the firing rate of this on-center ganglion cell be in these positions?

7. How do on-off ganglion cells relate to edge detector cells?

   on-off ganglion cells - in the ganglion layer in the retina, react to dots. edge detector cells - in V1, react to vertical/horizontal bars. Hubel and Wiesel postulated that simple cortical receptive fields gain complexity and an intricate spatial arrangement through the patterned convergence of multiple "on" or "off" projections from lateral geniculate cells onto single cortical cells. Neurons at different stages in the visual pathway have receptive fields that differ not only in size but also…