Neuron

Neurons

Purkinje cells from cerebellum, dendrites showing calcium concentration

Synaptic connection

Eye

Neural circuitry of the retina

Receptors Density - Fovea

Photoreceptors

Photoreceptors

CCD Well

Image Capture

• Huge dynamic range

• Photons: poisson process.

• Noisy at low levels

• For low light: large receptors, slow integration

• Rods/cones, local adaptation,change of amplitude and time constant, motion deblur

Visual receptor types

Spectral sensitivity

Color Mixing

Center-surround Receptive Fields

Modified from PSY280F

LGN Layers

Physiological Recording

Orientation Selectivity

V1: Direction selectivity

Modified from PSY280F

End-stopped cell

Simple Cells

Visual Areas

Bi-directional Computation

fMRI Magnet

fMRI Activation Slice

fMRI Activation