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Law and Constantine-Paton transplanted eye primordia between tadpoles to create three-eyed frogs.

The additional eyes connected to the frogs' contralateral tecta and created competition of inputs which is not usually present in frogs (where the optic chiasm is perfect).

The result were tecta in which alternating stripes are responsive to input from different eyes.

Similar results result if one of the tecta is removed and both natural retinae project to the remaining tectum.

Spatial attention does not seem to affect the selectivity of visual neurons—just the vigour of their response.

Response properties of superficial SC neurons are different in different animals.

There are cells in the rabbit retina which are selective of direction of motion.

Some visual processing occurs already in the retina.

Both visual and auditory neurons in the deep SC usually prefer moving stimuli and are direction selective.

The range of directions deep SC neurons are selective for is usally wide.

Visuo-somatosensory neurons in the putamen with somatosensory RFs in the face are very selective: They seem to respond to visual stimuli consistent with an upcoming somatosensory stimulus (close-by objects approaching to the somatosensory RFs of the neurons).

There are reports of highly selective, purely visual cells in the putamen. One report is of a cell which responded best to a human face.

Cells in MST respond to and are selective to optic flow.

Cells in MST respond to vestibular motion cues.

Some cells in MST are multisensory.

Visuo-vestibular cells tend to be selective for visual and vestibular self-motion cues which indicate motion in the same direction.

Weber presents a Helmholtz machine extended by adaptive lateral connections between units and a topological interpretation of the network. A Gaussian prior over the population response (a prior favoring co-activation of close-by units) and training with natural images lead to spatial self-organization and feature-selectivity similar to that in cells in early visual cortex.

According to Wilson and Bednar, wire-length optimization presupposes that neurons need input from other neurons with similar feature selectivity. Under that assumption, wire length is minimized if neurons with similar selectivities are close to each other. Thus, the kind of continuous topological feature maps we see optimize wire length.

The idea that neurons should especially require input from other neurons with similar spatial receptive fields is unproblematic. However, Wilson and Bednar argue that it is unclear why neurons should especially require input from neurons with similar non-spatial feature preferences (like orientation, spatial frequency, smell, etc.).

Koulakov and Chklovskii assume that sensory neurons in cortex preferentially connect to other neurons whose feature-preferences do not differ more than a certain amount from their own feature-preferences. Further, they argue that long connections between neurons incur a metabolic cost. From this, they derive the hypothesis that the patterns of feature selectivity seen in neural populations are the result of minimizing the distance between similarly selective neurons.

Koulakov and Chklovsky show that various selectivity patterns emerge from their theorized cost minimization, given different parameterizations of preference for connections to similarly-tuned neurons.

Pooling the activity of a set of similarly-tuned neurons is useful for increasing the sharpness of tuning. A neuron which pools from a set of similarly-tuned neurons would have to make shorter connections if these neurons are close together. Thus, there is a reason why it can be useful to connect preferentially to a set of similarly-tuned neurons. This reason might be part of the reason behind topographic maps.

The neurons in the superficial (rhesus) monkey SC do not exhibit strong selectivity for specific shapes, stimulus orientation, or moving directions. Some of them do show selectivity to stimuli of specific sizes.

The neurons in the superficial (rhesus) monkey SC largely prefer moving stimuli over non-moving stimuli.

Ocular dominance stripes are stripes in visual brain regions in which retinal projections of one eye or the other terminate alternatingly.

Ocular dominance stripes have been shown to exist in the monkey SC. In some places, they weren't crisp but ran into each other.