A 52-Year-Old Woman With Dysarthria, Ataxia, Xanthelasmas, and Miliary Pulmonary Nodules.

CASE PRESENTATION: A 52-year-old woman with no significant medical history was referred to our hospital for expedited workup of progressive dysarthria and ataxia over the past year. Prior CT angiography of the head and neck showed no relevant neurologic findings but did reveal miliary lesions in the lung apices, which was later confirmed via dedicated CT chest scan (Fig 1). Review of systems was negative for any respiratory, constitutional, or rheumatologic symptoms, except for new xanthelasma-like lesions over her forehead. She previously had smoked with 20 pack-years and had no TB risk factors. MRI of the face showed a 21-mm mass within the left external temporal fascia. MRI of the head showed diffuse leptomeningeal enhancement, right frontal lobe enhancement, and cerebellar and brainstem T2/fluid-attenuated inversion recovery hyperintensity, which prompted her admission to hospital.

Stereoscopic depth adaptation from binocularly correlated versus anti-correlated noise: Test of an efficient coding theory of stereopsis.

Stereoscopic, or "3D" vision in humans is mediated by neurons sensitive to the disparities in the positions of objects in the two eyes' views. A disparity-sensitive neuron is typically characterized by its responses to left- and right-eye monocular signals, SL and SR, respectively. However, it can alternatively be characterized by sensitivity to the sum of the two eyes' inputs, S+ = SL + SR, and the difference, S- = SL - SR. Li and Atick's theory of efficient binocular encoding proposes that the S+ and S- signals can be separately weighted to maximize the efficiency with which binocular information is encoded. This adaptation changes each neuron's sensitivity and preferred binocular disparity, resulting in predicted effects on the perceived stereoscopic depth of objects. To test these predictions, we measured the apparent depth of a random-dot stereogram with an 'in-front' target following adaptation to binocularly correlated or anti-correlated horizontally-oriented grating stimuli, which reduce sensitivity to the S+ and S- signals, respectively, but which contain no conventional stereo-depth signals. The anti-correlated noise adaptation made the target appear relatively closer to the background than the correlated noise adaptation, with differences of up to 60%. We show how this finding can be accommodated by a standard model of binocular disparity processing, modified to incorporate the binocular adaptation suggested by Li and Atick's theory.