Retinal SD wave segment propagating (blue arrows) with free open ends that grow (red arrow) and therefore curl in to form a double spiral.

<p>At lower susceptibility values, reaction-diffusion models of SD predict that open ends retract (green arrows) and the wave vanishes.</p

Typical propagation pattern of a visual migraine aura.

<p>(a) Right visual hemifield (dotted polar grid) with five subsequent sketched “snapshots” of a traveling visual migraine aura symptom in the shape of a crescent pattern. Numbers inside the scotom gives the time passed (in minutes) since first occurrence. Data is taken from Ref. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0005007#pone.0005007-Lashley1" target="_blank">[1]</a> (b) Visual field disturbance shown by reversed retinotopic mapping projecting the affected area onto a flat model of the primary visual cortex.1.</p

Creation of an SD wave segment with free open ends in submerged chicken retina.

<p>(a) Mechanical stimulation with sharp glass needle s, (b) circular SD wave evolves, (c)–(d) local application of Mg²⁺ via pipette p, (e) wave propagation is locally blocked and consequently SD front brakes open and curls in to form a spiral at the lower open end, while the upper open end is guided by the Mg2+-pipette to the border of the retina where it attaches.</p

Schematic view of the spatio-temporal course of a reaction-diffusion wave for different tissue susceptibility values σ: wave front (red), recovery phase (yellow), blue arrows indicate normal velocity, future location is dashed (red).

<p>(a) sustained wave, (b) retracting wave, indicated by green arrow heads, (c) collapsing wave, (d) no spread. The gray σ interval is defined as weakly susceptible.</p

3D form of primary visual cortex (V1).

<p>The representation of the azimuthal coordinate of the two visual hemifields is given by the hue, value, saturation color model: (a) right V1 (b) left visual hemifield (c) left V1 (d) right visual hemifield. The current position of the visual field defect, occurring during two different migraine aura attacks and each exclusively in one visual hemifield, are indicated by white lines, with numbers denoting the time in minutes after onset.</p

Lateral exploration as a function of developmental age.

<p>For each child, the results of the 4 protocol items are displayed separately.</p

Analysis of gaze directed toward faces.

<p><i>in FoV</i>: Percentage of time a face was in the broad field of view. <i>in CV</i>: Percentage of time a face was in central vision.</p

2-way ANCOVAs on the variables <i>In CV</i> and <i>Episode Duration</i>, controlling for Developmental Age.

*<p>lines in bold correspond to significant effects.</p

Eye-Tracking process.

<p>1<i>^st</i> column: the location of the eyes in the image is extracted automatically during post-hoc calibration. 2<i>^nd</i> column: the direction of gaze is computed automatically from the eyes image through support vector regression. 3<i>^rd</i> column: to highlight the direction of central vision (indicated by a crosshair), the image is blurred except for an area of 10 degrees radius around the center of the gaze. 4<i>^th</i> & 5<i>^th</i> columns Gaze tracking example while looking downwards: the system uses the whole eye region (shading of the eyelids, shape of the eyelashes, etc) to compute the gaze direction.</p

Comparison of gaze factors for TD and ASD groups.

<p>Refer to text for a detailed description of each factor.</p>*<p>lines in bold present significant differences.</p