<html><head><meta http-equiv="Content-Type" content="text/html charset=windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;">hi everyone,<div><br></div><div>the following talk sounds like it’d be of interest:</div><div><br></div><div>best,</div><div>denis<br><div><br><div>Begin forwarded message:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;"><span style="font-family:'Helvetica'; color:rgba(0, 0, 0, 1.0);"><b>From: </b></span><span style="font-family:'Helvetica';">Etienne Farcot <<a href="mailto:etienne.farcot@nottingham.ac.uk">etienne.farcot@nottingham.ac.uk</a>><br></span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;"><span style="font-family:'Helvetica'; color:rgba(0, 0, 0, 1.0);"><b>Subject: </b></span><span style="font-family:'Helvetica';"><b>[Maths-CMMB] CMMB Seminar - Tuesday 27 May at 11am - Jonathan Touboul</b><br></span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;"><span style="font-family:'Helvetica'; color:rgba(0, 0, 0, 1.0);"><b>Date: </b></span><span style="font-family:'Helvetica';">22 May 2014 12:19:22 BST<br></span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;"><span style="font-family:'Helvetica'; color:rgba(0, 0, 0, 1.0);"><b>To: </b></span><span style="font-family:'Helvetica';">CMMB list <<a href="mailto:maths-cmmb@lists.nottingham.ac.uk">maths-cmmb@lists.nottingham.ac.uk</a>><br></span></div><br><div>Dear all,<br><br>Next Tuesday the CMMB seminar will be given by Jonathan Touboul, from <br>Collège de France and Inria.<br><br><br>Note the UNUSUAL TIME AND LOCATION: 11am in room UP-MATHS-A17<br><br><br>If someone is interested in meeting with the speaker in person, please<br>let us know.<br><br><br><br>Title/Abstract:<br><br>Pinwheel-dipole configurations in the visual cortex reveals fundamental <br>neocortical organizing principles<br><br>In the early visual cortex, information is processed within functional <br>maps whose layout is thought to underlie visual perception. We show that <br>spatial frequency representation exhibits singularities around which the <br>map organizes like an electric dipole potential. These singularities are <br>precisely co-located with singularities of the orientation map: the <br>pinwheel centers. Mathematically, we show that both architectures are <br>the most parsimonious topologies ensuring local exhaustive <br>representation. Simulations of a pinwheel-dipole model, accurately <br>fitting optical imaging data, show improved coding capabilities compared <br>to previously proposed architectures. We demonstrate that a trade-off in <br>the local perception of orientation and spatial frequency can arise, <br>however for spatial frequency tuning widths smaller than those <br>previously reported. This prompted re-examination of the physiological <br>data, confirming that spatial frequency selectivity is sharpened near <br>pinwheels. These results shed new light on the functional architecture <br>of cortical maps and their underlying organizing principles.<br><br><br><br><br>Etienne and Daniele<br><br>--<br><br>_______________________________________________<br>Maths-CMMB mailing list<br><a href="mailto:Maths-CMMB@lists.nottingham.ac.uk">Maths-CMMB@lists.nottingham.ac.uk</a><br>http://lists.nottingham.ac.uk/mailman/listinfo/maths-cmmb<br></div></blockquote></div><br><div apple-content-edited="true">
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 13px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; -webkit-text-decorations-in-effect: none; text-indent: 0px; -webkit-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>--</div><div><a href="mailto:denis.schluppeck@nottingham.ac.uk">denis.schluppeck@nottingham.ac.uk</a></div><div><br class="khtml-block-placeholder"></div></div><br class="Apple-interchange-newline"></span></div></span><br class="Apple-interchange-newline"></span><br class="Apple-interchange-newline">
</div>
<br></div></body></html>