CINXE.COM

<!DOCTYPE HTML> <html lang="en-US"> <head> <meta charset="UTF-8" /> <meta name="generator" content="devn" /> <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no"/> <meta name="apple-mobile-web-app-capable" content="yes" /> <meta name="description" content="" /> <meta name="keywords" content="" /> <meta property="og:type" content="devn:photo" /> <meta property="og:url" content="https://purveslab.net/news-2/" /> <meta property="og:title" content="News" /> <meta property="og:description" content=" Recently Published What does AI’s success playing complex board games tell brain scientists? Author: Dale Purves a,1 Affiliations: Duke Institute for Brain Sciences, Duke University, Durham, NC 27708 Rea..." /> <meta property="og:image" content="https://www.youtube.com/embed/Nnh-RDFqUHk?rel=0&showinfo=0" /> <meta http-equiv="content-language" content="en-us" /> <meta name="author" content="DEVN CO" /> <meta name="contact" content="contact@devn.co" /> <meta name="copyright" content="Copyright (c)1997-2004 DEVN CO. All Rights Reserved." /> <link rel="pingback" href="https://purveslab.net/xmlrpc.php" /> <link rel="shortcut icon" href="https://purveslab.net/wp-content/uploads/purveslab_favicon3.png" type="image/x-icon" /><title>News | Purves Lab</title> <title>News – Purves Lab</title> <meta name='robots' content='noindex,follow' /> <link rel='dns-prefetch' href='//ajax.googleapis.com' /> <link rel='dns-prefetch' href='//fonts.googleapis.com' /> <link rel='dns-prefetch' href='//s.w.org' /> <link rel="alternate" type="application/rss+xml" title="Purves Lab » Feed" href="https://purveslab.net/feed/" /> <link rel="alternate" type="application/rss+xml" title="Purves Lab » Comments Feed" href="https://purveslab.net/comments/feed/" /> <script type="text/javascript"> window._wpemojiSettings = {"baseUrl":"https:\/\/s.w.org\/images\/core\/emoji\/12.0.0-1\/72x72\/","ext":".png","svgUrl":"https:\/\/s.w.org\/images\/core\/emoji\/12.0.0-1\/svg\/","svgExt":".svg","source":{"concatemoji":"https:\/\/purveslab.net\/wp-includes\/js\/wp-emoji-release.min.js?ver=5.2.21"}}; !function(e,a,t){var n,r,o,i=a.createElement("canvas"),p=i.getContext&&i.getContext("2d");function s(e,t){var a=String.fromCharCode;p.clearRect(0,0,i.width,i.height),p.fillText(a.apply(this,e),0,0);e=i.toDataURL();return p.clearRect(0,0,i.width,i.height),p.fillText(a.apply(this,t),0,0),e===i.toDataURL()}function c(e){var t=a.createElement("script");t.src=e,t.defer=t.type="text/javascript",a.getElementsByTagName("head")[0].appendChild(t)}for(o=Array("flag","emoji"),t.supports={everything:!0,everythingExceptFlag:!0},r=0;r<o.length;r++)t.supports[o[r]]=function(e){if(!p||!p.fillText)return!1;switch(p.textBaseline="top",p.font="600 32px Arial",e){case"flag":return s([55356,56826,55356,56819],[55356,56826,8203,55356,56819])?!1:!s([55356,57332,56128,56423,56128,56418,56128,56421,56128,56430,56128,56423,56128,56447],[55356,57332,8203,56128,56423,8203,56128,56418,8203,56128,56421,8203,56128,56430,8203,56128,56423,8203,56128,56447]);case"emoji":return!s([55357,56424,55356,57342,8205,55358,56605,8205,55357,56424,55356,57340],[55357,56424,55356,57342,8203,55358,56605,8203,55357,56424,55356,57340])}return!1}(o[r]),t.supports.everything=t.supports.everything&&t.supports[o[r]],"flag"!==o[r]&&(t.supports.everythingExceptFlag=t.supports.everythingExceptFlag&&t.supports[o[r]]);t.supports.everythingExceptFlag=t.supports.everythingExceptFlag&&!t.supports.flag,t.DOMReady=!1,t.readyCallback=function(){t.DOMReady=!0},t.supports.everything||(n=function(){t.readyCallback()},a.addEventListener?(a.addEventListener("DOMContentLoaded",n,!1),e.addEventListener("load",n,!1)):(e.attachEvent("onload",n),a.attachEvent("onreadystatechange",function(){"complete"===a.readyState&&t.readyCallback()})),(n=t.source||{}).concatemoji?c(n.concatemoji):n.wpemoji&&n.twemoji&&(c(n.twemoji),c(n.wpemoji)))}(window,document,window._wpemojiSettings); </script> <style type="text/css"> img.wp-smiley, img.emoji { display: inline !important; border: none !important; box-shadow: none !important; height: 1em !important; width: 1em !important; margin: 0 .07em !important; vertical-align: -0.1em !important; background: none !important; padding: 0 !important; } </style> <link rel='stylesheet' id='wp-block-library-css' href='https://purveslab.net/wp-includes/css/dist/block-library/style.min.css?ver=5.2.21' type='text/css' media='all' /> <link rel='stylesheet' id='layerslider-css' href='https://purveslab.net/wp-content/plugins/LayerSlider/static/css/layerslider.css?ver=5.3.2' type='text/css' media='all' /> <link rel='stylesheet' id='ls-google-fonts-css' href='https://fonts.googleapis.com/css?family=Lato:100,300,regular,700,900%7COpen+Sans:300%7CIndie+Flower:regular%7COswald:300,regular,700&subset=latin%2Clatin-ext' type='text/css' media='all' /> <link rel='stylesheet' id='contact-form-7-css' href='https://purveslab.net/wp-content/plugins/contact-form-7/includes/css/styles.css?ver=5.1.3' type='text/css' media='all' /> <link rel='stylesheet' id='devn-bootstrap-css' href='https://purveslab.net/wp-content/themes/hoxa/SuperComposer/assets/css/bootstrap3/css/bootstrap.min.css?ver=2.1' type='text/css' media='all' /> <link rel='stylesheet' id='devn-bootstrap-resp-css' href='https://purveslab.net/wp-content/themes/hoxa/SuperComposer/assets/css/bootstrap_responsive.css?ver=2.1' type='text/css' media='all' /> <link rel='stylesheet' id='devn-stylesheet-css' href='https://purveslab.net/wp-content/themes/hoxa/style.css?ver=2.1' type='text/css' media='all' /> <link rel='stylesheet' id='devn-flexslider-css-css' href='https://purveslab.net/wp-content/themes/hoxa/css/flexslider.css?ver=1741067199' type='text/css' media='all' /> <link rel='stylesheet' id='devn-options-css' href='https://purveslab.net/wp-content/themes/hoxa/css/options.css?ver=1741067199' type='text/css' media='all' /> <link rel='stylesheet' id='devn-responsive-css' href='https://purveslab.net/wp-content/themes/hoxa/css/responsive.css?ver=1741067199' type='text/css' media='all' /> <link rel='stylesheet' id='fancybox-css' href='https://purveslab.net/wp-content/plugins/easy-fancybox/css/jquery.fancybox.min.css?ver=1.3.24' type='text/css' media='screen' /> <script type='text/javascript' src='https://purveslab.net/wp-includes/js/swfobject.js?ver=2.2-20120417'></script> <script type='text/javascript' src='https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js'></script> <script type='text/javascript' src='https://purveslab.net/wp-content/plugins/jquery-manager/assets/js/jquery-migrate-1.4.1.min.js'></script> <script type='text/javascript' src='https://purveslab.net/wp-content/plugins/LayerSlider/static/js/greensock.js?ver=1.11.8'></script> <script type='text/javascript' src='https://purveslab.net/wp-content/plugins/LayerSlider/static/js/layerslider.kreaturamedia.jquery.js?ver=5.3.2'></script> <script type='text/javascript' src='https://purveslab.net/wp-content/plugins/LayerSlider/static/js/layerslider.transitions.js?ver=5.3.2'></script> <script type='text/javascript' src='https://purveslab.net/wp-content/themes/hoxa/js/custom.js?ver=2.1'></script> <script type='text/javascript' src='https://purveslab.net/wp-content/themes/hoxa/js/viewportchecker.js?ver=2.1'></script> <script type='text/javascript' src='https://purveslab.net/wp-content/themes/hoxa/js/pretty/js/jquery.prettyPhoto.js?ver=2.1'></script> <script type='text/javascript' src='https://purveslab.net/wp-content/themes/hoxa/js/jquery.flexslider.js?ver=2.1'></script> <script type="text/javascript" charset="utf-8"> (function(){ try { // Disabling SWFObject's Autohide feature if (typeof swfobject.switchOffAutoHideShow === "function") { swfobject.switchOffAutoHideShow(); } } catch(e) {} })(); </script> <link rel='https://api.w.org/' href='https://purveslab.net/wp-json/' /> <link rel="EditURI" type="application/rsd+xml" title="RSD" href="https://purveslab.net/xmlrpc.php?rsd" /> <link rel="wlwmanifest" type="application/wlwmanifest+xml" href="https://purveslab.net/wp-includes/wlwmanifest.xml" /> <meta name="generator" content="WordPress 5.2.21" /> <link rel="canonical" href="https://purveslab.net/news-2/" /> <link rel='shortlink' href='https://purveslab.net/?p=2' /> <link rel="alternate" type="application/json+oembed" href="https://purveslab.net/wp-json/oembed/1.0/embed?url=https%3A%2F%2Fpurveslab.net%2Fnews-2%2F" /> <link rel="alternate" type="text/xml+oembed" href="https://purveslab.net/wp-json/oembed/1.0/embed?url=https%3A%2F%2Fpurveslab.net%2Fnews-2%2F&format=xml" />  <script src="https://purveslab.net/wp-content/plugins/wp-swfobject/2.0/swfobject.js" type="text/javascript"></script> <script type="text/javascript">var site_uri = "https://purveslab.net";var theme_uri = "https://purveslab.net/wp-content/themes/hoxa";</script><script type="text/javascript" src="https://purveslab.net/wp-content/themes/hoxa/js/script.js"></script> <script type="text/javascript"> // <![CDATA[] var research_areas = [[],[],[],[],[],[],[]]; research_areas[0].push(new demo('Brightness contrast: standard','In viewing this stimulus, people invariably perceive the square on the brighter surround (left) to be darker than the square on the darker surround (right). Click on the "Play" button to convince yourself that the squares are equiluminant or click on the "Move mask" button to manually position the mask over the squares.', 'simultaneous-brightness-contrast/', 'SBC1.swf','null','bcs')); research_areas[0].push(new demo('Brightness contrast: gradient','In this example of simultaneous brightness contrast, the brightness of the circle is perceived to increase as it moves to the darker side (right) of the gradient and to decrease as it moves to the left side. Click on the "Move mask" button to position a mask over the gradient and convince yourself that that the luminance of the circle remains constant.','simultaneous-brightness-contrast/','SBCgr.swf')); research_areas[0].push(new demo('Brightness contrast: cube scene','As can be seen by masking out the context, the gray diamonds on the upper and lower front face of the cubes are identical, but look very different in the unmasked scene. When the information in a scene indicates that, on statistical grounds, two targets are differently reflective surfaces under different illuminants, they look differently bright (or light). (Image from: An empirical explanation of brightness. Williams, SM, McCoy AN, Purves D. Proc. Natl. Acad. Sci. 95: 13301-13306 [1998])','simultaneous-brightness-contrast/','SBC0.swf',null,'bcc')); research_areas[0].push(new demo('Brightness contrast: multiple cues','When diverse statistical information about the sources of a visual stimulus is mutually consistent, two equiluminant surfaces can be made to appear dramatically different than they do in standard presentations. In this case, the empirical information indicates a high probability that the two surfaces are differently reflective materials under different levels of illumination, making the same patch in one part of the scene look very dark gray, and in another part of the scene very light gray. (Image by Beau Lotto)','simultaneous-brightness-contrast/','SBC3.swf',null,'bcx')); research_areas[0].push(new demo('Brightness contrast with color: cube','Just as achromatic patches can be made to look differently bright by empirical information, color patches can be dramatically affected by empirical cues about the amount of illumination they are likely to be under. In this example, the effect is primarily on the color brightness of the relevant tiles rather than on sensations of hue or saturation as such. (Image by Beau Lotto)','brightness/brightness.html','BCC.swf',null,'bccc')); research_areas[0].push(new demo('Craik-O\'Brien-Cornsweet effect','In viewing this scene, people invariably perceive the surface of the top block to be darker than the bottom block. Click on the play button to see that these territories are in fact identical. Covering the center section, including the shaded gradients, shows that the source of the difference is this component of the scene. (Image by Beau Lotto)','craik-obrain-cornsweet-effect/','COC2.swf',null,'coc')); research_areas[0].push(new demo('Mach Bands','(Left) Photograph of a real-world cube manifesting a photometric highlight and lowlight (see luminance profile beneath the photo). (Right) A computer- generated image of a similar object, but lacking the highlight and lowlight. Despite the objective absence of these adornments, brightness maxima and minima (Mach bands) are apparent in the positions of their photometric counterparts in A. (Image from: Mach bands as empirically derived associations. Lotto RB, Williams SM, Purves D., Proc. Natl. Acad. Sci. 96: 5245-5250 [1999])','mach-bands-2/','mach.swf')); research_areas[0].push(new demo('Chubb Illusion (variant)','When the dark and light segments of both the inner and outer disks are not aligned, the gray portions of the inner disk look different (more contrast) than when they are aligned (press the rotate button to shift from the unaligned to aligned configuration to see this effect). The original version of this illusion appears in Chubb, C, Sperling, G and Solomon, JA (1989) Texture interactions determine perceived contrast. PNAS 86:9631-9635.','chubb-illusion/','Chubb.swf')); research_areas[0].push(new demo('Emmert\'s effect','This fascinating demonstration clearly indicates the ambiguity of retinal images. By staring at the first stimulus, a retinal after-image is created that occupies a fixed retinal area. Nonetheless, the form and size of the after-image changes according to the surface on which it is seen, as will be apparent by looking at the after-image on a nearby sheet of white paper or a more distant, light colored wall.',null,'Emmt.swf')); research_areas[0].push(new demo('Test 1: Brightness Contrast: Standard','Directions for taking the test: Using the adjustment buttons below at right, adjust the brightness of the target square on the darker background to match the brightness of the target on the lighter background. The + button increases target brightness, the – button decreases brightness. When the targets appear to be equally bright, click the "DONE" button. A second image will appear. Again, adjust the brightness of the target square on the darker background to match the brightness of the target on the lighter background. After selecting the "DONE" button, a graph of your results and a brief explanation will be displayed.','simultaneous-brightness-contrast/','Brightness1.swf','Explanation of results: In both of the test images, the two target squares appear unequally bright but are in fact identical. The graph (right) illustrates this brightness misperception. The blue bar in the graph indicates the initial grayscale value of both squares. The yellow bar indicates the value of the target on the dark surround after your adjustments. For most people, the degree of misperception is greater for the image indicated by the icon on the right. See the Research section of the website for the biological explanation of this effect.')); research_areas[0].push(new demo('Test 2: Brightness Contrast: Cube Scene','Directions for taking the test: Using the adjustment buttons below at right, adjust the brightness of the target diamond on the darker background (top face of the cube in the foreground) to match the brightness of the target on the lighter background (left face of the cube in the foreground). The + button increases target brightness, the – button decreases brightness. When the targets appear to be equally bright, click the "DONE" button. A second image will appear. Again, adjust the brightness of the target on the darker background (this time the left face of the cube in the foreground) to match the brightness of the target on the lighter background (top face of the cube in the foreground). After selecting the "DONE" button, a graph of your results and a brief explanation will be displayed.','simultaneous-brightness-contrast/','Brightness2.swf','Explanation of results: In both of the test images, the two targets (diamonds) appear unequally bright but are in fact identical. The graph (right) illustrates this brightness misperception. The blue bar in the graph indicates the initial grayscale value of both diamonds. The yellow bar indicates the value of the diamond on the dark surround after your adjustments. For most people, the degree of misperception is greater for the image indicated by the icon on the right in which the dark surround appears to be in shadow, that is when the left face of the cube is darker. See the Research section of the website for the biological explanation of this effect.')); research_areas[0].push(new demo('Test 3: Brightness Contrast: Rotated Cube','Directions for taking the test: Using the adjustment buttons below at right, adjust the brightness of the target diamond on the darker background (top face of the cube) to match the brightness of the target on the lighter background (bottom face). The + button increases target brightness, the – button decreases brightness. When the targets appear to be equally bright, click the "DONE" button. A second image will appear. Again, adjust the brightness of the target (diamond) on the darker background (this time, the bottom face) to match the brightness of the target on the lighter background (top face). After selecting the "DONE" button, a graph of your results and a brief explanation will be displayed.','simultaneous-brightness-contrast/','Brightness3.swf','Explanation of results: In both of the test images, the two targets (diamonds) appear unequally bright but are in fact, identical. The graph (right) illustrates this brightness misperception. The blue bar in the graph indicates the initial grayscale value of both diamonds. The yellow bar indicates the value of the diamond on the dark surround after your adjustments. For most people, the degree of misperception is greater for the image (scene) indicated by the icon on the right in which the dark surround appears to be in shadow, that is when the bottom face of the cube is darker. It should be noted that in this test the two cube images are identical except that the second image is rotated 180 degrees. See the Research section of the website for the biological explanation of this effect.')); research_areas[1].push(new demo('Color contrast: standard','It has been known for more than 150 years that spectrally identical patches can look differently colored when placed in spectrally different surrounds. The two central targets here are identical, as can be seen by masking out the surround.','color-contrast-and-constancy-2/','Color2.swf',null,'ccs')); research_areas[1].push(new demo('Color contrast: multiple cues','Moving the mask makes it apparent that statistical information about probable sources strongly affects color, as well as lightness and/or brightness. Here, two spectrally identical patches (indicated with a dot) appear gray-green when viewed in isolation, but look reddish and bluish, respectively, when viewed in the context of empirical information that makes different surfaces under different chromatic illuminants a highly likely source of the stimulus. (Image by Beau Lotto)','color-contrast-and-constancy-2/','Color1.swf',null,'ccx')); research_areas[1].push(new demo('Color contrast: cube','In this remarkable demonstration, physically identical patches that appear neutral gray when viewed in isolation can be made to look either yellow or blue, depending on the context in which they appear. Although quite unbelievable at first glance, the reality of the demonstration can be confirmed by masking out the context. (Image by Beau Lotto)','color-contrast-and-constancy-2/','Cntrst_cube.swf',null,'ccc')); research_areas[1].push(new demo('Color constancy: cube','In this equally remarkable example, differently colored patches can be made to look more or less the same color (red in this case) by empirical information, which changes the probable spectral sources of the differently colored tiles. These demonstrations show that color contrast and constancy are both manifestations of the same empirically determined visual strategy for seeing color. (Image by Beau Lotto)','color-contrast-and-constancy-2/','Cnstcy_cube.swf',null,'ccc2')); research_areas[1].push(new demo('Chromatic adaptation','The effects of chromatic adaptation can be experienced by focusing on the central white dot in for 20-30 seconds (press the Play button to set timer), and then refocusing on the corresponding dot in the subsequently displayed image. The colors elicited by the two physically identical scenes but seen by components of the visual system "adapted" to red and green, respectively, look appreciably different.','color-contrast-and-constancy-2/','Chromat.swf')); research_areas[2].push(new demo('Perception of angles','A wide range of empirical factors influences the perception of angles. In this scene, the subtenses of the four angular objects in the retinal stimulus are identical, each measuring approximately 90°. As a result of this variety of depicted cues about the attributes of the possible real-world sources (see text), the subtenses of the four identical angles look quite different. Press the "Play" button to convince yourself. (Image by Beau Lotto)','angles-4/','angles.swf',null,'line')); research_areas[2].push(new demo('Poggendorff','Drag the red line on the right until it appears continuous (colinear) with the red line on the left. When you are done, click the highlighted button below the image to remove the mask.',null,'pg.swf',null,'line')); research_areas[2].push(new demo('Line length','Which line is longer? Use the plus or minus buttons to adjust the length of the horizontal (bottom) line until it appears to match the length of the vertical (top) line. Click the done button to see how your adjusted line compares to the actual line length.',null,'ll.swf',null,'line')); research_areas[2].push(new demo('Müller-Lyer','Drag the red arrowhead until the line between the arrowheads appears to be the same length as the line between the inverted arrowheads above. When you are done, click the highlighted button below the image to see how your adjusted line compares to the actual line length.',null,'ml.swf',null,'line')); // no depth demos research_areas[4].push(new demo('Objective and perceived motion','This demonstration indicates the profound ambiguity of the image sequences that generate perceptions of motion. The stimulus is always a line translating from left to right. The apparent direction and speed of the line, however, are markedly changed by the context, as can be seen by clicking on the appropriate buttons. (Images after: A wholly empirical explanation of perceived motion. Yang, Z, Shimpi, A., Purves, D., Proc. Natl. Acad. Sci. 9:5252-5257 [2001])','objective-and-perceived-motion-2/','Motion2.swf')); research_areas[4].push(new demo('Motion perception from simple sequential stimuli','When two or more stimuli are presented in temporal succession and at different spatial locations, the perception of motion can be elicited. In this example, two frames are alternated at a constant interval (~100 ms): the first frame contains diagonally opposed stimuli in the upper left and lower right locations of an imaginary rectangle; the second frame contains diagonally opposed stimuli in the upper right and lower left locations of the same imaginary rectangle. As the spatial separation between stimuli increases along the vertical axis, the perception of motion between horizontal and vertical sequential stimuli changes. This change suggest that the visual system generates motion percepts on an empirical basis, according to the stimulus patterns that sources have most often projected on the retinal image plane.',null,'4point.swf',null,null)); // no geo forms demos research_areas[6].push(new demo('Tonal preferences','This demonstration provides an opportunity to evaluate the pleasantness of different tone combinations. Each slider represents one of 13 musical intervals (an interval is defined by two tones played together). You can listen to each interval by clicking on the button below it. Use the sliders above each icon to rank the intervals in terms of how pleasant each one sounds. For example, decide which interval sounds best and move its slider up to the #1 position. Then choose the next best sounding interval and move its slider to the #2 position. Continue playing the sounds and adjusting the sliders until you have ranked all the intervals and are satisfied with the preference order you have produced (preview by pressing "Play by Ranking"). When you are finished, press the "Done" button to see how your ranking compares to the median preference order derived from studies in the literature.','sound-2/','sound_consonance.swf','Although individuals differ in their preference orders, listeners generally agree about which intervals sound pleasing and which do not. Your choices are indicated by the yellow line; the blue line indicates the median preference order derived from studies in the literature (from Malmberg, 1918). The fact that listeners hear musical intervals in more or less the same way suggests that the perception of musical tones is based on some fundamental aspect of human hearing. We have proposed that tone perception is determined by experience with the natural sources of tonal stimuli for human listeners, namely speech.')); research_areas[6].push(new demo('Missing fundamental','In this segment you will be able to vary the number of harmonics in a complex tone. The point is to demonstrate the surprising fact that the pitch one hears always corresponds to the fundamental frequency of the harmonic series even when there is no energy at that frequency. This phenomenon is referred to as "hearing the missing fundamental", the fundamental being mathematically defined as the common divisor of a harmonics series. The harmonics are integer multiples of the fundamental frequency, and arise from the physics of naturally vibrating objects such as a guitar string (or the vocal cords in the human larynx). You can elicit the effect by subtracting the fundamental, leaving only the overtones. When the fundamental is missing the pitch remains that of the fundamental, even though the overall sound has a different quality (called "timbre").','sound-2/','sound_fundamental.swf','[explanation for missing fundamental]')); var active_demo = null; function demo(name, desc, link, swf, expl, dl) { this.title = name; this.description = desc; this.link = link; this.swf = swf; this.explanation = expl; this.download = dl; } function do_demo(j, k) // research area, demo # { if(active_demo == research_areas[j][k]) return; active_demo = research_areas[j][k]; document.getElementById('demo_title').innerHTML = active_demo.title; do_setText('description'); window.frames.player.location = '/player.html?' + active_demo.swf; } function do_setText(fld) { var o = active_demo; var desc = document.getElementById('demo_desc'); if(fld == 'description') { var s = o.description; if(o.link != null) { s += '<div style="padding-top: 6px;"><a href="https://purveslab.net/' + o.link + '">» Read the empirical explanation<' + '/a><' + '/div>'; } if(o.download) { s += '<div style="padding-top: 6px;"><a href="https://purveslab.net/downloads-2#' + o.download + '">» Download high resolution images<' + '/a><' + '/div>'; } desc.innerHTML = s; } else { var s = o.explanation; if(o.link != null) { s += '<div style="padding-top: 6px;" class="explain"><a href="https://purveslab.net/' + o.link + '">» Read the empirical explanation<' + '/a><' + '/div>'; } if(o.download) { s += '<div style="padding-top: 6px; "><a href="https://purveslab.net/downloads-2#' + o.download + '">» Download high resolution images<' + '/a><' + '/div>'; } desc.innerHTML = s; } } function init_custom() { if(window.location.search.length > 1) { var n = parseFloat(window.location.search.slice(1)); if(!isNaN(n) && n < 7 && n >= 0) { do_demo(Math.floor(n), Math.round((n - Math.floor(n)) * 100)); return; } } do_demo(0,0); } // ]]> </script> <style type="text/css"> .demo { float: none; width: 48px; height: 48px; border: 1px solid #999999; padding: 1px; margin-right: 5px; margin-top: 5px; } .ccc { border-bottom-width: 0px; margin-bottom: 15px; padding-bottom: 0px; } </style><style type="text/css">.sysdevn0{min-height:110px;width:100% !important;margin-left:0% !important;}.sysdevn1{min-height:380px;width:100% !important;margin-left:0% !important;}.sysdevn2{min-height:380px;width:100% !important;margin-left:0% !important;}.blkheaderdevn0{min-height:100px;width:100% !important;margin-left:0% !important;}.blkheaderdevn1{min-height:70px;width:100% !important;margin-left:0% !important;}.blkfooterdevn0{min-height:70px;width:100% !important;margin-left:0% !important;}</style> <style type="text/css" id="wp-custom-css"> .home #execphp-_x_system-9687063 .one_fourth { width: 18%; } .effHidden {visibility:visible !important;} </style> <link rel="stylesheet" type="text/css" href="https://purveslab.net/wp-content/uploads/lazyest-stylesheet.css" /> </head> <body class="page-template-default page page-id-2 page-parent"> <div id="main" class="layout-wide news-2"> <div id="container-group-header" class="container-fluid container-set container-group-header"><div class="devn-group container-group__header " id="trueHeader"> <div id="container-group-header_x_system-1415612528" class="container-group container-group-header_x_system-1415612528 top_nav animated fadeIn logoarea"> <div class="rowlevelone row-fluid row wrpestdevn rowFullWidth limit-width container row-devn-system-row"> <div class="spanlevelone col-md-12"> <div class="widgetdevn sidebardevn blkheaderdevn0" id="sidebar-group-header_x_system-1415612528"> <aside id="execphp-_x_system-1416726459" class="widget widget_execphp"> <div class="execphpwidget"><div class="logo animated flipInX"> <a href="https://purveslab.net" id="logo"> <img src=" https://purveslab.net/wp-content/uploads/purveslab_white-300x60.png" /> </a> </div> </div> </aside> </div> </div> </div> </div> <div id="container-group-header_x_system-1416736354" class="container-group container-group-header_x_system-1416736354"> <div class="rowlevelone row-fluid row wrpestdevn rowFullWidth limit-width container row-devn-system-row"> <div class="spanlevelone col-md-12"> <div class="widgetdevn menu_main animated fadeIn blkheaderdevn1" id="sidebar-group-header_x_system-1416736354"> <aside id="execphp-_x_system-1416736370" class="widget widget_execphp"> <div class="execphpwidget"><div class="navbar yamm navbar-default"> <div class="container"> <div id="navbar-collapse-1" class="navbar-collapse collapse"> <div class="menu-main-menu-container"><ul id="devn-mainmenu" class="nav navbar-nav"><li id="menu-item-1538" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-home dropdown menu-item-1538"><a href="https://purveslab.net/">Home</a></li> <li id="menu-item-1409" class="menu-item menu-item-type-post_type menu-item-object-page current-menu-item page_item page-item-2 current_page_item menu-item-has-children dropdown menu-item-1409"><a href="https://purveslab.net/news-2/">News</a> <ul class="dropdown-menu three"> <li id="menu-item-2326" class="menu-item menu-item-type-post_type menu-item-object-page dropdown menu-item-2326"><a href="https://purveslab.net/forthcoming-articles/">Forthcoming Articles</a></li> <li id="menu-item-2390" class="menu-item menu-item-type-custom menu-item-object-custom dropdown menu-item-2390"><a href="https://purveslab.net/news-2/recently-published/">Recently Published</a></li> <li id="menu-item-2325" class="menu-item menu-item-type-post_type menu-item-object-page dropdown menu-item-2325"><a href="https://purveslab.net/recent-talks/">Recent Talks</a></li> <li id="menu-item-2324" class="menu-item menu-item-type-post_type menu-item-object-page dropdown menu-item-2324"><a href="https://purveslab.net/interviews/">Interviews</a></li> <li id="menu-item-2323" class="menu-item menu-item-type-post_type menu-item-object-page dropdown menu-item-2323"><a href="https://purveslab.net/courses/">Courses</a></li> <li id="menu-item-2322" class="menu-item menu-item-type-post_type menu-item-object-page dropdown menu-item-2322"><a href="https://purveslab.net/recent-books/">Recent Books</a></li> </ul> </li> <li id="menu-item-2228" class="menu-item menu-item-type-post_type menu-item-object-page dropdown menu-item-2228"><a href="https://purveslab.net/people-2/">People</a></li> <li id="menu-item-1776" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-has-children dropdown menu-item-1776"><a href="https://purveslab.net/theory-2/">RESEARCH</a> <ul class="dropdown-menu three"> <li id="menu-item-1778" class="menu-item menu-item-type-post_type menu-item-object-page dropdown menu-item-1778"><a href="https://purveslab.net/theory-2/">THEORY</a></li> <li id="menu-item-1792" class="menu-item menu-item-type-post_type menu-item-object-page dropdown menu-item-1792"><a href="https://purveslab.net/lightnessbrightness-2/">LIGHTNESS/BRIGHTNESS</a></li> <li id="menu-item-1858" class="menu-item menu-item-type-post_type menu-item-object-page dropdown menu-item-1858"><a href="https://purveslab.net/color-2/">COLOR</a></li> <li id="menu-item-1896" class="menu-item menu-item-type-post_type menu-item-object-page dropdown menu-item-1896"><a href="https://purveslab.net/motion-4/">MOTION</a></li> <li id="menu-item-1985" class="menu-item menu-item-type-post_type menu-item-object-page dropdown menu-item-1985"><a href="https://purveslab.net/geometry-and-space/">GEOMETRY AND SPACE</a></li> <li id="menu-item-1984" class="menu-item menu-item-type-post_type menu-item-object-page dropdown menu-item-1984"><a href="https://purveslab.net/sound-and-music-2/">SOUND AND MUSIC</a></li> </ul> </li> <li id="menu-item-1463" class="menu-item menu-item-type-post_type menu-item-object-page dropdown menu-item-1463"><a href="https://purveslab.net/publications-3/">PUBLICATIONS</a></li> <li id="menu-item-1410" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-has-children dropdown menu-item-1410"><a href="https://purveslab.net/resources-2/">RESOURCES</a> <ul class="dropdown-menu three"> <li id="menu-item-1724" class="menu-item menu-item-type-post_type menu-item-object-page dropdown menu-item-1724"><a href="https://purveslab.net/downloads-2/">DOWNLOADS</a></li> </ul> </li> <li id="menu-item-1841" class="menu-item menu-item-type-post_type menu-item-object-page dropdown menu-item-1841"><a href="https://purveslab.net/see-for-yourself/">See For Yourself</a></li> <li id="menu-item-1505" class="menu-item menu-item-type-post_type menu-item-object-page dropdown menu-item-1505"><a href="https://purveslab.net/contact-2/">Contact</a></li> </ul></div><div id="wrap"> <form action=" https://purveslab.net" autocomplete="on"> <input id="search" name="s" type="text" placeholder=""> <input id="search_submit" value="Search" type="submit"> </form> </div> </div> </div> </div> </div> </aside> </div> </div> </div> </div> </div> </div> <div id="container-page-2_x_system-9161296" class="container-fluid container-set container-page-2_x_system-9161296 breadcrumbs page_title2"> <div class="rowlevelone row-fluid row wrpestdevn rowFullWidth limit-width container row-devn-system-row"> <div class="spanlevelone col-md-12"> <div class="widgetdevn sidebardevn sysdevn0" id="sidebar-page-2_x_system-9161296"> <aside id="execphp-_x_system-1429823423" class="widget widget_execphp"> <div class="execphpwidget"><H1> NEWS </H1></div> </aside> </div> </div> </div> </div> <div id="container-page-2_x_system-7584781" class="container-fluid container-set container-page-2_x_system-7584781"> <div class="rowlevelone row-fluid row wrpestdevn rowFullWidth limit-width container row-devn-system-row"> <div class="spanlevelone col-md-2"> <div class="widgetdevn sidebardevn sysdevn1" id="sidebar-page-2_x_system-7584781"> <aside id="nav_menu-_x_system-3359032" class="widget widget_nav_menu"><h3 class="widget-title">News</h3><div class="menu-news-sidebar-container"><ul id="menu-news-sidebar" class="menu"><li id="menu-item-2389" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-2389"><a href="https://purveslab.net/news-2/recently-published/">Recently Published</a></li> <li id="menu-item-1666" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-1666"><a href="https://purveslab.net/recent-talks">Recent Talks</a></li> <li id="menu-item-1667" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-1667"><a href="https://purveslab.net/interviews">Interviews</a></li> <li id="menu-item-2161" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-2161"><a href="https://purveslab.net/courses">Courses</a></li> <li id="menu-item-1665" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-1665"><a href="https://purveslab.net/recent-books">Recent Books</a></li> </ul></div></aside> </div> </div> <div class="spanlevelone col-md-10"> <div class="widgetdevn content sidebardevn sysdevn2" id="sidebar-content"> <aside id="contents-3" class="widget widget_contents-component"> <article id="post-2" class="post-2 page type-page status-publish hentry"> <div class="entry-content blog_postcontent"> <p></p> <p><a name="published"></a></p> <h2>Recently Published</h2> <h3>What does AI’s success playing complex board games tell brain scientists?</h3> <div class="page" title="Page 1"> <div class="layoutArea"> <div class="column"> <p><b>Author</b>: Dale Purves <sup>a,1</sup></p> <p><b>Affiliations:</b></p> </div> </div> </div> <div class="page" title="Page 1"> <div class="layoutArea"> <div class="column"> <div class="page" title="Page 1"> <div class="layoutArea"> <div class="column"> <p>Duke Institute for Brain Sciences, Duke University, Durham, NC 27708<br /> <a title="Read full article" href="https://purveslab.net/wp-content/uploads/Purves-Go.pdf" target="_blank">Read full article</a> </div> </div> </div> </div> </div> </div> <hr /> <h3>The Demands of Geometry on Color Vision</h3> <div class="page" title="Page 1"> <div class="layoutArea"> <div class="column"> <p><b>Authors</b>: Dale Purves <sup>1,2,3,</sup>* and Chidambaram Yegappan<sup>1</sup></p> <p><b>Affiliations</b>:</p> </div> </div> </div> <div class="page" title="Page 1"> <div class="layoutArea"> <div class="column"> <div class="page" title="Page 1"> <div class="layoutArea"> <div class="column"> <p>Neuroscience and Behavioral Disorders Program, Duke-NUS Graduate Medical School Singapore, 8 College Road, Singapore 169857, Singapore; chidam.yegappan@gmail.com<br /> Department of Neurobiology, Duke University Medical Center, Durham, NC 27708, USA<br /> Duke Institute for Brain Sciences, Duke University, Durham, NC 27708, USA<br /> <a title="Read full article" href="https://purveslab.net/wp-content/uploads/vision-01-00009.pdf" target="_blank">Read full article</a></p> </div> </div> </div> </div> </div> </div> <div class="page" title="Page 1"> <div class="layoutArea"> <div class="column"> <p><strong>Abstract:</strong><br /> While studies of human color vision have made enormous strides, an overarching rationale for the circular sense of color relationships generated by two classes of color opponent neurons and three cone types is still lacking. Here we suggest that color circularity, color opponency and trichromacy may have arisen, at least in part, because of the geometrical requirements needed to unambiguously distinguish all possible spectrally different regions on a plane.</p> </div> </div> </div> <hr /> <h3 class="p1"><span class="s1">A new book by Purves, “Music as Biology,” was published by Harvard University Press in February 2017</span></h3> <p class="p1"><a href="https://purveslab.net/wp-content/uploads/Purves.pdf" target="_blank">Read the flier for a full description</a><br /> <a href="https://today.duke.edu/2017/04/new-reads-spring-duke-authors">Read more about the book at Duke Today.</a><br /> <strong>(Harvard University Press, Feb 2017)</strong></p> <p><iframe width="560" height="315" src="https://www.youtube.com/embed/Nnh-RDFqUHk?rel=0&showinfo=0" frameborder="0" allowfullscreen></iframe></p> <p><a name="article1"></a></p> <hr /> <h3>Perception and Reality: Why a Wholly Empirical Paradigm is Needed to Understand Vision</h3> <p class=""><b>Authors</b>: Dale Purves<sup>1</sup>, Yaniv Morgenstern<sup>2</sup> and William T. Wojtach<sup>1,2</sup><br /> <b>Affiliations</b>: <sup>1</sup>Duke Institute for Brain Sciences, Duke University, Durham, NC, USA<br /> <sup>2</sup>Duke-NUS Graduate Medical School, Singapore, Singapore<br /> <a title="Read full article" href="http://journal.frontiersin.org/article/10.3389/fnsys.2015.00156/full?utm_source=Email_to_authors_&utm_medium=Email&utm_content=T1_11.5e1_author&utm_campaign=Email_publication&field=&journalName=Frontiers_in_Systems_Neuroscience&id=163471" target="_blank">Read full article</a></p> <p><b>Abstract:</b><br /> A central puzzle in vision science is how perceptions that are routinely at odds with physical measurements of real world properties can arise from neural responses that nonetheless lead to effective behaviors. Here we argue that the solution depends on: (1) rejecting the assumption that the goal of vision is to recover, however imperfectly, properties of the world; and (2) replacing it with a paradigm in which perceptions reflect biological utility based on past experience rather than objective features of the environment. Present evidence is consistent with the conclusion that conceiving vision in wholly empirical terms provides a plausible way to understand what we see and why.</p> <hr /> <h3>A Biological Rationale for Musical Consonance</h3> <div> <p class=""><b>Authors</b>: Daniel L. Bowling<sup>1</sup> and Dale Purves<sup>2</sup><br /> <b>Affiliations</b>: <sup>1</sup>Department of Cognitive Biology, University of Vienna<br /> <sup>2</sup>Duke Institute for Brain Science, Duke University; Corresponding authors</p> </div> <div> <p><b>Abstract:</b><br /> The basis of musical consonance has been debated for centuries without resolution. Three interpretations have been considered: 1) that consonance derives from the mathematical simplicity of small integer ratios; 2) that consonance derives from the physical absence of interference between harmonic spectra; and 3) that consonance derives from the advantages of recognizing biological vocalization, human vocalization in particular. Whereas the mathematical and physical explanations are at odds with the evidence that has now accumulated, biology provides a plausible explanation for this central issue in music and audition.</p> </div> <hr /> <h3 style="padding-top: 20px;">Does Understanding Vision Require a New Paradigm?</h3> <div> <p class=""><b>Authors</b>: Dale Purves<sup>1</sup>, Yaniv Morgenstern<sup>2</sup> and William T. Wojtach<sup>3</sup><br /> <b>Affiliations</b>: <sup>1</sup>Duke Institute for Brain Sciences, Duke University, Durham, North Carolina<br /> <sup>2</sup>Neuroscience and Behavioral Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore, Singapore<br /> <sup>3</sup>Department of Neurobiology, Duke University, Durham, North Carolina</p> </div> <div> <p><b>Abstract:</b><br /> Based on electrophysiological and anatomical studies, a prevalent conception is that the visual system recovers features of the world from retinal images as a basis for action. This paradigm, however, is unable to explain why visual perceptions differ from physical measurements, or how behavior could routinely succeed on this basis. An alternative framework supported by present evidence is that vision does not recover features of the world, but assigns perceptual qualities by associating stimuli patterns with perceptual and other behavioral responses that have been rewarded by reproductive success.</p> </div> <div class="clearfix divider_dashed2"></div> <h2>Recent Talks</h2> <p><a title="UCM/UCSD Purves Talk" href="https://www.youtube.com/watch?v=D9NzWP-CqKs" target="_blank"><img class="alignleft size-full wp-image-9" style="margin-top: 15px;" src="https://50.28.85.69/%7Epurves/wp-content/uploads/cogsci.ucmerced.png" alt="cogsci.ucmerced" width="170" height="" /></a></p> <p class=""><b>Date</b>: May 2014<br /> <b>Location</b>: UCM/UCSD Summer School<br /> <b>Topic</b>: Language, Music and Cognition<br /> <b>Link</b>: <a title="UCM/UCSD Purves Talk" href="https://www.youtube.com/watch?v=D9NzWP-CqKs" target="_blank">Video of May 2014 UCM/UCSD Purves talk</a></p> <p> </p> <p><img class="alignleft size-full wp-image-8" style="margin-top: 40px;" src="https://purveslab.net/wp-content/uploads/redwood.png" alt="redwood" width="170" height="" /></p> <p class=""><b class="">Speaker</b>: Dale Purves<br /> <b>Location</b>: Duke University<br /> <b>Audience</b>: Redwood Center for Theoretical Neuroscience at UC Berkeley<br /> <b>Link</b>: <a title="March 2013 Purves Redwood Talk" href="http://archive.org/details/Redwood_Center_2013_03_27_Dale_Purves" target="_blank">Video of March 2013 Purves Redwood (UC Berkeley) talk</a><a name="6"></a><br /> <b>Summary</b>: Information about the physical world is excluded from visual stimuli by the nature of biological vision (the inverse optics problem). Nonetheless, humans and other visual animals routinely succeed in their environments. The talk explains how the assignment of perceptual values to visual stimuli according to the frequency of occurrence of stimulus patterns resolves the inverse problem and determines the basic visual qualities we see. This interpretation of vision implies that the best (and perhaps the only) way to understand visual system circuitry is to evolve it, an idea supported by recent work.</p> <p> </p> <p><a title="Arthur M. Sackler Talk" href="https://www.youtube.com/watch?v=QORWM3Pl760&feature=youtu.be" target="_blank"><img class="alignleft size-full wp-image-2138" style="width: 170px;" src="https://purveslab.net/wp-content/uploads/arthur.png" alt="arthur" /></a></p> <p class=""><b>Date</b>: Jan 2014<br /> <b>Location</b>: Beckman Center in Irvine, CA<br /> <b>Topic</b>:Light of Evolution VIII: Darwinian Thinking in the Social Sciences<br /> <b>Link</b>: <a title="Arthur M. Sackler Talk" href="https://www.youtube.com/watch?v=QORWM3Pl760&feature=youtu.be" target="_blank">Video of Jan 2014 Arthur M. Sackler Talk</a></p> <p><a href="https://purveslab.net/wp-content/uploads/JHM_2C_P_V.jpg"><img class="alignleft size-medium wp-image-2149" style="width: 170px;" src="https://purveslab.net/wp-content/uploads/JHM_2C_P_V-300x245.jpg" alt="JHM_2C_P_V" srcset="https://purveslab.net/wp-content/uploads/JHM_2C_P_V-300x245.jpg 300w, https://purveslab.net/wp-content/uploads/JHM_2C_P_V-750x613.jpg 750w, https://purveslab.net/wp-content/uploads/JHM_2C_P_V.jpg 941w" sizes="(max-width: 300px) 100vw, 300px" /></a></p> <p class=""><b>Date</b>: Dec 2013<br /> <b>Location</b>: John Hopkins<br /> <b>Topic</b>: Current Topics in Neuroscience<br /> <b>Link</b>: <a title="John Hopkins Talk" href="http://webcast.jhu.edu/Mediasite/Play/580c9e3e3c0343b991e34a7fce3907321d" target="_blank">Video of Dec 2013 John Hopkins Talk</a></p> <div class="clear"></div> <div class="clearfix divider_dashed2"></div> <h2>Interviews</h2> <p><a href="https://www.youtube.com/watch?v=SYHX8MikUWQ"><img class="alignleft size-medium wp-image-2353" src="https://purveslab.net/wp-content/uploads/dukenus_vert-300x300.jpg" alt="dukenus_vert" width="170" srcset="https://purveslab.net/wp-content/uploads/dukenus_vert-300x300.jpg 300w, https://purveslab.net/wp-content/uploads/dukenus_vert-150x150.jpg 150w, https://purveslab.net/wp-content/uploads/dukenus_vert.jpg 500w" sizes="(max-width: 300px) 100vw, 300px" /></a></p> <p class="" style="margin-top: 50px;"><b>Date</b>: May 2015<br /> <b>Location</b>: Duke University<br /> <b>Topic</b>: Duke-NUS Dean’s Conversations – with Prof Dale Purves<br /> <b>Link</b>: <a title="Duke Nus" href="https://www.youtube.com/watch?v=SYHX8MikUWQ" target="_blank">Video of May 2015 Duke-NUS Interview</a></p> <div class="clear"></div> <p><a title="Neuro TV Talk" href="https://www.youtube.com/watch?t=1865&v=fAtdg5xR62E" target="_blank"><img class="alignleft size-medium wp-image-2145" style="width: 170px;" src="https://purveslab.net/wp-content/uploads/LOGOneurotv2-300x117.png" alt="LOGOneurotv2" srcset="https://purveslab.net/wp-content/uploads/LOGOneurotv2-300x117.png 300w, https://purveslab.net/wp-content/uploads/LOGOneurotv2-1024x399.png 1024w, https://purveslab.net/wp-content/uploads/LOGOneurotv2-750x293.png 750w, https://purveslab.net/wp-content/uploads/LOGOneurotv2.png 1528w" sizes="(max-width: 300px) 100vw, 300px" /></a></p> <p class=""><b>Date</b>: Apr 2014<br /> <b>Location</b>: Duke University<br /> <b>Topic</b>: The Function and Evolution of the Visual System<br /> <b>Link</b>: <a title="Neuro TV Talk" href="https://www.youtube.com/watch?t=1865&v=fAtdg5xR62E" target="_blank">Video of Apr 2014 Neuro TV Talk</a></p> <div class="clear"></div> <p><a title="Neuro TV Talk" href="https://www.youtube.com/watch?v=vGvS6MVetF8" target="_blank"><img class="alignleft size-medium wp-image-2145" style="width: 170px;" src="https://purveslab.net/wp-content/uploads/twit.png" alt="TWiT" /></a></p> <p class=""><b>Date</b>: Jun 2010<br /> <b>Host:</b> Dr. Kirsten Sanford<br /> <b>Topic</b>: Dr. Kiki’s Science Hour 51: What’s In A Brain?<br /> <b>Link</b>: <a title="Neuro TV Talk" href="https://www.youtube.com/watch?v=vGvS6MVetF8" target="_blank">Dr. Kiki’s Science Hour 51</a></p> <p> </p> <p class=""><a href="http://www.pbs.org/newshour/bb/science-july-dec02-sight_12-25/"><img class="alignleft size-medium wp-image-2145" style="margin-top: 30px; width: 170px;" src="https://purveslab.net/wp-content/uploads/pbs.jpg" alt="" /></a><br /> <b>Date</b>: Dec 2002<br /> <b>Host</b>: Tom Bearden<br /> <b>Topic</b>: How We See<br /> <b>Summary</b>: Appearance on News Hour with Jim Lehrer “An account of some of the work considered on this site was featured on the PBS News Hour with Jim Lehrer on December 25, 2002. A transcript and other information is available on the <a href="http://www.pbs.org/newshour/bb/science-july-dec02-sight_12-25/" target="_blank">PBS website</a>. The broadcast can be viewed in its entirety by clicking the image to the left.”<br /> <b>Link</b>: <a href="http://www.pbs.org/newshour/bb/science-july-dec02-sight_12-25/">PBS Website</a></p> <p><a name="course"></a></p> <div class="clear"></div> <div class="clearfix divider_dashed2"></div> <h2>Courses</h2> <p class=""><img class="alignleft" src="https://purveslab.net/wp-content/uploads/coursera.png" alt="" width="150" /></p> <p class=""><b>Name of Course</b>: Music As Biology<br /> <b>Course Summary</b>: Auditory perception, like visual perception, appears to be determined by the need to contend with sensory signals—sound signals in this case—that are inherently unable to specify their physical sources, the very information we need to behave appropriately. This quandary has led to an unusual strategy that promises to provide some insight into the operating principles of the brain. The course will explore these issues with the aim of discussing new ideas about music and audition that speak broadly to aesthetics.</p> <div class="clear"></div> <p> </p> <p class=""><img class="alignleft" src="https://purveslab.net/wp-content/uploads/coursera.png" alt="" width="150" /></p> <p class=""><b>Name of Course</b>: Visual Perception and the Brain<br /> <b>Course Summary</b>: The course considers how what we see is generated by the visual system, and what visual perception indicates about how the brain works. The evidence is drawn from neuroscience, psychology, science history and philosophy. Although the discussions is informed by visual system anatomy and physiology, the focus is on perception.<br /> <b>Link</b>: <a title="Coursera" href="https://www.coursera.org/course/visualpercepbrain" target="_blank">Coursera</a></p> <p> </p> <div class="clear"></div> <div class="clearfix divider_dashed2"></div> <h2>Recent Books</h2> <div class="clear"></div> <p><a name="5"></a></p> <h3 class="top-margin">Purves, Brains as Engines of Association: An Operating Principle for Nervous Systems<br /></h3> <h3 class="top-margin"><img src="https://purveslab.net/wp-content/uploads/comp_BrainWalnutWingnutEngine_BrainsAsEnginesAssociation_Purves-197x300.jpg" style="float: left;" alt="Brains as Engines of Association: An Operating Principle for Nervous Systems" width="197" height="300" class="alignleft size-medium wp-image-2561" srcset="https://purveslab.net/wp-content/uploads/comp_BrainWalnutWingnutEngine_BrainsAsEnginesAssociation_Purves-197x300.jpg 197w, https://purveslab.net/wp-content/uploads/comp_BrainWalnutWingnutEngine_BrainsAsEnginesAssociation_Purves-768x1167.jpg 768w, https://purveslab.net/wp-content/uploads/comp_BrainWalnutWingnutEngine_BrainsAsEnginesAssociation_Purves-674x1024.jpg 674w, https://purveslab.net/wp-content/uploads/comp_BrainWalnutWingnutEngine_BrainsAsEnginesAssociation_Purves-657x999.jpg 657w" sizes="(max-width: 197px) 100vw, 197px" /></h3> <p><br style="font-family: "Open Sans", sans-serif; font-size: 14px;"><b class="" style="font-size: 14px; background-color: rgba(0, 0, 0, 0.01); font-family: "Open Sans", sans-serif;">Author</b><span style="font-size: 14px; background-color: rgba(0, 0, 0, 0.01); font-family: "Open Sans", sans-serif;">: Dale Purves</span><br style="font-family: "Open Sans", sans-serif; font-size: 14px;"><b class="" style="font-size: 14px; background-color: rgba(0, 0, 0, 0.01); font-family: "Open Sans", sans-serif;">Summary</b><span class="" style="font-size: 14px; background-color: rgba(0, 0, 0, 0.01); font-family: "Open Sans", sans-serif;">: This book concerns a fundamental question in neuroscience: what is the operating principle of human brain? While a similar question has been asked and answered for virtually every other human organ during the last few centuries, how the brain operates has remained a central challenge in biology. Based on evidence derived from vision, audition, speech and music—much of it based on the author’s own work over the last twenty years—the gist of the argument is that brains operate wholly on the basis of trial and error experience, encoded in neural circuitry over evolutionary and individual time. This concept of neural function runs counter to current concepts of the brain as a computing machine, and research programs based on the idea that the only way to answer such questions is reconstructing the connectivity of brains in their entirety. The implication of the book’s argument is that the best way to understand the details of brain function is to recapitulate their history using artificial neural networks. This viewpoint has received support in the last few years from work showing that computers win complex games (though not as complex as the “game” of biological survival) entirely on the basis of past experience.</span><br style="font-family: "Open Sans", sans-serif; font-size: 14px;"><strong class="" style="font-size: 14px; background-color: rgba(0, 0, 0, 0.01); font-family: "Open Sans", sans-serif;">(Oxford University Press)</strong></p> <div class=""></div> <hr> <h3 class="top-margin">Music as Biology</h3> <p class=""><a href="https://purveslab.net/wp-content/uploads/Purves_comp_11.png"><img class="alignleft size-medium wp-image-2416" style="margin-right: 5px;" src="https://purveslab.net/wp-content/uploads/Purves_comp_11-197x300.png" alt="Purves_comp_11" width="150" srcset="https://purveslab.net/wp-content/uploads/Purves_comp_11-197x300.png 197w, https://purveslab.net/wp-content/uploads/Purves_comp_11.png 600w" sizes="(max-width: 197px) 100vw, 197px" /></a><br /> <b>Author</b>: Dale Purves<br /> <b>Summary</b>: The universality of musical tones has long fascinated philosophers, scientists, musicians and ordinary listeners. Why do human beings worldwide find some tone combinations consonant and others dissonant? Why do we make music using only a small number of scales out the billions that are possible? Why do differently organized scales elicit different emotions? Why are there so few notes in scales? Music as Biology argues that biology offers answers to these and other questions on which conventional music theory is silent.</p> <p><strong>(Harvard University Press, Fall 2016)</strong></p> <div class="clear"></div> <p><a name="4"></a></p> <h3 class="top-margin">Why We See What We Do Redux</h3> <p class=""><img class="alignleft size-full wp-image-166" style="margin-right: 5px;" src="https://purveslab.net/wp-content/uploads/why-we-see.jpg" alt="why-we-see" width="150" height="195" /><br /> <b>Author</b>: Dale Purves & R. Beau Lotto<br /> <b>Summary</b>: “Although the ideas and evidence about the genesis of what we see in the First Edition were appreciated in some quarters, the reception in others was distinctly cool. Given the opinion of some critics that the wholly empirical concept of vision we proposed was either unbelievable or incomprehensible, we felt duty bound to try again. Our objective was, and remains, to present a different and seemingly inevitable framework for understanding perception and its underlying neural mechanisms.…We hope this new edition will encourage more readers to consider this concept of vision and its implications for interpreting, modeling, and ultimately understanding the structure and function of the human visual system.”</p> <p><a href="https://purveslab.net/wp-content/uploads/purves_lotto_flyer2010.pdf">Download Flyer for New Edition (pdf)</a></p> <div class="clear"></div> <p><a name="3"></a></p> <h3 class="top-margin">Brains</h3> <p class=""><img class="alignleft size-full wp-image-18" src="https://purveslab.net/wp-content/uploads/Brains.jpg" alt="Brains" width="138" height="189" /><br /> <b>Author</b>: Dale Purves<br /> <b>Title</b>: Brains: How They Seem to Work<br /> <b>Publisher</b>: Pearson/Financial Times Press, 2010<br /> Available at <a href="http://www.amazon.com/Brains-How-They-Seem-Work/dp/0137055099/ref=sr_1_1?s=books&ie=UTF8&qid=1279046257&sr=1-1" target="_blank">Amazon!</a></p> <div class="clear"></div> <h4 class=""><strong class="">Comments<br /> </strong></h4> <p class="">“Dale Purves’ Brains is my favorite sort of reading—an engaging and intelligent scientific autobiography full of vivid personal and historical accounts; the story not only of a life but of an intellectual pursuit. Purves has a unique voice, lively, outspoken, and very human—and his love of science comes through on every page.”<b class=""><br /> –Oliver Sacks</b></p> <p class="">“The ‘Brains’ in Dale Purves’ book are both the focus of his research and the intellectual giants with whom he mixed in his remarkable career. At one level Brains is a charming autobiography; at another a vivid personal account of 50 years in the evolution of neuroscience. But it also lays down a challenge to the mainstream view that simple, sequential analysis of nerve cells and their responses can explain the apparently impossible task of seeing the world as it really is on the basis of the infinitely ambiguous retinal image. Brains is a delight—for its insights into both the scientists and the science of the brain.”<b class=""><br /> –Colin Blakemore, Oxford University<br /> </b></p> <p class="">“Dale Purves has been a leading figure in brain science for 40 years: He has made numerous discoveries, founded departments, and written major textbooks. In Brains, he tells the story of his scientific journey and intertwines it in an elegant and accessible way with two others: the uneven progress of the field over the past half century and the new view of brain function to which the field’s shortcomings have led him. Some neuroscientists are likely to disagree with Purves’ heretical theories, but none can afford to ignore them.”<b class=""><br /> –Josh Sanes, Harvard University<br /> </b></p> <p class="">“Brains is much more than a book about brains. It is a journey that takes the reader through the modern history of neurobiology, a personal account that illuminates both what we know about brains and the mysteries that remain in understanding how brains work.”<b class=""><br /> –Terry Sejnowski, Salk Institute<br /> </b></p> <p class="">“This is a lucid, easy-to-read summary that is fascinating reading for anyone interested in what we know and do not know about how brains work. Purves brings together a unique expertise and priceless personal observations about several subfields of brain research and the scientists who have shaped our present understanding of it over the past eventful fifty years.”<b class=""><br /> –Pasko Rakic, Yale University School of Medicine<br /> </b></p> <p class="">“’Brains’ is an engaging tour of human neuroscience from one of its most distinguished and opinionated practitioners. Dale Purves is a lively and informative guide to the field, having been at the scene of some of its great discoveries and having made many important discoveries himself.”<b class=""><br /> –Steven Pinker, Harvard University<br /> </b></p> <p class="">“A rare account of both the modern history of key discoveries in brain research by someone who was there and responsible for many of them and also a heartfelt account of the joy of it all. Dale Purves has given us an inside view of a life in science and explains with clarity what it all means.”<b><br /> –Michael S. Gazzaniga, University of California, Santa Barbara<br /> </b></p> <p class="">“’Brains’ is a delightful book that weaves together Dale Purves’ personal neuroscience history with the history and current status of the field. I enjoyed it start to finish.<br /> <b class="">–Joseph LeDoux, New York University<br /> </b></p> <p class="">“This book is many things. It’s the memoir of an immensely likeable human (who I only previously knew as a distant giant in my field). It’s people with strong personalities that give lie to the notion that science is an affectless process. But most of all, it is a clear, accessible, affectionate biography of neuroscience. This is a terrific book.”<b class=""><br /> –Robert Sapolsky, Stanford University<br /> </b></p> <p class="">“Both highly entertaining and educational. A masterpiece.”<b><br /> –Bert Sakmann, Max Planck Institute of Medical Research<br /> </b></p> </div> </article> </aside> </div> </div> </div> </div> <div id="container-group-footer" class="container-fluid container-set container-group-footer"><div class="devn-group container-group__footer footer1" id="footer-group"> <div id="container-group-footer_x_system-1416477861" class="container-group container-group-footer_x_system-1416477861"> <div class="rowlevelone row-fluid row wrpestdevn rowFullWidth limit-width container row-devn-system-row"> <div class="spanlevelone col-md-12"> <div class="widgetdevn sidebardevn blkfooterdevn0" id="sidebar-group-footer_x_system-1416477861"> <aside id="execphp-_x_system-1416477881" class="widget widget_execphp"> <div class="execphpwidget"><div class="clearfix divider_dashed10"> </div> <div class="copyright_info"> <div class="one_half"> Copyright © 2015 Purves Lab. All rights reserved. </div> </div> </aside> </div> </div> </div> </div> </div> </div> </div> <script type="text/javascript"> //<![CDATA[ //]]> </script><a href="#" class="scrollup" id="scrollup" style="display: none;">Scroll</a> <script type='text/javascript'> /* <![CDATA[ */ var wpcf7 = {"apiSettings":{"root":"https:\/\/purveslab.net\/wp-json\/contact-form-7\/v1","namespace":"contact-form-7\/v1"}}; /* ]]> */ </script> <script type='text/javascript' src='https://purveslab.net/wp-content/plugins/contact-form-7/includes/js/scripts.js?ver=5.1.3'></script> <script type='text/javascript' src='https://purveslab.net/wp-includes/js/comment-reply.min.js?ver=5.2.21'></script> <script type='text/javascript' src='https://purveslab.net/wp-content/plugins/easy-fancybox/js/jquery.fancybox.min.js?ver=1.3.24'></script> <script type='text/javascript'> var fb_timeout, fb_opts={'overlayShow':true,'hideOnOverlayClick':true,'showCloseButton':true,'margin':20,'centerOnScroll':true,'enableEscapeButton':true,'autoScale':true }; if(typeof easy_fancybox_handler==='undefined'){ var easy_fancybox_handler=function(){ jQuery('.nofancybox,a.wp-block-file__button,a.pin-it-button,a[href*="pinterest.com/pin/create"],a[href*="facebook.com/share"],a[href*="twitter.com/share"]').addClass('nolightbox'); /* IMG */ var fb_IMG_select='a[href*=".jpg"]:not(.nolightbox,li.nolightbox>a),area[href*=".jpg"]:not(.nolightbox),a[href*=".jpeg"]:not(.nolightbox,li.nolightbox>a),area[href*=".jpeg"]:not(.nolightbox),a[href*=".png"]:not(.nolightbox,li.nolightbox>a),area[href*=".png"]:not(.nolightbox)'; jQuery(fb_IMG_select).addClass('fancybox image'); var fb_IMG_sections=jQuery('.gallery,.wp-block-gallery,.tiled-gallery,.wp-block-jetpack-tiled-gallery'); fb_IMG_sections.each(function(){jQuery(this).find(fb_IMG_select).attr('rel','gallery-'+fb_IMG_sections.index(this));}); jQuery('a.fancybox,area.fancybox,li.fancybox a').each(function(){jQuery(this).fancybox(jQuery.extend({},fb_opts,{'type':'image','transitionIn':'elastic','easingIn':'easeOutBack','transitionOut':'elastic','easingOut':'easeInBack','opacity':false,'hideOnContentClick':false,'titleShow':true,'titlePosition':'over','titleFromAlt':true,'showNavArrows':true,'enableKeyboardNav':true,'cyclic':false}))}); /* Inline */ jQuery('a.fancybox-inline,area.fancybox-inline,li.fancybox-inline a').each(function(){jQuery(this).fancybox(jQuery.extend({},fb_opts,{'type':'inline','autoDimensions':true,'scrolling':'no','easingIn':'easeOutBack','easingOut':'easeInBack','opacity':false,'hideOnContentClick':false,'titleShow':false}))}); /* SWF */ jQuery('a[href*=".swf"],area[href*=".swf"],a[href*=".SWF"],area[href*=".SWF"]').not('.nolightbox,li.nolightbox>a').addClass('fancybox-swf'); jQuery('a.fancybox-swf,area.fancybox-swf,li.fancybox-swf a').each(function(){jQuery(this).fancybox(jQuery.extend({},fb_opts,{'type':'swf','width':680,'height':495,'titleShow':true,'titlePosition':'float','titleFromAlt':true,'swf':{'wmode':'opaque','allowfullscreen':true}}))});}; jQuery('a.fancybox-close').on('click',function(e){e.preventDefault();jQuery.fancybox.close()}); }; var easy_fancybox_auto=function(){setTimeout(function(){jQuery('#fancybox-auto').trigger('click')},1000);}; jQuery(easy_fancybox_handler);jQuery(document).on('post-load',easy_fancybox_handler); jQuery(easy_fancybox_auto); </script> <script type='text/javascript' src='https://purveslab.net/wp-content/plugins/easy-fancybox/js/jquery.easing.min.js?ver=1.4.1'></script> <script type='text/javascript' src='https://purveslab.net/wp-content/plugins/easy-fancybox/js/jquery.mousewheel.min.js?ver=3.1.13'></script> <script type='text/javascript' src='https://purveslab.net/wp-includes/js/wp-embed.min.js?ver=5.2.21'></script> </body> </html>