The basic neurobiology behind the 12-dot illusion
The worst trait I see when domain experts try to write &quot;introductory&quot; material is a depressingly-common amnesia toward what it was like to <i>not already know</i> their subject matter. This article is so badly written, so overly and needlessly wordy, that I&#x27;m honestly considering deconstructing it <i>line-by-line</i> as a case study in how <i>not</i> to write articles for the layman.<p>Here&#x27;s a brief example, using the most jarring line I&#x27;ve been derailed by so far (I still haven&#x27;t finished reading this article, getting hung up on runs like this):<p>&gt; So what is the purpose of lateral inhibition in the retina? Let’s consider what kind of stimuli are optimal for activating this bipolar cell.<p>&quot;What is <i>the purpose of lateral inhibition in the retina</i>?&quot; Uh, hi - I <i>just got here</i>. We are <i>zero lines</i> from the place where we were first <i>introduced</i> to <i>any</i> of these terms (the <i>last two words</i> of the preceding <i>illustration&#x27;s detail</i> are literally the <i>first place</i> the phrase &quot;lateral inhibition&quot; even <i>appears</i>).<p>We&#x27;ve just been <i>shown</i> this concept, <i>at all</i>, for the first time - in a literally <i>microscopic</i> illustration, with some concepts so unexplained they were just left for us to <i>hunt</i> for (&quot;Notice that a single neuron pools information&quot; - notice <i>what</i>? Notice <i>how</i>?) - and now we&#x27;re supposed to be considering <i>the ultimate purpose</i> for this obliquely-introduced phenomenon? Not only that - we&#x27;re supposed to be pondering this now using a <i>neurologist&#x27;s lexicon</i>?<p>If we were <i>actually supposed to be following</i> what the author is saying here, we&#x27;d be given some time to <i>reiterate</i> this concept we were just presented from <i>one angle</i>, to consider it in different approaches, with descriptions we <i>don&#x27;t</i> immediately understand reinforcing a model we could build with <i>other</i> descriptions we <i>could</i> better understand.<p>Instead of <i>reinforcing its subject</i>, the article spends time on aside paragraphs mocking what a non-neurological model of human vision might be (talking about Dennett&#x27;s Cartesian Theatre), despite the way that <i>nobody reading this</i> would have that misconception, and <i>introducing</i> it only adds a concept so unrelated that it <i>actively impedes understanding</i> of the material. Passages like this are just thrown in, like the author wants to say &quot;I know more than you, and I want you to know that I don&#x27;t just know neurology, I also took a philosophy course.&quot;<p>The line I excerpted <i>doesn&#x27;t even have to spend more time describing the concept</i>. Indeed - it&#x27;s actually <i>more effective</i> if you make it <i>less wordy</i>, because a <i>high-level general description</i> tells us which things we <i>don&#x27;t strictly have to understand</i> to follow the next part. Here&#x27;s how I&#x27;d write that whole paragraph - note how much <i>less</i> I hang meaning on unexplained jargon:<p>&gt; So, when a wide area of photoreceptors see the same signal, they actually <i>reduce</i> the signal seen by the tight cluster in the center. Why reduce the signal like this? Because this way, when we see a <i>small detail</i> - one that <i>isn&#x27;t</i> surrounded by a big area of the same kind of light - that wider group of photoreceptors (connected to the horizontal cell) <i>doesn&#x27;t</i> inhibit the signal. Getting stronger signals for <i>just the smaller details</i> is what makes stuff like dots and edges visually obvious to our human eyes.<p>It&#x27;s not <i>perfectly</i> clear - it still needs a round or two of editing to be truly <i>smooth</i> to read - but, even as a <i>rough</i> draft, that&#x27;s smoother than anything in the linked publication, which reads like <i>didactic sandpaper</i>.