scintillating scotoma 2

another aura! (no post in a month, and now it is forced!)

right now it's flying out to the far left field, but there's also a weird 'rough patch', a bit nearer in that appeared late on. i got a good map. i didn't expect this one coming on at all, except for what i think is just sort of standard low-level paranoia which i've developed since this all started. it's hard to tell what's prodrome and what's just coincidental suspicion.

anyways, i was reading through a section of the classification image manuscript, and, yep, can't see the letters. i think that 8/10 of these things so far have begun while i was reading. not sure if that's because i spend the majority of my time working with text in one way or another, or if that actually pushes things over the edge.

***

it's been a few hours now. here's the map i drew of this last event:

similar to last time, except that it's in the left field this time. it started out below fixation, and did the slow arc outward, following a really similar path as the last one. below, i'll show you below just how similar they are.

as for the rough patch: in the plot above, notice that in the superior field there's some green (and hard-to-see gray) scribbles over the neat arcs; that was a region that i noticed late which wasn't blind, and wasn't flickering, but was clearly..  unclear. it's at about 10 degrees eccentricity, so it's hard to see well out there anyways, but it was obvious that something was wrong. i could see the scribbles that had already been drawn, but it was all very indistinct and jumbled, and i couldn't see the motion of the cursor even though i could tell that it was laying down green/gray scribbles of its own. without any other explanation, i'm going to guess that this was the fabled extrastriate scotoma - my V2 was getting some CSD!

ok, now some analysis. first, log-polar maps. i haven't gone and gotten/worked out a cortical remapping scheme, but putting things in in log-polar coordinates is almost as good. actually, what you do is put them in log(ecc+1)-polar space, so you can see where the fovea is (zero in case you're dull). here are logecc+1-polar-time plots for the last two events (lets say L = log(ecc+1), for easier reference):

time is measured here from start of recording. these data are smoothed versions of the drawn maps in 10 degree radial steps. the scales are the same except that these are for opposite hemifields. the z-axis is color coded.

i mean, you can just see that those two maps are almost identical. i got more data the second time because i wasn't occupied with working out a system (btw i was caught off-guard; i wrote a matlab script to record in real time, but it not work in matlab-64, and i put off doing the -32 install because... ah.. it's done now). the origin is similar - look at these plots:

sorry about the colors. these are the same data as in the scatter plots above, except these are collapsed over the x(angle)-axis. actually they aren't quite the same: here i've used linear regression to estimate the earliest time (before recording began) that the visual event could have begun, and subtracted it out of the time axis, so these plots start when recording began with respect to when i estimate the event began. so, basically, this aligns the data. 2 things: one, the rate of advance (remember that it's radial advance, so these technically are distorted plots; i assume that's why the slope changes with angle) is basically identical in the two cases, ~.16 L/m. and the origin, ie where it all begins, is ~180-170 degrees in both cases (that's directly below fixation).

i've got other analyses, but the above sums up the interesting stuff. i know i've seen these things do weirder things, following more difficult-to-understand courses, and i hope i see one of those next time i'm able to record this business.

scintillating scotoma

a few minutes ago (~22:35), reading, and i notice that letters are hard to see. that sensation of having a bright afterimage at fixation; it's moving rightward, usually it's been leftward (I haven't taken notes on the past 2 occurrences, sadly..); this it is at least the first of the last 4 to go through the right field, if not longer.

it begins with just a weird sense of scotoma-ness, very near fixation, but the blind areas are hard to pin down - they seem to change very rapidly, or else it's more a sensation of blindness rather than actual blindness. it's strange how it sticks at fixation even as it arcs out into the periphery; it seems it always arcs into the lower field, after arcing just a bit above fixation. i've not noticed yet one passing across the field, maybe it is restricted to hemisphere?

it's almost gone at this point (almost 30 minutes after the first signs), and all that's left is a flickering at the very top of my visual field, as if there's a light flashing on my eyebrows; interestingly, if i look up, it disappears, which is strange because it should be attached to the field location. i can look up, it disappears, look down again and it reappears. maybe was an interaction with the reflection of room/computer lights off my eyeglass frames? can't test, it's all gone now..

and i have a headache (actually it started a few minutes in; the light show was so slow to start, i thought we were skipping straight to the headache for a few minutes, a bit of disappointment, but it worked out!)

also, some hints: today and yesterday, i several times wondered if i wasn't going to get a headache soon, without understanding why. not sure what sets off those feelings.. this afternoon, i thought i saw some flashes at some point when i was walking down the hallway, and that really made me suspicious; and, all day, really tight, painful muscle spasm throughout my upper back, both sides trapezius.

23:05

map below: i have a few of these now, should get to processing them this summer..

Edit: look at what this guy has done: http://www.pvanvalkenburgh.com/MigraineAura/MigraineAuraMaps.html. pretty amazing.

also, i did wind up writing a script to analyze these plots; once I get some stuff settled, i'll post those in a new entry.

lazy friday dark adapt

Spent afternoon of Friday, 4-20-12, with a ~3 log unit (~.2%) ND filter over my right eye. Made the following observations:

(Took the filter off after about 4 hours. It wasn’t bothering me much anymore, but I think the plastic and rubber stuff in the goggles was irritating my eyes, which were starting to feel kind of dry and red. Light adaptation is really fast, it’s just been a minute and the (formerly dark adapted) right eye’s image only seems slightly brighter than the left’s.)

1. Noise: the dark adapted eye’s view is noisy, and the noise intrudes into the dominant view. It’s irritating. The dark adapted view isn’t being suppressed, though, it’s there like a ghost. Double images, from depth, are strikingly noticeable, not sure why.
2. Pulfrich effect: first time I’ve really seen this work. I put my index fingers tip-to-tip and move one from side to side, fixating on the still one, and the moving finger looks like it’s rotating. My hand even feels like it’s rotating.
3. Pulfrich effect 2: Fusion isn’t always working, but I seem to be ortho a lot of the time. I just noticed, though, that if I make quick motions, e.g. a flick of a finger, there’s a delay in the motion between the two eyes; the dark adapted image is delayed by several hundred milliseconds! Especially obvious if I focus at distance so I have a double image of the finger. Explains the strong Pulfrich effect.
4. Noise 2: Just looked at some high frequency gratings. With the dark-adapted eye, the noise was very interesting, looked like waves moving along the grating orientation, i.e. along the bright and dark bars there’s a sort of undulating, grainy fluctuation.
5. I still have foveal vision and color vision, but both are very weak. Dim foveal details are invisible. High contrast details (text, the high frequency gratings) are low contrast, smudgy..
6. Motion is kind of irritating, I think because it brings about lots of uncomfortable Pulfrich-type effects. Even eye movements over a page of text can be bothersome, because there is always an accompanying, delayed motion. I’m guessing that the saccade cancellation is being dominated by the light-adapted eye, and so I’m seeing the dark-adapted saccades. I don’t notice a depth effect, but walking around in the hallways I do feel kind of unsteady, maybe because of motion interfering with stereopsis. If objects are still, stereopsis seems to be okay.
7. If I take vertical and horizontal gratings (64c/512px), add them together, then look at them at 25% contrast from about 30cm (here at my desk), I don’t see a compound grating – I see patches of vertical and patches of horizontal. I’ve never noticed this before; I wonder what differences there are with scotopic vision and cross-orientation suppression..
8. I tried to watch my light-adapted eye move in a mirror, but the dark-adapted eye just couldn't see well enough. I think a weaker filter would make it possible.

Memes and Pharmacies

That rivalry proposal went in last Monday with no problems, along with a long-festering manuscript, so it seems I took a week off from writing. Now I have progress reports to do, presentations to prepare, other manuscripts to complete, on and on.. I need to make sure I keep up with this journal, which seems to be helping in keeping my writing pace up.

Vacation is over!

About 12 years ago, I read the Meme Machine by Susan Blackmore. It was around the time that I decided to major in psychology, and I was reading all this Dan Dennett Douglas Hofstadter stuff, but it was her popular science book that really had a big effect on me - I would say that it changed my worldview completely, to the extent that I would identify myself as a memeticist when discussions of religion or that sort of thing came up (it was still college, see) - I really felt like it was a great idea, that human culture and human psychology could be explained as essentially a type of evolutionary biology. I still believe it, and so I suppose this book still really sits near the base of my philosophical side, even though I don't think about these things so much anymore.

I bring this up because the other night Jingping and I were talking about being tricked, since this was the topic of a Chinese textbook lesson I had just read, and I recounted the story of being completely conned by a thief once when I was a clerk working at CVS. I wound up going on more generally about working there, and I remembered that I had worked out a memetics-inspired 'model' of that store, which I hadn't thought about in a long time. One of the things about the memetics idea that had really gotten to me was that you could see social organizations as living creatures with their own biological processes - not that this is an idea original to Blackmore, and I'm sure that's not the first place I had heard it (like I said, I was also reading Dennett and Hofstadter at the time), but she did work it into a larger sort of scientistic system which seemed to simplify and unify a lot of questions.

Now I realize that the criticisms of memetics that I heard from professors in college (when I questioned them about it) were mostly right, in that it mostly consists of making analogies between systems; only in the last few years, with the whole online social networking advent, has a real science of something like memetics actually gotten off the ground (this is a neat example from a few weeks ago), and it's very different from what had been imagined when the idea was first getting around.

Anyways, I thought I'd detail here my biology-inspired model of a CVS store, ca. 2001. I have a notebook somewhere where I had detailed a whole system, with functional syntax and everything, for describing social organizations in terms of cellular, metabolic systems. This might have been the first time that I had tried to put together a comprehensive model of a system, now that I think of it. The store, I thought, was itself a cell in a larger CVS system dispersed across the city, which itself was a system dispersed across the country. I was mainly interested in the store level, where you could see different components acting as reagents. It was a strongly analogical system, but not completely analogical, to plant metabolism: a plants needs carbon, so it uses sunlight to break down carbon dioxide, releasing the unneeded oxygen back into the world. A store needs money, so it uses salable products to break down a money-human bond, releasing the human back into the world.

Of course, with plants the sunlight comes free from heaven - all the plant can do is spread out and try to catch it - while salable products must be delivered from another part of the CVS system: the distribution center. The distribution center emits reagents to the stores, where the money-human bond is broken down. The CVS system also emits catalytic agents into the world - advertisements - to facilitate the crucial reaction. The money absorbed by the system is energy which is used to drive the system through a reaction not unlike oxidation - the money-human bond is reformed systematically, with employees as the human component. This reformation is what really drives the system. Those new human-money bonds then go out into the world and fulfill the same function, breaking apart, as they interact with other businesses.

Looking at a business in this way totally changed the way I understood the world. Businesses, churches, governments, political parties, armies - all of them can be thought of as living creatures, or as organs of larger creatures, rather than as some sort of human means-to-an-end. By changing perspective between levels, we can see ourselves as means to the ends of these larger systems, just as our cells and organs are means to ours. Now I'm finally getting around to reading straight through Hofstadter's GEB, and so I can see that this general idea of shifting perspective across levels is an old one that has been astonishing people for a long time. But for me, coming to see human culture as as being alive was a fundamental shift in my intellectual development, one that hasn't really been superseded since. I haven't become a real memeticist yet, but it's all still there, underneath... these tiny tendrils of memetics live yet...