Thursday, June 28, 2012

priorities, summer 2012

augh... so bored... let's do a post on what i'm supposed to be doing right now, that i'm not doing: yes, it's time to catch up with the priority worksheet!

yes, i've been keeping it up to date every month or so.


there it is. the CI manuscript (MS_Class) is with E* right now, so i have a couple of days i could be devoting to the equivalent priority: ProjADI. but i don't want to do ProjADI. i am depressed about my failed fellowship application and all i want to do is work on modeling my stupid migraine auras, which is not what i am being paid to do, and which, as far as i can tell, does not promise to reveal anything sufficiently new or interesting to warrant spending my time on - i.e. unless i actually do start collection of real psychophysical data on that, it's not publishable. and, it's not on the priority list. migraine modeling has a priority of 0, do you hear that?

the next highest priority is ProjPrism, which i should get on with before all my subjects have moved on to other places. that's going to take some creative programming though, and i don't have a good idea yet of just how i'm going to do it. i really need to go and just sit down in the lab and figure it out. but i'm depressed, so that's my excuse. instead i'm here looking at the internet and writing a stupid journal entry on what i should be doing.

one more thing:


there you can see the evolution of my priorities over time. i do think this system is helpful in my evaluation of my projects. i do seem to be kicking off things with high priorities, though nothing has officially dropped off the list yet. waiting for reviews on two papers (MS_class and MS_blur); if those go okay, then maybe they can both be off the chart by end of the year. maybe MS_class, too.

Projs, though, need to get Projs moving. just sitting there. you're just sitting there. get up. go to the lab. go. go go go.

Tuesday, June 26, 2012

scintillating scotoma 3.a

I went ahead and figured out how to do the cortex transform. there are many papers describing the equations; some good recent ones (like this one) which are basically reviews at the same time that they are tweaking one or another aspect of the basic model. It's not really that complicated; the log-polar transform is very similar, except that the angles are calculated outside the logarithm. The space-V1 transform is the logarithm of a complex number representing the spatial coordinates plus the limit of the foveal confluence. The paper I linked above describes what further steps can be taken to get the transform more precise, accounting for meridional anisotropies. they go further, but I stopped there. The basic model was proposed by E.L. Schwartz in 1977, and hasn't changed much since then; I'm using Schira et al's version with their shear equation, and some parameters they cite in another paper.



This is similar to the second plot from the last post, but you will notice the geometry is different, as it gets narrower towards the fovea (lower part). Colors indicate time in minutes as shown by the colorbar. The grid drawn in the background isn't labeled, but it's easy to understand if you've seen these before. The lines going up and down are, from left to right, the superior vertical meridian, the left superior 45 degree meridian, the left horizontal meridian, and so on. From bottom to top, the left-right lines are spaced 5 degrees of visual angle apart. You don't see the first one until about 30mm up. The origin in this plot, (0,0), is where the foveal representation converges with V2 and V3, the foveal confluence.

This is interesting, the foveal confluence. I probably had heard of this before and forgotten it. I actually stated to E* yesterday that I didn't know what was on the other side of the foveal edge of V1, though I knew that the edges are flanked all the way around by V2. In fact, V1, V2, and V3 foveae all meet in the same place. This is apparently a relatively poorly understood region of visual cortex; imaging and physiology studies have focused on the more peripheral regions. The reason is that it can't be certain of what is being studied if one looks closely at the confluence, since the three areas are mixed together in a fashion that is still not well understood. I'm going to read more about this (the main writing on it is by the same group as the paper I cited at top; this one explains things up front).

Okay, so that map. What can I do with it, now that I have the coordinates right (or as close to right as I can)? Yes: I can measure the rate of progression of the wave in cortical distance over time. Awesome. I don't have the best method worked out just yet, but here's my approximation, summarized in the last figure below:

On the left, we have the same coordinates as in the figure above. The plotted line is the mean, over time, of the recorded scotoma regions. This is not a great measure of position of the waves, since as they got further out and larger, I couldn't trace them completely, and because it took time to trace them, so at a given epoch a trace might be in one place, or another, and that shows up here as a back-and-forth wave, on top of whatever sort of limiting bias is imposed by the screen size, etc. Still, it's okay. We know this because of the next plot: On the right, we have the distance of that waggly trace (from its starting point near the bottom of the left plot) as a function of time. A straight line. That's not why we know it's okay; it's because of the slope of this line: 2.76 mm/min. This is extremely slow, but exactly in the realm of cortical spreading depression. Not going to give references on that (need to save some work for an actual paper on this business), but they're there. Pretty sure I'm doing this right.




Monday, June 25, 2012

scintillating scotoma 3

another event is now shimmering its way out into my far left periphery. i used the dynamic perimetry program i had written; seems to work. some improvements can be made; need to include warnings or preventions for the cursor going out of screen. should implement cursor size info/adjustment. maybe cursor color or shape.

i mention the last two because definitely, there is a general sort of aftereffect. it's scotoma-like, but with no clear location of the scotoma; i.e., it feels like things are missing, e.g. if i put my hand out about 15-20 degrees left, stuff just feels kind of scrambled. actually, there is definitely a blind spot about 30 degrees left, i just found it. this is too far to measure with this screen; perimetry stops at ~20 degrees, i guess.

again, i don't know what the precursors were. been depressed all weekend (see previous post); saw some funny spots yesterday, and got preoccupied with some really visible floaters yesterday afternoon at tkd, which is probably unrelated. seems like the main indicator is just a superstitious feeling that "i wonder if it's going to happen again". maybe that's the CSD running through my frontal lobe somewhere.

note that i'm basically having a monthly period: the first of these (that i recorded here) was April 24, then May 28, and now it's June 25 (24).

i've been meaning for a while to list the other occasions that i can remember. i may be able to remember them all. before these past three, it happened twice earlier this year: once was during, uh, sex, which was weird, in China (within a few days of new years), and the second was on a sunday afternoon in late january or early february, when i was on my way to tkd, walking around cleveland circle.

before that, probably have to go back a year. it's happened several times with me just sitting here at my computer; probably half the times. i announced a few on facebook. i woke up once, early last year, with the SS starting right off. makes me wonder if it happens sometimes when i'm sleeping. it's happened after sex a couple of times. only once in the lab, i think, after j** checking my eyes. except for that morning one, i think it's almost always at night.

i would guess that, all together, this has happened 10-15 times in the last 2.5 years. until now, i don't think it had happened in summertime, only winter and spring. lots of headaches, maybe biweekly on average, without interesting symptoms.

i think these map data will be usable, and better quality than the paint drawings. not as pretty, but i can just generate post hoc pictures. i'll process them in the next couple of days, probably tomorrow. basically, it seemed very similar to the last two times, except that after the first minute or two of scotoma (again, i noticed it had started because, suddenly, i couldn't read), which i managed to record, the scotoma disappeared, or at least i couldn't find it. i thought maybe i had scared it away, but then it returned, right on track. anyways, update later when maps and stats are done.

*update*

some plots: sorry, didn't label any axes. descriptions accompany each:


This is the progression in spatial coordinates. color represents time in minutes, which you see in the colorbar. i also tied marker size to time, to help represent the thickening of the scotoma with time. 


This is progression in logpolar coordinates; x-axis is degrees from leftwards (in the last post, i was coding angle relative to 'up'), y-axis is log(degecc + 1). now it looks a lot more like a straight wave, though there is a bend to it, as if the wave has a 160° trailing angle. maybe that would be straighter with a more realistic cortical space transform? maybe not. i'll get around to finding out later this summer.
 


This last one is just binning the previous plot into 10° strips, plotting logecc+1 against time (like in the previous headache post). if i assume that the speed of the wave is closest to the fastest estimate that i get from these kinds of fits (it must be faster, since i'm only measuring at an angle to the wave), then i estimate that for this event, the speed of the wave was at least 0.248 logecc+1 / min. this compares with estimates of 0.250 and 0.258 for the last two events (i cited a lower number last time; that was the median, this is the max). once i learn to transform logpolar into v1 coordinates, i'll bother to do the extra geometry to measure the true transverse speed of the wave.

Sunday, June 24, 2012

nope

okay, so, that grant i applied for? failed. not discussed. not.. even.. discussed.

so, that's disappointing. hit rate was just 10-15%, but i felt like i had something. i've seen others with the same fellowship, and i don't think what i was proposing was of any lower quality. maybe a bit further from the norm, proposing things two steps from what anyone had done before - probably better to go one step at a time. there's also the fact that i'm obviously an underachiever. i can't hide it anymore - CVs don't lie. an underachiever with an abnormal proposal.

hurts my feelings, i guess. how can it not? well.. like i've been telling everyone, as a preemptive defense, i knew i wouldn't get it. a long shot. but it wasn't some self-fulfilling bullshit. i did my best. there's good stuff in there, and i'll do it anyways. but not putting it in the top half, not putting it on par with the rest of the proposals. that does hurt. i was hoping for a rejection despite a good score.

i think i'll probably still get comments back on it. i think. d** got comments even when his wasn't discussed in the last round.

let's rephrase the bit about being an abnormal underachiever. how about.. outsider?

let's get romantic.
tell the truth.
you see yourself as an outsider,
don't you?

i don't do it on purpose.
i don't try to be on the outside
in order to satisfy some requirement
that i've set for myself.

it's just what happens.
it's what i'm drawn to.
i'm drawn away.

you make choices
that put you on the outside.
your mentor is an outsider, and
you are the outsider in the lab.

in groups of friends,
i am the one who isn't
part of the group,
who tagged along,
happily accepting all invitations.

the underachiever.
the one you don't know.
i reject what they accept.

always the quiet one.
the different one
who finds himself in strange places.

it shines through
even in an NIH fellowship proposal:
you are a risk.

yeah, screw you. i wrote all that. i wrote it, then edited it into a poem. it's because of my self consciousness, not in spite of it. i am afraid to confront what i am, but i just did it. fine, i'm mad, and my feelings are hurt. i'm a pretentious kid. i'm used to it.

have to get used to this, kid. i hear there's a whole career of this ahead. have to keep writing these things and sending them in. some will succeed, some won't. i'll keep doing what i want to do, this is my guarantee.