Sunday, March 17, 2013

Exercising the Memory Muscle

It's been a while since I've written a proper post - I've found myself consumed with more distractions than ever in the last couple of months, although in a very positive and very healthy way overall. I'm excited to have so many new experiences swinging my way!

Putting that aside for the moment, while having a conversation with my parents via Skype the other day I realized that there has been one very curious, very strange new development recently with my hearing that I haven't blogged about yet. In short, I have a very, very bad auditory memory. Hilariously bad, in fact.

Now, I've blogged about auditory memory before, but mostly referring to the meaning or the context of being able to retrieve and recognize words that I hear. Since I started my CI rehab process from ground zero, or that of having nearly no familiarity with how words actually sound or are supposed to sound, most of my learning process with speech and words has been a process of painstakingly figuring out normal English speech patterns and committing them to some location in my memory. Then I "activate" that memory to recognize words when I come across them at some point in the future. Grossly oversimplified, what I'm hearing in the present moment matches my brain's existing memory map for the corresponding word from somewhere in the past, and there it is - I recognize it and the word presents its meaning to my consciousness. (Actually I don't think this is what happens all the time, since according to this definition I would need to drill every word in the English language over and over again to form the initial memory imprint in my brain - the process seems far more organic, with my brain learning to break down individual sounds to reassemble and recognize words I've never heard before, however familiar they might be to me otherwise. So much going on, it boggles my mind. I just realized the other day how many words I routinely use in high-level written English that have never entered my auditory or spoken world - I have no idea how they're pronounced, how they sound, how I might say them. This appears to me less of a limitation than an opportunity for future discovery.)

The form of auditory memory described in the above paragraph is still improving - the memory for specific sounds and specific words that allows me to recognize speech in real time. I've discovered recently that, contrary to my wildest expectations at the very beginning of the listening process, I'm growing rather skilled at listening to completely or mostly open-set paragraph-length utterances in quiet with a familiar speaker and understanding about 60-80% of what is being said. This is huge. My auditory therapist can speak to me in complete sentences, sometimes several sentences, and while sitting there and letting my auditory memory thrum and guide me through what I'm hearing, I feel the regular click of understanding. Got that. Got that. Got that. Got that, too. Amazing. Except...

Back to auditory memory, placing a different emphasis on "memory." While I feel like I've made leaps and bounds in being able to break down and understand speech as it comes to me in real time, in those controlled situations, there's still another important part to language processing. That is, being able to hold on to everything you've heard long enough to make meaning of it. Which is something that, again, I'm laughably abysmal at.

Let me put this another way. Suppose I'm listening to a long sentence or sequence of words. They click by, and I feel the distant regions of my brain light up and correspond with meaning, and feel as though I'm understanding everything, or nearly everything. That felt great. Then the test comes; my auditory therapist says, "Repeat that back to me." And... I can't. I realize I've forgotten almost everything except the last few words.

But - but I understood those words as I was hearing them! I swear I did. My brain just failed to use whatever pathway to store those words safely away in short-term memory. For strings of about six to eight words long, no problem; the fleeting imprint of auditory memory still allows me to retrieve the entire thing from the beginning and recite it with confidence. But for longer strings of words, or complex sentences with clauses, catalogues, or other syntactical challenges like the ones I'm writing right now, I lose it. I can't remember what I've heard, even if I did hear it and remember the self-satisfied glint of understanding. This doesn't mean my overall memory is bad. Actually, it's excellent - I'm able to look at things and remember them very well even a while later, and always have been. I'm recognizing the difference between the visual and the auditory pathways, between all the uses of memory I've grown accustomed to and the style of memory I'm now asking my brain to use. I've long prided myself on having a good memory - it bemuses me that it could be so bad when I try to listen with it.

Another tough exercise: listen to a string of individual words (example: "cat," "dog," "bird," "chair") and then store them in memory while listening to another phrase or question that forces me to select which of the words classify together and which do not (example: "it is an animal with four legs"). For the preceding examples, the answer would be the first two words, "cat" and "dog" - if I missed the word "animal," I might mistakenly include chair, since it does have four legs. Ditto for missing the words "four legs," at which I might include bird. This exercise requires me to reach back to my auditory memory for the initial sequence, using this new information, and analyze what I've heard using my existing language skills. But I often find that, once I've heard and understood the second part of the exercise, the phrase or question, I reach back and... not all the words are there anymore. Or I struggle to remember them. Maybe I can only remember two or three of them, even though ten seconds ago I was solid on all four. Somewhere, in exerting the auditory pathway, my brain let its previous efforts slip from memory. I'm getting better at this exercise over time, but it remains elusive sometimes, for something so seemingly elementary-level.

Who knew that memory could be such a complex and multifaceted thing? Or that it linked so intimately to speech processing, language, and speech comprehension? I'm experiencing this disjunction firsthand, and I'm in awe of how many things our brains must juggle to execute seemingly the most basic and simple actions. Time to exercise those memory pathways and memory muscles! Someday it will all be connected: auditory memory, sound processing, speech recognition, long and short-term memory, linguistic and syntactical structures, real-time analysis... maybe a little room for daydreaming in there.

Wednesday, March 13, 2013

"Seeing at the Speed of Sound"

I'm really happy to report that a revised version of an essay of mine has been published in Stanford magazine as a feature. Check it out here!:

Many thanks to the writers, bloggers, tweeters, etc. who have reposted this across the web. (And be sure to read the sidebar, "Now Hearing This," linked with the main article - I always find it interesting to reflect upon how these experiences with lipreading and conversation have changed since I first wrote this essay nearly three years ago, right before I got my cochlear implant.)