Hacker News Reader

Comment by SamBam | Hacker News Reader

> We were able to take stimuli that were initially not consciously perceived, and induce a conscious percept after the stimulus had disappeared by manipulating exogenous attention.

That's cool! Can you say more about how the experiment worked?

View on HN

My wife does this to me. She'll be talking about something and I'm not listening but I make semi-plausible automatic responses. Sometimes she catches on that I wasn't paying attention and calls me out on it. At that point the last 6-7 seconds of speech pops into my mind like magic and I can pay attention to it and respond. Sadly sometimes that's not enough to deduce what she was talking about.

Yes! We informally referred to this as the "double-take phenomenon", and our hunch is that this is exactly what is going on.

During my Ph.D, I would often spot this on my way to the lab. I would be seated in the subway early in the morning, and suddenly realize that the name of a station had just been announced, but that I hadn't heard it. Then, it was suddenly like I had heard it -- as if the trace sensory signal in auditory cortex had been isolated and amplified by my attentional system, before it fully dissipated.

It was (and still is) super cool.

Probably quite a separate phenomenon, but if I wake when it's still night and I want to know what time it is, I'll often blink my eyes open for a tiny fraction of a second to see the glowing alarm clock. I often don't know what time it is until I "read" the time from my memory. (It's either my memory or the after-image on my retina.)

Sounds like inattentive ADHD or auditory processing disorder, where symptoms like this are typical. Unless you are thoughtfully meaning to give plausible responses instead of pay attention, then nvm!

Please don't throw around diagnoses like that. You're not wrong, but the hallmark of psychiatric disorders is usually degree, not nature. Everybody checks out from time to time; ADHD people just do it more. You are not equipped to make that call, here.

You never heard women nagging?

My wife and I say “I back heard you”. it’s kind of a funny in-joke for us because of the quasi non-sense word.

I use similar techniques (plus muscle memory, visual, etc.) as a short term memory scratch pad - especially when highly sleep deprived.

When my partner does this to me I call it his "audio buffering" mode -- he'll be absorbed in something and make no indication that he's heard me, but if I wait long enough (in the 15-60 second range), it'll suddenly make it all the way to his conscious attention and he'll respond as though there was no gap at all.

https://journals.plos.org/plosone/article?id=10.1371/journal...

Here's a pure psychophysics study we performed. It gets at the essence of the mechanism without forcing you to wade through pages of fMRI-related esoterica.

I'm happy to answer any questions :)

That's a cool experiment, and a well-written article, thanks!

I've had a tiny bit of experience dealing with the visual system in a related but distant field (the feedback loops of visual accommodation and vergence and conflicts that can emerge with stereoscopic 3d - and I wish I had understood and done actually insightful things..). This left me wondering about the important place of vision-based experiments in the theories of perception as well as consciousness. What are your thoughts about that subject? For example, would similar research be doable with other senses just as well, or is that something that we have a harder time grasping or even formulating (due to a certain bias towards vision) ?

edit: I've read the other comment about the double-take so in this case there seems to be some ways to test that out on other senses, but my question still holds when talking about the overall field and the prevalence of vision in this kind fo research

> For example, would similar research be doable with other senses just as well [...]?

Yes, very much so! I believe there is less bias towards vision than you think. Once you have a paradigm that works in vision, replicating it in other sensory modalities is generally low-hanging fruit for subsequent publication. I didn't get the sense that consciousness research was terribly biased towards vision. The fields of audition and haptics are alive and thriving.

Here's an experiment I did with MEG in the auditory domain:

http://www.unicog.org/publications/Marti%20Thibault%20Dehaen...

It's probably the projection of my own bias there, thanks for your perspective! (and for the link)

In all fairness, there probably is some bias towards vision. More exactly, there is bias towards things that are easy to study. Vision and audition are easy to study because screens and speakers are widely available. Touch and proprioception are harder, but still common. Smell and taste are rare.

So your point is far from crazy. However, there is sufficient multi-modal evidence that I don't think our current theories of access consciousness are mere visual artifacts.

Reply on news.ycombinator.com