From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bobcat.rjmcmahon.com (bobcat.rjmcmahon.com [45.33.58.123]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 642583CB41 for ; Fri, 17 Nov 2023 12:27:57 -0500 (EST) Received: from mail.rjmcmahon.com (bobcat.rjmcmahon.com [45.33.58.123]) by bobcat.rjmcmahon.com (Postfix) with ESMTPA id 6D9591B252; Fri, 17 Nov 2023 09:27:56 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 bobcat.rjmcmahon.com 6D9591B252 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rjmcmahon.com; s=bobcat; t=1700242076; bh=KwQly7x4oLASOLXRb5HVuIgS9nuI1UlyQsq8mNkAGmc=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=lMUzaCpuDZyNbVaq3ai8u7vzjwA8GGP07ppQJLD6q0OIqjvogyeOEJ45twAZGQrLy duKuEdnsDg/PMizIiDg0WhnrW6Y/lsEgRuPv3d1+ckWUE9NJCUvOuXQQqJnQDPfQLi ILHD4r9P4wOKDlvCEOk4uVb1ooERXwCAUkSPhfy0= MIME-Version: 1.0 Date: Fri, 17 Nov 2023 09:27:56 -0800 From: rjmcmahon To: =?UTF-8?Q?Network_Neutrality_is_back!_Let=C2=B4s_make_the_technical_a?= =?UTF-8?Q?spects_heard_this_time!?= In-Reply-To: References: Message-ID: <965f84c27d3d7c00ebcbaae5382234cd@rjmcmahon.com> X-Sender: rjmcmahon@rjmcmahon.com Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Subject: Re: [NNagain] Fwd: separable processes for live in-person and live zoom-like faces X-BeenThere: nnagain@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: =?utf-8?q?Network_Neutrality_is_back!_Let=C2=B4s_make_the_technical_aspects_heard_this_time!?= List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 17 Nov 2023 17:27:57 -0000 The human brain is way too complicated to make simplified analysis like this is the latency required. It's a vast prediction machine and much, much more. I found at least three ways to understand the brain; 1) Read A Thousand Brains: A New Theory of Intelligence 2) Make friends with high skilled psychologists, people that assist world athletes can be quite good 3) Have a daughter study neuroscience so she can answer my basic question from an expert position Bob > sending again as my server acted up on this url, I think. sorry for the > dup... > > ---------- Forwarded message --------- > From: Sebastian Moeller > Date: Fri, Nov 17, 2023 at 3:45 AM > Subject: Re: [NNagain] separable processes for live in-person and live > zoom-like faces > To: Network Neutrality is back! Let´s make the technical aspects heard > this time! > Cc: , Dave Täht > > > Hi Dave, dear list > > here is the link to the paper's web page: > https://direct.mit.edu/imag/article/doi/10.1162/imag_a_00027/117875/Separable-processes-for-live-in-person-and-live > from which it can be downloaded. > > This fits right in my wheel house# ;) However I am concerned that the > pupil diameter differs so much between the tested conditions, which > implies significant differences in actual physical stimuli, making the > whole conclusion a bit shaky*)... Also placing the true face at twice > the distance of the "zoom" screens while from an experimentalist > perspective understandable, was a sub-optimal decision**. > > Not a bad study (rather the opposite), but as so often poses even more > detail question than it answers. Regarding your point about latency, > this seems not well controlled at all, as all digital systems will > have some latency and they do not report anything substantial: > "In the Virtual Face condition, each dyad watched their partner’s > faces projected in real time on separate 24-inch 16 × 9 computer > monitors placed in front of the glass" > > I note technically in "real-time" only means that the inherent delay > is smaller than what ever delay the relevant control loop can > tolerate, so depending on the problem at hand "once-per-day" can be > fully real-time, while for other problems "once-per-1µsec" might be > too slow... But to give a lower bound delay number, they likely used a > web cam (the paper I am afraid does not say specifically) so at best > running at 60Hz (or even 30Hz) rolling shutter, so we have a) a > potential image distortion from the rolling shutter (probably small > due to the faces being close to at rest) and a "lens to RAM" delay of > 1000/60 = 16.67 milliseconds. Then let's assume we can get this pushed > to the screen ASAP, we will likely incur at the very least 0.5 refresh > times on average for a total delay of >= 25ms. With modern "digital" > screens that might be doing any fancy image processing (if only to > calculate "over-drive" voltages to allow or faster gray-to-gray > changes) the camera to eye delay might be considerably larger (adding > a few frame times). This is a field where older analog systems could > operate with much lower delay... > > I would assume that compared to the neuronal latencies of actually > extracting information from the faces (it takes ~74-100ms to drive > neurons in the more anterior face patches in macaques, and human > brains are noticeably larger) this delay will be smallish, but it will > certainly be only encountered for the "live" and not for the in-person > faces. > > > Regards > Sebastian > > P.S.: In spite of my arguments I like the study, it is much easier to > pose challenges to a study than to find robust and reliable solutions > to the same challenges ;) > > > #) Or it did, as I am not directly working on the face processing > system any more > *) Pupil diameter is controlled by multiple factors, ranging from its > "boring" physiologic function as adaptive aperture the visual system > uses to limit the amount of light hitting the retina, to some effect > of cognitive processes or states of the sympathetic nervous system see > e.g. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6634360/ the paper, > IMHO does over play the pupil diameter reasponses by not acknoledging > that these might result from things as boring as not having the true > faces and zoom faces sufficiently luminosity matched. > **) Correcting the size of the projected image to match in degrees of > visual angle only gets you so far, as we do have some sense of > distance, so the same visual angle at 70cm corresponds to a smaller > head/face than the same visual angle at 140cm... this is both > nit-picky, but also important. I also note that 70cm is at the edge of > a typical reach distance, while 1.4 m is clearly outside, yet we do > treat peri-personal space with-in effector reach differently from > space beyond that. > > >> On Nov 16, 2023, at 22:57, Dave Taht via Nnagain >> wrote: >> >> Dear Joy: >> >> good paper that extends the idea of zoom fatigue into something closer >> to zoom-induced somnolence. Thanks for doing this kind of detailed >> measurements! >> >> I would be very interested in a study of brain activity while varying >> latency alone as the variable for videoconferencing. One being say, a >> live video feed between the participants (0 latency) vs zoom (at >> 500ms), or with one jittering around, or one at, say 60ms vs 500ms. I >> tend to be much happier after a day using "galene.org" which tries for >> minimum latency than zoom, and still find my ability to interact >> quickly across a dinner table hard to get into after too many hours on >> it. Are y'all pursuing further studies? >> >> The link to the paper is mildly puzzling in that the token is >> required, and I am assuming that perhaps it is generating a >> watermarked version differently on every download? >> >> https://watermark.silverchair.com/imag_a_00027.pdf?token=AQECAHi208BE49Ooan9kkhW_Ercy7Dm3ZL_9Cf3qfKAc485ysgAAAzQwggMwBgkqhkiG9w0BBwagggMhMIIDHQIBADCCAxYGCSqGSIb3DQEHATAeBglghkgBZQMEAS4wEQQMBvAQsisJ_ABhWglzAgEQgIIC5womb1HIyE-rX0v_xte9EwVGyabIjMO6g80txKAFqHmQPVEv7FostAfIK-4yXUZnSyLivNxp6pummVVwxB_kCJEyG2DtAH2R8ywkWTTjGw22vpotfz5injZM6fMRQNyTq8dcjtMTTFpEjbsrbupEoMFo7Z0wxqV8bmbPD8xO6hu1T8I8gg5579PZNHt7-PMNgqJVlEaxPY3nMvc1XkKYdh1RIhFetQkAdhhro2eWfu_njMvzdRWVeN2ohY6OnSJSDljWiWxyUOqnKX6tps2XFtVBWUh2sE3HK-EsI-w0EmpBlAC7huyQsXkXW7tmPOwA7yiGQm4uSfcOn_EKGhvzhjHsdP8Mm1QJat6_rWSPZZGwhFzPB2Wl92DDfiSOesKKQBv_OvmGc3FUmFAhqIeAlzlyNkdBydk2hQqvS46OTGfdBEvwpIH_AZclDiLeuyJPP5v2YaoByFQ7w4uXHMyNhEo5mR2_pQ3WM7CpzknZixRvA5TQySW830iH0k00QZwt6a3nphgV6R4int5Pl-QdmCKzFoJ2EuPIBKvG9H5yBq18E6r1jyk1mdFKpo0-OEpLNIBpGm-1SomHw2qo5uCRWoAW6MO7K-sKZokirXGgJ7rIdRznq3BXvYxFKVn7tqJlIAAX6qDrC0bkefj8PEweuk2zIraj1Ri3otbdX3h0zBsKgmdY6qiOn8LtyxIy3vvXLnbiaIColztgAt1cHuI6b0w3rLg7BGSE2cetBDTyGS9OS0NKq91xqljwDAZBFkuKwtfYLzxIeeBy4KrG- PBqGtUEholGjHHyKCwxytw12qvgrTjdX7cXhYJSrs-HBJtRgiP5Yb6DJAQrlqEKeGnyTlPv2o3jNVvT0CZ9zWX8Qm0O6wiGo1PqpxCM3VLw0VXVsWcHJ39eLYN30GuHznYCaH5INdtgZoJdQbmZO3o_tF7itz1uYHItxNK_ZQ3oFKoUQd0e7sx51xaFj6VnNNo39Ms3mdyEQOEp >> >> >> -- >> :( My old R&D campus is up for sale: https://tinyurl.com/yurtlab >> Dave Täht CSO, LibreQos >> _______________________________________________ >> Nnagain mailing list >> Nnagain@lists.bufferbloat.net >> https://lists.bufferbloat.net/listinfo/nnagain