WEBVTT 00:00:00.000 --> 00:00:02.520 align:middle line:84% So Laura, we both do pupillometry research. 00:00:02.520 --> 00:00:05.230 align:middle line:84% But we use it in very different ways. 00:00:05.230 --> 00:00:09.990 align:middle line:84% So my own work focuses more on these evoked pupil responses, 00:00:09.990 --> 00:00:14.160 align:middle line:84% happen on a much smaller, quicker, time scale in the lab. 00:00:14.160 --> 00:00:17.730 align:middle line:84% Whereas you work more with steady-state changes, overall, 00:00:17.730 --> 00:00:18.930 align:middle line:90% in the pupil, right? 00:00:18.930 --> 00:00:20.160 align:middle line:90% Most of the time, yeah. 00:00:20.160 --> 00:00:22.800 align:middle line:84% So this means that I am capturing 00:00:22.800 --> 00:00:26.130 align:middle line:84% pupil data over a period of minutes, for example. 00:00:26.130 --> 00:00:28.980 align:middle line:84% And then taking an average of the pupil 00:00:28.980 --> 00:00:31.590 align:middle line:84% size across that period and comparing it 00:00:31.590 --> 00:00:35.890 align:middle line:84% to the average pupil size that's captured several minutes later. 00:00:35.890 --> 00:00:38.760 align:middle line:84% So these are capturing more slowly, 00:00:38.760 --> 00:00:42.300 align:middle line:84% unfolding changes that are in response to a condition that 00:00:42.300 --> 00:00:44.620 align:middle line:84% endures for a longer period of time. 00:00:44.620 --> 00:00:46.210 align:middle line:90% Great, really interesting stuff. 00:00:46.210 --> 00:00:48.480 align:middle line:84% And so what kind of things are you 00:00:48.480 --> 00:00:51.540 align:middle line:84% looking to capture with these longer time windows? 00:00:51.540 --> 00:00:54.900 align:middle line:84% Well, since I'm usually working with performing musicians, 00:00:54.900 --> 00:00:58.860 align:middle line:84% I'm usually looking at how the musicians are responding 00:00:58.860 --> 00:01:02.220 align:middle line:84% with their attention to a particular playing condition 00:01:02.220 --> 00:01:05.040 align:middle line:90% that I have set up. 00:01:05.040 --> 00:01:07.860 align:middle line:84% For example, I might have them playing 00:01:07.860 --> 00:01:10.320 align:middle line:84% for an audience for several minutes 00:01:10.320 --> 00:01:12.750 align:middle line:84% and compare this to their attention states 00:01:12.750 --> 00:01:15.180 align:middle line:90% when they're rehearsing. 00:01:15.180 --> 00:01:17.880 align:middle line:84% So I think this is quite different from what you're 00:01:17.880 --> 00:01:20.220 align:middle line:84% doing because I'm usually working 00:01:20.220 --> 00:01:23.490 align:middle line:84% in quite an ecological situation where 00:01:23.490 --> 00:01:25.440 align:middle line:84% I have to preserve the musician's 00:01:25.440 --> 00:01:26.430 align:middle line:90% normal way of behaving. 00:01:26.430 --> 00:01:30.570 align:middle line:84% But I think you're looking at actually a lot more detailed 00:01:30.570 --> 00:01:31.300 align:middle line:90% responses. 00:01:31.300 --> 00:01:34.890 align:middle line:84% So you cannot capture this kind of data out in the wild 00:01:34.890 --> 00:01:36.160 align:middle line:90% in the real world. 00:01:36.160 --> 00:01:40.140 align:middle line:84% Yeah, as much as I'd like to, I do have to bring people in 00:01:40.140 --> 00:01:44.157 align:middle line:84% and subject them to laboratory conditions which, so far, 00:01:44.157 --> 00:01:46.740 align:middle line:84% I can proudly announce only one person is fallen asleep on me. 00:01:46.740 --> 00:01:48.960 align:middle line:90% That's not too bad. 00:01:48.960 --> 00:01:50.550 align:middle line:84% Yeah, it's a totally different way 00:01:50.550 --> 00:01:52.230 align:middle line:90% of investigating these things. 00:01:52.230 --> 00:01:55.307 align:middle line:84% Because I think for these small changes, 00:01:55.307 --> 00:01:57.390 align:middle line:84% you really have to have very controlled conditions 00:01:57.390 --> 00:01:59.460 align:middle line:90% if you want to see the effect. 00:01:59.460 --> 00:02:02.190 align:middle line:84% And can we talk a little bit about what the process is 00:02:02.190 --> 00:02:06.900 align:middle line:84% for going from where you have just captured data to where 00:02:06.900 --> 00:02:08.729 align:middle line:84% you're prepared to analyse your data? 00:02:08.729 --> 00:02:12.600 align:middle line:84% I think you have a demonstration of what your data looks like 00:02:12.600 --> 00:02:14.790 align:middle line:90% just after you've captured it. 00:02:14.790 --> 00:02:18.900 align:middle line:84% Yeah, this is the output that we get directly 00:02:18.900 --> 00:02:21.600 align:middle line:90% from the eye tracker. 00:02:21.600 --> 00:02:26.040 align:middle line:84% So I work with an EyeLink system and it spits out these plots. 00:02:26.040 --> 00:02:28.800 align:middle line:84% Personally, I try to export it as early 00:02:28.800 --> 00:02:31.230 align:middle line:84% as possible to something that's a little bit more 00:02:31.230 --> 00:02:33.780 align:middle line:90% user-friendly for me, anyway. 00:02:33.780 --> 00:02:35.100 align:middle line:90% And so I've exported it. 00:02:35.100 --> 00:02:39.070 align:middle line:84% I get something that looks more like this. 00:02:39.070 --> 00:02:42.210 align:middle line:84% And as you can see, we have the subject number, some time 00:02:42.210 --> 00:02:43.320 align:middle line:90% stamps-- 00:02:43.320 --> 00:02:46.560 align:middle line:84% which will take a little bit of preprocessing, actually. 00:02:46.560 --> 00:02:48.930 align:middle line:84% Well, after a little bit of preprocessing magic 00:02:48.930 --> 00:02:54.200 align:middle line:84% which everybody will learn about sooner, or later this week, 00:02:54.200 --> 00:02:56.240 align:middle line:84% then we start to get prettier plots 00:02:56.240 --> 00:03:00.990 align:middle line:84% like this, where I can show the pupil trace over time. 00:03:00.990 --> 00:03:03.690 align:middle line:84% And I also work with averages, as well. 00:03:03.690 --> 00:03:06.120 align:middle line:84% And so I've got that showed here, as well. 00:03:06.120 --> 00:03:08.630 align:middle line:84% So this is an average, per condition, 00:03:08.630 --> 00:03:10.430 align:middle line:90% across number of participants? 00:03:10.430 --> 00:03:12.830 align:middle line:84% Yeah, so this is group level averages now. 00:03:12.830 --> 00:03:17.960 align:middle line:84% And you're looking at a rhythmic complexity that's increasing 00:03:17.960 --> 00:03:21.800 align:middle line:84% and the pupil will dilate with increasing rhythmic complexity. 00:03:21.800 --> 00:03:25.130 align:middle line:84% And this also is modulated by whether or not people are 00:03:25.130 --> 00:03:28.880 align:middle line:84% simply listening to it or if they're tapping and listening. 00:03:28.880 --> 00:03:29.990 align:middle line:90% This is very interesting. 00:03:29.990 --> 00:03:32.600 align:middle line:84% Yeah, so what's your data look like, actually? 00:03:32.600 --> 00:03:36.450 align:middle line:84% Well, this is an example of what some of my data looks like. 00:03:36.450 --> 00:03:41.150 align:middle line:84% This is data, just in the software 00:03:41.150 --> 00:03:45.480 align:middle line:84% that is used to do the initial stages of processing. 00:03:45.480 --> 00:03:49.160 align:middle line:84% And so here you can see the video, actually 00:03:49.160 --> 00:03:51.950 align:middle line:84% that's captured from the mobile eye trackers. 00:03:51.950 --> 00:03:53.990 align:middle line:84% And you can see on the bottom there's 00:03:53.990 --> 00:03:56.730 align:middle line:84% some indication of the pupil curve. 00:03:56.730 --> 00:03:58.610 align:middle line:90% So this is the pupil data. 00:03:58.610 --> 00:04:01.640 align:middle line:84% This is interesting and useful to look 00:04:01.640 --> 00:04:03.410 align:middle line:84% at the quality of your data and see 00:04:03.410 --> 00:04:05.270 align:middle line:90% what's going on with the gaze. 00:04:05.270 --> 00:04:07.190 align:middle line:84% But, actually, I would also prefer 00:04:07.190 --> 00:04:10.670 align:middle line:84% to export my data into a text format. 00:04:10.670 --> 00:04:14.095 align:middle line:84% And mine looks quite similar to yours. 00:04:14.095 --> 00:04:17.200 align:middle line:90% 00:04:17.200 --> 00:04:21.480 align:middle line:84% So it's just a lot of time stamps, participant numbers, 00:04:21.480 --> 00:04:24.090 align:middle line:90% and pupil sizes. 00:04:24.090 --> 00:04:29.400 align:middle line:84% And so after processing this kind of data, 00:04:29.400 --> 00:04:34.870 align:middle line:84% I would end up with plots that look like this, for example. 00:04:34.870 --> 00:04:39.220 align:middle line:84% So these are violin and box plots together, 00:04:39.220 --> 00:04:40.970 align:middle line:84% which I find is a useful way of showing 00:04:40.970 --> 00:04:44.910 align:middle line:84% the distribution of data once you've aggregated it, 00:04:44.910 --> 00:04:48.940 align:middle line:84% in this case, per condition across many participants. 00:04:48.940 --> 00:04:52.140 align:middle line:84% So you can see the way that the data is distributed 00:04:52.140 --> 00:04:53.570 align:middle line:90% within each condition. 00:04:53.570 --> 00:04:55.890 align:middle line:84% Yeah, you can see that some of them, like the grey one, 00:04:55.890 --> 00:04:58.020 align:middle line:84% are quite skewed towards the low end. 00:04:58.020 --> 00:04:59.160 align:middle line:90% Yes, yes. 00:04:59.160 --> 00:05:01.770 align:middle line:84% So this is also a good way of checking 00:05:01.770 --> 00:05:04.320 align:middle line:84% the quality of your data and making sure you're not 00:05:04.320 --> 00:05:05.490 align:middle line:90% missing anything. 00:05:05.490 --> 00:05:07.530 align:middle line:90% Beautiful. 00:05:07.530 --> 00:05:09.120 align:middle line:90% Now we want to hear from you. 00:05:09.120 --> 00:05:12.350 align:middle line:84% How do you plan on using pupil analysis? 00:05:12.350 --> 00:05:23.000 align:middle line:90%