Marius 't Hart

This data was recorded in 2022 or so... I finally got my act together to finish all the data analyses. But... data does not expire!

If you want to get your 2 cents in before we get reviews from the journal, now's your chance!

We find that the influence of the frame extends somewhat in space, but not in time. Motion signals don't play much of a role; the frame effect is dominated by the perceived position of the frame. This tells us that our visual system localizes objects relative to their reference frame.

Here we test what happens when there are offsets in space and time between the frame and probes. And technically also effects of two motion signals apart from those of the frame. Videos linked in the pdf!

Frame Effects Across Space and Time When two probes are flashed at different times within a moving frame they can be perceived as dramatically separated from each other even though they are at the same location in the display. This effe...

Preprint: Frame Effects Across Time and Space (FEAST): www.biorxiv.org/cgi/content/...

In the frame effect people perceive a large horizontal separation between two horizontally aligned flashed probes when they are flashed within a left-right moving frame.

Agree with most stuff. Gaming the numbers is impossible if we don't rely on them anymore: reading > h-index, yes! But APCs are used by good journals to make science more open. Maybe Math is less open? Or preprints already make it open?

Interview with Ilja Agricola (from Marburg) about publication fraud in math.

retractionwatch.com/2025/09/24/m...

tomatoes, onions and garlic roasting on a baking sheet on a BBQ

pergola partially overgrown with Ivy with some patio lights in the evening

bee with big clumps of pollen sucking nectar out of a flower on a butterfly bush

hummingbird drinking from a feeder hanging from a pergola

Enjoying the end of summer!

The myth of optimality in human movement science The concept of optimality dominates contemporary human movement science, with researchers across biomechanics, motor control, and neuroscience routine…

The myth of optimality in human movement science

www.sciencedirect.com/science/arti...

This shows that dual adaptation experiments can be done in standard VR setups, opening new research questions to be tested in more immersive settings and with more freedom of movement.

However, the incongruent movement group learned about as much as the single adaptation group. This reproduces effects of lead-in movements on dual adaptation, as found before.

The congruent movement tools and color control groups only learned within each 8 trials, showing that color didn't work, as expected, but also that the tool identity was not sufficient for dual adaptation.

In 4 groups, people switch between tools and rotations every 8 trials: 1) using two different colored paddles (color control), 2) using the paddle and curling rod (congruent movement), 3) the paddle and slingshot (incongruent movement) or 4) use one tool for a long time (single adaptation).

People used one of 3 tools for this: an air-hockey paddle and a curling rod are moved forward, and either impact with the ball, or shove it for some time. There is also a slingshot that is pulled back and released to launch the ball.

In this paper, Andrew King looked at tools as cues for dual adaptation. He used a VR task, where a ball had to be launched to a target with a 30 degree rotation.

With @deniseyph.bsky.social and @jjodx.bsky.social as well as Gaurav Sharma and Mireille Broucke.

In this paper we use a new approach from control theory (engineering), a "disturbance observer", to see if it can be applied to visuomotor adaptation. This "DO model" is doing reasonably well.

Looking for a suitable journal now, feedback welcome in the meantime!

6. The 38 older participants were not different from the others. Don't worry too much about getting older!

5. Neither the speed nor the extent of learning could be predicted by any of our measures. Like some -but not all- previous findings, this argues against the eploration-exploitation hypothesis.

4. Visually guided reaches and both measures of proprioception showed comparable levels of precision, with only no-cursor reaches showing increased noise. I.e. proprioception is not necessarily noisy.

3. In contrast to our previous attempt to gauge the contribution of efferent-based signals in our measure of proprioception, we now find a small contribution. This still indicates that proprioception plays a large role in estimating the state of our limbs.

2. There are the expected relationships between precision in the directions of reaches with and without visual feedback and also between our two measures of proprioception: active and passive hand localization.

1. The main finding is that implicit reach aftereffects are best predicted by a combination of aligned proprioceptive precision and the amount of proprioceptive recalibration.

In this study @deniseyph.bsky.social and I take data from 4 previous studies, and their pilots, with N=270 to look into potential relationships between precision of reaching directions and proprioception and various other measures.

Very happy to share my first preprint on proprioception and aging. Check it out! doi.org/10.1101/2025...

A big thanks to @jjodx.bsky.social

These boxes are not moving. A mind-bending optical illusion by Japanese artist Jagarikin.

Are you telling me it's different in British academia, but in a very indirect way? 😉

Why the Dutch don't say sorry There's one thing the Dutch rarely do: saying sorry.

interesting... to me, the brits are not direct at all... bbc.com/reel/video/p...

I guess it's time to donate to Brent Sutton's campaign ahead of the by-election

Here's a pdf: mariusthart.net/NCM_2025_tHa... And I'd be happy to chat about it!