Will Harrison
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willjharrison.bsky.social
Will Harrison
@willjharrison.bsky.social
Vision scientists and horror film enthusiast.

I also lecture at the University of the Sunshine Coast when I'm not at the beach.
Hi Mauro! From memory John Greenwood also didn’t replicate our “offset asynchrony” condition either. I wonder what the difference is?
November 25, 2025 at 8:58 PM
who does this guy think he is
November 21, 2025 at 9:20 AM
"I note, however, that when using natural image stimuli, image factors MUST differ between images. It is up to the researcher to determine which image statistics they are interested in, and which ought to be matched across [conditions]."

🍲🫖👺
November 21, 2025 at 9:20 AM
Looks like a really nice study. Seems like you replicated the preview effect we found, but not the post view increase in thresholds (what we called the "offset asynchrony" condition)?
November 21, 2025 at 12:01 AM
Awesome. I did indeed mean the oldest possible published reference :D I'll take the dusty one, thanks!
November 6, 2025 at 12:05 AM
Fantastic demo. Is there a paper I can cite if I use this in teaching?
November 4, 2025 at 10:56 PM
Yes but the specifics will matter. I'm referring to microscopic confound effect sizes that usually don't matter even when N = 100. For example, did the experiment instructions have the word "fast" in one condition and "quick" in another condition? Tiny real effects exist and will appear at higher N.
November 3, 2025 at 7:39 AM
I like the idea of doing my yearly fire safety training in the world of Left 4 Dead
November 1, 2025 at 12:57 AM
Reposted by Will Harrison
As this is my final PhD paper to be published, I want to give a special shout-out to my supervisors, @willjharrison.bsky.social and Jason. There’s no way to do them justice in 300 characters, so I’ve attached an excerpt from my thesis acknowledgements that still rings true today.

11/11
October 8, 2025 at 7:13 AM
doing the lord's work there David. Thanks.
October 9, 2025 at 3:14 AM
I swear the fact that if two more people cite this my h-index will get a bump has nothing to do with me sharing rn
September 24, 2025 at 8:42 AM
Yes I agree that it’s very easy to lose.

After 12,000 trials (plus all the piloting) I can attest to the effort required to allocate attention to force a certain figure-ground percept 🙃

link.springer.com/article/10.3...
Voluntary control of illusory contour formation - Attention, Perception, & Psychophysics
The extent to which visual inference is shaped by attentional goals is unclear. Voluntary attention may simply modulate the priority with which information is accessed by the higher cognitive functions involved in perceptual decision making. Alternatively, voluntary attention may influence fundamental visual processes, such as those involved in segmenting an incoming retinal signal into a structured scene of coherent objects, thereby determining perceptual organization. Here we tested whether the segmentation and integration of visual form can be determined by an observer’s goals, by exploiting a novel variant of the classical Kanizsa figure. We generated predictions about the influence of attention with a machine classifier and tested these predictions with a psychophysical response classification technique. Despite seeing the same image on each trial, observers’ perception of illusory spatial structure depended on their attentional goals. These attention-contingent illusory contours directly conflicted with other, equally plausible visual forms implied by the geometry of the stimulus, revealing that attentional selection can determine the perceived layout of a fragmented scene. Attentional goals, therefore, not only select precomputed features or regions of space for prioritized processing, but under certain conditions also greatly influence perceptual organization, and thus visual appearance.
link.springer.com
September 24, 2025 at 8:41 AM