Psychological / physical effects of frame rate on the human body

[CyclingBen]

I’ve been contemplating some of the ideas posited in this article for the last few weeks:

As time passes

I’ve also read other “research” from a specific political party in Germany from the 30s and 40s that came to some similar conclusions.

12-24 fps is similar to how our brain dreams and when we are at rest with no threats around. Normal or lower heart rate and blood pressure.

30-48 fps slightly heightened awareness. Your brain is primed for something to happen, good or bad. Increased respiration and heart rate.

50-96 fps our brains enter flight or fight mode. Increased heart rate and blood pressure. Threats perceived.

100-180 fps our brains sense something isn’t right and we are primed to act. 
 

I don’t post this to say that one frame rate is better than another. I found it interesting from a creator perspective and also from a parenting / health perspective.

Most sports are at 50 or 60 fps and our brains are primed for and expecting something exciting to happen. What about cable news that is at 60 fps? Is that why so many people get addicted to it and enraged by it?

Video games are generally 60 fps to 120fps is that why I personally have trouble falling asleep after playing?

Most animation is 12 or 24 fps, is that part of the reason why old Chip n Dale cartoons calm my children down?

My wife didn’t seem to care about it, I thought all of you might find it interesting.

[EduPortas]

3 hours ago, CyclingBen said:

12-24 fps is similar to how our brain dreams and when we are at rest with no threats around. Normal or lower heart rate and blood pressure.

There's a huge difference between 12-24 fps.

As mentioned here various times a great deal of experimentation was requiered to place the exact number of fps for something to look "right" at 24.

8-12-14-18 look very dreamy for sure yet no quite "right".

The other and much higher fps you mentioned from the article look sharper = more real = more prone to danger.

[fuzzynormal]

Gotta start making horror films @120fps.

[ac6000cw]

On 8/16/2024 at 10:08 PM, CyclingBen said:

I’ve been contemplating some of the ideas posited in this article for the last few weeks:

As time passes

I’ve also read other “research” from a specific political party in Germany from the 30s and 40s that came to some similar conclusions.

12-24 fps is similar to how our brain dreams and when we are at rest with no threats around. Normal or lower heart rate and blood pressure.

30-48 fps slightly heightened awareness. Your brain is primed for something to happen, good or bad. Increased respiration and heart rate.

50-96 fps our brains enter flight or fight mode. Increased heart rate and blood pressure. Threats perceived.

100-180 fps our brains sense something isn’t right and we are primed to act. 
 

I don’t post this to say that one frame rate is better than another. I found it interesting from a creator perspective and also from a parenting / health perspective.

Most sports are at 50 or 60 fps and our brains are primed for and expecting something exciting to happen. What about cable news that is at 60 fps? Is that why so many people get addicted to it and enraged by it?

Video games are generally 60 fps to 120fps is that why I personally have trouble falling asleep after playing?

Most animation is 12 or 24 fps, is that part of the reason why old Chip n Dale cartoons calm my children down?

My wife didn’t seem to care about it, I thought all of you might find it interesting.

By my reading of the research paper you linked to, the frame rate of the video made no significant difference to the perception of time (which is what was being tested). The speeding up and slowing down of the video by 20% (which was of people walking across an indoor market) did change the test subjects estimation of time after watching 8 minutes of speed-changed video (which could be described as a subtle form of brainwashing/suggestion, to produce a temporary 'new normal' perception of time):

Manipulating viewers perceptions/expectations is how many movies work e.g. lull the viewer into a relaxed state with characters chatting in a cafe - then suddenly a bomb goes off outside and all hell breaks loose...

[JulioD]

Douglas Trumbull is a VFX legend. His first credit is 2001.  He has said many times he tested HFR on people, but it was never exactly published.  You find general quotes online like this…

 

“What reaction did you get when you showed the higher frame rates to viewers? 

We did tests at 24, 36, 48, 60, 66 and 72fps. We filmed a first person point of view shot in a car driving down a winding road. We brought in people to look at these movies at these frame rates, and hooked them up to an electrocardiogram [records electrical activity in the heart], electroencephalogram [records electrical activity on the scalp], galvanic skin response [measures electrical conductivity of skin], and electromyogram [records electrical activity in muscles]. We found out that people’s physiological stimulation levels would rise tremendously as a result of frame rate. It showed a perfect bell-shaped curve that peaked around 66 frames per second. We created the company Showscan, raised money, and started making films at 60 frames per second in 65mm format. We saw only a very subtle difference between 60 and 66fps, and so that was where we set Showscan.”

(Don’t forget he’s talking about film, not digital and it’s a hell of thing to make a film projector run that fast. They sure are noisy.)

He just died recently.  With the Hobbit failure I do remember him coming out and saying HFR isn’t good for drama, it should be used for heightened experienced only, but more recent comments were more that 120FPS was the answer!

Think about it though.  Do you want everyone’s heart rate RAISED for a 2 hour movie?  

[Ilkka Nissila]

Since motion in the physical world causes changes in our field of vision which are not limited to a discrete frame rate (essentially the frame rate is infinite), and this causes no psychological adverse effects, I would argue that the frame rate itself has only a minor effect on perception if it is fast enough. The human vision of course has limited speed of observation of events, and when this is combined with a discrete frame rate of presentation of a video it can cause a different perception than seeing motion in real life. There is also the effect of camera shutter speed on perception of movement. I would argue that if the video is taken at a very fast rate and presented at the same rate, a higher fps would result in a more natural perception of movement than slow frame rates. However, most monitors operate at 60 fps (while some displays and TVs can operate at the fps rate of the source) and so this kind of a fully continuous movement cannot be conveyed perfectly and the video always looks a bit different from seeing the action with one's own eyes in real life, due to technological limitations (which may be lifted over time). Whether one wants to present video like things look in real life or as purposefully different from real life, to make sure the viewer immediately sees that it's a fantasy, an illusion (not only frame rate, but deliberate use of colour, costumes, and lighting contribute to this). Probably there will be both in the future: "as-is" presentation of events such as sports etc. where realistic presentation is the aim, and more stylized "artistic" films which tell fictional stories. Television in Finland has moved from analog (quite fuzzy) to SD to HD and now 50 fps as standard and a lot of the footage probably is shot on 4K sensors now, allowing a higher-quality HD presentation. This was evident in watching the Paris Olympics, the picture quality has evolved quite amazingly over the past 20 years and this really helps in seeing clearly the sports events and it was really a pleasure to watch.

I didn't read the paper you linked carefully, I briefly skimmed through it, but it left me the impression that they were comparing speeded-up or slowed-down footage to normal speed (25 fps and 50 fps capture were used in some experiments, but didn't seem to have statistically significant effects) and I don't think the psychological effects were attributed so much to frame rate of capture but simply presenting the video at the "wrong" speed and how that affected the perception of time. Just by shooting at 120 fps and presenting at 120 fps (if you can find a monitor that will display at 120 fps) is unlikely to have any adverse psychological effects as it simply makes the video more fluid and realistic. Slow flickering can cause the brain to have to work harder and it can also trigger epileptic seizures on rare occasions. But use of faster frame rates that go beyond the ability of the brain to notice the frame changes as discrete steps should not cause problems as long as there are no dark frames etc. (With CRT displays the image was never really stable but flat displays don't show visible flicker when the content is static).

>Most sports are at 50 or 60 fps and our brains are primed for and expecting something exciting to happen. What about cable news that is at 60 fps? Is that why so many people get addicted to it and enraged by it?

 

I doubt it. It's likely the presented content that causes those effects.

 

>Video games are generally 60 fps to 120fps is that why I personally have trouble falling asleep after playing?

 

In that case the image is synthetic and there could be a number of issues that cause agitation compared to seeing things in the real world with one's own eyes. For sure games are designed to get the players hooked and addicted so they don't stop playing. They even collect user behavioral data to adjust the games to become more addictive. Again, I doubt the frame rate is responsible for these effects, at least not as a primary factor, but the presented content and the nature of the interaction between the game and the player. One factor  that is known to increase arousal is the presence of blue light in the display light. This can cause problems falling asleep. I got these blue-light blocking eyeglasses some years ago and my sleep quality and falling-asleep times immediately improved which I was very happy about. I do spend a lot of time at screens though not playing games. Another way to fight these issues is simply not to play games for 1-2 hours before going to bed.