I recently woke up, remembering a dream that tied together the following:
- how does our consciousness surface a certain subset of the huge amount of input that is processed in the brain?
- how can we best handle all of the events in our computing systems, and render a UI that represents a valid state?
- how can we build a UI representation that helps users, with their consciousness, actually get something useful done?
It wasn’t shocking that I had this dream, given that I fell asleep listening to Anil Seth as a guest on Sam Harris’ podcast, which I turned on right after coding.
When we write programs that model the world, one of the areas that we often struggle with is the notion of representing time, and how state changes over time. It is a source of many bugs, and has lead many to look toward immutable state as a way to avoid foot guns. Rich Hickey famously explains his experience on the topic in Are We There Yet?
How our consciousness batches time
When you zoom in with concurrency and time, you get into the notion of something happening at the same time. At first blush this is a simple concept, but when you look deeper at how our consciousness deals with this, it is fascinating. As we get new tools to probe the brain, we are uncovering a lot of new information, such as learning that decisions have been made before you thought you made them.
Simple experiments show the layers of filtering and input changing that occurs. If you touch your finger to your nose, it always “feels” like the touch happens at the same time for both digit and nose, yet your arm is longer than your nose. Inputs from the nerves must reach the brain at slightly different times at therefore at some point they get put together as a batch.
It appears that our component systems are getting masses of input that we are processing, and there is competition for the right level of info to reach our consciousness. We can direct things at times (e.g. we can take control of our breathing, but fortunately don’t have to focus on it to always happen) but mostly we are observing and our consciousness is revealing what has happened.
Back to programming
This shares some similarity with painting the right UI for our users (and vsync). We can gather information from our components, batch together the state, and prioritize what to render. With the appropriate amount of complexity in our state, especially considering the difference between app state and UI state, it may make sense to use a system such as Redux to manage the batching, or maybe you prefer TJ’s state management library https://twitter.com/tjholowaychuk/status/957853652483416064.
Elsewhere, it is common to debounce, sometimes with exponential backoff, to make sure we aren’t wasting a lot of time and resources.
Immutability also has huge side benefits. We can save snapshots that enable improved testing and time travel debugging. Also, any excuse to bring back a VCR is surely a win 😉
Using the past to change the future
Having snapshots of state is one thing, but what about using old states to help you in the now? While we often save past state snapshots, we don’t often use them in rich ways to help change future state, but your brain does just that. Experiment after experiment shows the importance of context.
This video shows how you can be primed to see color in a black and white photo. There are examples of this across our senses. You can listen to some audio that sounds like gibberish, hear key words, and listen to it again and suddenly you understand the gibberish.
Examples of illusions fill books, and are what magicians use to trick our senses. This all makes me wonder if we are going to see richer ML models that help the user based on the past context?
Good UI is magic
A lot of this trickery feels like magic and illusion. This is absolutely true, but great UI is jam packed with this type of illusion. We can use motion and progressive rendering to make it feel like things are happening, keeping the user engaged. We can make sure to prioritize which parts of the UI to update and delay on others.
To do this correctly, often requires you to take the time to map out the SLO of various pieces. For example, when you visit an e-commerce product page, show the core information asap, and wait on data below the fold such as reviews. You should also consider the freshness requirements across these elements too (e.g. the price has to be fresh, but you don’t need to block on that new review!).
I am having a lot of fun learning about how the brain works, and our psychology, and have a feeling like this knowledge is going to be useful for our industry as we get better at delivering UI that truly helps our users consciousness understand the view of the world that matters to them as they get done what they need to get done.
Isn’t building software products fun?