We live on the age of content. There are hours upon hours of videos and podcasts that have been and continue to be created every single day, and since everything is interesting and we are short on time, the most obvious solution is to detox from social media and try slow living. Well, that might be true, but the reality is that we are a lot more prone to just put everything at twice the upload speed to try to get to everything and not miss out. The problem with this is that, despite technically consuming the content, we might be doing to our brains a lot more harm than good, as doing this can cause cognitive overload and what may be worse, not retaining anything we have consumed.
That might have been a bit dramatic, but it really is a trend nowadays that younger people listed to most things, even important ones like university lectures at 1.25x or 1.5x minimum speed. The reasoning seems sound, you can consume more material in less time, or rewatch the same video multiple times to really make it stick, which if you are a student, will give you extra time for practice quizzes or note review. Plus, no one said that all lectures are interesting or that lecturers are engaging, and so many have discovered that they focus better when the pace is fast, and are reducing the chance of zoning out halfway through.
The issue with speeding up your content
Our brains have evolved through millennia to what they are now, and they have a very specific way of handling spoken information. Basically, there are three stages: encoding, storing, and retrieving. When you first hear something, your brain needs a moment to make sense of it, which entails breaking it into pieces, attaching meaning to those pieces, and pulling related info from memory.
Most people speak around 150 words per minute, but we can usually keep up even if that doubles or triples, but that is not the problem, as we do not need to just understand, we need to remember information. All the information that we hear is first stored in our working memory, but this memory has a maximum capacity, so if we dump too much information into it too fast, it will go away before it can become long-term memory, and that is when we stop learning.
Science backs this up, a recent meta-analysis looked at 24 different studies where people learned from watching lecture videos. Some watched them at regular speed and others at faster rates, 1.25x, 1.5x, even up to 2.5x. Everyone took the same test afterward, which usually involved recalling facts or answering multiple choice questions and the results were clear, as playback speed went up, test performance went down.
Up to 1.5x, the drop was pretty minor, but once viewers hit 2x speed or more, the decline became more noticeable. For example, if students normally scored around 75%, turning up the speed to 1.5x might knock off just 2 points. But at 2.5x speed it could mean losing 17 points on average. Another interesting twist came from comparing the result by age, younger adults (18–36) did better when it came to fast playback but those in the older brackets (61–94) struggled a lot more. This might be because memory capacity tends to decline with age, even in otherwise healthy individuals, but we are not sure whether the negative effects can be reduced with practice like other types of cognitive impairments.
We also do not know yet if this habit of fast-watching will have long-term effects, positive or negative, on the brain, as maybe regularly pushing your brain to process things faster could improve how it handles tough mental tasks. Or maybe it leads to burnout or mental fatigue.