Introduction
Many of us have adopted the habit of listening to podcasts, audiobooks, and other online content at higher playback speeds. For younger generations, it might even be the norm. A survey of California students revealed that 89% altered playback speeds for online classes, and numerous articles in the media have highlighted the widespread adoption of fast-forwarding.
Benefits of Speeding Up Content
It’s easy to think about the advantages of consuming content more quickly. It allows us to absorb more material in less time or review the same content multiple times to maximize understanding.
This could be particularly useful in an educational context, freeing up time to reinforce knowledge, practice skills, and so on. Watching videos at faster speeds might also be a good way to ensure attention and interest are maintained throughout, preventing the mind from wandering.
Drawbacks of Speeding Up Content
However, there are more drawbacks than one might initially consider.
When exposed to spoken information, researchers distinguish three stages of memory: encoding the information, storing it, and eventually retrieving it. During encoding, the brain needs time to process and comprehend the incoming words. Words must be extracted, and their contextual meaning retrieved from memory in real-time.
People typically speak at a rate of about 150 words per minute, and doubling the speed to 300 or tripling it to 450 words per minute is still within the range of what we consider comprehensible. The real concern, however, lies in the quality and longevity of the memories formed.
Incoming information is temporarily stored in a working memory system, allowing fragments of information to be transformed, combined, and manipulated until they are ready for transfer to long-term memory. Given the limited capacity of our working memory, too much information arriving too quickly can cause it to overflow. This results in cognitive overload and loss of information.
Fast Visualization and Information Retrieval
A recent meta-analysis examined 24 studies on learning from conference videos. While the designs varied, most involved playing a video conference to one group at normal speed (1x) and another group at a higher speed (1.25x, 1.5x, 2x, and 2.5x).
Similar to a randomized controlled trial used for testing medical treatments, participants were randomly assigned to either group and then completed identical tests after watching the video to assess their knowledge of the material. The tests consisted of recalling information or answering multiple-choice questions to evaluate their recall ability, or both.
Meta-analysis findings
The meta-analysis showed that increasing playback speed had increasingly negative effects on test performance. At speeds up to 1.5x, the cost was minimal. However, from 2x onwards, the negative effect was moderate to large.
To put this into context, if the average score of a student group was 75%, increasing playback speed to 1.5x would reduce the average score per person by 2 percentage points. Increasing speed to 2.5x would result in an average loss of 17 percentage points.
Age Matters
Interestingly, one of the studies included in the meta-analysis also investigated older adults (61 to 94 years) and found they were more affected by consuming content at faster speeds than younger adults (18 to 36 years). This could reflect a weakening of memory capacity in otherwise healthy individuals, suggesting that older adults should visualize content at normal speed or even slower playback rates to compensate.
However, it remains unclear if regularly speeding up content can mitigate its negative effects. Thus, younger adults might simply have more experience with fast playback and be better equipped to handle the increased cognitive load. Similarly, it’s unknown if younger individuals can offset negative effects on their information retention capacity by using fast playback more frequently.
Another unknown is whether watching videos at higher playback speeds has long-term effects on mental function and brain activity. In theory, these effects could be positive, such as increased capacity to handle greater cognitive load. Alternatively, they might be negative, like increased mental fatigue due to the higher cognitive load. Currently, there’s no scientific evidence to answer this question.
Lastly, even if speeding up content doesn’t affect memory performance, evidence suggests that the experience might be less enjoyable. This could impact motivation and learning experiences, potentially making people more likely to avoid it. However, fast playback has gained popularity, so perhaps users will adapt without issues. Hopefully, we’ll better understand these processes in the coming years.
Key Questions and Answers
- What are the benefits of speeding up videos? It allows for consuming more content in less time, reviewing material multiple times to maximize understanding, and potentially maintaining attention during educational content.
- What are the drawbacks of speeding up videos? It can negatively impact memory encoding, storage, and retrieval due to insufficient processing time for incoming words. Cognitive overload may result from too much information arriving too quickly, causing loss of information.
- How does age affect the impact of speeding up videos? Older adults (61-94 years) appear more affected by faster playback than younger adults (18-36 years), possibly due to a weakened memory capacity. Older adults might benefit from visualizing content at normal or slower speeds.
- Can regular fast playback mitigate its negative effects? There’s no evidence yet to confirm if regularly speeding up content can offset its drawbacks.
- What are the long-term effects of fast playback on mental function and brain activity? The potential positive effects include increased cognitive load handling capacity, while negative effects might involve heightened mental fatigue. However, there’s currently no scientific evidence to confirm these outcomes.
