What the studies actually compare
The core comparison is straightforward: people first do something mentally tiring, then look at natural scenery or urban scenery, and then take a working-memory test. Working memory is the short-term mental workspace used to hold and manipulate information, such as remembering a list of digits while doing something else with them. The studies differ in whether the scenery is viewed as images, videos, or a walk, and in whether the test is a digit-span task or a more complex operation-span task [1][2][3].
These design differences matter because a photograph on a screen is not the same experience as a walk outdoors. One study used a 30-minute walk in natural versus urban environments and measured working memory with the Operation Span task [3]. Another used nature versus urban images and a backward digit-span task [2]. A third used videos with natural versus urban scenery [4]. The question is the same, but the dose and type of exposure are not.
Where a benefit appears
Some results are consistent with a small restorative effect. One study found that observing nature, compared with urban scenery, had positive effects on verbal working memory after a depletion task [1]. Another reported that working-memory performance improved after viewing nature images but not urban-environment images [2]. These findings suggest that, under some conditions, nature exposure may help working memory recover.
The size of any benefit is likely modest. One study notes that prior work has suggested an effect size for working-memory improvements in nature of about g = 0.162 [3]. An effect size of this kind is a statistical way of expressing how large a difference is; 0.162 is generally considered small. That does not make the effect unimportant, but it means individual studies need enough participants to detect it reliably.
Where the benefit fails to appear
A stricter test found no working-memory benefit. A pre-registered within-subject experiment compared watching videos with natural scenery against a control with urban scenery and did not find that the nature videos restored working memory [4]. Pre-registration means the researchers specified their analysis plan before collecting data, which reduces the risk of finding a pattern by chance. This null result is important because it directly tests the same basic claim under controlled conditions.
The contrast between positive and null results does not necessarily mean one set of studies is wrong. It may mean the effect depends on the type of exposure. Watching a video is a weaker and more passive experience than walking in a natural environment [3][4]. It is also possible that the working-memory test used affects whether a benefit is detected, since different tasks place different demands on the mental workspace [1][2].
What this means for a curious reader
If you are asking whether a short dose of nature will reliably clear mental fatigue and restore working memory, the honest answer is: not reliably, and probably only slightly. The most controlled recent test found no benefit from nature videos [4], while other studies using images or walks report small improvements [1][2]. The balance of evidence suggests that nature exposure is not a dependable cognitive reset, but it may provide a small boost for some people under some conditions.
The practical implication is to treat nature exposure as a low-cost, low-risk option rather than a guaranteed fix. A walk outdoors may offer other benefits, but the working-memory evidence is not strong enough to promise restoration. The key unresolved question is which ingredients of nature exposure—duration, physical activity, real versus simulated scenery, or the specific working-memory task—determine whether a benefit appears [3][4].
Sources used in this answer
Restorative effects of observing natural and urban scenery after working memory depletion
Observing nature, compared with urban scenery, had positive effects on verbal working memory after a depletion task, as measured by a digit span test.
The Positive Impact of Exposure to Nature versus Urban-Environment Images on Cognitive Processing: Working Memory and Problem Solving
Working-memory performance improved after viewing nature images but not urban-environment images, measured with a backward digit-span task.
Measuring affect and complex working memory in natural and urban environments
A 30-minute walk in natural versus urban environments was used to examine working-memory changes with the Operation Span task, noting a prior suggested effect size of g = 0.162 for working-memory improvements in nature.
Does watching videos with natural scenery restore attentional resources? A critical examination through a pre-registered within-subject experiment.
A pre-registered within-subject experiment found that watching videos with natural scenery, compared with urban scenery, did not restore working memory.
