Home > Attention, Memory > You will remember this post. Why? Because it is weird!

You will remember this post. Why? Because it is weird!


Did you notice that you are actually very good at remembering weird things? You may not remember every single person who walks a dog on your way home because it’s just normal. However, if you see a dog walking a dog, you are very unlikely to forget the dogs. Why? Because they are weird! As you may expect, research supports that people do remember “weird” things better than normal things.

Von Restorff (1933) demonstrated that people are more likely to remember a distinctive item in a list of homogeneous items than in a list of heterogeneous items (e.g., an orange in a bunch of bananas vs. an orange in a bunch of different fruit). This is called the Von Restorff effect or the isolation effect.


In reality, the isolation effect is common in our daily life. For example, you are more likely to remember the yellow bottle in a set of purple bottles due to its distinctive color. People can easily achieve a physical isolation effect by manipulating color, size, and spacing of the items (e.g., Cimbalo, Capria, Neider, & Wilkins, 1977). Gumenik & Levitt (1968) also found that the effect is stronger when the contrast between the isolated item and the background is larger.

In addition to physical distinctiveness, semantic distinctiveness can also produce the isolation effect. Semantic isolation requires people to interpret the meaning of the isolated item. A classic way to study physical and semantic isolations in a lab experiment:

  1. Researchers present word lists that consist of about ten homogeneous words and one distinctive word to the participants.
  2. Then they ask them to report whatever they remember from the lists and check whether participants remember the distinctive word better.

Physical isolation can be created by making the isolation word’s color/font different from other words(e.g. sky, blue, sun, car, bird, etc.), and semantic isolation can be created by inserting an isolation word that doesn’t belong to the same category that other words belong to (e.g., black, green, yellow, car, blue, etc.).




So, what does the isolation effect require? Early explanations proposed that people remembered the distinctive item better because they paid more attention to it when they saw it (e.g., Jenkins & Postman, 1948). The amount of attention paid during a certain task determines whether the task is more automatic or more controlled. Automatic processes don’t need attention while controlled processes need attention. For instance, breathing is usually automatic, while learning how to dance is usually controlled because you really need to pay attention to follow up the motions. Therefore, how attention can affect people’s performance on certain tasks depends on what processes (i.e. automatic or controlled) the task involves.

Bireta and Mazzei (2015) propose that we process other things’ physical characteristics in automatic processes and their semantic characteristics in controlled processes. For example, we don’t need to pay attention to notice a red word in a bunch black words,  but we need to pay attention to understand which category that word belongs to.

Then they performed an experiment to examine whether physical and semantic isolation effects require attention. Participants were shown with lists of words and completed memory tests on those words. The word lists are consist of eleven homogeneous words and a distinctive word. There were two types of lists: a list that contains a word that doesn’t belong to the category of other words in the list (semantic isolation) and a list that contains a word of a different color (physical isolation). When studying the words, half of the participants fully focused on the words while another half of participants were distracted by another task. The performances on memory tests showed that both focusing participants and distracted participants memorized the word of different color better than other normal words in the list. However, only focusing participants memorized the out-of-category word better than other words in the list. Distracted participants didn’t show any difference in memory of distinctive word and other words. In short, when people are distracted, they do notice physical distinctiveness, such as color and font, but they don’t notice semantic distinctiveness, such as differences in categories. (To read the original paper, click here.)

For example, when we glance at a list of bird species written on the wall without paying attention to it, we won’t notice if there is a dinosaur species inside. However, if one word in the sentence is written in red while all other words are in black, we are more likely to remember the word even if we aren’t really paying attention.

I wrote it in Keynote.


The isolation effect is widely applied in marketing and political campaigns. Businesses and politicians love to use it to make you remember them better. After learning about the effect, we can see various advertisements with a more critical view.

Old Spice commercials are typical marketing examples. When you get bored of a celebrity holding a random body wash and telling you how good it is, Old Spice seldom fails to capture your attention with its weird commercials. In their least weird commercials, the main character constantly changes the scene setting in unexpected and creative ways. In their more weird commercials, sometimes the main character’s body parts are scattered, and sometimes the character becomes a razor or a spray. Everything seems to contradict common sense. Their distinctiveness to other normal body wash commercials attracted people’s attention, and that made them better remembered. No matter whether you love it or hate it, it is hard to forget. In the Elder React video, although one of the elders didn’t remember what she saw, others remembered them pretty well.

In the political domain, the new president of the U.S. makes good use of the isolation effect. When people talk about a presidential campaign, what do you think about?



Or this?


Differently, this is what President Trump did during his campaign in addition to routine speech.



Trump massively expressed radical opinions in a vulgar manner in social media and formal speech and interviews, and his words had been shocking people since he decided to run the campaign. In the beginning, the public looked down at him and referred to him as a clown. However, he won the election and became the 45th president of the United States. How did he make that? There were 17 republic candidates in the 2016 presidential campaign. How did Trump stand out? The isolation effect. His weird motions during speeches or interviews made him physically different from other candidates. Furthermore, Trump’s behaviors were so different from what people expected a presidential candidate would do so it challenged people’s common sense and hence was semantically distinctive. His distinctiveness never failed to capture people’s attention, and it made him unforgettable. It was his strangeness that made him famous, and his opinions reach the public and hence received echoes from his potential supporters. Furthermore, his ridiculous behaviors kept the media reporting about him, and it might make him more favorable to some people due to the mere exposure effect (another blog post about it), which states that the more people are exposed to something, the more likable it is.




The isolation effect can be useful when used to promote products, but it can also distract people from what really matters. Learning more about cognitive biases can help you be more conscious about things that you might be subconsciously susceptible to and make more-informed decisions. Being different does not indicate being better. Even though we are more likely to pay attention to distinctive choices, we should pay attention to other choices that are normal but potentially better. For example, it might be significant to learn more about “normal” presidential candidates next time…



Bireta, T. J., & Mazzei, C. M. (2016). Does the isolation effect require attention?. Memory & Cognition, 44(1), 1-14. doi:10.3758/s13421-015-0538-y

Cimbalo, R. S., Capria, R. A., Neider, L. L., & Wilkins, M. C. (1977). Isolation effect: Overall list-facilitation in short-term memory. Acta Psychologica, 41, 419–432. doi:10.1016/0001-6918(77)90001-4

Gumenik, W. E., & Levitt, J. (1968). The von Restorff effect as a function of the difference of the isolated item. American Journal of Psychology, 81, 247–252. doi:10.1037/h0029722

Jenkins, W. O., & Postman, L. (1948). Isolation and the spread of effect in serial learning. American Journal of Psychology, 61, 214–221.

von Restorff, H. (1933). Über die Wirkung von Bereichsbildungen im Spurenfeld [On the effect of sphere formations in the trace field]. Psychologische Forschung, 18, 299–342. doi:10.1007/BF02409636

  1. ahnacc20
    May 10th, 2017 at 11:44 | #1

    It is fascinating to see how this cognitive bias can be observed in everything from advertising to politics! Your points about Trump make me wonder whether we would have seen the same outcome from the 2016 election if Trump had had the same political agenda but did not act so “weird” and distinctive compared to the other candidates.
    I interpreted the isolation effect as having a lot to do with the exogenous orientation of one’s attention, or attentional capture. As you pointed out, this redirection of attention happens automatically when we perceive something out of the ordinary, so we have no choice but to notice the weird stimulus. Since encoding something into memory requires paying attention to it, we will be more likely to remember things that trigger the isolation effect in our cognition. So, it makes sense as to why so many advertisements take advantage of it by making the products stand out.
    The Bireta and Mazzei study reminded me of the shadowing task done by Cherry (1953). You mentioned that the participants noticed physical distinctiveness of the presented words while they were distracted, but did not notice semantic differences relating to their categories. This mimics the results from Cherry’s study, in which the participants noticed the stimulus-driven changes (such as a change in the tone) in the passage in the unattended ear, but not the meaningful ones (such as the direction of the speech). In other words, they were more likely to pay attention to the distinct physical changes in the features of the audio, but not the less obvious semantic changes.
    Also, the tidbit about the dinosaur species mixed in with the list of bird species reminded me of the amusing picture of the woman feeding “pigeons” that were actually tiny velociraptors. It makes me wonder how top-down and bottom-up processing ties in to the isolation effect; perhaps our expectations about what we see prevent attentional capture from taking place when it comes to semantic distinctiveness.

  2. Yi Feng
    May 10th, 2017 at 23:36 | #2

    Thank you for your thoughtful comment. As you said, the isolation effect does have a lot to do with the endogenous and exogenous orientation of one’s attention. I think it might also have something to do with the level of processing effect, which suggests that things that are more paid attention to are deeper encoded, and hence better remembered. Attention does play a significant role in memory processes.
    Thanks for bringing up the shadowing task. I believe it could explain why physical isolation doesn’t require attention to take place while semantic isolation does. The reason for can be people encoding perceptual characteristics but not encoding semantic features of information without paying attention to it.
    Last but not least, I also believe that top-down processes play important roles in the isolation effect. We rely on our prior knowledge to interpret the world. Therefore, we will have expectations when we perceive information from the outside environment. You are right. Our expectations might make us ignore the semantic distinctiveness because we might fill in our expectations, same as the phoneme restoration effect. In addition, I think top-down processes also have a lot to do with spotting semantic distinctiveness. For instance, we need to rely on our prior knowledge to find out all words in the word list belong to the same category except for the isolation word.

  3. jbperlmu
    May 11th, 2017 at 02:00 | #3

    This was definitely an “eye-catching” post, practicing what it preaches – I will definitely remember this post more than the other posts because of the distinctiveness of it. While I found the concept of the isolation effect to be very relatable, I couldn’t help but think about what we learned about Inattentional Blindness in class. Particularly, the study by Daniel Simons, where most people don’t notice the gorilla walking through the people passing the basketball around, seemed to somewhat dispute this model. It was said in the Bireta and Mazzei (2015) study that even distracted people memorized the words of the “different color” better than that of the normals. If this study applied to the case of inattentional blindness in Simons’ study, you would expect people to notice the abnormal gorilla stimulus more than the normal stimulus of the basketball passes. Nonetheless, the isolation effect is definitely supported by much of what we learned in class, such as the fact that we generally have slower reaction times with things that are similar than things that are slower because they don’t stand out as much!

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