The Von Restorff effect

The Von Restorff effect, also known as the "isolation effect", predicts that when multiple homogeneous stimuli are presented, the stimulus that differs from the others is more likely to be remembered.

The theory was coined by German psychiatrist and pediatrician Hedwig von Restorff (1906–1962), who, in her 1933 study, found that when participants were presented with a list of categorically similar items with one distinctive, isolated item on the list, memory for the item was improved. even if it was not the most important or relevant item on the list.

The Von Restorff effect arises from principles of commonality and distinctiveness, as when an item is unexpected or stands out from its surroundings, it captures attention and is more likely to be remembered.

Neuroscientists think that a person’s brain is set to recognize the differences amongst similarities and reduce cognitive loads. This prioritises remembering one thing over those other items around it that appear the same. The human brain has evolved to pay more attention to different or unusual things since they seem more important or relevant

Across studies, the Von Restorff effect activated the brain's prefrontal cortex, specifically in memory and word recall. The findings show a link between intelligence and isolated concepts. The isolation effect may also extend to how memories associated with strong emotions have a better recall than other life events.

In the daily course of life, trying to remember a list of items will more likely mean a person recalls the item that is a different color, size, or shape over others. If one creates a list of numbers and adds a letter, the letter will stand out. The effect also extends to motion and orientation.

The effect is partly echoed through gestalt - the laws of human perception - and the similarity or balance principles. It utilises the isolation paradigm - linking back again to the semiotic application of differentiation or exception - which refers to a distinctive feature of an item in a list that differs from the others by way of dimension. The distinctiveness of the effect can be generated from changing the meaningfulness or physical nature of the stimulus in some way, such as size, shape, color, spacing or underlining. In practice, the effect is therefore highly beneficial to establishing visual hierarchy in a design. The designer should remember the following points when utilising: -

1. Apply differentiation to make important information or key actions visually distinctive;
2. Use restraint when placing emphasis on visual elements to avoid them competing with one another and to ensure salient items don’t get mistakenly identified as surplus;
3. Don’t exclude those with a color vision deficiency or low vision by relying exclusively on color to communicate contrast.
4. Carefully consider viewers with motion sensitivity when using motion to communicate contrast.

The nature of the effect prompts a question of what something is to be considered unusual or weird. The answer is relative, but it concerns things that might be considered unusual, bizarre, or unexpected. Those who think laterally can achieve this by producing work that is singular and original. It is commonly used in advertising where  ‘unusual’ becomes distinctive; not ‘bizarre’, entertaining; not ‘unexpected’. By leaning into weirdness, brands can have a memorable impression on audiences. 

As Byron Sharp explains in ‘How brands grow’, brands all too often focus on explaining to customers why their product is different from their competitor’s version. The main priority is to create distinctive communications.

The most common uses of the Von Restorff effect pertain to learning and marketing. It can also benefit people in other areas of life, such as in taking care of their health.

The effect significantly impacts learning too, mainly due to its effect on memory. A study shows that this effect is more potent for physical differences than for mental ones. In other words, hearing words or thinking about verbal differences is less potent than seeing a physical contrast in one's environment. If so, the findings mean that the effect’s use with colors, fonts, images, and distinct formatting has a greater impact on learning over organizing the content to emphasise a difference. People are more likely to pay attention and retain the information by incorporating unexpected elements into learning materials.

The Restorff effect may also enhance memory during aging. Indeed, while age may play a role in lowering the effectiveness of the Von Restorff effect, it can also improve memory retention to older adults. By incorporating isolated elements into learning materials or healthcare interventions, older adults may be more likely to remember important information. It therefore has potential to enhance recall in amnesia and memory impairment. For instance, there is a further y in study which shows that individuals with amnesia were more likely to remember isolated items than non-amnesic individuals.

While the Von Restorff effect significantly impacts memory and attention, critics quickly highlight its limitations. Some researchers argue that the effect may not be as strong as initially thought and that alternative explanations, such as the distinctiveness effect, may play a role in the observed results. For instance, boundary conditions may also influence it, such as the type of material presented or the individual's level of attention.

In respect of possible flaws, aging, neurological conditions, and inattentional blindness are a few situations where the isolation effect loses potency. Sometimes also, the contrasting element remains hidden because it is too unexpected. This phenomenon is known as inattentional blindness, where people fail to notice unanticipated objects or events because they are too focused on a specific task or stimulus. Evidence suggests that inattentional blindness works from similar neural principles to the isolation effect and that the two are related.

Research has also shown that age may influence the isolation effect. A study published in Sage Journal's Quarterly Journal of Experimental Psychology found that older adults were less likely to remember isolated items than younger adults.

Age-related changes in attention and memory processes may underpin these findings, which can reduce the effectiveness of the Von Restorff effect. Other studies confirm this by revealing those with early-stage Alzheimers disease experience even less benefit from the Restorff Effect than healthy older adults.

As with any cognitive bias, alternative explanations may explain the observed results. In the case of the Von Restorff effect, other factors such as attention, motivation, and individual differences may also play a role in memory recall.

The Von Restorff effect is a powerful cognitive bias that considerably impacts memory and attention. By incorporating unexpected elements into learning materials, marketing strategies, and healthcare interventions, individuals can improve their memory and retention of important information. While the effect may have its limitations and criticisms, it is a valuable tool for enhancing learning, creating attention-grabbing campaigns, and improving patient care. By understanding the principles and real-life applications of the Von Restorff effect, we can unleash its power and use it to our advantage in various aspects of our lives.