Neuroscience of Unexpected Stimuli

When people encounter an event that does not align with what their brains anticipate, the nervous system produces a prediction error—a signal that something in the environment is inconsistent with expectation (Friston, 2010). This response stems from predictive coding, the process by which the brain continually compares incoming information with internal models. A deviation forces the brain to update its assumptions, highlighting the new stimulus as significant and drawing attention to it.

This shift in processing often involves the dopaminergic system, which becomes active during surprising or novel encounters. Dopamine release heightens alertness and sharpens focus, temporarily diverting mental resources away from routine activities to analyze unexpected input (Schultz, 2016). In this way, unexpected images or events act as attention magnets, drawing cognitive energy that might otherwise be distributed elsewhere.

The consequences of surprise extend to the formation of memory. Research indicates that novel experiences strongly activate the hippocampus, a brain structure essential for encoding information into memory. At the same time, the amygdala helps prioritize stimuli that carry emotional or unexpected qualities, thereby strengthening consolidation processes (Lisman & Grace, 2005). Due to this hippocampal–amygdala interaction, unusual or striking visuals are more likely to be encoded vividly and retained in long-term memory.

On a perceptual level, unexpected input interrupts habituation—the brain’s tendency to suppress attention to repeated or predictable patterns. By breaking this routine, surprising visuals stand apart from the background and resist being ignored (Desimone & Duncan, 1995). Furthermore, when such stimuli are embedded within meaningful contexts, such as an instructional lesson or a brand message, they can enhance retrieval by linking the element of surprise to relevant information. This “novelty boost” effect improves later recall by anchoring memory traces more securely (van Kesteren et al., 2012).

Together, these findings suggest that unpredicted stimuli influence cognition in two powerful ways: they demand immediate perceptual and attentional resources, and they leave behind stronger, more enduring memory traces. This dual effect explains why unexpected images are not only noticed in the moment but also remembered more clearly over time.

Applications in Advertising and Visual Design

The neuroscience of unexpected stimuli offers practical insights for anyone working with imagery in advertising, branding, or communication design. Because the brain is wired to notice and encode surprises, marketers and designers can strategically use novelty to make messages more memorable.

Selecting Advertising Imagery

• Break the Pattern: Ads that deviate from predictable imagery—such as showing an unexpected context for a familiar product—disrupt habituation and immediately draw attention. For instance, a beverage commercial set in zero gravity will stand out more than one set in a beach scene.

• Emotional Layering: Pairing surprise with emotional cues (such as joy, curiosity, or shock) activates both the amygdala and hippocampus, thereby reinforcing long-term recall. This is why unusual celebrity endorsements, humor, or clever visual twists are so effective.

Design Applications Beyond Ads

• Branding & Packaging: A small, unexpected design element (e.g., playful typography on a luxury package, or a hidden illustration inside a box) can delight consumers, strengthening brand loyalty through memorability.

• UX/UI Design: In digital products, subtle yet surprising microinteractions—such as a button animation that behaves differently than expected—can increase engagement, as long as they enhance usability rather than disrupting it.

• Instructional & Educational Design: Embedding novelty into infographics or learning materials (e.g., bold metaphors, unexpected color contrasts) can anchor key information, making it easier to retrieve later.

Balance Is Critical

While surprise is powerful, it must be contextually relevant. Neuroscience suggests that stimuli linked to a meaningful message are more likely to be recalled (van Kesteren et al., 2012). In advertising, this means the unexpected element should amplify the brand’s story—not distract from it.

In short, the unexpected works best when it is not random, but when it creates a memorable connection between the viewer and the message.

References

Bridger, D. (2017). Neuro Design: Neuromarketing insights to boost engagement and profitability. Kogan Page.

Damasio, A. R. (1994). Descartes’ error: Emotion, reason, and the human brain. Putnam.

Desimone, R., & Duncan, J. (1995). Neural mechanisms of selective visual attention. Annual Review of Neuroscience, 18(1), 193–222. https://doi.org/10.1146/annurev.ne.18.030195.001205

Friston, K. (2010). The free-energy principle: A unified brain theory? Nature Reviews Neuroscience, 11(2), 127–138. https://doi.org/10.1038/nrn2787

Lisman, J. E., & Grace, A. A. (2005). The hippocampal-VTA loop: Controlling the entry of information into long-term memory. Neuron, 46(5), 703–713. https://doi.org/10.1016/j.neuron.2005.05.002

Livingstone, M. (2002). Vision and art: The biology of seeing. Harry N. Abrams.

Schultz, W. (2016). Dopamine reward prediction-error signaling: A two-component response. Nature Reviews Neuroscience, 17(3), 183–195. https://doi.org/10.1038/nrn.2015.26

Van Kesteren, M. T. R., Ruiter, D. J., Fernández, G., & Henson, R. N. (2012). How Schema and Novelty Augment Memory Formation. Trends in Neurosciences, 35(4), 211–219. https://doi.org/10.1016/j.tins.2012.02.001

Ware, C. (2008). Visual thinking for design. Morgan Kaufmann.

Weinschenk, S. M. (2011/2020). 100 Things Every Designer Needs to Know About People (1st & 2nd eds.). New Riders.

Zaltman, G. (2003). How customers think: Essential insights into the mind of the market. Harvard Business Press.