When you watch television or walk outside on the street, it is not hard to find advertisement with celebrities on it. Including the information of products or services in advertisement is not surprising. There is no question about it, but what is the reason that so many celebrities are shown in advertisement? The simple answer for this question is that people are interested in celebrities, and showing celebrities in advertisement possibly affects to the people who is watching the advertisement. This is very intuitive description, and looks make sense. In this article, I want to show you neuro-scientific evidences, how showing celebrities in advertisement works.
Attracting human gaze is important in advertisement. According to the work of Cerf et al. , people tend to easily recognize faces than other objects or letters when pictures are shown, it turns out human faces are the first viewers respond to. This is why experts in advertising want to hire actors or actresses in making commercial messages. But why actors or actresses? Because celebrities can easily catch viewers’ intention, and there is a neurological reason support this idea.
Human brain encodes data extracted from outer world. In general, neuro-scientists say there are two coding schemes in human brain. One is explicit coding and the other is implicit coding (=population coding). In short, explicit coding means that one neuron remembers one person, and population coding means that a set of neuron remembers more than 2 people. (This is not clear definition of explicit/implicit coding, but I think the description above is enough to explain the key idea of those. For more about coding scheme, please see .) Population coding can be expressed like the followings; Let’s assume that there are two light bulbs. You can turn on and off each of the bulbs. With those two light bulbs, we can represent four different states – on/on, on/off, off/on and off/on. While you can represent two states with two bulbs in explicit coding, you can represent four different states in terms of implicit coding. The reason why the coding scheme is important is that the coding scheme is highly related to the logical depth of computation. Human brain reacts to information explicitly coded in comparatively short time than implicitly coded information. Therefore, the brain encodes important information using explicit coding scheme. This is why people can find celebrities faster than normal people in watching movies and walking on a street. (There is a scientific evidence that there is a single neuron in brain encodes celebrities or other important people .) This also can be a reason that people can more easily recognize celebrities than other people.
According to those results of research above show that celebrities in advertisement attract viewer’s attention and have influence on them in neuro-scientific point of view. After watching advertisement with celebrities on it, people may learn a correlation between the celebrities and the advertisement (see cartoon above). The people who unconsciously or consciously learned the correlation will possibly think about the products or services what they saw before. This is why we can usually saw celebrities in advertisement. Many financial institutes also use this strategy in their advertisement, and this can also affect to their customers.
 M. Cerf, E. Paxon Frady and C. Koch. Faces and text attract gaze independent of the tast: Experimental data and computer model. Journal of Vision (2009).
 C. Koch. The Quest for Consciousness: A Neurobiological Approach. Roberts & Company Publishers (2004).
 R. Quian Quiroga, L. Reddy, G. Kreiman, C. Koch and I. Fried. Invariant Visual Representation by Single Neurons in the Human Brain. Nature (2005).