As we can see in figure 1 we get an overview of what is easy perceptible and what is more difficult to see (Face, Gender, Type and most difficult the Name of the presented person).
This is determined, it does not explain why it is as it is.
The same applies in natural science if we want to test e.g. the hardness of solids, for this the scratch test has been developed that says that if you rub two different materials over each other then the softer material will get scratch marks. In this way we can draw up a hierarchy of hardness. A smart person can take advantage of this. If you do not have this knowledge, you will receive it through experience, trial and error.

With two tachistoscopes we can, as Calis shows, do research in the field of cognition. The perception of the position of a face takes place earlier (is a necessary condition for more differentiated perception) than determining whether someone is wearing glasses or not.
The theory explains the results: there is logic in the course of the perceptual process. This course goes from global to specific.

If, however, we carry out research of emotions with two tachistoscopes, we will lose explanation in the absolute sense, it will be describing again, but interpretation will be added. For example, we present a picture of a dog and then the person in question misses the second picture that is presented repeatedly, then we interpret that as fear of dogs or fear of this specific breed of dogs. It is in a certain sense an explanation, but we are not 100% sure of it, as is the case with cognition research. The fear can also be explained differently e.g. the presented dog is exactly the same dog as the neighbor's dog and the fear is linked to the neighbor and not so much to the dog. Apart from this, it can put the investigating psychologist on a track.

We can strengthen the emotion approach by using three (or more) tachistoscopes, using two tachistoscopes to present the first picture and using the third tachistoscope to present the second picture to be identified.
The advantage of two tachistoscopes for the first picture is that we can give that first picture more life: for example, we first show a small dog followed by the same dog but then a little larger: this gives the impression that the dog is getting closer and if there is fear for dogs, this approaching movement will evoke even more fear. In other words: an even worse result for the picture to be identified.
The same applies to people we fear when they approach us, the fear increases.

So to be able to do all three types of research optimally, an arrangement with three tachistoscopes is ideal.

When this form of research becomes more widely known, perhaps more than three tachistoscopes will be needed to improve the research on emotions. I hope that the fast Japanese projector will become available (a 2d version of the fast projector is sufficient for this type of research).

We are talking about fear of dogs, but it will be even more interesting if we can use this approach to track down abusers.
For example, we can present photos of people around a child as the first photo and see by which photo or photos there is a lot of loss in the identification of the second photo. This of course does not mean that the individuals on the first photo who cause bad scores are by definition abusers, but it does give the psychologist data to investigate certain relationships more closely.
We can also get in this way a better picture of bullying behavior.

The same as with DNA determination: it is a good thing that there will be more awareness in the public domain that "you will not get away with it".

The phenomenological approach and cognition approach are important for a scientific foundation of psychology as a discipline.
The emotion approach is important for the practice of the individual psychologist. With this approach, every psychologist can further develop and shape his or her own field of expertise.

After 40 years of research and building on the work of Gé Calis and Frans Coppelmans, I hope that with all of this I have contributed to a solid foundation for a scientific and practical psychology.

Many people have supported me over the years, I am very grateful to them. Without this support this development path would not have been possible. In particular I want to mention Chris van der Linden, Frans Duijf and Jerry Ent for their support and encouragement in the final phase of this project.

Arnhem, 12-2-2018
Jan Sterenborg

Calis, G.J.J. Op het eerste gezicht. Onmiddellijke waarneming en gelaatsherkenning. Thesis Nijmegen 1974


Summarizing we can say that research with one tachistoscope, as Calis shows, leads to a description of phenomena in the visual domain.
The question was: what does a person see when pictures of famous people are presented to him or her in a very short way. The presentation time increased slowly with the next presentation (see presentation times in milliseconds on the X-axis).

Figure1. Percentage of correct identifications for some "open-end"
categories with unexpected portrait presentations in function
of the presentation time.