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A skull or two ladies?

The pciture used for the survey

The questions I asked in the survey were: 

1. What do you see in this picture?

2. Do you see anything else in this picture?

Yes 

No 

3. If yes, what do you see?

4. Was it easy for you to see the second image, or did you have to concentrate really hard to see it?

It was easy I saw both at the same time! I had to concentrate really hard to see the other image I could see only one image

The results I collected are displayed in these graphs: 

Graph showing the responses to the two images

Level of difficulty in viewing the images

Most people saw the skull first because it is a bigger whole than the lady. The image of the two ladies is one that is more detailed and hence can be brought to focus by looking at the picture in detail. Thus I found that the brain looks at the whole or bigger picture first. Thus the ‘top down’ method of perception was at work here.

I also found that two people who were not able to see the other image – that of the two ladies incorrectly assumed a second one because of the way the questions were phrased. Even though the second question of my survey enabled people to say that they did not see a second image, because the following question was about the second image, they assumed that there was definitely a second image and worked at developing it. Thus the brain took cues from the environment and made an estimated guess.

Most people however found it easy to see both the images in the illusion. Half of them saw both the pictures at the same time. Yet they chose to report the skull first because of the reasons already discussed.

This made me realise that our brain often takes the liberty of interpreting things for us and chooses the most obvious answer first.