Research has debunked the common belief that a sixth sense does exist.
"People could reliably sense when a change had occurred, even when they could not see exactly what had changed," said researchers from University of Melbourne.
According to lead researcher Piers Howe from the Melbourne School of Psychological Sciences, the research is the first to show that people can reliably sense changes that they cannot visually identify.
For example, a person might notice a general change in someone's appearance but not be able to identify that the person had had a haircut, said the study published in the journal PLOS ONE.
There is a common belief that people can experience changes directly with their mind, without needing to rely on the traditional physical senses such as vision, hearing, taste, smell and touch to identify it.
This alleged ability is sometimes referred to as a sixth sense or extrasensory perception (ESP).
"We were able to show that while observers could reliably sense changes that they could not visually identify, this ability was not due to extrasensory perception or a sixth sense," Howe said.
In the study, observers were presented with pairs of colour photographs, both of the same female.
In some cases, her appearance would be different in the two photographs. For example, the individual might have a different hairstyle.
Each photograph was presented for 1.5 seconds with a 1 second break between them.
After the last photograph, the observer was asked whether a change had occurred and, if so, identify the change from a list of nine possible changes.
Results showed study participants could generally detect when a change had occurred even when they could not identify exactly what had changed.
This resulted in the observer "feeling" or "sensing" that a change had occurred without being able to visually identify the change.
"The result that observers can reliably feel or sense when a change has occurred without being able to visually identify the change could be explained without invoking an extrasensory mechanism," said Margaret Webb from the Melbourne School of Psychological Sciences, University of Melbourne.
