See In Pics: The unresolved mystery of consciousness

Christof Koch and David Chalmers started investigating the mystery of consciousness in 1998. (Image: News18 Creative)

Christof Koch and David Chalmers bet that the mystery of consciousness would be solved by 2023.(Image: News18 Creative)

Galileo's scientific method focused on objective qualities thus hindering with our understanding of consciousness (Image:News18 Creative)

Chalmers won the bet because no theory could correctly predict brain activity (Image: News18 Creative)

The free-energy principle provides alternative perspectives on consciousness (Image: News18 Creative)

The symmetry theory of valence proposes that positive or negative feeling of consciousness depends on symmetry of neural activity patterns (Image: News18 Creative)

Despite the progress, the mystery of consciousness may persist even after next 25 years (Image: News18 Creative)