Washington, Feb 24 (IANS) There is something about the rhythm and texture of early cinema that has a very different feel than modern films. But it's hard to put one's finger on just what that something is. New research may help explain this elusive quality.

Cognitive psychologist (and film buff) James Cutting of Cornell University, along with his students Jordan DeLong and Christine Nothelfer, decided to use the sophisticated tools of modern perception research to deconstruct 70 years of film, shot by shot.

They measured the duration of every shot in every scene of 150 of the most popular films released from 1935 to 2005.

The films represented five major genres - action, adventure, animation, comedy and drama. Using a complex mathematical formula, they translated these sequences of shot lengths into 'waves' for each film.

What these researchers looked for were patterns of attention. Specifically, they looked for a pattern called the 1/f fluctuation.

The 1/f fluctuation is a concept from chaos theory, and it means a pattern of attention that occurs naturally in the human mind.

Indeed, it's a rhythm that appears throughout nature, in music, in engineering, economics, and elsewhere. In short, it's a constant in the universe, though it's often undetectable in the apparent chaos.

Cutting and his students found that modern films - those made after 1980 - were much more likely than earlier films to approach this universal constant.

That is, the sequences of shots selected by director, cinematographer and film editor have gradually merged over the years with the natural pattern of human attention.

This may explain the more natural feel of newer films - and the 'old' feel of earlier ones. Modern movies may be more engrossing - we get 'lost' in them more readily - because the universe's natural rhythm is driving the mind.

These researchers don't believe that filmmakers have deliberately crafted their movies to match this pattern in nature.

Instead, they believe the relatively young art form has gone through a kind of natural selection, as the edited rhythms of shot sequences were either successful or unsuccessful in producing more coherent and gripping films.

The most engaging and successful films were subsequently imitated by other filmmakers, so that over time and through cultural transmission the industry as a whole evolved toward an imitation of this natural cognitive pattern.

Overall, action movies are the genre that most closely approximates the 1/f pattern, followed by adventure, animation, comedy and drama, says a Cornell release.

As Cutting, DeLong and Nothelfer said, individual films from every genre have almost perfect 1/f rhythms.

'The Perfect Storm', released in 2000, is one of them, as is 'Rebel Without a Cause', though it was made in 1955. So too is 'The 39 Steps', Hitchcock's masterpiece from way back in 1935.

These findings were published in Psychological Science, a journal of the Association for Psychological Science.