Sony's research and hardware development divisions trialled a number of PS4 controllers, including one that measures skin conductance for real-time data on player emotions, a new report has revealed.
In January, CVG revealed that Sony was abandoning its DualShock design in favour of a controller that features biometric sensors.
However the final prototype, called DualShock 4, did not feature the aforementioned biometric strips or LCD touch screen.
But the chief PlayStation 4 architect, Mark Cerny, has revealed in a new interview that the PS4 controller was subject to "a long research project where we looked at pretty much any idea we could think of".
In an interview with Stuff, he said: "Would it help to measure the galvanic response of the skin? We tried out a tremendous number of things - and then we went to the game teams to ask them what they thought they could use from the controller."
Sony's final design took into consideration first person shooters, which has become one of the most prevalent triple-A game genres in recent years.
"Historically we have heard many times that our controllers have not been ideal for first-person shooters, so we wanted to make sure we had something that would be much better for that genre," Cerny said.
"We tested the throw of the triggers, the position of the triggers, how much pressure it takes. We looked at the joysticks, the dead spot, we looked at convexity and concavity."
The end result, he says, "feels extraordinarily natural."
"I haven't heard a negative comment about it yet. For a controller with a very different form factor that was just amazing to see."
It is not known how well a biometric sensor controller works in practice, though PC games giant Valve has stated it is developing a pad that measures the player's state through biometric data.
Valve president Gabe Newell said that one of the important factors in developing a games controller would be "higher precision and lower latency".
The company is still thought to be developing its own living-room hardware design, known as the Steam Box.