Yamaoka began by discussing the differences between Japanese and Hollywood-style horror. For example, Japanese horror tends to feature an invisible enemy, themes of vengeance and hatred, and a sad storyline. Hollywood horror, he said, often focuses on evil spirits, zombies, and shocking visuals. Silent Hill, he explained, had many Western elements to it. "A lot of modern American horror -- like David Lynch and Stephen King -- really influenced us. We are Japanese, so for us to create Western-style horror may be unusual."
Then Yamaoka launched into the meat of his presentation, his "concept of horror." This was split into three parts. The first concept? Keep the story sparse. In fact, make it downright confusing and unclear. Yep, that's apparently intentional because Yamaoka and team believe that the disorientation helps create a greater sense of horror.
This lead into his second concept of horror, which revolved around making the player uneasy through a lack of information. The player starts off feeling uneasy thanks to little data and no logical explanations for what's happening around them. Through their perception, they begin making a logical reconstruction of what may have occurred. The need to assemble this fragmented information leaves a lot of room for imagination, letting the player make up their own bits of story to fill in the gaps. This is key, Yamaoka said. Later, the game finally gives a bit of more substantial information, "resolving" the first part of the horror. Finally, the "true horror" gets revealed in the end.
Finally, Yamaoka's third concept revolved around realism and reality. He explained this with an anecdote about a bug. A software error was causing a human character's left eye to stare ever-so-slightly off-center, so it wasn't clear where they were "looking." This deviation from normalcy resulted in a surprisingly disturbing effect, even if only subconsciously. In fact, Yamaoka believes that what can be conveyed subconsciously is more important than more obvious, concrete elements. Other ways Yamaoka screws with your subconscious include having lots of right turns (which are scarier, apparently) and varying floor and ceiling heights. Who'da thunk?
Yamaoka wrapped up his presentation by discussing ideas for the future. He wants to see interactive sound play a bigger role in horror games, but specifically mentioned that it shouldn't change when something bad is about to happen -- giving away the surprise like that is no good. In the end, he aspires to create games that will "shake the five senses," which raises at least one fascinating question: What does interactive horror taste like? Perhaps Yamaoka can delve into that one at GDC 2006.