Game Development Reference
tive processing. When a statement is tested, the
corresponding results and influences are updated
for future reference.
In addition to decisions, there is an additional
process contained in this subsystem known as
the influence process. Influence can modify
the decision of a collaborative partner so it is
either in more agreement or less agreement with
another partner. As the collaborative computer
game scenario is executed (and executed many
times), influences between the partners emerge.
These influences form forces upon the decision
made by the partner causing the decision to shift
slightly based on the influencing forces.
Cognitive Layer Implementation
Integrating a problem solving technique into a
collaborative computer game involves several
steps. When integrating a new problem-solving
technique into an already existing computer game,
many of the following elements shall already be
defined. Due to the nature of some techniques, it is
important to ensure that each element is addressed
to verify whether changes may be required as part
of the integration process.
The Action subsystem is the process of changing
the response of the Decision-Making process into
a form that may be conveyed to other collabora-
tive FEPs via the Physical Layer effectors. This
process is undertaken for all verbal and non-verbal
messages. The decision-making process outputs
the results in the same structured message format
used within the cognitive layer.
This process is essentially the opposite pro-
cess to the Perception processes, changing the
internal message structure into messages that can
be transmitted by the physical layer's effectors.
Integrating a Problem
The cognitive layer is a set of inter-connected
subsystems, each responsible for a particular
function and partitioned from the other operations
(Figure 11). Underpinning these subsystems is the
Cognitive Data Subsystem (Figure 12).
Each subsystem is designed to be modular and
therefore replaceable (and replaceable separately
of the other subsystems). The following sections
detail how a new problem-solving technique may
be integrated into a virtual being's cognitive
Supporting these subsystems are the various data
elements required in order for the cognitive layer
to interpret, evaluate and act upon the informa-
tion received via its sensors (including messages
between partners): The game scenario instance or
model is created from a game scenario definition,
along with the information required to understand
and manipulate the model. The cognitive data store
also maintains lists of common concepts that are
used to assist in perceiving and manipulating the
game scenario model.
Historical actions and the results of decisions
made are also preserved for further use in cogni-
Internal Message Structure
The internal message structure is used to pass sen-
sor input information between each of the cognitive
layer subsystems. In order to integrate a problem
solving technique it is important to understand
what information is produced by the Perception
subsystem and contained in this structure.
Given the modularity of the computer game
layered collaborative architecture, this structure
has had opportunity to undergo incremental