Introduction

So far I've talked about Language and Thought, Emotions and Behavior as well as some goals such as giving the appearance of intelligent individuals living in groups and societies. In order to allow entities to "think" in unique ways - they must have different personalities, skills, goals and memories - there must be a unique data about every agent (at least every agent that the play has come in contact with or who is part of the local group the player is interacting with). In addition, entities must be able to learn, or give the appearance of learning, as well as being given a set of skills and knowledge ahead of time. In order to accomplish this, there must be a single brain or cognitive architecture and the knowledge, personality, experience, memories and so on are data that feeds this architecture. In other words THOUGHT is derived from DATA plus ARCHITECTURE.

While this architecture isn't based on a single Cognitive Architecture, it is inspired from many well-known architectures such as SOAR, ACT-R, EPIC and CLARION. So some of the concepts contained within may seem familiar - however all aspects of this will be tuned and implemented to match the task at hand. In other words, some of the concepts are familiar but the implementation and final design is my own.

Emotional states will have a large impact on the final thought process of an agent and will play a much larger role than in most (if not all) existing Cognitive Architectures. In this sense, the final architecture may not be considered a true Cognitive Architecture - but the primary goal is provide the appearance of a intelligent and emotional beings not to put forth a new theory of Cognition.

Memory

Memory is dividing into Long Term Memory and Short Term Memory (also known as Working Memory). Long Term Memory is like a hard drive for a computer, it stores all the facts, memories, rules and so on that a person knows and remembers over the long term. Short Term Memory serves as a work area, where facts go when recalled as well as where short term sensory data is stored. If someone tells you a phone number, it goes into Short Term Memory where it can be used in some mental processing (such as dialing the number or writing it down) and may be forgotten afterwards. Data is short term memory decays and is forgotten after a time unless it is refreshed (repeating a phone number to yourself in order to remember it long enough to get to the phone) or committed to long term memory. This short term memory also serves as a "scratch pad" of sorts for the thinking process.

Long Term Memory is split into several categories. ACT-R uses 2 categories: Declarative memory and Procedural memory. SOAR uses these same categories, though they call the Declarative memory Semantic instead, but they add a third category: Episodic Memory. I take a similar approach. Many of these cognitive architectures do not include emotional state in the memory, however the Cognitive Architecture in Alien Awakening will include emotional affects as discussed in the last post. In addition a belief system has been added to the Declarative Memory - it stores not only facts but beliefs as well. It is possible for an entity to be unsure about an absolute fact, thus even facts are beliefs with this system.

Declarative Memory: Declarative or Semantic memory stores facts and beliefs. Examples include: 1 plus 1=2, California is a state in the United States, Smith's hair is black and so on. A belief rating is stored along with each entry, indicating the strength of the entity's belief. If an entity is looking for Smith in a crowd, they will look up pertinent information about Smith (such as black hair) and try to find a match to the information stored in working memory. If Smith is found and it turns out that his hair is brown - maybe the description was incorrect - then the belief that his hair is black can be replaced by the belief (with very high percentage belief) that it is brown. Declarative memories can also illicit an emotion response, depending on the emotional state when the memory was obtained. For example, a fact such as that the sun is red when setting may be stored along with an emotion of awe - since that was the emotional state the entity was experiencing when acquiring the fact. This would result in an increase in awe or associated emotions when thinking about a sunset or the color red.

Procedural Memory: Procedural memory is basically a set of rules in the general form if x then y. External stimuli and memories are eventually distilled into rules using learning processes. Internal learning is possible, converting from facts and beliefs or episodic memories into general or specific rules. In addition rules can explicitly learned, such as from direct instruction. Like beliefs in Declarative Memory, rules also have a belief rating - how likely the entity feels that this rule is correct and accurate.

Episodic Memory: Episodic memory stores small memories or episodes in an entity's life. Things such as "I caught a large bass when fishing in the river, it was difficult because the pole was too short." This could give rise to learning, such as picking a longer pole when fishing for bass next time. Emotions are also attached to these memories, which allows the emotional state to be modified when recalling specific events. This should also give rise to generalized emotional categories, in this case about fishing.

In this way there is a goal oriented use of memory, attempting to generate and use rules and strong beliefs in order to decide on actions (more on this to follow) as well as emotional responses to stimuli and memories. An object, person, smell or sight may illicit a memory that generates an emotional response regardless of the overall goal or task. If the emotional response is strong enough, such as seeing a place where a grave tragedy occurred, the emotional behavior may override the cognitive behavior or affect it in some way. Emotional as well as logical cognitive responses work together to determine the final actions taken by an entity.

Stay tuned for Part II which will talk about group cognition, group memory, shared memory and more. It should be obvious that each entity cannot have completely unique memories about everything, such as how to use objects or facts - there must be a way to share the burden and yet keep the entities unique. More on that next time...