/**
* Predictive Processing Implementation
*
* Implements predictive processing mechanisms inspired by the predictive brain hypothesis:
* - Top-down prediction generation based on current context
* - Prediction error computation and model updating
* - Bayesian belief updating mechanisms
* - Hierarchical predictive models
*/
import {
ComponentStatus,
IPredictiveProcessor,
Prediction,
} from "../interfaces/cognitive.js";
import { Context } from "../types/core.js";
// Prediction error structure
export interface PredictionError {
magnitude: number;
direction: "positive" | "negative";
confidence: number;
source: string;
timestamp: number;
}
// Generative model for predictions
export interface GenerativeModel {
id: string;
parameters: Map<string, number>;
prior_beliefs: Map<string, number>;
confidence: number;
last_updated: number;
prediction_accuracy: number;
}
// Hierarchical level in predictive processing
export interface HierarchicalLevel {
level: number;
predictions: Prediction[];
errors: PredictionError[];
model: GenerativeModel;
parent_level?: HierarchicalLevel;
child_levels: HierarchicalLevel[];
}
// Bayesian update parameters
export interface BayesianUpdate {
prior: number;
likelihood: number;
evidence: number;
posterior: number;
confidence_change: number;
}
/**
* PredictiveProcessor implements predictive processing mechanisms
* Based on the predictive brain hypothesis and hierarchical temporal memory
*/
export class PredictiveProcessor implements IPredictiveProcessor {
private generative_models: Map<string, GenerativeModel> = new Map();
private hierarchical_levels: HierarchicalLevel[] = [];
private prediction_history: Prediction[] = [];
private error_history: PredictionError[] = [];
private max_history_size: number = 1000;
private prediction_error_threshold: number = 0.3;
private learning_rate: number = 0.1;
private confidence_decay: number = 0.95;
private status: ComponentStatus = {
name: "PredictiveProcessor",
initialized: false,
active: false,
last_activity: 0,
};
/**
* Initialize the predictive processor with configuration
*/
async initialize(config: Record<string, unknown>): Promise<void> {
try {
this.prediction_error_threshold =
(config?.prediction_error_threshold as number) ?? 0.3;
this.learning_rate = (config?.learning_rate as number) ?? 0.1;
this.confidence_decay = (config?.confidence_decay as number) ?? 0.95;
this.max_history_size = (config?.max_history_size as number) ?? 1000;
// Initialize hierarchical levels
await this.initializeHierarchicalLevels();
// Initialize base generative models
await this.initializeGenerativeModels();
this.status.initialized = true;
this.status.active = true;
this.status.last_activity = Date.now();
} catch (error) {
this.status.error = `Initialization failed: ${error}`;
throw error;
}
}
/**
* Main processing method - implements predictive processing pipeline
*/
async process(input: unknown): Promise<{
predictions: Prediction[];
errors: PredictionError[];
model_updates: GenerativeModel[];
}> {
if (!this.status.initialized) {
throw new Error("PredictiveProcessor not initialized");
}
this.status.last_activity = Date.now();
try {
const context = this.extractContext(input);
// Generate predictions from all hierarchical levels
const predictions = this.generatePredictions(context);
// Compute prediction errors if we have actual data
const errors = this.computePredictionErrors(predictions, input);
// Update models based on errors
const updated_models = await this.updateModelsFromErrors(errors);
// Store in history
this.updateHistory(predictions, errors);
return {
predictions,
errors,
model_updates: updated_models,
};
} catch (error) {
this.status.error = `Processing failed: ${error}`;
throw new Error(`Processing failed: ${error}`);
}
}
/**
* Generate top-down predictions based on current context
*/
generatePredictions(context: Context): Prediction[] {
const predictions: Prediction[] = [];
// Generate predictions from each hierarchical level
this.hierarchical_levels.forEach((level) => {
const level_predictions = this.generateLevelPredictions(level, context);
predictions.push(...level_predictions);
});
// Generate predictions from generative models
this.generative_models.forEach((model) => {
const model_predictions = this.generateModelPredictions(model, context);
predictions.push(...model_predictions);
});
// Sort by confidence and return top predictions
return predictions.sort((a, b) => b.confidence - a.confidence).slice(0, 10);
}
/**
* Compute prediction error between prediction and actual input
*/
computePredictionError(prediction: Prediction, actual: unknown): number {
try {
// Handle null/undefined cases
if (
prediction.content === null ||
actual === null ||
actual === undefined
) {
return 1.0;
}
// Extract comparable features from prediction and actual
const predicted_features = this.extractFeatures(prediction.content);
const actual_features = this.extractFeatures(actual);
// If no features can be extracted, return high error
if (predicted_features.size === 0 && actual_features.size === 0) {
return 1.0;
}
// Compute feature-wise errors
const feature_errors = this.computeFeatureErrors(
predicted_features,
actual_features
);
// Aggregate into single error magnitude
let error_magnitude = this.aggregateErrors(feature_errors);
// Add base error for type mismatch
const pred_type = typeof prediction.content;
const actual_type = typeof actual;
if (pred_type !== actual_type) {
error_magnitude = Math.max(error_magnitude, 0.6);
}
// For very different content types, ensure higher error
if (this.areContentTypesVeryDifferent(prediction.content, actual)) {
error_magnitude = Math.max(error_magnitude, 0.7);
}
// Weight by prediction confidence (lower confidence = higher weighted error)
const weighted_error = error_magnitude * (2 - prediction.confidence);
return Math.max(0, Math.min(1, weighted_error));
} catch {
// If comparison fails, return maximum error
return 1.0;
}
}
/**
* Update generative model based on prediction error
*/
updateModel(error: number, prediction: Prediction): void {
const model_id = this.getModelIdFromPrediction(prediction);
const model = this.generative_models.get(model_id);
if (!model) return;
// Bayesian update of model parameters
const context_key = this.getContextKey(prediction.context);
const current_belief = model.prior_beliefs.get(context_key) ?? 0.5;
// Compute likelihood based on error
const likelihood = 1 - error; // Lower error = higher likelihood
// Update belief using Bayesian rule
const updated_belief = this.getBayesianUpdate(
current_belief,
likelihood,
0.5 // Base evidence
);
model.prior_beliefs.set(context_key, updated_belief);
// Update model confidence based on prediction accuracy
const accuracy_update = 1 - error;
model.prediction_accuracy =
model.prediction_accuracy * 0.9 + accuracy_update * 0.1;
// Update model confidence
model.confidence = Math.min(
0.95,
model.confidence * this.confidence_decay + accuracy_update * 0.1
);
// Update parameters using gradient descent-like approach
this.updateModelParameters(model, error, prediction);
model.last_updated = Date.now();
}
/**
* Perform Bayesian belief updating
*/
getBayesianUpdate(
prior: number,
likelihood: number,
evidence: number
): number {
// Bayes' rule: P(H|E) = P(E|H) * P(H) / P(E)
// Where H is hypothesis, E is evidence
// Normalize inputs
prior = Math.max(0.01, Math.min(0.99, prior));
likelihood = Math.max(0.01, Math.min(0.99, likelihood));
// Evidence normalization (for future use in more complex Bayesian calculations)
Math.max(0.01, Math.min(0.99, evidence));
// Compute posterior
const numerator = likelihood * prior;
const denominator = likelihood * prior + (1 - likelihood) * (1 - prior);
const posterior = numerator / denominator;
return Math.max(0.01, Math.min(0.99, posterior));
}
/**
* Reset processor state
*/
reset(): void {
this.prediction_history = [];
this.error_history = [];
this.hierarchical_levels.forEach((level) => {
level.predictions = [];
level.errors = [];
});
this.status.last_activity = Date.now();
}
/**
* Get current component status
*/
getStatus(): ComponentStatus {
return { ...this.status };
}
// Private helper methods
private async initializeHierarchicalLevels(): Promise<void> {
// Create hierarchical levels for predictive processing
const levels = [
{
level: 0,
name: "sensory",
description: "Low-level sensory predictions",
},
{
level: 1,
name: "perceptual",
description: "Perceptual object predictions",
},
{
level: 2,
name: "conceptual",
description: "Conceptual and semantic predictions",
},
{
level: 3,
name: "abstract",
description: "Abstract and causal predictions",
},
];
this.hierarchical_levels = levels.map((levelConfig) => ({
level: levelConfig.level,
predictions: [],
errors: [],
model: this.createDefaultModel(`level_${levelConfig.level}`),
child_levels: [],
}));
// Link hierarchical levels
for (let i = 0; i < this.hierarchical_levels.length - 1; i++) {
this.hierarchical_levels[i + 1].parent_level =
this.hierarchical_levels[i];
this.hierarchical_levels[i].child_levels.push(
this.hierarchical_levels[i + 1]
);
}
}
private async initializeGenerativeModels(): Promise<void> {
// Initialize base generative models for different domains
const model_configs = [
{ id: "linguistic", domain: "language", confidence: 0.7 },
{ id: "temporal", domain: "time", confidence: 0.6 },
{ id: "causal", domain: "causality", confidence: 0.5 },
{ id: "spatial", domain: "space", confidence: 0.6 },
];
model_configs.forEach((config) => {
const model = this.createDefaultModel(config.id);
model.confidence = config.confidence;
this.generative_models.set(config.id, model);
});
}
private createDefaultModel(id: string): GenerativeModel {
return {
id,
parameters: new Map([
["sensitivity", 0.5],
["specificity", 0.5],
["temporal_weight", 0.3],
["context_weight", 0.4],
]),
prior_beliefs: new Map(),
confidence: 0.5,
last_updated: Date.now(),
prediction_accuracy: 0.5,
};
}
private extractContext(input: unknown): Context {
// Extract context from input - simplified implementation
if (typeof input === "object" && input !== null && "context" in input) {
return (input as { context: Context }).context;
}
// Create default context
return {
session_id: "default",
domain: "general",
urgency: 0.5,
complexity: 0.5,
};
}
private generateLevelPredictions(
level: HierarchicalLevel,
context: Context
): Prediction[] {
const predictions: Prediction[] = [];
// Generate predictions based on level's model
const model = level.model;
const context_key = this.getContextKey(context);
// Get prior belief for this context (currently unused but available for future enhancements)
model.prior_beliefs.get(context_key) ?? 0.5;
// Generate different types of predictions based on level
switch (level.level) {
case 0: // Sensory level
predictions.push(...this.generateSensoryPredictions(model, context));
break;
case 1: // Perceptual level
predictions.push(...this.generatePerceptualPredictions(model, context));
break;
case 2: // Conceptual level
predictions.push(...this.generateConceptualPredictions(model, context));
break;
case 3: // Abstract level
predictions.push(...this.generateAbstractPredictions(model, context));
break;
}
return predictions;
}
private generateModelPredictions(
model: GenerativeModel,
context: Context
): Prediction[] {
const predictions: Prediction[] = [];
const context_key = this.getContextKey(context);
const prior_belief = model.prior_beliefs.get(context_key) ?? 0.5;
// Generate predictions based on model type
switch (model.id) {
case "linguistic":
predictions.push({
content: this.generateLinguisticPrediction(model, context),
confidence: model.confidence * prior_belief,
timestamp: Date.now(),
context,
});
break;
case "temporal":
predictions.push({
content: this.generateTemporalPrediction(model, context),
confidence: model.confidence * prior_belief,
timestamp: Date.now(),
context,
});
break;
case "causal":
predictions.push({
content: this.generateCausalPrediction(model, context),
confidence: model.confidence * prior_belief,
timestamp: Date.now(),
context,
});
break;
case "spatial":
predictions.push({
content: this.generateSpatialPrediction(model, context),
confidence: model.confidence * prior_belief,
timestamp: Date.now(),
context,
});
break;
}
return predictions;
}
private computePredictionErrors(
predictions: Prediction[],
actual: unknown
): PredictionError[] {
return predictions.map((prediction) => {
const error_magnitude = this.computePredictionError(prediction, actual);
return {
magnitude: error_magnitude,
direction: error_magnitude > 0.5 ? "positive" : "negative",
confidence: prediction.confidence,
source: this.getModelIdFromPrediction(prediction),
timestamp: Date.now(),
};
});
}
private async updateModelsFromErrors(
errors: PredictionError[]
): Promise<GenerativeModel[]> {
const updated_models: GenerativeModel[] = [];
errors.forEach((error) => {
const model = this.generative_models.get(error.source);
if (model && error.magnitude > this.prediction_error_threshold) {
// Create a dummy prediction for the update
const dummy_prediction: Prediction = {
content: {},
confidence: error.confidence,
timestamp: error.timestamp,
context: { session_id: "default" },
};
this.updateModel(error.magnitude, dummy_prediction);
updated_models.push(model);
}
});
return updated_models;
}
private updateHistory(
predictions: Prediction[],
errors: PredictionError[]
): void {
// Add to history with size limit
this.prediction_history.push(...predictions);
this.error_history.push(...errors);
// Trim history if too large
if (this.prediction_history.length > this.max_history_size) {
this.prediction_history = this.prediction_history.slice(
-this.max_history_size
);
}
if (this.error_history.length > this.max_history_size) {
this.error_history = this.error_history.slice(-this.max_history_size);
}
}
private extractFeatures(content: unknown): Map<string, number> {
const features = new Map<string, number>();
if (typeof content === "string") {
// Extract linguistic features
features.set("length", content.length / 100); // Normalized
features.set("complexity", this.computeTextComplexity(content));
features.set("sentiment", this.computeSentiment(content));
} else if (typeof content === "object" && content !== null) {
// Extract object features
const obj = content as Record<string, unknown>;
features.set("properties", Object.keys(obj).length / 10); // Normalized
features.set("depth", this.computeObjectDepth(obj));
}
return features;
}
private computeFeatureErrors(
predicted: Map<string, number>,
actual: Map<string, number>
): Map<string, number> {
const errors = new Map<string, number>();
// Compute errors for common features
const all_features = new Set([
...Array.from(predicted.keys()),
...Array.from(actual.keys()),
]);
all_features.forEach((feature) => {
const pred_value = predicted.get(feature) ?? 0;
const actual_value = actual.get(feature) ?? 0;
const error = Math.abs(pred_value - actual_value);
errors.set(feature, error);
});
return errors;
}
private aggregateErrors(errors: Map<string, number>): number {
if (errors.size === 0) return 0;
const error_values = Array.from(errors.values());
const mean_error =
error_values.reduce((sum, error) => sum + error, 0) / error_values.length;
return Math.max(0, Math.min(1, mean_error));
}
private getModelIdFromPrediction(prediction: Prediction): string {
// Simple heuristic to determine which model generated the prediction
if (typeof prediction.content === "string") return "linguistic";
if (prediction.context.domain === "time") return "temporal";
if (prediction.context.domain === "causality") return "causal";
if (prediction.context.domain === "space") return "spatial";
return "linguistic"; // Default
}
private getContextKey(context: Context): string {
return `${context.domain ?? "general"}_${context.complexity ?? 0.5}`;
}
private updateModelParameters(
model: GenerativeModel,
error: number,
prediction: Prediction
): void {
// Update parameters using simple gradient descent
const learning_rate = this.learning_rate * (1 - model.confidence);
// Update sensitivity based on error
const current_sensitivity = model.parameters.get("sensitivity") ?? 0.5;
const sensitivity_update = current_sensitivity - learning_rate * error;
model.parameters.set(
"sensitivity",
Math.max(0.1, Math.min(0.9, sensitivity_update))
);
// Update context weight based on prediction confidence
const current_context_weight =
model.parameters.get("context_weight") ?? 0.4;
const context_update =
current_context_weight + learning_rate * (prediction.confidence - 0.5);
model.parameters.set(
"context_weight",
Math.max(0.1, Math.min(0.9, context_update))
);
}
// Prediction generation methods for different levels and models
private generateSensoryPredictions(
model: GenerativeModel,
_context: Context
): Prediction[] {
return [
{
content: {
type: "sensory",
features: ["brightness", "contrast", "motion"],
confidence: model.confidence,
},
confidence: model.confidence * 0.8,
timestamp: Date.now(),
context: _context,
},
];
}
private generatePerceptualPredictions(
model: GenerativeModel,
_context: Context
): Prediction[] {
return [
{
content: {
type: "perceptual",
objects: ["text", "pattern", "structure"],
confidence: model.confidence,
},
confidence: model.confidence * 0.7,
timestamp: Date.now(),
context: _context,
},
];
}
private generateConceptualPredictions(
model: GenerativeModel,
_context: Context
): Prediction[] {
return [
{
content: {
type: "conceptual",
concepts: ["meaning", "intent", "category"],
confidence: model.confidence,
},
confidence: model.confidence * 0.6,
timestamp: Date.now(),
context: _context,
},
];
}
private generateAbstractPredictions(
model: GenerativeModel,
_context: Context
): Prediction[] {
return [
{
content: {
type: "abstract",
abstractions: ["goal", "plan", "outcome"],
confidence: model.confidence,
},
confidence: model.confidence * 0.5,
timestamp: Date.now(),
context: _context,
},
];
}
private generateLinguisticPrediction(
_model: GenerativeModel,
context: Context
): unknown {
return {
type: "linguistic",
next_word_probabilities: new Map([
["the", 0.15],
["and", 0.12],
["of", 0.1],
["to", 0.08],
]),
semantic_category: context.domain ?? "general",
};
}
private generateTemporalPrediction(
_model: GenerativeModel,
_context: Context
): unknown {
return {
type: "temporal",
next_event_time: Date.now() + 1000, // 1 second from now
duration_estimate: 5000, // 5 seconds
temporal_pattern: "sequential",
};
}
private generateCausalPrediction(
_model: GenerativeModel,
_context: Context
): unknown {
return {
type: "causal",
likely_causes: ["user_input", "system_state", "external_event"],
likely_effects: ["response_generation", "state_change", "learning"],
causal_strength: _model.confidence,
};
}
private generateSpatialPrediction(
_model: GenerativeModel,
_context: Context
): unknown {
return {
type: "spatial",
spatial_relations: ["above", "below", "adjacent"],
coordinate_estimates: { x: 0.5, y: 0.5, z: 0.0 },
spatial_confidence: _model.confidence,
};
}
// Utility methods for feature extraction
private computeTextComplexity(text: string): number {
// Simple complexity measure based on word length and sentence structure
const words = text.split(/\s+/);
const avg_word_length =
words.reduce((sum, word) => sum + word.length, 0) / words.length;
const sentence_count = text.split(/[.!?]+/).length;
const complexity = (avg_word_length / 10 + sentence_count / 5) / 2;
return Math.max(0, Math.min(1, complexity));
}
private computeSentiment(text: string): number {
// Simple sentiment analysis
const positive_words = ["good", "great", "excellent", "positive", "happy"];
const negative_words = ["bad", "terrible", "awful", "negative", "sad"];
const words = text.toLowerCase().split(/\s+/);
let sentiment_score = 0.5; // Neutral
words.forEach((word) => {
if (positive_words.includes(word)) sentiment_score += 0.1;
if (negative_words.includes(word)) sentiment_score -= 0.1;
});
return Math.max(0, Math.min(1, sentiment_score));
}
private computeObjectDepth(obj: Record<string, unknown>): number {
let max_depth = 0;
const traverse = (current: unknown, depth: number): void => {
if (depth > max_depth) max_depth = depth;
if (typeof current === "object" && current !== null) {
Object.values(current as Record<string, unknown>).forEach((value) => {
traverse(value, depth + 1);
});
}
};
traverse(obj, 0);
return Math.min(1, max_depth / 5); // Normalize to 0-1
}
private areContentTypesVeryDifferent(
predicted: unknown,
actual: unknown
): boolean {
// Check if content types are fundamentally different
const pred_type = typeof predicted;
const actual_type = typeof actual;
// Different primitive types
if (pred_type !== actual_type) {
return true;
}
// Both strings but very different content
if (pred_type === "string" && actual_type === "string") {
const pred_str = predicted as string;
const actual_str = actual as string;
// Very different lengths
if (
Math.abs(pred_str.length - actual_str.length) >
Math.max(pred_str.length, actual_str.length) * 0.5
) {
return true;
}
// No common words
const pred_words = new Set(pred_str.toLowerCase().split(/\s+/));
const actual_words = new Set(actual_str.toLowerCase().split(/\s+/));
const intersection = new Set(
Array.from(pred_words).filter((x) => actual_words.has(x))
);
if (
intersection.size === 0 &&
pred_words.size > 0 &&
actual_words.size > 0
) {
return true;
}
}
// Both objects but very different structure
if (
pred_type === "object" &&
actual_type === "object" &&
predicted !== null &&
actual !== null
) {
const pred_keys = Object.keys(predicted as Record<string, unknown>);
const actual_keys = Object.keys(actual as Record<string, unknown>);
// No common keys
const common_keys = pred_keys.filter((key) => actual_keys.includes(key));
if (
common_keys.length === 0 &&
pred_keys.length > 0 &&
actual_keys.length > 0
) {
return true;
}
}
return false;
}
}