Hopfield + Hebbian hybrid memory system for LLMs. Two nights of experiments (16 iterations), validated on LongMemEval (ICLR 2025). Architecture: - Single-hop: Two-Stage Hopfield (NN top-20 → softmax settle) - Multi-hop: Hebbian W matrix with WTA pattern separation - 64% on LongMemEval (500 questions), retrieval-only, no LLM dependency - 4ms latency @ 20K memories, ~1GB VRAM Key findings: - Hopfield attention solved noise tolerance (20% → 100% vs flat Hebbian) - WTA pattern separation enables 20K+ capacity - Multi-hop associative chains (6 hops, CosSim=1.0) — RAG can't do this - MiniLM-L6 is optimal (discrimination gap > absolute similarity) - Paraphrase cue augmentation: 55% → 100% on synthetic, 36% → 64% on benchmark - SNN encoder viable (CosSim 0.99) but not needed for current architecture
317 lines
11 KiB
Python
317 lines
11 KiB
Python
"""Experiment 3: Sleep Consolidation Effects.
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Test questions:
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1. Does consolidation (replay + homeostasis) help or hurt recall?
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2. Does replay with noise improve noise tolerance?
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3. How does pruning affect capacity?
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4. Multi-night scenario: learn day 1, consolidate, learn day 2, consolidate.
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Do day 1 memories survive?
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5. Selective consolidation: replay important memories more → priority memory
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"""
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import sys
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import time
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import json
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from pathlib import Path
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import torch
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import torch.nn as nn
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import numpy as np
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sys.path.insert(0, str(Path(__file__).parent.parent / "src"))
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from nuonuo.consolidation import MemoryConsolidator, winner_take_all
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DEVICE = "cuda"
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RESULTS_DIR = Path(__file__).parent.parent / "doc"
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def cosine(a, b):
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if a.norm() == 0 or b.norm() == 0:
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return 0.0
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return nn.functional.cosine_similarity(a.unsqueeze(0), b.unsqueeze(0)).item()
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class TestableMemory:
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"""Memory with consolidation support for testing."""
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def __init__(self, input_dim=768, code_dim=16384, k=20):
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self.k = k
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self.code_dim = code_dim
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self.proj = (torch.randn(input_dim, code_dim, device=DEVICE)
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* (1.0 / input_dim**0.5))
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self.target_proj = (torch.randn(input_dim, code_dim, device=DEVICE)
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* (1.0 / input_dim**0.5))
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self.W = nn.Parameter(torch.zeros(code_dim, code_dim, device=DEVICE),
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requires_grad=False)
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self.consolidator = MemoryConsolidator(code_dim, k)
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def sep(self, x):
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return winner_take_all(x @ self.proj, self.k)
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def sep_target(self, x):
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return winner_take_all(x @ self.target_proj, self.k)
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def learn(self, cue, target, record=True):
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cc = self.sep(cue)
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tc = self.sep_target(target)
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self.W.data += torch.outer(tc, cc)
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if record:
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self.consolidator.record(cc, tc)
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def recall(self, cue):
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cc = self.sep(cue)
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raw = self.W @ cc
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return winner_take_all(raw, self.k)
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def test_recall(self, cues, targets, noise_std=0.0):
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"""Test recall accuracy."""
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correct = []
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for i in range(len(cues)):
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if noise_std > 0:
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c = nn.functional.normalize(
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cues[i] + torch.randn_like(cues[i]) * noise_std, dim=0)
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else:
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c = cues[i]
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recalled = self.recall(c)
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tc = self.sep_target(targets[i])
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correct.append(cosine(recalled, tc))
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return np.mean(correct), np.mean([s > 0.5 for s in correct])
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def consolidate(self, **kwargs):
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return self.consolidator.consolidate(
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self.W, self.proj, self.target_proj, **kwargs)
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def gen_memories(n, dim=768):
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cues = [nn.functional.normalize(torch.randn(dim, device=DEVICE), dim=0)
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for _ in range(n)]
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targets = [nn.functional.normalize(torch.randn(dim, device=DEVICE), dim=0)
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for _ in range(n)]
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return cues, targets
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def test_basic_consolidation():
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"""Does replay + homeostasis help?"""
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print("=== Test 1: Basic Consolidation Effect ===")
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for n_pairs in [100, 500]:
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mem = TestableMemory()
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cues, targets = gen_memories(n_pairs)
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# Learn
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for i in range(n_pairs):
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mem.learn(cues[i], targets[i])
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# Before consolidation
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cos_before, rate_before = mem.test_recall(cues, targets)
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w_norm_before = mem.W.data.norm().item()
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print(f"\n {n_pairs} pairs:")
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print(f" Before: CosSim={cos_before:.4f}, Rate={rate_before:.2%}, "
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f"W_norm={w_norm_before:.2f}")
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# Consolidation with different settings
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for epochs in [1, 3, 5, 10]:
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# Clone memory for each test
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mem_test = TestableMemory()
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mem_test.W.data.copy_(mem.W.data)
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mem_test.proj = mem.proj
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mem_test.target_proj = mem.target_proj
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mem_test.consolidator.replay_buffer = list(mem.consolidator.replay_buffer)
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stats = mem_test.consolidate(
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num_epochs=epochs, homeostasis_factor=0.95, prune_threshold=0.001)
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cos_after, rate_after = mem_test.test_recall(cues, targets)
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print(f" After (epochs={epochs}): CosSim={cos_after:.4f}, "
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f"Rate={rate_after:.2%}, "
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f"W_norm={stats['final_w_norm']:.2f}, "
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f"Sparsity={stats['final_sparsity']:.2%}")
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def test_noisy_replay():
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"""Does replay with noise improve noise tolerance?"""
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print("\n=== Test 2: Noisy Replay for Robustness ===")
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n_pairs = 100
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mem_base = TestableMemory()
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cues, targets = gen_memories(n_pairs)
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for i in range(n_pairs):
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mem_base.learn(cues[i], targets[i])
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# Test at different noise levels
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test_noises = [0.0, 0.05, 0.1, 0.2]
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# No consolidation (baseline)
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print("\n No consolidation:")
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for ns in test_noises:
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cos, rate = mem_base.test_recall(cues, targets, noise_std=ns)
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print(f" test_noise={ns:.2f}: CosSim={cos:.4f}, Rate={rate:.2%}")
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# Consolidation with different replay noise
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for replay_noise in [0.0, 0.1, 0.5, 1.0]:
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mem_test = TestableMemory()
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mem_test.W.data.copy_(mem_base.W.data)
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mem_test.proj = mem_base.proj
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mem_test.target_proj = mem_base.target_proj
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mem_test.consolidator.replay_buffer = list(mem_base.consolidator.replay_buffer)
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mem_test.consolidate(num_epochs=5, replay_noise=replay_noise,
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homeostasis_factor=0.95)
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print(f"\n Consolidated (replay_noise={replay_noise}):")
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for ns in test_noises:
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cos, rate = mem_test.test_recall(cues, targets, noise_std=ns)
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print(f" test_noise={ns:.2f}: CosSim={cos:.4f}, Rate={rate:.2%}")
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def test_multi_night():
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"""Multi-night scenario: learn, consolidate, learn more.
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Do old memories survive?"""
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print("\n=== Test 3: Multi-Night Memory Survival ===")
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mem = TestableMemory()
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# Day 1: Learn 100 memories
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cues_d1, targets_d1 = gen_memories(100)
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for i in range(100):
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mem.learn(cues_d1[i], targets_d1[i])
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cos_d1, _ = mem.test_recall(cues_d1, targets_d1)
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print(f" After Day 1 (100 memories): CosSim={cos_d1:.4f}")
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# Night 1: Consolidate
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stats = mem.consolidate(num_epochs=5, homeostasis_factor=0.95)
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cos_d1_after, _ = mem.test_recall(cues_d1, targets_d1)
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print(f" After Night 1 consolidation: CosSim={cos_d1_after:.4f}, "
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f"W_norm={stats['final_w_norm']:.2f}")
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mem.consolidator.selective_clear(keep_fraction=0.3)
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# Day 2: Learn 100 more memories
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cues_d2, targets_d2 = gen_memories(100)
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for i in range(100):
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mem.learn(cues_d2[i], targets_d2[i])
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cos_d1_mid, _ = mem.test_recall(cues_d1, targets_d1)
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cos_d2_mid, _ = mem.test_recall(cues_d2, targets_d2)
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print(f" After Day 2 (100 more): Day1={cos_d1_mid:.4f}, Day2={cos_d2_mid:.4f}")
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# Night 2: Consolidate (with day 1 carryover + day 2)
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stats = mem.consolidate(num_epochs=5, homeostasis_factor=0.95)
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cos_d1_final, _ = mem.test_recall(cues_d1, targets_d1)
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cos_d2_final, _ = mem.test_recall(cues_d2, targets_d2)
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print(f" After Night 2: Day1={cos_d1_final:.4f}, Day2={cos_d2_final:.4f}, "
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f"W_norm={stats['final_w_norm']:.2f}")
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# Continue for 5 more days
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for day in range(3, 8):
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mem.consolidator.selective_clear(keep_fraction=0.3)
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cues_new, targets_new = gen_memories(100)
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for i in range(100):
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mem.learn(cues_new[i], targets_new[i])
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mem.consolidate(num_epochs=5, homeostasis_factor=0.95)
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cos_d1_now, _ = mem.test_recall(cues_d1, targets_d1)
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cos_d2_now, _ = mem.test_recall(cues_d2, targets_d2)
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cos_new, _ = mem.test_recall(cues_new, targets_new)
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w_norm = mem.W.data.norm().item()
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sparsity = (mem.W.data.abs() < 0.001).float().mean().item()
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print(f" After Day {day}: Day1={cos_d1_now:.4f}, Day2={cos_d2_now:.4f}, "
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f"Latest={cos_new:.4f}, W_norm={w_norm:.1f}, Sparsity={sparsity:.2%}")
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def test_priority_replay():
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"""Test selective consolidation: replay important memories more."""
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print("\n=== Test 4: Priority Replay ===")
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mem = TestableMemory()
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# 50 "important" memories (replay 5x)
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cues_imp, targets_imp = gen_memories(50)
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for i in range(50):
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mem.learn(cues_imp[i], targets_imp[i])
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# Record extra copies for priority replay
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cc = mem.sep(cues_imp[i])
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tc = mem.sep_target(targets_imp[i])
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for _ in range(4): # 4 extra = 5x total
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mem.consolidator.record(cc, tc)
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# 50 "unimportant" memories (replay 1x, normal)
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cues_unimp, targets_unimp = gen_memories(50)
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for i in range(50):
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mem.learn(cues_unimp[i], targets_unimp[i])
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cos_imp_before, _ = mem.test_recall(cues_imp, targets_imp)
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cos_unimp_before, _ = mem.test_recall(cues_unimp, targets_unimp)
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print(f" Before consolidation: Important={cos_imp_before:.4f}, "
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f"Unimportant={cos_unimp_before:.4f}")
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# Consolidate with strong homeostasis (will decay unimportant more)
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mem.consolidate(num_epochs=10, homeostasis_factor=0.90)
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cos_imp_after, _ = mem.test_recall(cues_imp, targets_imp)
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cos_unimp_after, _ = mem.test_recall(cues_unimp, targets_unimp)
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print(f" After consolidation: Important={cos_imp_after:.4f}, "
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f"Unimportant={cos_unimp_after:.4f}")
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print(f" Priority effect: Δimportant={cos_imp_after-cos_imp_before:+.4f}, "
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f"Δunimportant={cos_unimp_after-cos_unimp_before:+.4f}")
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def test_forgetting_curve():
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"""Measure memory decay over multiple consolidation cycles without replay."""
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print("\n=== Test 5: Forgetting Curve ===")
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mem = TestableMemory()
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cues, targets = gen_memories(100)
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for i in range(100):
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mem.learn(cues[i], targets[i])
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cos0, _ = mem.test_recall(cues, targets)
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print(f" Day 0: CosSim={cos0:.4f}")
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# Simulate nights with homeostasis but NO replay
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for night in range(1, 11):
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# Only homeostasis + pruning, no replay
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mem.W.data *= 0.95
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mask = mem.W.data.abs() >= 0.001
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mem.W.data *= mask.float()
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cos, rate = mem.test_recall(cues, targets)
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w_norm = mem.W.data.norm().item()
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print(f" Night {night:2d} (no replay): CosSim={cos:.4f}, "
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f"Rate={rate:.2%}, W_norm={w_norm:.2f}")
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# Same but WITH replay
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print("\n --- With replay ---")
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mem2 = TestableMemory()
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mem2.proj = mem.proj
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mem2.target_proj = mem.target_proj
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for i in range(100):
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mem2.learn(cues[i], targets[i])
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for night in range(1, 11):
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mem2.consolidate(num_epochs=1, homeostasis_factor=0.95)
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cos, rate = mem2.test_recall(cues, targets)
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w_norm = mem2.W.data.norm().item()
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print(f" Night {night:2d} (with replay): CosSim={cos:.4f}, "
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f"Rate={rate:.2%}, W_norm={w_norm:.2f}")
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def main():
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print("=" * 60)
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print("Experiment 3: Sleep Consolidation")
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print("=" * 60)
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test_basic_consolidation()
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test_noisy_replay()
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test_multi_night()
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test_priority_replay()
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test_forgetting_curve()
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if __name__ == "__main__":
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main()
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