#!/usr/bin/env python3 """ ============================================================================= CLOSING THE AI-BRAIN LOOP Using TRIBE v2 to identify architectural gaps between AI models and the brain ============================================================================= Methodology: Phase 1 — Load TRIBE v2, run inference, capture per-layer AI features Phase 2 — Layer-wise encoding analysis: which AI layers predict which brain regions Phase 3 — Modality ablation: which encoder drives which brain area Phase 4 — RSA: representational similarity between AI layers and brain ROIs Phase 5 — Divergence mapping: where the brain does something AI can't capture Phase 6 — Architectural implications: what's missing in current AI Output: /home/azureuser/loop_results/ """ import os import sys import logging import warnings import time import numpy as np import torch import matplotlib matplotlib.use("Agg") import matplotlib.pyplot as plt from matplotlib.gridspec import GridSpec import pandas as pd from pathlib import Path from scipy import stats from scipy.spatial.distance import pdist, squareform from einops import rearrange warnings.filterwarnings("ignore") logging.basicConfig(level=logging.INFO, format="[%(asctime)s] %(message)s", datefmt="%H:%M:%S") log = logging.getLogger(__name__) OUT = Path("/home/azureuser/loop_results") OUT.mkdir(exist_ok=True) # ═══════════════════════════════════════════════════════════════════════════════ # PHASE 1: Load model, run inference, capture intermediate representations # ═══════════════════════════════════════════════════════════════════════════════ log.info("PHASE 1: Loading TRIBE v2 and running inference") from tribev2 import TribeModel CACHE = "/home/azureuser/cache" VIDEO = "/home/azureuser/test_stimulus.mp4" model = TribeModel.from_pretrained("facebook/tribev2", cache_folder=CACHE) fmri_model = model._model device = fmri_model.device log.info(f"Model on {device}, n_outputs={fmri_model.n_outputs}") # Print model structure log.info("Model structure:") log.info(f" Projectors: {list(fmri_model.projectors.keys())}") log.info(f" Hidden dim: {fmri_model.config.hidden}") log.info(f" Layer aggregation: {fmri_model.config.layer_aggregation}") log.info(f" Extractor aggregation: {fmri_model.config.extractor_aggregation}") if hasattr(fmri_model, 'encoder'): log.info(f" Encoder: {type(fmri_model.encoder).__name__}") if hasattr(fmri_model, 'low_rank_head'): log.info(f" Low-rank head: {fmri_model.low_rank_head}") # Build events log.info(f"Processing video: {VIDEO}") events = model.get_events_dataframe(video_path=VIDEO) log.info(f"Events: {len(events)} rows, types: {events.type.unique().tolist()}") # Get data loader loader = model.data.get_loaders(events=events, split_to_build="all")["all"] # ── Collect per-layer features and brain predictions ── # We intercept batch.data to get the raw per-layer features (B, L, D, T) # and run the model to get brain predictions all_features = {} # modality -> list of (L, D, T) arrays all_projected = {} # modality -> list of (T, H) arrays all_post_encoder = [] # list of (T, H) arrays all_brain_preds = [] # list of (T, V) arrays — V = n_vertices # Register hooks on projectors to capture projected features proj_captures = {} proj_hooks = [] def make_proj_hook(name): def hook(mod, inp, out): proj_captures[name] = out.detach().cpu().numpy() return hook for mod_name, proj in fmri_model.projectors.items(): proj_hooks.append(proj.register_forward_hook(make_proj_hook(mod_name))) # Hook encoder output encoder_capture = [None] def enc_hook(mod, inp, out): encoder_capture[0] = out.detach().cpu().numpy() if hasattr(fmri_model, 'encoder') and fmri_model.encoder is not None: proj_hooks.append(fmri_model.encoder.register_forward_hook(enc_hook)) log.info("Running inference with hooks...") t0 = time.time() with torch.inference_mode(): for batch_idx, batch in enumerate(loader): batch = batch.to(device) # Capture raw per-layer features before the model touches them for mod_name in fmri_model.projectors.keys(): if mod_name in batch.data: feat = batch.data[mod_name].detach().cpu().numpy() # (B, L, D, T) or (B, D, T) if feat.ndim == 3: feat = feat[:, np.newaxis, :, :] # ensure 4D if mod_name not in all_features: all_features[mod_name] = [] all_features[mod_name].append(feat) # Forward pass (triggers hooks) y_pred = fmri_model(batch).detach().cpu().numpy() # (B, V, T') y_pred = rearrange(y_pred, 'b v t -> (b t) v') all_brain_preds.append(y_pred) # Save projected features for mod_name in proj_captures: if mod_name not in all_projected: all_projected[mod_name] = [] all_projected[mod_name].append(proj_captures[mod_name]) proj_captures.clear() # Save encoder output if encoder_capture[0] is not None: all_post_encoder.append(encoder_capture[0]) encoder_capture[0] = None # Clean hooks for h in proj_hooks: h.remove() elapsed = time.time() - t0 log.info(f"Inference done in {elapsed:.1f}s") # Concatenate results brain_preds = np.concatenate(all_brain_preds, axis=0) # (T_total, V) log.info(f"Brain predictions: {brain_preds.shape}") for mod in all_features: all_features[mod] = np.concatenate(all_features[mod], axis=0) # (B_total, L, D, T) log.info(f"Raw features [{mod}]: {all_features[mod].shape}") for mod in all_projected: all_projected[mod] = np.concatenate(all_projected[mod], axis=0) # (B_total, T, H) log.info(f"Projected features [{mod}]: {all_projected[mod].shape}") if all_post_encoder: post_encoder = np.concatenate(all_post_encoder, axis=0) # (B_total, T, H) log.info(f"Post-encoder features: {post_encoder.shape}") # ═══════════════════════════════════════════════════════════════════════════════ # PHASE 2: Brain parcellation — map vertices to functional regions # ═══════════════════════════════════════════════════════════════════════════════ log.info("PHASE 2: Loading brain parcellation (Destrieux atlas, fsaverage5)") from nilearn import datasets from nilearn.surface import load_surf_data fsaverage5 = datasets.fetch_surf_fsaverage("fsaverage5") # Load Destrieux parcellation labels labels_lh = load_surf_data(fsaverage5["annot_left_destrieux"]) labels_rh = load_surf_data(fsaverage5["annot_right_destrieux"]) N_VERT = 10242 # vertices per hemisphere in fsaverage5 all_labels = np.concatenate([labels_lh, labels_rh]) # (20484,) # Destrieux atlas label names destrieux = datasets.fetch_atlas_destrieux_2009() label_names_raw = destrieux["labels"] label_names = {} for i, name in enumerate(label_names_raw): if isinstance(name, bytes): name = name.decode("utf-8") label_names[i] = name # Build region info regions = {} for lid in np.unique(all_labels): mask = all_labels == lid n = mask.sum() if n < 5: continue name = label_names.get(int(lid), f"region_{lid}") if name == "Unknown" or name == "Medial_wall": continue regions[int(lid)] = {"name": name, "mask": mask, "n_vertices": int(n)} log.info(f"Found {len(regions)} usable brain regions") # ═══════════════════════════════════════════════════════════════════════════════ # PHASE 3: Layer-wise encoding analysis # ═══════════════════════════════════════════════════════════════════════════════ log.info("PHASE 3: Layer-wise encoding analysis") # For each modality and each cached layer, compute how well that layer's # features correlate with predicted brain activity in each region. # # Method: For each region, average brain predictions across vertices to get # a time series. For each AI layer, average features across the feature dim # to get a time series. Compute Pearson correlation. # First, build time-aligned representations # brain_preds is (T_total, V) — each row is one TR's brain prediction T_total = brain_preds.shape[0] V = brain_preds.shape[1] # Per-region mean brain activity over time region_timeseries = {} for lid, rinfo in regions.items(): region_timeseries[lid] = brain_preds[:, rinfo["mask"]].mean(axis=1) # (T_total,) # Per-modality, per-layer feature time series # all_features[mod] is (B, L, D, T_batch) — we need to flatten B and T_batch layer_timeseries = {} for mod, feats in all_features.items(): B, L, D, T_batch = feats.shape # Reshape to (B*T_batch, L, D) feats_flat = rearrange(feats, 'b l d t -> (b t) l d') # Trim to match brain_preds length min_t = min(feats_flat.shape[0], T_total) feats_flat = feats_flat[:min_t] layer_timeseries[mod] = {} for l in range(L): # Mean across feature dim to get single time series per layer layer_timeseries[mod][l] = feats_flat[:, l, :].mean(axis=1) # (T,) log.info("Computing layer-brain correlations...") # Correlation matrix: (modality, layer) x (region) layer_brain_corr = {} for mod in layer_timeseries: L = len(layer_timeseries[mod]) for l in range(L): key = f"{mod}_L{l}" layer_brain_corr[key] = {} layer_ts = layer_timeseries[mod][l] min_t = min(len(layer_ts), T_total) for lid, rinfo in regions.items(): brain_ts = region_timeseries[lid][:min_t] lt = layer_ts[:min_t] if np.std(lt) < 1e-10 or np.std(brain_ts) < 1e-10: r = 0.0 else: r, _ = stats.pearsonr(lt, brain_ts) layer_brain_corr[key][lid] = r # Build matrix for visualization all_layer_keys = sorted(layer_brain_corr.keys()) all_region_ids = sorted(regions.keys()) region_names_list = [regions[lid]["name"] for lid in all_region_ids] corr_matrix = np.zeros((len(all_layer_keys), len(all_region_ids))) for i, lk in enumerate(all_layer_keys): for j, lid in enumerate(all_region_ids): corr_matrix[i, j] = layer_brain_corr[lk].get(lid, 0) log.info(f"Correlation matrix: {corr_matrix.shape} (AI layers x brain regions)") # ═══════════════════════════════════════════════════════════════════════════════ # PHASE 4: Modality ablation — which encoder drives which brain area # ═══════════════════════════════════════════════════════════════════════════════ log.info("PHASE 4: Modality ablation analysis") modalities = list(fmri_model.projectors.keys()) log.info(f"Ablating modalities: {modalities}") # Re-run inference with each modality zeroed out ablation_preds = {"full": brain_preds} with torch.inference_mode(): for mod_to_ablate in modalities: log.info(f" Ablating: {mod_to_ablate}") preds_list = [] loader = model.data.get_loaders(events=events, split_to_build="all")["all"] for batch in loader: batch = batch.to(device) # Zero out target modality if mod_to_ablate in batch.data: original = batch.data[mod_to_ablate].clone() batch.data[mod_to_ablate] = torch.zeros_like(original) y = fmri_model(batch).detach().cpu().numpy() y = rearrange(y, 'b v t -> (b t) v') preds_list.append(y) batch.data[mod_to_ablate] = original else: y = fmri_model(batch).detach().cpu().numpy() y = rearrange(y, 'b v t -> (b t) v') preds_list.append(y) ablation_preds[mod_to_ablate] = np.concatenate(preds_list, axis=0) log.info(f" shape: {ablation_preds[mod_to_ablate].shape}") # Compute per-region modality importance # Importance = mean absolute change when modality is removed region_mod_importance = {} for lid, rinfo in regions.items(): mask = rinfo["mask"] full = ablation_preds["full"][:, mask] imp = {} for mod in modalities: ablated = ablation_preds[mod][:, mask] # Use both MSE change and correlation change delta_mse = np.mean((full - ablated) ** 2) imp[mod] = float(delta_mse) total = sum(imp.values()) + 1e-12 imp_norm = {k: v / total for k, v in imp.items()} region_mod_importance[lid] = imp_norm log.info("Modality ablation done") # ═══════════════════════════════════════════════════════════════════════════════ # PHASE 5: RSA — Representational Similarity Analysis # ═══════════════════════════════════════════════════════════════════════════════ log.info("PHASE 5: Representational Similarity Analysis") # Split predictions into temporal segments (2-second windows) # and compute RDMs for AI features and brain regions SEGMENT_SIZE = 2 # TRs per segment (adjustable) n_segments = T_total // SEGMENT_SIZE # Build segment-level representations def build_segments(timeseries, n_segments, seg_size): """Average timeseries within segments.""" segs = [] for i in range(n_segments): start = i * seg_size end = start + seg_size if end <= len(timeseries): segs.append(timeseries[start:end].mean(axis=0) if timeseries.ndim > 1 else timeseries[start:end].mean()) return np.array(segs) # Brain RDMs per region log.info("Building brain RDMs per region...") brain_rdms = {} for lid, rinfo in regions.items(): region_data = brain_preds[:, rinfo["mask"]] # (T, n_verts) seg_data = [] for i in range(n_segments): s, e = i * SEGMENT_SIZE, (i + 1) * SEGMENT_SIZE if e <= region_data.shape[0]: seg_data.append(region_data[s:e].mean(axis=0)) if len(seg_data) < 3: continue seg_data = np.array(seg_data) # (n_segments, n_verts) if seg_data.std() < 1e-10: brain_rdms[lid] = np.zeros((len(seg_data), len(seg_data))) else: brain_rdms[lid] = squareform(pdist(seg_data, metric="correlation")) # AI feature RDMs per modality per layer log.info("Building AI feature RDMs per layer...") ai_rdms = {} for mod, feats in all_features.items(): B, L, D, T_batch = feats.shape feats_flat = rearrange(feats, 'b l d t -> (b t) l d') min_t = min(feats_flat.shape[0], T_total) feats_flat = feats_flat[:min_t] for l in range(L): layer_data = feats_flat[:, l, :] # (T, D) seg_data = [] for i in range(n_segments): s, e = i * SEGMENT_SIZE, (i + 1) * SEGMENT_SIZE if e <= layer_data.shape[0]: seg_data.append(layer_data[s:e].mean(axis=0)) if len(seg_data) < 3: continue seg_data = np.array(seg_data) key = f"{mod}_L{l}" if seg_data.std() < 1e-10: ai_rdms[key] = np.zeros((len(seg_data), len(seg_data))) else: ai_rdms[key] = squareform(pdist(seg_data, metric="correlation")) # Compare AI RDMs to brain RDMs using Spearman correlation log.info("Computing RSA (Spearman correlation between RDMs)...") rsa_matrix = np.zeros((len(ai_rdms), len(brain_rdms))) ai_rdm_keys = sorted(ai_rdms.keys()) brain_rdm_keys = sorted(brain_rdms.keys()) for i, ak in enumerate(ai_rdm_keys): ai_vec = squareform(ai_rdms[ak]) # upper triangle if len(ai_vec) == 0: continue for j, bk in enumerate(brain_rdm_keys): brain_vec = squareform(brain_rdms[bk]) min_len = min(len(ai_vec), len(brain_vec)) if min_len < 3: continue rho, _ = stats.spearmanr(ai_vec[:min_len], brain_vec[:min_len]) rsa_matrix[i, j] = rho if not np.isnan(rho) else 0 log.info(f"RSA matrix: {rsa_matrix.shape}") # ═══════════════════════════════════════════════════════════════════════════════ # PHASE 6: Divergence identification # ═══════════════════════════════════════════════════════════════════════════════ log.info("PHASE 6: Identifying AI-brain divergences") results = [] for idx_j, lid in enumerate(brain_rdm_keys): rinfo = regions[lid] imp = region_mod_importance.get(lid, {}) # Best RSA alignment across all AI layers rsa_col = rsa_matrix[:, idx_j] best_rsa = np.max(np.abs(rsa_col)) if len(rsa_col) > 0 else 0 best_rsa_layer = ai_rdm_keys[np.argmax(np.abs(rsa_col))] if len(rsa_col) > 0 else "none" # Best encoding correlation across all AI layers region_corrs = corr_matrix[:, all_region_ids.index(lid)] if lid in all_region_ids else np.zeros(1) best_encoding = np.max(np.abs(region_corrs)) best_enc_layer = all_layer_keys[np.argmax(np.abs(region_corrs))] if len(region_corrs) > 0 else "none" # Modality entropy probs = np.array(list(imp.values())) + 1e-10 probs = probs / probs.sum() entropy = -np.sum(probs * np.log2(probs)) # Temporal dynamics temporal_var = float(brain_preds[:, rinfo["mask"]].mean(axis=1).var()) # Divergence score: high temporal dynamics but poor AI alignment divergence = temporal_var * (1 - best_rsa) * entropy results.append({ "region_id": lid, "region": rinfo["name"], "hemisphere": "LH" if lid < 100 else "RH", # approximate "n_vertices": rinfo["n_vertices"], "temporal_variance": temporal_var, "best_rsa_alignment": best_rsa, "best_rsa_layer": best_rsa_layer, "best_encoding_corr": best_encoding, "best_encoding_layer": best_enc_layer, "modality_entropy": entropy, "divergence_score": divergence, **{f"imp_{k}": v for k, v in imp.items()}, }) df = pd.DataFrame(results) df = df.sort_values("divergence_score", ascending=False) df.to_csv(OUT / "full_analysis.csv", index=False) # ═══════════════════════════════════════════════════════════════════════════════ # PHASE 7: Visualization and reporting # ═══════════════════════════════════════════════════════════════════════════════ log.info("PHASE 7: Generating visualizations and report") # ── Plot 1: Layer-brain correlation heatmap ── fig, ax = plt.subplots(figsize=(20, max(8, len(all_layer_keys) * 0.3))) im = ax.imshow(corr_matrix, aspect="auto", cmap="RdBu_r", vmin=-1, vmax=1) ax.set_yticks(range(len(all_layer_keys))) ax.set_yticklabels(all_layer_keys, fontsize=6) ax.set_xticks(range(len(region_names_list))) ax.set_xticklabels(region_names_list, fontsize=4, rotation=90) ax.set_title("Layer-wise Encoding: AI Layer ↔ Brain Region Correlation", fontsize=14) ax.set_ylabel("AI Encoder Layer") ax.set_xlabel("Brain Region (Destrieux)") plt.colorbar(im, ax=ax, label="Pearson r") fig.tight_layout() fig.savefig(OUT / "01_layer_brain_correlation.png", dpi=200) plt.close(fig) log.info("Saved 01_layer_brain_correlation.png") # ── Plot 2: RSA heatmap ── fig, ax = plt.subplots(figsize=(20, max(8, len(ai_rdm_keys) * 0.3))) im = ax.imshow(rsa_matrix, aspect="auto", cmap="RdBu_r", vmin=-0.5, vmax=0.5) ax.set_yticks(range(len(ai_rdm_keys))) ax.set_yticklabels(ai_rdm_keys, fontsize=6) brain_region_names_rsa = [regions[lid]["name"] for lid in brain_rdm_keys] ax.set_xticks(range(len(brain_region_names_rsa))) ax.set_xticklabels(brain_region_names_rsa, fontsize=4, rotation=90) ax.set_title("RSA: AI Layer ↔ Brain Region Representational Similarity", fontsize=14) ax.set_ylabel("AI Encoder Layer") ax.set_xlabel("Brain Region (Destrieux)") plt.colorbar(im, ax=ax, label="Spearman ρ") fig.tight_layout() fig.savefig(OUT / "02_rsa_heatmap.png", dpi=200) plt.close(fig) log.info("Saved 02_rsa_heatmap.png") # ── Plot 3: Divergence scatter ── fig, ax = plt.subplots(figsize=(12, 10)) sc = ax.scatter( df["best_rsa_alignment"], df["temporal_variance"], s=df["n_vertices"] * 0.5, c=df["divergence_score"], cmap="YlOrRd", alpha=0.7, edgecolors="k", linewidths=0.3, ) # Label top divergent for _, row in df.head(12).iterrows(): ax.annotate( row["region"], (row["best_rsa_alignment"], row["temporal_variance"]), fontsize=6, alpha=0.9, arrowprops=dict(arrowstyle="-", alpha=0.3), textcoords="offset points", xytext=(5, 5), ) ax.set_xlabel("Best RSA Alignment (max |Spearman ρ| across AI layers)", fontsize=11) ax.set_ylabel("Temporal Variance (brain dynamics)", fontsize=11) ax.set_title("AI-Brain Divergence Map\nBottom-right = active brain regions poorly captured by AI", fontsize=13) plt.colorbar(sc, label="Divergence Score") fig.tight_layout() fig.savefig(OUT / "03_divergence_scatter.png", dpi=200) plt.close(fig) log.info("Saved 03_divergence_scatter.png") # ── Plot 4: Modality importance per region (stacked bar) ── imp_cols = [c for c in df.columns if c.startswith("imp_")] if imp_cols: top_30 = df.nlargest(30, "temporal_variance") fig, ax = plt.subplots(figsize=(14, 8)) bottom = np.zeros(len(top_30)) colors = plt.cm.Set2(np.linspace(0, 1, len(imp_cols))) for ci, col in enumerate(imp_cols): vals = top_30[col].values ax.barh(range(len(top_30)), vals, left=bottom, color=colors[ci], label=col.replace("imp_", "").upper()) bottom += vals ax.set_yticks(range(len(top_30))) ax.set_yticklabels(top_30["region"].values, fontsize=7) ax.set_xlabel("Relative Modality Importance") ax.set_title("Modality Contribution per Brain Region (top 30 by dynamics)", fontsize=13) ax.legend(loc="lower right") fig.tight_layout() fig.savefig(OUT / "04_modality_importance.png", dpi=200) plt.close(fig) log.info("Saved 04_modality_importance.png") # ── Plot 5: Brain surface divergence map ── try: from nilearn.plotting import plot_surf_stat_map vertex_divergence = np.zeros(N_VERT * 2) for _, row in df.iterrows(): lid = row["region_id"] if lid in regions: vertex_divergence[regions[lid]["mask"]] = row["divergence_score"] fig = plt.figure(figsize=(16, 12)) for idx, (hemi, view) in enumerate([ ("left", "lateral"), ("left", "medial"), ("right", "lateral"), ("right", "medial") ]): ax = fig.add_subplot(2, 2, idx + 1, projection="3d") if hemi == "left": data = vertex_divergence[:N_VERT] else: data = vertex_divergence[N_VERT:] plot_surf_stat_map( fsaverage5[f"pial_{hemi}"], data, hemi=hemi, view=view, cmap="YlOrRd", title=f"Divergence ({hemi} {view})", figure=fig, axes=ax, ) fig.suptitle("Brain Surface: AI-Brain Divergence Scores", fontsize=14, y=1.02) fig.tight_layout() fig.savefig(OUT / "05_brain_surface_divergence.png", dpi=200, bbox_inches="tight") plt.close(fig) log.info("Saved 05_brain_surface_divergence.png") except Exception as e: log.warning(f"Brain surface plot failed: {e}") # ── Plot 6: Per-modality best layer alignment profile ── for mod in all_features: mod_keys = [k for k in all_layer_keys if k.startswith(f"{mod}_")] if not mod_keys: continue mod_indices = [all_layer_keys.index(k) for k in mod_keys] mod_corr = corr_matrix[mod_indices, :] # (n_layers_mod, n_regions) fig, ax = plt.subplots(figsize=(14, 6)) im = ax.imshow(mod_corr, aspect="auto", cmap="RdBu_r", vmin=-1, vmax=1) ax.set_yticks(range(len(mod_keys))) ax.set_yticklabels([f"Layer {i}" for i in range(len(mod_keys))], fontsize=8) ax.set_xticks(range(len(region_names_list))) ax.set_xticklabels(region_names_list, fontsize=4, rotation=90) ax.set_title(f"{mod.upper()} Encoder: Layer-wise Brain Alignment", fontsize=13) ax.set_ylabel("Encoder Layer (early → late)") ax.set_xlabel("Brain Region") plt.colorbar(im, ax=ax, label="Pearson r") fig.tight_layout() fig.savefig(OUT / f"06_{mod}_layer_alignment.png", dpi=200) plt.close(fig) log.info(f"Saved 06_{mod}_layer_alignment.png") # ═══════════════════════════════════════════════════════════════════════════════ # PHASE 8: Final report # ═══════════════════════════════════════════════════════════════════════════════ report = [] report.append("=" * 100) report.append("CLOSING THE AI-BRAIN LOOP: Analysis Report") report.append(f"Generated: {pd.Timestamp.now()}") report.append("=" * 100) report.append("\n\n--- DATASET ---") report.append(f"Stimulus: {VIDEO}") report.append(f"Total time points: {T_total}") report.append(f"Brain vertices: {V} (fsaverage5)") report.append(f"Brain regions analyzed: {len(regions)} (Destrieux atlas)") report.append(f"AI modalities: {modalities}") for mod, feats in all_features.items(): report.append(f" {mod}: {feats.shape[1]} layers, {feats.shape[2]}-dim features") report.append("\n\n--- TOP 15 DIVERGENCE REGIONS ---") report.append("(Brain regions with high dynamics but poor AI alignment)") report.append("") cols = ["region", "temporal_variance", "best_rsa_alignment", "best_rsa_layer", "modality_entropy", "divergence_score"] cols_present = [c for c in cols if c in df.columns] report.append(df[cols_present].head(15).to_string(index=False, float_format="%.4f")) report.append("\n\n--- TOP 15 WELL-ALIGNED REGIONS ---") report.append("(Brain regions where AI encoders match brain representations well)") well_aligned = df.nlargest(15, "best_rsa_alignment") report.append(well_aligned[cols_present].to_string(index=False, float_format="%.4f")) report.append("\n\n--- MODALITY DOMINANCE ---") for mod in modalities: col = f"imp_{mod}" if col not in df.columns: continue report.append(f"\n{mod.upper()}-dominated regions (top 5):") top = df.nlargest(5, col) for _, row in top.iterrows(): report.append(f" {row['region']:45s} importance={row[col]:.4f} rsa={row['best_rsa_alignment']:.4f}") report.append("\n\n--- ARCHITECTURAL IMPLICATIONS ---") report.append(""" Based on the divergence analysis, here are the gaps in current AI architectures and proposed solutions: 1. HIGH-ENTROPY DIVERGENCE REGIONS (multiple modalities contribute equally, but overall alignment is poor): → The brain performs CROSS-MODAL INTEGRATION that the concatenation-based fusion in TRIBE v2 (and most multimodal AI) doesn't capture. → Proposed fix: EARLY FUSION with cross-attention between modality streams at intermediate layers, not just late concatenation. 2. HIGH TEMPORAL VARIANCE + LOW ALIGNMENT: → The brain has strong TEMPORAL DYNAMICS (prediction, memory, feedback loops) that feedforward AI encoders miss entirely. → Proposed fix: Add RECURRENT connections or PREDICTIVE CODING layers that generate top-down predictions and propagate prediction errors. 3. REGIONS WHERE NO SINGLE LAYER ALIGNS WELL: → The brain's computation in these areas may involve representations that DON'T EXIST in any layer of V-JEPA2, LLaMA, or Wav2Vec-BERT. → Proposed fix: Train a NEW encoder objective that explicitly optimizes for brain alignment in these gap regions (brain-guided contrastive learning). 4. LAYER DEPTH PATTERNS: → If early AI layers align with sensory cortex and late layers align with association cortex, this confirms the HIERARCHICAL CORRESPONDENCE between DNNs and the cortical hierarchy. → Where this breaks (e.g., late layers don't align with prefrontal cortex), it suggests the model lacks EXECUTIVE/ABSTRACT processing. """) report.append("\n--- FILES ---") report.append(f"Full CSV: {OUT / 'full_analysis.csv'}") report.append(f"Plots: {OUT / '*.png'}") report.append("=" * 100) report_text = "\n".join(report) print(report_text) with open(OUT / "report.txt", "w") as f: f.write(report_text) log.info(f"All results saved to {OUT}") log.info("Done.")