Organizations: Department of Civil Engineering Building and Architecture (DICEA), Universit`a Politecnica delle Marche, Via Brecce Bianche 12, Ancona, 60131, Italy · Department of Political Sciences, Communication and International Relations, University of Macerata, Via Don Minzoni 22A, Macerata, 62100, Italy · Horizon Intelligence Labs · Harvard Medical School (HMS), Precision Neuromodulation Program & Network Control Laboratory, Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Horizon Intelligence Labs, Boston, MA, USA
Reconstructing visual stimuli from non-invasive electroencephalography (EEG) remains challenging due to its low spatial resolution and high noise, particularly under realistic low-density electrode configurations. To address this, we present EEG2Vision, a modular, end-to-end EEG-to-image framework that systematically evaluates reconstruction performance across different EEG resolutions (128, 64, 32, and 24 channels) and enhances visual quality through a prompt-guided post-reconstruction boosting mechanism. Starting from EEG-conditioned diffusion reconstruction, the boosting stage uses a multimodal large language model to extract semantic descriptions and leverages image-to-image diffusion to refine geometry and perceptual coherence while preserving EEG-grounded structure. Our experiments show that semantic decoding accuracy degrades significantly with channel reduction (e.g., 50-way Top-1 Acc from 89% to 38%), while reconstruction quality slight decreases (e.g., FID from 76.77 to 80.51). The proposed boosting consistently improves perceptual metrics across all configurations, achieving up to 9.71% IS gains in low-channel settings. A user study confirms the clear perceptual preference for boosted reconstructions. The proposed approach significantly boosts the feasibility of real-time brain-2-image applications using low-resolution EEG devices, potentially unlocking this type of applications outside laboratory settings.
Figures & tables
Figure 1: Overview of the EEG2Vision framework. The visual stimulus is encoded into a noisy latent via the Image processing module and also fed into the Semantic prior generation module, which utilizes both visual and EEG signals to derive coarse class-level controls. Simultaneously, EEG signals undergo Neural embedding extraction to produce fine-grained spatiotemporal features. These inputs condition the Diffusion-based reconstruction module through ControlNet to synthesize the generated image. Finally, the Prompt-guided post-reconstruction boosting module refines the output via text-guided image-to-image diffusion.
System Prompt : ”You are an expert in textual description from a single image. Given an image, you will provide a concise and accurate description of the content, without saying ‘the image shows’ or ‘the image depicts’ at the start.” User Prompt : ”Write a description for this image in one sentence. You should answer with the prompt only. Do not insert the first part where you say ‘the image shows’ or ‘the image depicts’ in the answer.”
Table 1: Prompt template used for the MLLM to generate concise image descriptions.
pref= ”A realistic, high-quality photo of a [d] , with clean and correct geometry, natural lighting, consistent textures, and accurate proportions. No visual glitches, no distorted shapes, no rendering artifacts. The object appears physically plausible and professionally photographed, with all structures logically and realistically aligned.”
Table 2: Prompt template used for the image-to-image diffusion model, conditioned on the image description.
Channels
CFG
50-way Accuracy
IS ↑
FID ↓
LPIPS ↓
CLIP-Sim ↑
Top-1 ↑
Top-5 ↑
128
4
0.876
0.928
33.93
79.14
0.770
0.723
7.5
0.890
0.935
34.82
76.77
0.770
0.733
64
4
0.800
0.869
33.45
83.05
0.773
0.700
7.5
0.823
0.877
34.11
78.27
0.777
0.714
32
4
0.375
0.458
33.26
86.00
0.785
0.620
Table 3: Quantitative results of different channel configurations and CFGs across multiple performance metrics.
Figure 2: Qualitative results of the evaluation for different channel resolutions and CFG configurations. Some failure cases are also shown for low accuracy classes (highlighted in red).
128 Channels
64 Channels
32 Channels
24 Channels
Metric
Raw
Boosted
Gain
Raw
Boosted
Gain
Raw
Boosted
Gain
Raw
Boosted
Gain
IS ↑
34.82
37.23
+6.69%
34.11
37.37
+9.12%
33.28
36.51
+9.71%
34.24
37.16
+8.53%
FID ↓
76.77
77.06
+0.38%
78.27
77.75
+0.67%
80.55
79.26
+1.60%
80.51
79.77
+0.92%
LPIPS ↓
0.770
0.769
+0.13%
0.777
0.773
+0.52%
0.791
0.787
+0.51%
0.790
0.785
+0.63%
Table 4: Quantitative evaluation of raw and boosted reconstructions across different electrode configurations. Percentage gains indicate improvement of the boosted method over the original.
Figure 3: Qualitative comparison of reconstructions across electrode configurations. Columns from left to right show: GT reference image, raw generated reconstruction and our refined output (boosted).
Figure 8
Channels
Boosted Preference Rate
Mean Confidence
Weighted Preference Rate
128
71.43%
3.7
74.17%
64
82.35%
3.5
85.35%
32
76.97%
3.6
79%
24
82.73%
3.6
87.13%
Overall
78.34%
3.6
81.31%
Table 5: User study results showing preference for boosted images across different channel configurations. Confidence ratings are on a 5-point Likert scale.
Human visual reconstruction aims to reconstruct fine-grained visual stimuli based on subject-provided descriptions and corresponding neural signals. As a widely adopted modality, Electroencephalography (EEG) captures rich visual cognition information, encompassing complex spatial relationships and chromatic details within scenes. However, current approaches are deeply coupled with an alignment framework that forces EEG features to align with text or image semantic representation. The dependency may condense the rich spatial and chromatic details in EEG that achieved mere conditioned image generation rather than high-fidelity visual reconstruction. To address this limitation, we propose a novel Joint-Modal Visual Reconstruction (JMVR) framework. It treats EEG and text as independent modalities for joint learning to preserve EEG-specific information for reconstruction. It further employs a multi-scale EEG encoding strategy to capture both fine- and coarse-grained features, alongside image augmentation to enhance the recovery of perceptual details. Extensive experiments on the THINGS-EEG dataset demonstrate that JMVR achieves SOTA performance against six baseline methods, specifically exhibiting superior capabilities in modeling spatial structure and chromatic fidelity.
Zhijian Gong, Tianren Yao, Wenjia Dong +1
Beijing University of Technology, Beijing · Beijing Key Laboratory of Computational Intelligence and Intelligent System, Beijing
Objective: Decoding visual information from electroencephalography (EEG) is an important problem in neuroscience and brain-computer interface (BCI) research. Existing methods are largely restricted to natural images and categorical representations, with limited capacity to capture structural features and to differentiate objective perception from subjective cognition. We propose a Structure-Guided Diffusion Model (SGDM) that incorporates explicit structural information for EEG-based visual reconstruction. Approach: SGDM is evaluated on the Kilogram abstract visual object dataset and the THINGS natural image dataset using a two-stage generative mechanism. The framework combines a structurally supervised variational autoencoder with a spatiotemporal EEG encoder aligned to a visual embedding space via contrastive learning. Structural information is integrated into a diffusion model through ControlNet to guide image generation from EEG features. Results: SGDM outperforms existing methods on both abstract and natural image datasets. Reconstructed images achieve higher fidelity in low-level visual features and semantic representations, indicating improved decoding accuracy and strong generalization across diverse visual domains. Spatiotemporal analysis of EEG signals further reveals hierarchical structural encoding patterns, consistent with the neural dynamics of visual cognition. Significance: These findings validate the effectiveness of SGDM in capturing explicit structural geometry and generating images with high fidelity to individual cognitive representations. By enabling decoding of complex visual content from EEG signals, the framework extends neural decoding beyond low-dimensional or categorical outputs. This supports BCIs with increased degrees of freedom for intention decoding and more flexible brain-to-machine communication.
Yongxiang Lian, Yueyang Cang, Pingge Hu +2
Department of Automation Tsinghua University Haidian District, 100084, Beijing, China · China Academy of Information and Communications Technology Haidian District, 100084, Beijing, China
Reconstructing visual stimuli from electroencephalography (EEG) is difficult because scalp measurements have high temporal but limited spatial resolution, and paired EEG-image datasets remain small relative to modern generative-model training corpora. We present a reproducible single-subject baseline on THINGS-EEG2 that first tests the more defensible question of whether EEG can retrieve the viewed stimulus in a visual embedding space. A compact temporal-spatial convolutional encoder maps repetition-averaged EEG (63 by 250) to provided 512-dimensional ViT-B/32 image features. Model selection uses a concept-disjoint validation split, and final evaluation uses the official 200-image, 200-concept test gallery. Across three training seeds, the model obtains 12.83 +/- 0.58%, 39.17 +/- 1.76%, and 58.00 +/- 1.73% image recall at 1, 5, and 10 (mean +/- sample standard deviation), compared with analytical chance levels of 0.5%, 2.5%, and 5.0%. A session-balanced ablation shows that averaging more test repetitions generally improves ranking. Applying the Subject 01 model to the other nine subjects without adaptation causes a sharp performance drop, exposing subject specificity. We further report exploratory stress tests of direct conditional generators trained without external visual weights: single-subject and ten-subject variants produce noise-dominated outputs, with early validation improvements reversing after one to four epochs. Finally, we distinguish direct reconstruction from semantic rendering with a pretrained diffusion prior. The results support above-chance coarse semantic decoding under a closed-set, repetition-averaged protocol, but do not support faithful recovery of stimulus pixels.