Unified multimodal models (UMMs) receive image-generation supervision that exposes them to visual information not fully documented in text. Can learning to generate images expand what pretrained models know? We introduce Knowledge Transfer Probing (KTP), a controlled protocol that supplies new knowledge through image-generation training and tests its accessibility through text-only question answering. Across seven knowledge categories and three UMMs, we observe direct but uneven transfer from visual supervision to language. Motivated by these observations, we successively introduce Textual Alignment and Interleaved Image--Text Alignment, which connect generation and answering through shared knowledge and interleaved responses, respectively. Guidance on selected entities can improve knowledge access on other entities without QA supervision, with additional gains from interleaved alignment. Further analysis shows that knowledge correctly reproduced in images is often more accessible through text, although substantial gaps remain between the two forms of access. These findings support visual generation as a source of knowledge beyond textual supervision, and motivate joint investigation of training data design and model architecture to make this knowledge more broadly accessible.
Figures & tables
Figure 1: Can visual generation expand what unified multimodal models know? Left: Images contain rich visual information that accompanying text may leave unspecified. Middle: Knowledge reproduced in generated images is not necessarily accessible through text-only QA. Right: We first supply new facts only through training images and test text-only QA across seven knowledge categories. Direct transfer is partial; alignment on a subset of entities can improve access on the remaining entities, with interleaved image–text alignment yielding higher average accuracy than textual alignment.
Figure 2: Overview of the text-to-image dataset. Here we show examples from the seven visual knowledge categories. Each panel shows an entity, a training image, and the target attribute value.
Model
Metric
color
count
number
shape
size
spatial
text
Avg
Baseline
random guessing
16.7
25.0
0.0
20.0
50.0
0.0
0.0
15.96
BAGEL
textual accessibility
14.0
14.0
0.0
10.0
24.0
0.0
0.0
8.86
visual accessibility
20.0
42.0
4.0
58.0
60.0
0.0
36.0
31.43
GLM-Omni
textual accessibility
16.0
24.0
2.0
20.0
40.0
0.0
0.0
14.57
visual accessibility
70.0
46.0
72.0
88.0
24.0
62.0
16.0
54.00
SenseNova-U1
textual accessibility
20.0
32.0
0.0
20.0
68.0
0.0
0.0
20.00
Table 1: Knowledge accessibility under direct transfer among 7 categories. Target knowledge is supplied through T2I supervision without target-specific QA supervision. Textual and visual accessibility measure correctness in text-only QA and image generation, respectively.
Figure 3: Visual and textual accessibility after T2I training. Target knowledge is supplied only through training images. Filled blue circles show visual accessibility; hollow red circles show textual accessibility. The accessibility gap Δ=Avis−Atext is reported in percentage points.
Figure 4: Overview of the KTP training and evaluation protocol. (a) Training: All entities receive T2I supervision, with target attribute values shown in images but omitted from captions. A subset of entities additionally receives textual or interleaved image–text alignment supervision. (b) Evaluation: For entities without alignment supervision, we measure textual accessibility through text-only QA and visual accessibility through image generation.
Model
Training Method
Color
Count
Number
Shape
Size
Spatial
Text
Avg
BAGEL
direct
14.0
14.0
0.0
10.0
24.0
0.0
0.0
8.86
textual alignment
4.0
28.0
0.0
24.0
52.0
0.0
0.0
15.43
interleaved alignment
12.0
32.0
0.0
20.0
56.0
0.0
0.0
17.14
GLM-Omni
direct
16.0
24.0
2.0
20.0
40.0
0.0
0.0
14.57
textual alignment
16.0
20.0
0.0
12.0
40.0
0.0
0.0
12.57
interleaved alignment
24.0
20.0
0.0
64.0
40.0
40.0
0.0
26.86
Table 2: Textual accessibility (%) under three training conditions. “interleaved alignment” indicates interleaved image-text alignment; “direct” indicates direct knowledge transfer. All conditions are evaluated using text-only QA.
Figure 5: Image-loss ablation in interleaved alignment on GLM-Omni. Masking the image loss retains the interleaved sequences and text supervision but substantially lowers performance.
Model
Inference
color
count
number
shape
size
spatial
text
Avg
BAGEL
Text-only
12.0
32.0
0.0
20.0
56.0
0.0
0.0
17.14
Visual CoT
16.0
20.0
4.0
56.0
48.0
0.0
0.0
20.57
GLM-Omni
Text-only
24.0
20.0
0.0
64.0
40.0
40.0
0.0
26.86
Visual CoT
24.0
48.0
36.0
68.0
48.0
64.0
0.0
41.14
SenseNova-U1
Text-only
4.0
16.0
0.0
84.0
96.0
0.0
0.0
28.57
Visual CoT
8.0
20.0
20.0
92.0
96.0
8.0
0.0
34.86
Table 3: Accuracy of text-only QA and Visual CoT (%).
Model
Training
Pr(T∣I) (%)
Pr(T∣¬I) (%)
Δassoc (pp)
BAGEL
Textual Alignment
23.91
12.40
+11.51
Interleaved Alignment
32.61
11.63
+20.98
GLM-Omni
Textual Alignment
6.90
18.18
−11.28
Interleaved Alignment
31.25
23.16
+8.09
SenseNova-U1
Textual Alignment
46.39
5.13
+41.26
Interleaved Alignment
44.00
8.00
+36.00
Table 4: Conditional T2T accuracy given T2I correctness. T and I denote correct T2T answers and correct T2I generations, respectively. Gap is measured in percentage points (pp).