The Narrow Gate: Localized Image-Text Communication in Native Multimodal Models

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Serra, Alessandro Pietro, Ortu, Francesco, Panizon, Emanuele, Valeriani, Lucrezia, Basile, Lorenzo, Ansuini, Alessio, Doimo, Diego, Cazzaniga, Alberto
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866912862264360960
author Serra, Alessandro Pietro
Ortu, Francesco
Panizon, Emanuele
Valeriani, Lucrezia
Basile, Lorenzo
Ansuini, Alessio
Doimo, Diego
Cazzaniga, Alberto
author_facet Serra, Alessandro Pietro
Ortu, Francesco
Panizon, Emanuele
Valeriani, Lucrezia
Basile, Lorenzo
Ansuini, Alessio
Doimo, Diego
Cazzaniga, Alberto
contents Recent advances in multimodal training have significantly improved the integration of image understanding and generation within a unified model. This study investigates how vision-language models (VLMs) handle image-understanding tasks, focusing on how visual information is processed and transferred to the textual domain. We compare native multimodal VLMs, models trained from scratch on multimodal data to generate both text and images, and non-native multimodal VLMs, models adapted from pre-trained large language models or capable of generating only text, highlighting key differences in information flow. We find that in native multimodal VLMs, image and text embeddings are more separated within the residual stream. Moreover, VLMs differ in how visual information reaches text: non-native multimodal VLMs exhibit a distributed communication pattern, where information is exchanged through multiple image tokens, whereas models trained natively for joint image and text generation tend to rely on a single post-image token that acts as a narrow gate for visual information. We show that ablating this single token significantly deteriorates image-understanding performance, whereas targeted, token-level interventions reliably steer image semantics and downstream text with fine-grained control.
format Preprint
id arxiv_https___arxiv_org_abs_2412_06646
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle The Narrow Gate: Localized Image-Text Communication in Native Multimodal Models
Serra, Alessandro Pietro
Ortu, Francesco
Panizon, Emanuele
Valeriani, Lucrezia
Basile, Lorenzo
Ansuini, Alessio
Doimo, Diego
Cazzaniga, Alberto
Computer Vision and Pattern Recognition
Machine Learning
Recent advances in multimodal training have significantly improved the integration of image understanding and generation within a unified model. This study investigates how vision-language models (VLMs) handle image-understanding tasks, focusing on how visual information is processed and transferred to the textual domain. We compare native multimodal VLMs, models trained from scratch on multimodal data to generate both text and images, and non-native multimodal VLMs, models adapted from pre-trained large language models or capable of generating only text, highlighting key differences in information flow. We find that in native multimodal VLMs, image and text embeddings are more separated within the residual stream. Moreover, VLMs differ in how visual information reaches text: non-native multimodal VLMs exhibit a distributed communication pattern, where information is exchanged through multiple image tokens, whereas models trained natively for joint image and text generation tend to rely on a single post-image token that acts as a narrow gate for visual information. We show that ablating this single token significantly deteriorates image-understanding performance, whereas targeted, token-level interventions reliably steer image semantics and downstream text with fine-grained control.
title The Narrow Gate: Localized Image-Text Communication in Native Multimodal Models
topic Computer Vision and Pattern Recognition
Machine Learning
url https://arxiv.org/abs/2412.06646