Pith Number

pith:CQZNRNRN

pith:2026:CQZNRNRNKOVFDEHTOFSPIYV4NW

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SpaMEM: Benchmarking Dynamic Spatial Reasoning via Perception-Memory Integration in Embodied Environments

Chih-Ting Liao, Chunlei Meng, Tianyang Wang, Weilin Zhou, Xin Cao, Xi Xiao, Xu Zheng, Yitong Qiao, Zhangquan Chen

Vision-language models maintain spatial beliefs only when given text histories and collapse without them in changing environments.

arxiv:2604.22409 v2 · 2026-04-24 · cs.CV

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\pithnumber{CQZNRNRNKOVFDEHTOFSPIYV4NW}

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Record completeness

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2 Internet Archive

3 Author claim open · sign in to claim

4 Citations open

5 Replications open

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The bundle contains the canonical record plus signed events. A mirror can host it anywhere and recompute the same current state with the deterministic merge algorithm.

Claims

C1strongest claim

Benchmarking representative open-source VLM families reveals a consistent stacked bottleneck: coordinate-consistent grounding remains a hard ceiling, and the sharp collapse from Level 2 to Level 3 exposes a pronounced symbolic scaffolding dependency, where models succeed with text-based bookkeeping but struggle to sustain robust visual memory.

C2weakest assumption

That the procedurally generated houses, action sequences (spawn, place, remove), and three-level task hierarchy isolate spatial belief evolution without introducing simulation artifacts or task-specific biases that do not appear in real embodied settings.

C3one line summary

SpaMEM benchmark shows multimodal LLMs succeed at spatial tasks with text histories but sharply fail at long-horizon belief maintenance from raw visual streams alone.

Cited by

1 paper in Pith

Do LLMs Build World Models From Text? A Multilingual Diagnostic of Spatial Reasoning

Receipt and verification

First computed	2026-05-29T01:05:10.479074Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

1432d8b62d53aa5190f37164f462bc6dba32d856b3ce508fc12ff40f933f6a22

Aliases

arxiv: 2604.22409 · arxiv_version: 2604.22409v2 · doi: 10.48550/arxiv.2604.22409 · pith_short_12: CQZNRNRNKOVF · pith_short_16: CQZNRNRNKOVFDEHT · pith_short_8: CQZNRNRN

Agent API

Resolver JSON Graph JSON Events JSON Schema Signing key

Verify this Pith Number yourself

curl -sH 'Accept: application/ld+json' https://pith.science/pith/CQZNRNRNKOVFDEHTOFSPIYV4NW \
  | jq -c '.canonical_record' \
  | python3 -c "import sys,json,hashlib; b=json.dumps(json.loads(sys.stdin.read()), sort_keys=True, separators=(',',':'), ensure_ascii=False).encode(); print(hashlib.sha256(b).hexdigest())"
# expect: 1432d8b62d53aa5190f37164f462bc6dba32d856b3ce508fc12ff40f933f6a22

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "5c6819cb01593edb325e8f0a29987e33fb3df71f7068b8f575f68e0331ad0835",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "cs.CV",
    "submitted_at": "2026-04-24T10:06:41Z",
    "title_canon_sha256": "88552223190eb8eab4e5a62e0269a9b12c58aef3119a7d9d3c437a1f48ed538f"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2604.22409",
    "kind": "arxiv",
    "version": 2
  }
}