Signs? AFAIK signs and symbols are a categorically under the grammar facility (ability).
So it’s a question of whether you grasp logic (facility) grammar (continuous recursive disambiguation) and rhetoric (persuasion, argument) as a series from basic to intermediate to complex; and whether you separate sounds, actions, and marks (marks, pictures, symbols, glyphs), or categorize them as the same.
Since the language facility is physically independent of sound, action, or mark, then whether we sound, act, or make marks is irrelevant. And the study of sounds, acts, and marks are just subsets, as is vocabulary.
The interesting question is what limits to our calculation (reasoning) exist without language, drawing, and symbols to assist in categorization, composition, narration, and memory substitutes.
SPECTRUM:
1. Sense(stimuli)
… … Perception (composition)
… … … Association
2. Logic Facility (constant relations)
… … Imagination Facility (prediction)
… … … Reason Facility (comparison, permutation)
3. Grammar facility (statements)
… … Paradigms (‘metaphysics’, ‘dimensions’)
… … Vocabulary
… … … Sounds
… … … Signs (acts, actions)
… … … Marks (records)
… … … … accidental
… … … … intentional
… … … … … Mark
… … … … … Symbol
… … … … … … Glyph
… … … … … Pictogram
… … … … … Picture
… … … … … Picture Series
… … … … … Animation
4. Communication Facility (“Language”)
… Truths
… … Logics (deflationary Grammars)
… … Rhetoric (argumentative, persuasive Grammars)
… Descriptions
… … Testimony
… Ordinary Language
… Narrations (inflationary Grammars)
… … Narrative (description)
… … … Storytelling (loading, framing)
… Deceits
… … … Fictionalism
… … … …. (idealism-> surrealism,
… … … …. supernaturalism->occult, and
… … … …. pseudoscience -> magic)
… … … Obscurantism (Obscuring, Overloading)
… … … … Propaganda
… … … Misdirection (Deceit)
… … … Fraud (for gain)
… … … Harm (Evil, for harm regardless of gain)
IN OTHER WORDS
The cognitive grammaticists are mostly right.