# Stand-out: A Systematic Review of the Role of Salience in Second Language Acquisition

**Source:** https://euroslajournal.org/articles/10.22599/jesla.131
**DOI:** 10.22599/jesla.131
**Journal:** Journal of the European Second Language Association (EuroSLA)
**Authors:** Georgia Knell, Saioa Cipitria, Ludovic de Cuypere, Alex Housen, Esli Struys (Vrije Universiteit Brussel)
**Saved:** 2026-02-20

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## Summary

Systematic review of 42 empirical studies examining how linguistic salience ("the degree to which a linguistic element stands out from its environment") affects second language (L2) acquisition.

## Key Framework: Three Salience Categories

The authors organize salience into three nested levels:

### 1. Perceptual Salience (Narrow definition)
- Physical properties of the linguistic form itself
- Examples: substance (phonological weight), syllabicity, position in utterance
- Does it physically stand out?

### 2. Psycholinguistic Salience (Medium definition)
- How linguistic context affects prominence
- Examples: semantic redundancy, formal redundancy/transparency
- Key insight: tense markers become invisible when temporal adverbs already carry the meaning. Redundancy reduces salience.

### 3. Experiential Salience (Wide definition)
- The learner's prior linguistic experience
- Examples: L1 experience (cross-linguistic influence), L2 experience (frequency, exposure)
- Prior experience shapes what stands out

## Key Findings

- **79% of tested variables showed fully or partially positive effects** ... increased salience correlates with better learning outcomes
- Most research has focused on perceptual properties; psycholinguistic manifestations are understudied
- The interaction between salience types is poorly understood

## Why This Matters for Agent Memory

The parallel to AI agent memory architecture:

| Salience Level | Language Acquisition | Agent Memory |
|---|---|---|
| Perceptual | Does the form physically stand out? | Is a memory chunk distinctive, or does it blend in with 150K others? |
| Psycholinguistic | Does context make it redundant? | If the same info exists in 5 places, the agent stops noticing any of them |
| Experiential | Does prior experience make it stand out? | Memories tied to identity or recent work should be more salient than generic tasks |

The core insight: **you can't recall what you didn't notice.** Storage is not enough. The memory system needs a salience layer that determines what "stands out" at the moment of retrieval, not just at the moment of capture.

## Key References to Follow

- **Schmidt (1990, 2001)** ... The Noticing Hypothesis. You can't learn what you don't notice. Attention is the gateway to memory.
- **Goldschneider & DeKeyser (2001)** ... Foundational work on morpheme acquisition and salience
- **Gass et al. (2017)** ... Comprehensive volume on salience in SLA
- **Ellis (2006, 2022)** ... Contingency, associative learning, and salience interactions
- **DeKeyser et al. (2017)** ... Stratification of salience definitions

## Diagram

The paper includes a nested diagram showing the three levels (saved as screenshot):
- Narrow (Perceptual) nested inside Medium (Psycholinguistic) nested inside Wide (Experiential)
- Source image: `/Users/lesa/Desktop/67dd4edc63fc6.png`
