Behavioral Signatures of Memory Resources for Language: Looking beyond the Lexicon/Grammar Divide.

Area of Science:

• Cognitive Psychology
• Neuroscience
• Linguistics

Background:

• The role of procedural and declarative memory in language is established, but their specific mappings to linguistic structures are unclear.
• A common assumption is declarative memory for lexical knowledge and procedural memory for grammar, a dual-route model.
• This study investigates the interplay between linguistic processing and memory systems.

Purpose of the Study:

• To experimentally differentiate the memory systems (procedural vs. declarative) underlying different linguistic phenomena.
• To test the hypothesis of a strict lexicon-grammar opposition versus a graded continuum.
• To inform the design and interpretation of future behavioral and neuroimaging studies on language cognition.

Main Methods:

• Utilized a concurrent task paradigm (grammaticality judgment + digit span) to manipulate attentional load and selectively impair declarative memory.
• Examined the processing of morphology (case, aspect), syntax (subordination), and lexical semantics (collocations) in native Polish speakers.
• Contrasted performance under single-task versus dual-task conditions to dissociate memory system involvement.

Main Results:

• Findings support a graded distinction between lexicon and grammar, aligning with a continuum rather than a strict dichotomy.
• Linguistic phenomena were placed on a spectrum from 'ruly' (grammatical) to 'idiosyncratic' (lexical).
• Not all linguistic knowledge is proceduralized to the same extent, requiring adjustments to usage-based models.

Conclusions:

• The lexicon-grammar distinction is not absolute but exists as a continuum, challenging strict dual-route models.
• Memory for language is more complex, with varying degrees of proceduralization across linguistic knowledge types.
• This research necessitates a re-evaluation of how memory for language is conceptualized and studied.