In what ways are language, cognition and perception interrelated? Do they influence each other? This book casts a fresh light on these questions by putting individual speakers' cognitive contexts, i.e. their usage-preferences and entrenched patterns of linguistic knowledge, into the focus of investigation. It presents findings from original experimental research on spatial language use which indicate that these individual-specific factors indeed play a central role in determining whether or not differences in the current and/or habitual linguistic behaviour of speakers of German and English are systematically correlated with differences in non-linguistic behaviour (visual attention allocation to and memory for spatial referent scenes).These findings form the basis of a new, speaker-focused usage-based model of linguistic relativity, which defines language-perception/cognition effects as a phenomenon which primarily occurs within individual speakers rather than between speakers or speech communities.