The brain’s hemispheres and controlled search of the lexicon: Evidence from fixated words and pseudowords

Difference between the brain’s hemispheres in efficiency of intentional search of the mental lexicon with phonological, orthographic, and semantic strategies was investigated. Letter strings for lexical decision were presented at fixation, with a lateralized distractor to the LVF or RVF. Word results revealed that both hemispheres were capable of using each of the three strategies, but the right hemisphere had better baseline processing of orthography and was better at processing semantics. Pseudoword results supported the right hemisphere advantage for orthography and showed a left hemisphere advantage for phonology and assessment of possible semantic relationships. Taken together, the data support the idea that the right hemisphere uses orthography to make efficient decisions about novelty of an item, while the left engages in grapheme-to-phoneme conversion to test hypotheses about unfamiliar items. The convergence of data with previous research reveals that the procedure, as well as analyses of pseudowords, inform laterality research.

► Tests laterality of controlled phonological, orthographic, semantic strategy use.
► Fixated letter strings presented with distractor to disengage opposite hemisphere.
► Lexical decision measures to pseudowords expanded on words.
► Right hemisphere may use orthography to make efficient decisions about novelty.
► Left hemisphere may use phonology to test hypotheses about the unfamiliar.