Topological Proofs of Some Rasiowa-Sikorski Lemmas

We give topological proofs of G?rnemann’s adaptation to Heyting algebras of the Rasiowa-Sikorski Lemma for Boolean algebras; and of the Rauszer-Sabalski generalisation of it to distributive lattices. The arguments use the Priestley topology on the set of prime filters, and the Baire category theorem. This is preceded by a discussion of criteria for compactness of various spaces of subsets of a lattice, including spaces of filters, prime filters etc.     

Prosody and lemma selection

In three picture-naming experiments, we examined the effect of prosodic context on the synonyms people use to name pictures in Mandarin Chinese. This was done without time pressure. The results showed that when monosyllabic and bisyllabic synonyms (e.g., hen/chicken) were embedded in a context of pictures with either bisyllabic or trisyllabic names, participants gave bisyllabic responses to the synonyms more often than they did in a condition without such a context. The difference was very similar in magnitude in both the bisyllabic and trisyllabic contextual conditions. These results suggest that people are biased toward using synonyms that have numbers of syllables equal or similar to those of the prosodic context. If it is assumed that prosodic effects originate at a stage of processing beyond the lemma level, then this suggests either that multiple phonological forms of synonyms can be activated or that there is feedback from prosodic processing that influences lemma selection.     

Stem homographs and lemma level representations

Previous studies have found that priming a target like cerr-o ("hill") with an unmasked stem-homograph (e.g., cerr-ar, "to close") or with an unmasked allomorph of a stem-homograph (e.g., cierr-a, "he/she/it closes") has an inhibitory effect on target recognition. We report evidence from stem-homograph priming studies that implicate both morphological parsing and lexical selection processes at the lemma level. We argue that stem-homograph inhibition is the product of lexical selection mechanisms that are engaged just when a fully ambiguous stimulus (here, an inflectional stem) must be assigned one of its viable interpretations in order to afford conscious perception of lexical identity.