Phonological neighbors cooperate during spoken-sentence processing: Evidence from a nonword detection task.

We used a novel nonword detection task to examine the lexical competition principle postulated in most models of spoken word recognition. To do so, in Experiment 1 we presented sequences of spoken words with half of the sequences containing a nonword, and the target nonword (i.e., press a response key whenever you detect a nonword in the sequence) could either be phonologically related (a phonological neighbor) or unrelated to the immediately preceding word. We reasoned that the reactivation of a phonological neighbor during target nonword processing should delay the moment at which a nonword decision can be made. Contrary to our hypothesis, participants were faster at detecting nonwords when they were preceded by a phonological neighbor compared with an unrelated word. In Experiment 2, an inhibitory effect of phonological relatedness on nonword decisions was observed in a classic priming situation using the same set of related and unrelated word-nonword pairs. We discuss the implications of these findings in regard to the main models of spoken word recognition, and conclude that our specific experimental set-up with phonological neighbors embedded in spoken sentences is more sensitive to cooperative interactions between co-activated sublexical representations than lexical competition between co-activated lexical representations, with the latter being modulated by whether or not the words compete for the same slot in time.

Effects of alternating letter case on processing sequences of written words.

In three grammatical decision experiments, we examined the impact of alternating letter case on sentence reading to determine the locus of case-alternation effects. Experiments 1 and 2 compared grammatical decision responses ("Is this a grammatically correct sequence of words or not?") in three different conditions: (1) SAME CASE/same case; (2) alternating CASE between WORDS; and (3) aLterNaTing cAsE wItHin WoRdS. For the grammatically correct sequences, we observed significantly faster responses in the same-case conditions compared with the between-word case manipulation, as well as a significant advantage for the between-word condition compared with within-word alternating case. These results confirm that case-alternation deteriorates sentence reading, but more so at the level of single word processing (within-word alternation) than at the sentence level (between-word alternation). Experiment 3 demonstrated that between-word case-alternation facilitates sentence processing compared with an all-lowercase condition when betweenWORDspacesAREremoved. Therefore, in the absence of between-word spacing, case changes across words facilitate sentence processing, possibly by guiding readers' eyes to optimal locations for word identification.

Constraints on integration of orthographic information across multiple stimuli: effects of contiguity, eccentricity, and attentional span.

Five flanked lexical decision experiments investigated the integration of information across spatially distinct letter strings. Experiment 1 found no significant difference between quadrigram flankers (e.g., CKRO ROCK CKRO) and double bigram flankers (e.g., CK RO ROCK CK RO). Experiment 2 varied the eccentricity of single bigram flankers and found that closer flankers generated greater effects. A combined analysis of these experiments revealed that the double bigram condition (Experiment 1) was less effective than the close single bigram condition (Experiment 2). Experiment 3 tested one explanation for this pattern - that the outer bigrams in the double bigram condition interfered with processing the inner bigrams, and that spatial integration only operates across adjacent stimuli. In Experiment 3, outer bigrams were now a repeat of the inner bigram (e.g., RO RO ROCK CK CK), and this repeated bigram condition was still found to be significantly less effective than single bigrams. Experiments 4 and 5 tested an alternative explanation whereby the addition of spatially distinct flanking stimuli increases the spread of spatial attention, hence reducing the impact of proximal flankers. In line with this explanation, we found no significant difference between repeated bigram flankers and a condition where only the inner bigram was related to the target (e.g., CA RO ROCK CK SH). We conclude that spatial integration processes only operate across the central target and proximal flankers, and that these effects are diluted by the increased spread of spatial attention caused by additional spatially distinct flankers.

Effects of letter case on processing sequences of written words.

In four experiments, we investigated the impact of letter case (lower case vs. UPPER CASE) on the processing of sequences of written words. Experiment 1 used the rapid parallel visual presentation (RPVP) paradigm with postcued identification of one word in a five-word sequence. The sequence could be grammatically correct (e.g., "the boy likes his bike") or be an ungrammatical reordering of the same words (e.g., "his boy the bike likes the"). We replicated the standard sentence superiority effect (more accurate identification of target words when embedded in a grammatically correct sequence compared with ungrammatical sequences), and also found that lowercase presentation led to higher word identification accuracy, but equally so for the grammatical and ungrammatical sequences. This pattern suggests that the lowercase advantage was mostly operating at the level of individual word identification. The following three experiments used the grammatical decision task to provide an examination of letter case effects on more global sentence processing measures. All these experiments revealed a significant lowercase advantage in grammatical decisions, independently of the nature of the ungrammatical sequence (Experiments 2 and 3) and independently of whether or not the letter case manipulation was blocked (Experiment 4). The size of the effects observed in grammatical decisions again points to individual word identification as the primary locus of the lowercase advantage. We conclude that letter case mainly affects early visuo-orthographic processing and access to case-independent letter and word identities. (PsycInfo Database Record (c) 2023 APA, all rights reserved).