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This experiment examined invariance in object representations through measuring event-related potentials (ERPs) to pictures in a masked repetition priming paradigm. Pairs of pictures were presented where the prime was either the same size or half the size of the target object and the target was either presented in a normal orientation or was a normal sized mirror reflection of the prime object. Previous masked repetition priming studies have found a cascade of priming effect sensitive to perceptual (N190/P190) and semantic (N400) properties of the stimulus. This experiment found that both early (N190/P190 effects) and later effects (N400) were invariant to size, whereas only the N190/P190 effect was invariant to mirror reflection. The combination of a small prime and a mirror reflected target led to no significant priming effects. Taken together, the results of this set of experiments suggests that object recognition, more specifically, activating an object representation, occurs in a hierarchical fashion where overlapping perceptual information between the prime and target is necessary, although not always sufficient, to activate a higher level semantic representation. (Contains 8 figures.)

This experiment examined event-related responses to targets preceded by semantically transparent morphologically related primes (e.g., farmer-farm), semantically opaque primes with an apparent morphological relation (corner-corn), and orthographically, but not morphologically, related primes (scandal-scan) using the masked priming technique combined with a semantic categorisation task. In order to provide information about possible early effects of morphology we focused our analysis on the N250 ERP component. Priming effects for transparent and opaque items patterned together in the early phase of the N250 (200-250 ms), whereas the transparent and orthographic items patterned together in the latter phase of this component (250-300 ms). These results provide further evidence in support of the rapid extraction of morphemes from morphologically complex stimuli independently of the semantic relatedness of the whole and its parts. (Contains 4 figures, 1 footnote and 2 tables.)

Two experiments tested language switching effects with bilingual participants in a priming paradigm with masked primes (duration of 50ms in Experiment 1 and 100ms in Experiment 2). Participants had to monitor target words for animal names, and ERPs were recorded to critical (non-animal) words in L1 and L2 primed by unrelated words from the same or the other language. Both experiments revealed language priming (switching) effects that depended on target language. For target words in L1, most of the language switch effect appeared in the N400 ERP component, with L2 primes generating a more negative going wave than L1 primes. For L2 target words, on the other hand, the effects of a language switch appeared mainly in an earlier ERP component (N250) peaking at approximately 250ms post-target onset, and showing greater negativity following an L1 prime than an L2 prime. This is the first evidence for fast-acting language-switching effects occurring in the absence of overt task switching.

In 2 experiments, the authors examined the electro-physiological auditory responses of monolingual French listeners to American English vowel contrasts as a function of the surrounding vowel context. The context was determined on the basis of behavioral results (C.Meunier, C. Frenck-Mestre, T. Lelekov-Boissard & M. Le Besnaris, 2003, 2004). In the 1st experiment, where the vowel /I/ was placed in a context in which it could easily be discriminated from the surrounding vowels (82% /i/ and 3% /ae/), the electro-physiological response to this vowel showed both acoustic and phonemic responses in line with behavioral results. In the 2nd experiment, where the same vowel /I/ was placed in a "difficult" context (82% /e/ and 3% /ae/), the electro-physiological response of French participants to this vowel revealed a greatly reduced phonemic response, showing assimilation of the vowel to the surrounding context, again in line with behavioral results. The results of a 3rd control experiment with American participants showed both an acoustic and a phonemic response to the vowel /I/ in the difficult context (82% /e/ and 3% /ae/). This pattern demonstrates the fluctuations in perception as a function of context, and hints at a supple system that may be modified through experience. (Contains 5 figures, 1 table and 3 footnotes.)

Deaf and hearing readers have different access to spoken phonology which may affect the representation and recognition of written words. We used ERPs to investigate how a matched sample of deaf and hearing adults (total n = 90) responded to lexical characteristics of 480 English words in a go/no-go lexical decision task. Results from mixed effect regression models showed (a) visual complexity produced small effects in opposing directions for deaf and hearing readers, (b) similar frequency effects, but shifted earlier for deaf readers, (c) more pronounced effects of orthographic neighbourhood density for hearing readers, and (d) more pronounced effects of concreteness for deaf readers. We suggest hearing readers have visual word representations that are more integrated with phonological representations, leading to larger lexically-mediated effects of neighbourhood density. Conversely, deaf readers weight other sources of information more heavily, leading to larger semantically-mediated effects and altered responses to low-level visual variables. [ABSTRACT FROM AUTHOR]

We examined how readers process content and function words in sentence comprehension with ERPs. Participants read simple declarative sentences using a rapid serial visual presentation (RSVP) with flankers paradigm. Sentences contained either an unexpected semantically anomalous content word, an unexpected syntactically anomalous function word or were well-formed with no anomalies. ERPs were examined when target words were in the parafoveal or foveal vision. Unexpected content words elicited a typically distributed N400 when displayed in the parafovea, followed by a longer-lasting, widely distributed positivity starting around 300 ms once foveated. Unexpected function words elicited a left lateralised LAN-like component when presented in the parafovea, followed by a left lateralised, posteriorly distributed P600 when foveated. These results suggested that both semantic and syntactic processing involve two stages – the initial, fast process that can be completed in parafovea, followed by a more in depth attentionally mediated assessment that occurs with direct attention. [ABSTRACT FROM AUTHOR]

Event-related potentials to critical verbs were measured as patients with schizophrenia and healthy controls read sentences word by word. Relative to their preceding context, critical verbs were (a) congruous, (b) incongruous and semantically unrelated to individual preceding words (pragmaticsemantic violations), (c) incongruous but semantically related to individual preceding words (animacy-semantic violations), or (d) syntactically anomalous. The N400 was modulated normally in patients, suggesting that semantic integration between individual words within sentences was normal in schizophrenia. The amplitude of the P600 to both syntactic and animacy-semantic violations was reduced in patients relative to controls. The authors suggest that, in schizophrenia, an abnormality in combining semantic and syntactic information online to build up propositional meaning leaves sentence processing to be primarily driven by semantic relationships between individual words. Keywords: language, schizophrenia, N400 event-related potential, semantics, syntax