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Prior research has found that iconicity facilitates sign production in picture-naming paradigms and has effects on ERP components. These findings may be explained by two separate hypotheses: (1) a task-specific hypothesis that suggests these effects occur because visual features of the iconic sign form can map onto the visual features of the pictures, and (2) a semantic feature hypothesis that suggests that the retrieval of iconic signs results in greater semantic activation due to the robust representation of sensory-motor semantic features compared to non-iconic signs. To test these two hypotheses, iconic and non-iconic American Sign Language (ASL) signs were elicited from deaf native/early signers using a picture-naming task and an English-to-ASL translation task, while electrophysiological recordings were made. Behavioral facilitation (faster response times) and reduced negativities were observed for iconic signs (both prior to and within the N400 time window), but only in the picture-naming task. No ERP or behavioral differences were found between iconic and non-iconic signs in the translation task. This pattern of results supports the task-specific hypothesis and provides evidence that iconicity only facilitates sign production when the eliciting stimulus and the form of the sign can visually overlap (a picture-sign alignment effect).

A picture-naming task and ERPs were used to investigate effects of iconicity and visual alignment between signs and pictures in American Sign Language (ASL). For iconic signs, half the pictures visually overlapped with phonological features of the sign (e.g., the fingers of CAT align with a picture of a cat with prominent whiskers), while half did not (whiskers are not shown). Iconic signs were produced numerically faster than non-iconic signs and were associated with larger N400 amplitudes, akin to concreteness effects. Pictures aligned with iconic signs were named faster than non-aligned pictures, and there was a reduction in N400 amplitude. No behavioral effects were observed for the control group (English speakers). We conclude that sensory-motoric semantic features are represented more robustly for iconic than non-iconic signs (eliciting a concreteness-like N400 effect) and visual overlap between pictures and the phonological form of iconic signs facilitates lexical retrieval (eliciting a reduced N400).

Previous attempts at modeling the neuro-cognitive mecha-nisms underlying word processing have used connectionist ap-proaches, but none has modeled spoken word architectures asthe input is presented in real-time. Hence, such models rely onthe ingenuity of the modeler to establish a mapping of real-time stimulus to the model’s input which may not preserveprocessing that happens during each time step. We present aneural field model which successfully replicates the effect ofimmediate auditory repetition of monosyllabic words and fitsit to a component of a well-studied mechanism for analyzinglanguage processing, the event-related potential (ERP). Thisrepresents a new modeling approach to studying the neuro-cognitive processes, one that is based on the bottom-up inter-action of real-time sensory information with higher-level cate-gories of cognitive processing.

We measured Event-Related Potentials (ERPs) and naming times to picture targets preceded by masked words (stimulus onset asynchrony: 80 ms) that shared one of three different types of relationship with the names of the pictures: (1) Identity related, in which the prime was the name of the picture ("socks"--[picture of socks]), (2) Phonemic Onset related, in which the initial segment of the prime was the same as the name of the picture ("log"--[picture of a leaf]), and (3) Semantically related in which the prime was a co-category exemplar and associated with the name of the picture ("cake"--[picture of a pie]). Each type of related picture target was contrasted with an Unrelated picture target, resulting in a 3 x 2 design that crossed Relationship Type between the word and the target picture (Identity, Phonemic Onset and Semantic) with Relatedness (Related and Unrelated). Modulation of the N400 component to related (versus unrelated) pictures was taken to reflect semantic processing at the interface between the picture's conceptual features and its lemma, while naming times reflected the end product of all stages of processing. Both attenuation of the N400 and shorter naming times were observed to pictures preceded by Identity related (versus Unrelated) words. No ERP effects within 600 ms, but shorter naming times, were observed to pictures preceded by Phonemic Onset related (versus Unrelated) words. An attenuated N400 (electrophysiological semantic priming) but longer naming times (behavioral semantic interference) were observed to pictures preceded by Semantically related (versus Unrelated) words. These dissociations between ERP modulation and naming times suggest that (a) phonemic onset priming occurred late, during encoding of the articulatory response, and (b) semantic behavioral interference was not driven by competition at the lemma level of representation, but rather occurred at a later stage of production. (Contains 5 figures.)

The present study explored when and how the top-down intention to speak influences the language production process. We did so by comparing the brain's electrical response for a variable known to affect lexical access, namely word frequency, during overt object naming and non-verbal object categorization. We found that during naming, the event-related brain potentials elicited for objects with low frequency names started to diverge from those with high frequency names as early as 152 ms after stimulus onset, while during non-verbal categorization the same frequency comparison appeared 200 ms later eliciting a qualitatively different brain response. Thus, only when participants had the conscious intention to name an object the brain rapidly engaged in lexical access. The data offer evidence that top-down intention to speak proactively facilitates the activation of words related to perceived objects. (Contains 1 table and 7 figures.)

ERPs were used to explore the different patterns of processing of cognate and noncognate words in the first (L1) and second (L2) language of a population of second language learners. L1 English students of French were presented with blocked lists of L1 and L2 words, and ERPs to cognates and noncognates were compared within each language block. For both languages, cognates had smaller amplitudes in the N400 component when compared with noncognates. L1 items that were cognates showed early differences in amplitude in the N400 epoch when compared with noncognates. L2 items showed later differences between cognates and noncognates than L1 items. The results are discussed in terms of how cognate status affects word recognition in second language learners.

Comparisons of word and picture processing using event-related potentials (ERPs) are contaminated by gross physical differences between the two types of stimuli. In the present study, we tackle this problem by comparing picture processing with word processing in an alphabetic and a logographic script, that are also characterized by gross physical differences. Native Mandarin Chinese speakers viewed pictures (line drawings) and Chinese characters (Experiment 1), native English speakers viewed pictures and English words (Experiment 2), and naive Chinese readers (native English speakers) viewed pictures and Chinese characters (Experiment 3) in a semantic categorization task. The varying pattern of differences in the ERPs elicited by pictures and words across the three experiments provided evidence for (i) script-specific processing arising between 150 and 200 ms post-stimulus onset, (ii) domain-specific but script-independent processing arising between 200 and 300 ms post-stimulus onset, and (iii) processing that depended on stimulus meaningfulness in the N400 time window. The results are interpreted in terms of differences in the way visual features are mapped onto higher-level representations for pictures and words in alphabetic and logographic writing systems. (Contains 10 figures and 1 table.)

Two experiments combined masked priming with event-related potential (ERP) recordings to examine effects of primes that are orthographic neighbors of target words. Experiment 1 compared effects of repetition primes with effects of primes that were high-frequency orthographic neighbors of low-frequency targets (e.g., faute-faune [error-wildlife]), and Experiment 2 compared the same word neighbor primes with nonword neighbor primes (e.g., aujel-autel [altar]). Word neighbor primes showed the standard inhibitory priming effect in lexical decision latencies that sharply contrasted with the facilitatory effects of nonword neighbor primes. This contrast was most evident in the ERP signal starting at around 300 ms posttarget onset and continuing through the bulk of the N400 component. In this time window, repetition primes and nonword neighbor primes generated more positive-going waveforms than unrelated primes, whereas word neighbor primes produced null effects. The results are discussed with respect to possible mechanisms of lexical competition during visual word recognition. (Contains 3 footnotes and 11 figures.)