Alberto Domínguez

Event-related Brain Potentials Elicited by Morphological, Homographic, Orthographic, and Semantic Priming

The morphological structure of words, in terms of their stem morphemes and affixes, could influence word access and representation in lexical memory. Three experiments were carried out to explore the attributes of event-related potentials evoked by different types of priming. Morphological priming, with pairs of words related by their stem (hijo/hija [son/ daughter]), produced a sustained attenuation (and even a tendency to positivity) of the N400 shown by unrelated words across the three experiments. Homographic priming (Experiment 1), using pairs of words with a superficially similar stem, but without morphological or semantic relation (foco/foca [floodlight/seal]), produced an initial attenuation similar to the morphological pairs, but which rapidly tended to form a delayed N400, due to the impossibility of integration. However, orthographic priming (rasa/rana [flat/frog]) in Experiment 2 does not produce attenuation of the N400 but an effect similar to that of unrelated pairs. Experiment 3 shows that synonyms advance more slowly than morphological pairs to meaning coherence, but finally produce a more positive peak around 600 msec.

The Processing of Grammatical Gender and Number in Spanish

The aim of the present study is to explore the representation and processing of inflectional morphology in Spanish. Experiment 1 compared the access time for words from the same base morpheme contrasted by the surface frequency of the masculine and feminine form, i.e., masculine-dominant items and feminine-dominant items. The results showed a surface frequency effect in both types of items. Experiment 2 compared the access time for masculine words having the same surface frequency but differing in their summed frequency (masculine plus feminine forms), the results showing no significant effect of this parameter. Finally, experiment 3 compared the access time for words from the same stem and contrasting by the surface frequencies for the singular and plural forms, i.e., singular-dominant and plural-dominant words. A clear frequency effect was observed for the singular-dominant words but not for plural-dominant ones. These results suggest that gender information is stored in the corresponding lexical entry and accessed from the full word form whereas the information about number is accessed from the stem corresponding to the singular form.

Human brain potentials indicate morphological decomposition in visual word recognition.

Stem homographs are pairs of words with the same orthographic description of their stem but which are semantically and morphologically unrelated (e.g. in Spanish: rata/rato (rat/moment)). In priming tasks, stem homographs produce inhibition, unlike morphologically related words (loca/loco (madwoman/madman)) which produce facilitation. An event-related potentials study was conducted to compare morphological and stem homographic priming effects. The results show a similar attenuation of the N400 component at the 350-500 ms temporal window for the two conditions. In contrast, a broad negativity occurs only for stem homographs at the 500-600 ms window. This late negativity is interpreted as the consequence of an inhibitory effect for stem homographs that delays the stage of meaning integration.

Determining the time course of lexical frequency and age of acquisition using ERP.

OBJECTIVE The main goal of the present study was to dissociate the effects on reading of frequency, age of acquisition (AoA) and imageability using the evoked response potential paradigm. METHOD Twenty participants read words from three experimental conditions: high and low frequency, late and early age of acquisition and high and low imageability. RESULTS High frequency words produced more positive mean amplitude than low frequency words in the 175-360 ms post-stimulus onset time window and late AoA produced more negative amplitudes than early AoA in the 400-610 ms window. Imageability did not produce any effect in any time window tested. Brain electromagnetic tomography showed the most activated cortical areas for each category of stimuli. CONCLUSIONS The lexical frequency of words seems to affect an early phase in the recognition process, perhaps at the level of the orthographic input lexicon, while AoA was observed at a later stage, indicating that this variable influence processing at a semantic level or at the links between semantics and phonology. SIGNIFICANCE EEG permits the researcher to investigate the time course, and approximate location in the brain, of psycholinguistic variables.

Event related potentials reveal differences between morphological (prefixes) and phonological (syllables) processing of words

Behavioral measures in visual priming tasks show opposite effects for syllables and morphemes, which indicate that they are processed by two independent systems. We used event related potentials (ERPs) to explore two priming situations in Spanish: prefix related words (reacción-REFORMA [reaction-reform]), in which prime and target words shared a first syllable that was also a prefix, and syllable related words (regalo-REFORMA [gift-reform.]), in which the shared first syllable was a pseudoprefix in the prime word. Prefix related pairs, unlike syllable related pairs, evoked a very early positivity in reaction to the target (at 150-250ms window), suggesting that the prefix information is immediately available, at a prelexical stage. By contrast, syllable related pairs showed a larger N400 effect. This late negativity may be caused by lateral inhibition among lexical candidates activated in the lexicon by the primes first syllable.

Efectos diferenciales de la frecuencia silábica: dependencia del tipo de prueba y características de los estímulos

ResumenLa frecuencia silabica posicional es una variable de reciente utilizacion en nuestro idioma. Por su caracter fonologico ha sido utilizada en este trabajo tanto para estudiar su papel en la lectura como para obtener algunas pistas sobre diferencias interlinguisticas entre nuestro idioma y otros que como el inglEs son mas opacos a la hora de traducir a sonidos su ortografia. Se utilizaron dos tipos de pruebas: decision lExica y lectura que presumiblemente implican diferentes demandas cognitivas. Los resultados de la tarea de decision lExica (Experimentos 1 y 3) muestran, en general, que la frecuencia silabica enlentece la respuesta del sujeto tanto en las palabras como en las pseudopalabras, confirmando algunos estudios previos (De Vega et al., 1990). Por el contrario, en la tarea de lectura (Experimentos 2 y 4) la frecuencia silabica tiende a acelerar la respuesta en la mayoria de los estimulos. Este comportamiento diferencial de los sujetos en funcion de la tEcnica utilizada sugiere que mientras la...

The contribution of prefixes to morphological processing of Spanish words

Three series of priming experiments were conducted to probe the morphological and phonological contributions to visual word recognition in Spanish. Prefixed, e.g., INCAPAZ (incapable), and pseudoprefixed, e.g., INDUSTRIA (industry) target words were presented for recognition following a prefixed, e.g., infeliz (unhappy), or pseudoprefixed, e.g., insulto (insult), prime starting with the same syllable as the target, at masked short or long stimulus onset asynchronies (SOAs). At long SOAs the recognition of prefixed targets was facilitated by prefixed primes and inhibited by pseudoprefixed ones, whereas both prefixed and pseudoprefixed primes facilitated the recognition at short SOAs. In contrast, the recognition of pseudoprefixed targets was unaffected by the kind of prime presented, even when we used pairs of words overlapping in syllables that cannot be prefixes in Spanish. These results support a special status for morphological elements in access to meaning in reading.

Repeated Exposure to “meaningless” Pseudowords Modulates LPC, but Not N(FN)400

Training readers to recognize pseudowords could decrease the processing differences between them and real words while clarifying the lexical acquisition processes. We analyze the effect of pseudoword repetition through the recording of EEG during a lexical decision task. Results showed a functional dissociation between two well-known ERP components: FN400 (Frontal N400, traditionally related to semantic processes) and LPC (Late Positive Complex, related to memory processes). On the one hand, FN400 was unaffected by pseudoword repetition and showed the typical lexicality effect. On the other hand, topographic and neural source analyses showed that LPC amplitude increased across repetitions, causing the lexicality effect to disappear, with the left inferior frontal, left superior temporal and right superior frontal gyri identified as the most likely neural sources. The lack of repetition effect on FN400 suggests that this component is unrelated to familiarity processes and is only influenced by semantic differences between stimuli. The LPC observations, however, reflect the construction and strengthening of visual memory traces for repeated pseudowords, facilitating their processing over the course of the task.

Sublexical and Lexico-Syntactic Factors in Gender Access in Spanish

The influence of sublexical and lexico-syntactic factors during the grammatical gender assignment process in Spanish was studied in two experiments using the gender decision task. In Experiment 1, the regularity of the ending of gender-marked nouns (masculine nouns ended in