Post-target Region Research Articles

Phonological and graphic representations of words in mental lexicon: Homophone processing while reading

This article presents an experimental study of the role of phonological representation of the word in lexical access during silent reading in Russian. The the phonological component in reading (i. e. whether semantics can be accessed via phonological decoding or directly from the orthographic image of the word) is actively discussed in modern psycholinguistics. Homophones can serve as a testing ground for these hypotheses: if graphemes are decoded into phonemes in silent reading in order to access semantics, then homophones will be processed like homonyms, but if semantics are accessed directly from the visual representation of the word, then homophones can be treated as all other orthographic neighbors. We address Russian homophones in order to investigate this question. In a self-paced reading experiment, we show that if a target word is substituted either by a homophone or a spelling control (an orthographic neighbor), semantic incongruence slows down the processing of the post-target region. We show that both homophones and spelling controls cause this processing load, and homophony does not facilitate the processing of semantically incongruent word. Our data give evidence for direct visual access to entries in mental lexicon as dual-route model predicts for experienced readers.

Similarity between referents constrains the processing of contrastive focus during reading.

Contrastive focus implies a contrast between two elements. However, it is unclear whether and how any interplay between such a contrast and similarity between potentially contrasting elements might affect focus processing. Accordingly, we report an eye movement experiment investigating this issue. The experiment used a background story to introduce eight characters whose social identities were manipulated to be similar or dissimilar. Participants first read this background story, then a series of two-sentence discourses while their eye movements were recorded. Each discourse referred to two characters from the passage who had either similar or dissimilar identities, with one (the target character) either focused using the Chinese particle zhiyou (meaning only) or unfocused. The results showed a typical focus facilitation effect, such that target character names were processed more quickly when focused than unfocused. We also observed a main effect of the similarity/dissimilarly of characters and, crucially, an interaction between this variable and focus. This interaction was due to slower processing of a post-target region when the target character was focused and the two characters had similar rather than dissimilar identities, but no such effect when the target character was unfocused. The findings suggest that establishing a contrast between referents is effortful during reading when these have similar rather than dissimilar social identities and so are more difficult to differentiate. The distinctiveness of referents in a discourse context may therefore constrain the establishment of contrastive focus during reading. We discuss these findings in relation to current theories of focus interpretation.

Emotion effects during reading: Influence of an emotion target word on eye movements and processing

Recently, Scott, O'Donnell and Sereno reported that words of high valence and arousal are processed with greater ease than neutral words during sentence reading. However, this study unsystematically intermixed emotion (label a state of mind, e.g., terrified or happy) and emotion-laden words (refer to a concept that is associated with an emotional state, e.g., debt or marriage). We compared the eye-movement record while participants read sentences that contained a neutral target word (e.g., chair) or an emotion word (no emotion-laden words were included). Readers were able to process both positive (e.g., happy) and negative emotion words (e.g., distressed) faster than neutral words. This was true across a wide range of early (e.g., first fixation durations) and late (e.g., total times on the post-target region) measures. Additional analyses revealed that State Trait Anxiety Inventory scores interacted with the emotion effect and that the emotion effect was not due to arousal alone.

Focus, Newness and Their Combination: Processing of Information Structure in Discourse

The relationship between focus and new information has been unclear despite being the subject of several information structure studies. Here, we report an eye-tracking experiment that explored the relationship between them in on-line discourse processing in Chinese reading. Focus was marked by the Chinese focus-particle “shi", which is equivalent to the cleft structure “it was… who…" in English. New information was defined as the target word that was not present in previous contexts. Our results show that, in the target region, focused information was processed more quickly than non-focused information, while new information was processed more slowly than given information. These results reveal differences in processing patterns between focus and newness, and suggest that they are different concepts that relate to different aspects of cognitive processing. In addition, the effect of new/given information occurred in the post-target region for the focus condition, but not for the non-focus condition, suggesting a complex relationship between focus and newness in the discourse integration stage.

An Eye-Movement Analysis of Ambiguity Resolution: Beyond Meaning Access

The research reported here addresses the status of the unselected meaning of a lexically ambiguous word in developing the larger meaning of the text by independently manipulating lexical and discourse-level variables in the text. In a series of 3 eye-movement experiments, participants read passages that contained 2 occurrences of an ambiguous word. The meaning of the ambiguous word either switched from 1 encounter to the next (Experiments 1 and 2) or remained consistent across encounters (Experiments 1 and 3), and the authors manipulated whether the second occurrence of the ambiguous word referred to the same discourse entity or a different entity. Facilitation was observed in initial processing time on ambiguous words when the meaning was consistent from first to second encounter, regardless of referential relations. Switching the meaning between encounters did not influence how accessible the initially unselected meaning was, but it did produce processing difficulty in the post-target region. These results suggest that the lexical status of the (initially) unselected meaning remains unchanged while the availability of this information for the purposes of text integration changes with changes in the configuration of the discourse representation.

Morphological priming during reading: Evidence from eye movements

We report an eye movement experiment that investigated whether prior exposure to morphologically related and unrelated primes influenced processing of a target word that appeared later in the same sentence. Prime-target pairs had a semantically transparent (e.g., marshy-marsh) or only an apparent morphological relationship (e.g., secretary-secret), or were morphologically unrelated but overlapped in orthography (e.g., extract-extra). Reading times for target words revealed facilitation effects in measures of both early and late processing only for targets that followed semantically transparent morphological primes, providing evidence of semantically mediated priming between words read normally in a sentence. In addition, an increase in target word skipping and in regressions from a posttarget region when targets followed primes rather than control words, regardless of the morphological relationship between the words, suggests that prime-target orthographic overlap influences parafoveal processing of target words. We discuss our findings in relation to morphological priming during isolated word recognition and the process of lexical identification during reading.

The time course of semantic and syntactic processing in Chinese sentence comprehension: Evidence from eye movements

In the present study, we examined the time course of semantic and syntactic processing when Chinese is read. Readers' eye movements were monitored, and the relation between a single-character critical word and the sentence context was manipulated such that three kinds of sentences were developed: (1) congruent, (2) those with a semantic violation, and (3) those with both a semantic and a syntactic violation. The eye movement data showed that the first-pass reading times were significantly longer for the target region in the two violation conditions than in the congruent condition. Moreover, the semantic+syntactic violation caused more severe disruption than did the pure semantic violation, as reflected by longer first-pass reading times for the target region and by longer go-past times for the target region and posttarget region in the former than in the latter condition. These results suggest that the effects of, at least, a semantic violation can be detected immediately by Chinese readers and that the processing of syntactic and semantic information is distinct in both first-pass and second-pass reading.

Syntactic boundaries and comma placement during silent reading of Chinese text: evidence from eye movements

In an eye-tracking experiment, we investigated whether and how a comma influences the reading of Chinese sentences comprised of different types of syntactic constituent such as word, phrase and clause. Participants read Chinese sentences that did or did not insert a comma at the end of a syntactic constituent. The results showed that the fixation times were shorter for the target word followed by a comma than for that followed by no comma, which suggests that a comma facilitated word identification during the reading of Chinese sentences. Furthermore, the insertion of commas shortened the total fixation times in the post-target region only for the clause condition. The data are consistent with previous findings concerning the role of segmentation cues in reading, and compatible with the implicit prosody hypothesis.

A Numerical Investigation of the Time Reversal Mirror Technique for Trans-skull Brain Cancer Ultrasound Surgery

Introduction: The medical applications of ultrasound on human brain are highly limited by the phase and amplitude aberrations induced by the heterogeneities of the skull. However, it has been shown that time reversing coupled with amplitude compensation can overcome these aberrations. In this work, a model for 2D simulation of the time reversal mirror technique is proposed to study the possibility of targeting any point within the brain without the need for craniotomy and to calculate the acoustic pressure field and the resulting temperature distribution within the skull and brain during a High Intensity Focused Ultrasound (HIFU) transcranial therapy. Materials and Methods: To overcome the sensitivity of the wave pattern to the heterogeneous geometry of the skull, a real MRI derived 2D model is constructed. The model should include the real geometry of brain and skull. The model should also include the couplant medium which has the responsibility of coupling the transducer to the skull for the penetration of ultrasound. The clinical substance used as the couplant is water. The acoustic and thermal parameters are derived from the references. Next, the wave propagation through the skull is computed based on the Helmholtz equation, with a 2D finite element analysis. The acoustic simulation is combined with a 2D thermal diffusion analysis based on Pennes Bioheat equation and the temperature elevation inside the skull and brain is computed. The numerical simulations were performed using the FEMLAB 3.2 software on a PC having 8 GB RAM and a 2.4 MHz dual CPU. Results: It is seen that the ultrasonic waves are exactly focalized at the location where the hydrophone has been previously implanted. There is no penetration into the sinuses and the waves are reflected from their surface because of the high discrepancy between the speed of sound in bone and air. Under the focal pressure of 2.5 MPa and after 4 seconds of sonication the temperature at the focus reached 51 °C and the temperature of the pre-target bone increased to 56.31 °C. In the post-target region the temperature of the sphenoid bone increased to 47.1 °C while the temperature of the occipital bones reached up to 46 °C. It is also shown that by using a cold water cooling system and cooling down the pre-target bones to 20 °C before sonication, the maximum pre-target bone temperature will not exceed 40 °C and hence the pre-target bone cells will remain intact. Discussion and Conclusion: In this study, it is well demonstrated that by using the time reversal mirror technique it is possible to target any point within the skull without the need for craniotomy. Although at higher acoustic frequencies compared to the lower ones such as 300 kHz the ultrasound undergoes more severe aberrations while passing through media having geometrical heterogeneity and discrepant sound velocities, the simulations performed in this work show that even at such frequencies it is still possible to correct these aberrations using the time reversal mirror technique. The thermal simulations show that by using this method the temperature of the deep seated tumors can be increased to cytotoxic temperature in a few seconds.

Eye movement assessment of emotional processing in anxiety.

Eye fixations of participants high or low in trait anxiety were monitored during reading of context sentences predicting threatening or nonthreat events, followed by sentences in which a target word represented the predictable event or an inconsistent event. No effects were found on the target word but on the regions following it. When this word represented a threatening event suggested by the context, high anxiety facilitated reading of the posttarget region. When the target word was inconsistent with a threatening event, high anxiety was associated with interference in the final region. No such effects occurred with nonthreat sentences. This reveals selective prediction of threat in high anxiety. However, rather than being automatic, this bias involves elaboration that takes time to develop.

Anxiety Gives Priority to Anticipation of Threatening Events

Reading times were collected to assess the probability and time course of inferences predictive of danger as a function of anxiety. Participants high or low in trait anxiety read (a) context sentences suggesting threat-related or nonthreat outcomes of events, followed by (b) disambiguating sentences in which a target word confirmed or disconfirmed the predicted outcome. The results revealed that low anxiety facilitated processing of nonthreat outcomes, whereas high anxiety facilitated processing of threatening outcomes. Furthermore, these selective effects occurred on a posttarget region of the disambiguating sentence; in contrast, all participants—regardless of anxiety level and threat content of stimuli—showed facilitation when reading the final region of that sentence. These findings indicate that anxiety leads one to prioritize (i. e., increased probability and reduced time) the anticipation of threat-related events.

Interpretation Bias in Test Anxiety: The Time Course of Predictive Inferences

The time course of the bias in predictive inferencing as a function of anxiety was examined. Ambiguous sentences (concerned with ego-threat, physicalthreat, or nonthreat events) were presented, followed by disambiguating sentences in which a target word either confirmed or disconfirmed the consequences implied by the ambiguous context. High- and low-anxiety subjects read the sentences at their own pace with the moving-window procedure. Effects on word reading times at different points were measured. Priming effects occurred for high-anxiety subjects when reading disambiguating ego-threat-related sentences: There was greater relative facilitation for confirming than for disconfirming ego-threat versions in high-anxiety subjects, compared with physical-threat and nonthreat versions, and with low-anxiety subjects. Because these effects were not observed in the target word itself but in the post-target region and the last word of the disambiguating sentence, we concluded that the bias towards ego-threat predictive inferences does not occur during the initial processing of the ambiguous information, but rather, is a post-lexical delayed phenomenon. The mechanisms of such bias are discussed in relation to current models of inferences in reading.

Predictive inferences occur on‐line, but with delay: Convergence of naming and reading times

Naming and word reading times were used to investigate the time course of predictive inferences. Priming contexts were followed to disambiguating sentences in which a target word either confirmed or disconfirmed the consequence suggested by the context. In Experiment 1, sentences were presented word by word at a predetermined pace; readers pronounced the target word, which appeared either 500 or 1250 ms after the onset of the last word in the priming context. In Experiment 2, the participants read sentences one to four words at a time using the self‐paced moving‐window technique; reading times for the target word, the posttarget region, and the last word in the disambiguating sentence were collected. There was facilitation (a) in naming the confirming target word when it was primed in the 1250‐ms stimulus onset asynchrony (SOA), but not in the 500‐ms SOA; and (b) in reading the confirming target word plus the posttarget region (spill‐over effect), but not in the target word itself. These results suggest t...