1,721,054 research outputs found
Effects of orthographic neighborhood on reading in Chinese - An fMRI study
Full text linkBACKGROUND: Much research has focused on neighborhood size in alphabetic languages. Results have consistently demonstrated that the neighborhood effect is a stimulating factor ill word reading. The present study addressed whether there are neighborhood effects ill Chinese character reading. OBJECTIVE: To investigate whether neighborhood effect exists, in Chinese character reading and wheather specific brain regions are responsible for it. DESIGN: An event-related design. SETTING: Beijing Anzhen Hospital. PARTICIPANTS: The experiment was conducted at Beijing Anzhen Hospital from October 2004 to December 2004. Undergraduate students, aged 19 24 years, were selected from Beijing Normal University, comprising 13 males and 16 females. Inclusive criteria: (1) Neurologcally normal and right-handed: (2) native-Chinese speakers. All subjects gave informed consent prior to experimentation. METHODS: (1) Behavioral experiment: the experiment utilized it 2 x 2 factorial design. The factors included orthographic neighborhood size (few or many neighbors) and lexical regularity (regular or irregular characters). There was no significant difference between the ratio of regular and irregular characters in each family. The experiment was performed on a notebook PC and was piloted by E-Prime software. A fixation point "+" Was presented oil the screen for 500 ins, and then the target item was displayed ill file same place of the fixation for 2 000 ms. Subjects were asked to read the character alound quickly and correctly. The target item disappeared once the subject read it. Reaction time (RT) and error ratios were collected and analyzed. (2) fMRI study: the study was an event-related design. Each character was presented for 500 ms, and the offset was followed by "+" presented for 1 500 - 26 000 ms. Each duration was divided by 500 exactly. The subject was required to read silently. AFNI software package was used to analyze the fMRI data. MAIN OUTCOME MEASURES: (1) RT and error ratio in behavioral experiment; (2) Brain mapping in fMRI study. Results: Twenty-nine undergraduate students were involved in the result analysis. (1) Behavioral experiment results of RT; the main effect of regularity was highly significant for participants (F-1) and items (F-2) [F-1 (1.28) = 135.74. P<0.01: F-2 (1.76) = 49.506. P < 0.01], with regular words being responded faster than irregular words. The main effect of N was not significant, but was localized in an uncertain area [F-1 (1.28) = 3.182, P> 0.05; F-2 not significant]. Moreover, there was an interaction between neighborhood and regularity [F-1 (1.28) = 6.666. P < 0.05: F-2 ( 1.76) = 3.157, P > 0.05]. Analyses of simple effect determined that when the characters were irregular, the RT of low neighborhoods was shorter than high neighborhoods. Behavioral experiment results of error ratio: similar analyses were performed on the number of errors in the naming task. ANOVA demonstrated a main effect of regularity [F-1 (1.28) = 10.475, P<0.01; F-2 (1.76) = 4.686, P < 0.05], with errors of regular words less than irregular words. The main effect of neighborhoods was not significant. Moreover, there was an interaction between neighborhood and regularity by subjects [F-1 1.28) = 7.632, P < 0.05], but not by items [F-2 ( 1.76) = 3.906. P > 0.05]. Analyses of simple effect found that when the characters were regular, the number of errors in high neighborhoods (23%) was greater than in low neighborhoods (11%). (2) fMRI results; bilateral fusiforms were sensitive to Chinese character shape. Both neighborhoods effect and regular effect mainly yielded right cerebral hemisphere and bilateral brain area. CONCLUSION: Neighborhood effect existed in character reading. However, results are contrary to what has been shown in English word reading. The fewer neighborhoods that one character had, the shorter the RT was. The fMRI results demonstrated the neighborhood effect and regular effect primarily stimulated right cerebral hemisphere and the bilateral brain area.BACKGROUND: Much research has focused on neighborhood size in alphabetic languages. Results have consistently demonstrated that the neighborhood effect is a stimulating factor ill word reading. The present study addressed whether there are neighborhood effects ill Chinese character reading
Biological motion cues trigger reflexive attentional orienting
No full textThe human visual system is extremely sensitive to biological signals around us. In the current study, we demonstrate that biological motion walking direction can induce robust reflexive attentional orienting. Following a brief presentation of a central point-light walker walking towards either the left or right direction, observers' performance was significantly better on a target in the walking direction compared with that in the opposite direction even when participants were explicitly told that walking direction was not predictive of target location. Interestingly, the effect disappeared when the walker was shown upside-down. Moreover, the reflexive attentional orienting could be extended to motions of other biological entities but not inanimate objects, and was not due to the viewpoint effect of the point-light figure. Our findings provide strong evidence that biological motion cues can trigger reflexive attentional orienting, and highlight the intrinsic sensitivity of the human visual attention system to biological signals. (C) 2010 Elsevier B.V. All rights reserved
Neuroimaging activation studies in the vegetative state: predictors of recovery?
Full text linkThe vegetative state (VS) is a devastating clinical condition characterised by wakefulness without awareness. Functional neuroimaging permits to objectively measure brain responsiveness to external stimuli in VS. The literature on functional magnetic resonance imaging and positron emission tomography studies in these patients has been reviewed. Results from 15 studies were classified in: absent cortical activation or 'typical' activation of 'low level' primary sensory cortices and 'atypical' activation spreading to 'higher level' associative cortices. This descriptive review on 48 published cases suggests that 'atypical' activation patterns seem to herald recovery from VS with a 93% specificity and 69% sensitivity. Passive stimulation paradigms, however, do not permit to make strong claims about the absence or presence of consciousness. Recently proposed mental imagery paradigms permit to identify signs of consciousness in non-communicative brain damaged patients. The clinical application of these functional neuroimaging techniques awaits validation from ongoing multi-centric cohort studies in these challenging patients with chronic disorders of consciousness.The vegetative state (VS) is a devastating clinical condition characterised by wakefulness without awareness. Functional neuroimaging permits to objectively measure brain responsiveness to external stimuli in VS. The literature on functional magnetic resonance imaging and positron emission tomography studies in these patients has been reviewed. Results from 15 studies were classified in: absent cortical activation or 'typical' activation of 'low level' primary sensory cortices and 'atypical' activation spreading to 'higher level' associative cortices. This descriptive review on 48 published cases suggests that 'atypical' activation patterns seem to herald recovery from VS with a 93% specificity and 69% sensitivity. Passive stimulation paradigms, however, do not permit to make strong claims about the absence or presence of consciousness. Recently proposed mental imagery paradigms permit to identify signs of consciousness in non-communicative brain damaged patients. The clinical application of these functional neuroimaging techniques awaits validation from ongoing multi-centric cohort studies in these challenging patients with chronic disorders of consciousness
Do Preschool Children Learn to Read Words from Environmental Prints?
No full textParents and teachers worldwide believe that a visual environment rich with print can contribute to young children's literacy. Children seem to recognize words in familiar logos at an early age. However, most of previous studies were carried out with alphabetic scripts. Alphabetic letters regularly correspond to phonological segments in a word and provide strong cues about the identity of the whole word. Thus it was not clear whether children can learn to read words by extracting visual word form information from environmental prints. To exclude the phonological-cue confound, this study tested children's knowledge of Chinese words embedded in familiar logos. The four environmental logos were employed and transformed into four versions with the contextual cues (i.e., something apart from the presentation of the words themselves in logo format like the color, logo and font type cues) gradually minimized. Children aged from 3 to 5 were tested. We observed that children of different ages all performed better when words were presented in highly familiar logos compared to when they were presented in a plain fashion, devoid of context. This advantage for familiar logos was also present when the contextual information was only partial. However, the role of various cues in learning words changed with age. The color and logo cues had a larger effect in 3- and 4-year-olds than in 5-year-olds, while the font type cue played a greater role in 5-year-olds than in the other two groups. Our findings demonstrated that young children did not easily learn words by extracting their visual form information even from familiar environmental prints. However, children aged 5 begin to pay more attention to the visual form information of words in highly familiar logos than those aged 3 and 4
A Stroop effect emerges in the processing of complex Chinese characters that contain a color-related radical
No full textThree experiments examined whether a Stroop effect emerges in the processing of complex Chinese characters that contain a color-related radical. In Experiment 1, a Stroop effect occurred when participants responded to the black or white color of the simple characters (black) and (white) by making a left or right keypress. For Experiment 2, in which the stimuli were complex characters whose meanings were unrelated to color but that contained or as a radical, a Stroop effect also occurred, although it was smaller than in Experiment 1. Furthermore, this Stroop effect as a function of radical meaning was shown again in Experiment 3 for low-frequency complex characters but not high-frequency ones. These results suggest that the semantic representations of the complex characters' color-related radicals are accessed in the context of a Stroop color word task, especially for low-frequency characters. Reduction of the Stroop effect in complex characters composed of one radical with color meaning and one without is similar to dilution of the Stroop effect that occurs when a color word is accompanied by a neutral word. Possible implications of the results for accounts of Stroop dilution are discussed
Perceptual Grouping without Awareness: Superiority of Kanizsa Triangle in Breaking Interocular Suppression
No full textMuch information could be processed unconsciously. However, there is no direct evidence on whether perceptual grouping could occur without awareness. To answer this question, we investigated whether a Kanizsa triangle (an example of perceptual grouping) is processed differently from stimuli with the same local components but are ungrouped or weakly grouped. Specifically, using a suppression time paradigm we tested whether a Kanizsa triangle would emerge from interocular continuous flash suppression sooner than control stimuli. Results show a significant advantage of the Kanizsa triangle: the Kanizsa triangle emerged from suppression noise significantly faster than the control stimulus with the local Pacmen randomly rotated (t(9) = -2.78, p = 0.02); and also faster than the control stimulus with all Pacmen rotated 180 degrees (t(11) = -3.20, p<0.01). Additional results demonstrated that the advantage of the grouped Kanizsa triangle could not be accounted for by the faster detection speed at the conscious level for the Kanizsa figures on a dynamic noise background. Our results indicate that certain properties supporting perceptual grouping could be processed in the absence of awareness
A longitudinal study of infants' early speech production and later letter identification.
Full text linkLetter identification is an early metric of reading ability that can be reliability tested before a child can decode words. We test the hypothesis that early speech production will be associated with children's later letter identification. We examined longitudinal growth in early speech production in 9 typically developing children across eight occasions, every 3 months from 9 months to 30 months. At each occasion, participants and their caregivers engaged in a speech sample in a research lab. This speech sample was transcribed for a variety of vocalizations, which were then transformed to calculate consonant-vowel ratio. Consonant-vowel ratio is a measure of phonetic complexity in speech production. At the age of 72 months, children's letter knowledge was measured. A multilevel model including fixed quadratic age change and a random intercept was estimated using letter identification as a predictor of the growth in early speech production from 9-30 months, measured by the outcome of consonant-vowel ratio. Results revealed that the relation between early speech production and letter identification differed over time. For each additional letter that a child identified, their consonant-vowel ratio at the age of 9 months increased. As such, these results confirmed our hypothesis: more robust early speech production is associated with more accurate letter identification
Do People Agree on What Makes One Feel Loved? A Cognitive Psychometric Approach to the Consensus on Felt Love.
No full textThis pragmatic study examines love as a mode of communication. Our focus is on the receiver side: what makes an individual feel loved and how felt love is defined through daily interactions. Our aim is to explore everyday life scenarios in which people might experience love, and to consider people's converging and diverging judgments about which scenarios indicate felt love. We apply a cognitive psychometric approach to quantify a receiver's ability to detect, understand, and know that they are loved. Through crowd-sourcing, we surveyed lay participants about whether various scenarios were indicators of felt love. We thus quantify these responses to make inference about consensus judgments of felt love, measure individual levels of agreement with consensus, and assess individual response styles. More specifically, we (1) derive consensus judgments on felt love; (2) describe its characteristics in qualitative and quantitative terms, (3) explore individual differences in both (a) participant agreement with consensus, and (b) participant judgment when uncertain about shared knowledge, and (4) test whether individual differences can be meaningfully linked to explanatory variables. Results indicate that people converge towards a shared cognitive model of felt love. Conversely, respondents showed heterogeneity in knowledge of consensus, and in dealing with uncertainty. We found that, when facing uncertainty, female respondents and people in relationships more frequently judge scenarios as indicators of felt love. Moreover, respondents from smaller households tend to know more about consensus judgments of felt love, while respondents from larger households are more willing to guess when unsure of consensus
Structural and functional correlates for language efficiency in auditory word processing
Full text linkThis study aims to provide convergent understanding of the neural basis of auditory word processing efficiency using a multimodal imaging. We investigated the structural and functional correlates of word processing efficiency in healthy individuals. We acquired two structural imaging (T1-weighted imaging and diffusion tensor imaging) and functional magnetic resonance imaging (fMRI) during auditory word processing (phonological and semantic tasks). Our results showed that better phonological performance was predicted by the greater thalamus activity. In contrary, better semantic performance was associated with the less activation in the left posterior middle temporal gyrus (pMTG), supporting the neural efficiency hypothesis that better task performance requires less brain activation. Furthermore, our network analysis revealed the semantic network including the left anterior temporal lobe (ATL), dorsolateral prefrontal cortex (DLPFC) and pMTG was correlated with the semantic efficiency. Especially, this network acted as a neural efficient manner during auditory word processing. Structurally, DLPFC and cingulum contributed to the word processing efficiency. Also, the parietal cortex showed a significant association with the word processing efficiency. Our results demonstrated that two features of word processing efficiency, phonology and semantics, can be supported in different brain regions and, importantly, the way serving it in each region was different according to the feature of word processing. Our findings suggest that word processing efficiency can be achieved by in collaboration of multiple brain regions involved in language and general cognitive function structurally and functionally
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