Search

The neural mechanism for the dyadic process of teaching is poorly understood. Although theories about teaching have proposed that before any teaching takes place, the teacher will predict the knowledge state of the student(s) to enhance the teaching outcome, this theoretical Prediction-Transmission hypothesis has not been tested with any neuroimaging studies. Using functional near-infrared spectroscopy-based hyperscanning, this study measured brain activities of the teacher-student pairs simultaneously. Results showed that better teaching outcome was associated with higher time-lagged interpersonal neural synchronization (INS) between right temporal-parietal junction (TPJ) of the teacher and anterior superior temporal cortex (aSTC) of the student, when the teacher's brain activity preceded that of the student. Moreover, time course analyses suggested that such INS could mark the quality of the teaching outcome at an early stage of the teaching process. These results provided key neural evidence for the Prediction-Transmission hypothesis about teaching, and suggested that the INS plays an important role in the successful teaching.

Successful visual word recognition requires the integration of phonological and semantic information, which is supported by the dorsal and ventral pathways in the brain. However, the functional specialization or interaction of these pathways during phonological and semantic processing remains unclear. Previous research has been limited by its dependence on correlational functional magnetic resonance imaging (fMRI) results or causal validation using patient populations, which are susceptible to confounds such as plasticity and lesion characteristics. To address this, the present study employed continuous theta‐burst stimulation combined with fMRI in a within‐subject design to assess rapid adaptation in regional activity and functional connectivity of the dorsal and ventral pathways during phonological and semantic tasks. This assessment followed the precise inhibition of the left inferior parietal lobule and anterior temporal lobe in the dorsal and ventral pathways, respectively. Our results reveal that both the dorsal and ventral pathways were activated during phonological and semantic processing, while the adaptation activation and interactive network were modulated by the task type and inhibited region. The two pathways exhibited interconnectivity in phonological processing, and disruption of either pathway led to rapid adaptation across both pathways. In contrast, only the ventral pathway exhibited connectivity in semantic processing, and disruption of this pathway alone resulted in adaptive effects primarily in the ventral pathway. These findings provide essential evidence supporting the interactive theory, phonological information processing in particular, potentially providing meaningful implications for clinical populations. [ABSTRACT FROM AUTHOR]

Using the blocked-translation paradigm with healthy participants, we examined Crutch and Warrington's hypothesis that concrete and abstract concepts are organized by distinct principles: concrete concepts by semantic similarities and abstract ones by associations. In three experiments we constructed two types of experimental blocking (similar vs. associative) for both abstract and concrete words. In Experiment 1, we first attempted to transfer previous findings observed in patients by Crutch and Warrington with semantic impairment to healthy participants. In Experiment 2 only noun stimuli were used, and we further included two semantically categorical conditions that differed by a degree of semantic similarity (close vs. distant). In Experiment 3, verbs were used exclusively. Consistent results were obtained across all three experiments: Significant interference effects were observed for abstract items that were blocked by an associative relationship and by a semantic similarity, and for concrete items that were blocked by a semantic similarity (category) but not when they were blocked by an association. The effect of similarity-close was greater than that of similarity-distant in the noun experiment. We argue that the results are in conflict with Crutch and Warrington's proposals, and can be accommodated by a theory of cooperating similarity and association connections for concrete and abstract concepts, with the association bearing more weight for abstract concepts.

This paper reports a conjunction analysis between semantic relatedness judgment and semantic associate generation of Chinese nouns and verbs with concrete or abstract meanings. The results revealed a verb-specific task-independent region in LpSTG&MTG, and task-dependent activation in a left frontal region in semantic judgment and the left SMG in semantic associate production. The observation of word class effects converged on Yu, Law, Han, Zhu, and Bi (2011), but contrasted with null findings in previous reports using a lexical decision task. While word class effects in the left posterior temporal cortices have been described in previous studies of languages with rich inflectional morphology, the significance of this study lies in its demonstration of the effects in these regions in a language known to have little inflectional morphology. In other words, differential neural responses to nouns and verbs can be observed without confounding from morphosyntactic operations or contrasts between actions and objects. (Contains 1 figure and 2 tables.)

The cognitive mechanisms for writing to dictation of Chinese syllables by healthy adults were investigated using large-sample multiple regression analyses. In the experiment, subjects wrote down a corresponding character upon hearing a syllable. We mainly examined the effects of three types of attributes (i.e., lexical, semantic, and phonology to orthography conversion [POC] ones) in predicting the production probability of specific characters out of the homophone families for target syllables. We observed significant effects for all three types of attributes, as well as interactions between POC and the lexical attributes, and between POC and the semantic attributes. We further found that the semantic effects vanished for the writing stimuli without homophones. A feedback procedure (i.e., phonetic radical transparency) was also observed to influence Chinese writing performances. Our results support the hypothesis that the extent of semantic involvement in writing (spelling) to dictation is influenced by the effectiveness of POC procedure in a certain language and/or word set. The existence of an interaction between the lexical semantic route and the POC route in writing is further consolidated.

Neuropsychological and neuroimaging studies have indicated that motor knowledge is one potential dimension along which concepts are organized. Here we present further direct evidence for the effects of motor knowledge in accounting for categorical patterns across object domains (living vs. nonliving) and grammatical domains (nouns vs. verbs), as well as the integrity of other modality-specific knowledge (e.g., visual). We present a Chinese case, XRK, who suffered from semantic dementia with left temporal lobe atrophy. In naming and comprehension tasks, he performed better at nonliving items than at living items, and better at verbs than at nouns. Critically, multiple regression method revealed that these two categorical effects could be both accounted for by the charade rating, a continuous measurement of the significance of motor knowledge for a concept or a semantic feature. Furthermore, charade rating also predicted his performances on the generation frequency of semantic features of various modalities. These findings consolidate the significance of motor knowledge in conceptual organization and further highlights the interactions between different types of semantic knowledge. (Contains 2 tables and 1 figure.)

The oral spelling process for logographic languages such as Chinese is intrinsically different from alphabetic languages. In Chinese only a subset of orthographic components are pronounceable and their phonological identities (i.e., component names) do not always correspond to the sound of the whole characters. We show that such phonological identities can nevertheless be selectively preserved when visual-motoric compositions are lost. We report a Chinese right-handed dysgraphic individual with left temporal and occipital damage, MZG, who was severely impaired in writing Chinese characters but was able to orally spell the same characters using the names of pronounceable components. MZG's writing deficit arose at the level of processing that is dedicated to the retrieval of the shapes (allographics) of the writing components. Such patterns show that phonological identities of components are part of the orthographic representation of Chinese characters, and that dissociation between oral and written spelling modalities is universal across different script systems. The temporal and occipital lobes in the language-dominant hemisphere are possibly important regions for allographic conversion in writing. (Contains 2 figures.)

A recent hypothesis proposes that reading depends on writing in a logographic language--Chinese. We present a Chinese individual (HLD) with brain damage whose profile challenges this hypothesis. HLD was severely impaired in the whole process of writing. He could not access orthographic knowledge, had poor orthographic awareness, and was poor at delayed- and direct-copying tasks. Nevertheless, he was perfect at visual word-picture matching and read aloud tasks, indicating his intact ability to access both the semantics and phonology in reading. He was also able to distinguish between fine visual features of characters. We conclude that reading does not depend on writing, even in Chinese. (Contains 2 figures and 1 table.)

We report a Chinese-speaking patient WJX with left temporal lobe ischemic damage resulting in dementia. Similar to English speaking patients with this pathology, WJX showed impaired semantic system functioning together with a well preserved ability to read aloud Chinese characters including characters with unpredictable mappings between orthography and phonology--so called irregular characters. The summation hypothesis [Hillis, A. E., & Caramazza, A. (1991). Mechanisms for accessing lexical representations for output--evidence from a category-specific semantic deficit. "Brain and Language," 40, 106-144; Hillis, A. E., & Caramazza, A. (1995). Converging evidence for the interaction of semantic and sublexical phonological information in accessing lexical representations for spoken output. "Cognitive Neuropsychology," 12, 187-227] proposes that the good reading performance can be explained by the integration of a semantic route of reading and a nonsemantic route. Most Chinese characters contain components that can give a clue to the pronunciation (phonetic radical) and the meaning (semantic radical) of the character. We compared his comprehension and oral reading performance by varying the consistency of phonetic radicals and the transparency of semantic radicals. We observed an interaction between WJX's character comprehension and the consistency of the phonetic radical on reading performance; however, the transparency of semantic radicals had no effect on performance. We argue that this case report provides converging evidence for the principles of the summation hypothesis for reading. (Contains 3 figures and 5 tables.)

Although prediction plays an important role in language comprehension, its precise neural basis remains unclear. This fMRI study investigated whether and how semantic-category-specific and common cerebral areas are recruited in predictive semantic processing during sentence comprehension. We manipulated the semantic constraint of sentence contexts, upon which a tool-related, a building-related, or no specific category of noun is highly predictable. This noun-predictability effect was measured not only over the target nouns but also over their preceding transitive verbs. Both before and after the appearance of target nouns, left anterior supramarginal gyrus was specifically activated for tool-related nouns and left parahippocampal place area was activated specifically for building-related nouns. The semantic-category common areas included a subset of left inferior frontal gyrus during the anticipation of incoming target nouns (activity enhancement for high predictability) and included a wide spread of areas (bilateral inferior frontal gyrus, left superior/middle temporal gyrus, left medial pFC, and left TPJ) during the integration of actually perceived nouns (activity reduction for high predictability). These results indicated that the human brain recruits fine divisions of cortical areas to distinguish different semantic categories of predicted words, and anticipatory semantic processing relies, at least partially, on top–down prediction conducted in higher-level cortical areas. [ABSTRACT FROM AUTHOR]