Differential prefrontal–temporal neural correlates of semantic processing in children

This study used functional magnetic resonance imaging (fMRI) to examine brain–behavior correlations in a group of 16 children (9- to 12-year-olds). Activation was measured during a semantic judgment task presented in either the visual or auditory modality that required the individual to determine whether a final word was related in meaning to one of two previous words (e.g., found–tank–lost). The main finding was that higher performers (i.e., accuracy) were associated with more activation in posterior representational systems including the inferior and middle temporal gyri, whereas lower performers were associated with more activation in anterior regions including the inferior and middle frontal gyri. This pattern of results was interpreted as reflecting an elaborated semantic representational system in temporal areas for the high accuracy performers that allowed them to efficiently and accurately make meaning based judgments. The low accuracy performers may have an inaccurate or weakly interconnected semantic system that results in greater use of frontal areas in a feature selection process.     

The role of form and meaning in the processing of written morphology: A priming study in French developing readers

Three visual priming experiments using three different prime durations (60 ms in Experiment 1, 250 ms in Experiment 2, and 800 ms in Experiment 3) were conducted to examine which properties of morphemes (form and/or meaning) drive developing readers’ processing of written morphology. French third, fifth, and seventh graders and adults (the latter as a control group) performed lexical decision tasks in which targets were preceded by morphological (e.g., tablette–TABLE, “little table–table”), pseudoderived (e.g., baguette–BAGUE, “little stick–ring”), orthographic control (e.g., abricot–ABRI, “apricot–shelter”), and semantic control (e.g., Tulipe–FLEUR, “tulip–flower”) primes. Across all groups, different patterns of priming were observed in both morphological and orthographic/semantic control conditions, suggesting that they all process morphemes as units when reading. In developing readers, the processing of written morphology is triggered by the form properties of morphemes, and their semantic properties are activated later in the time course of word recognition. In adults, patterns of priming were similar except that the activation of the form properties of morphemes decreased earlier in the time course of word recognition. Taken together, these findings indicate that French developing readers process both the form and meaning properties of morphemes when reading and support a progressive quantitative change in the development of morphological processing over the course of reading development.     

Constraints on the range of context-independent priming from ambiguous words

The semantic priming technique was used to explore the semantic information activated by the contextually irrelevant meanings of ambiguous words in sentence contexts. The nature of the relationship between prime and target was systematically manipulated. Evidence of priming was obtained when the target was an approximate synonym of the prime (e.g., coach-bus), and when the target was a category coordinate of low similarity, but high category typicality (e.g., raincoat jumper, in Italian). No priming was obtained when the target was event related to the prime (coach-driver), nor when it was a highly similar category co-ordinate (raincoat overcoat, in Italian). However, in these latter cases, robust priming effects were obtained when the prime was presented out of context. The results are discussed in terms of the different kinds of semantic-retrieval operations that may be performed, depending upon whether or not the subjects attend to the meaning of the prime.     

Famous people knowledge and the right and left temporal lobes

It is generally accepted that the anterior temporal lobes support knowledge of famous people. The specific roles of the right and left temporal lobe remain a subject of debate, with some studies suggesting differential roles based on modality (visual versus verbal information) and others category (person knowledge versus general semantics). The present study re-examined performance of semantic dementia patients with predominantly right and predominantly left temporal lobe atrophy on famous face, famous name and general semantic tasks, with the specific aim of testing the hypothesis that the right temporal lobe has a privileged role for person knowledge and the left temporal lobe for general semantic knowledge. Comparisons of performance rankings across tasks showed no evidence to support this hypothesis. By contrast, there was robust evidence from naming, identification and familiarity measures for modality effects: right-sided atrophy being associated with relatively greater impairment for faces and visual tasks and left-sided atrophy for names and verbal tasks. A double dissociation in test scores in two patients reinforced these findings. The data present a challenge for the influential `semantic hub' model, which views the anterior temporal lobes as an area of convergence in which semantic information is represented in amodal form.     

Automatic semantic feedback during visual word recognition

Four experiments were conducted to determine whether semantic feedback spreads to orthographic and/or phonological representations during visual word recognition and whether such feedback occurs automatically. Three types of prime-target word pairs were used within the mediated-priming paradigm: (1) homophonically mediated (e.g., frog-[toad]-towed), (2) orthographically mediated (e.g., frog-[toad]-told), and (3) associatively related (e.g., frog-toad). Using both brief (53 msec; Experiment 1) and long (413 msec; Experiment 3) prime exposure durations, significant facilitatory-priming effects were found in the response time data with orthographically, but not homophonically, mediated prime-target word pairs. When the prime exposure duration was shortened to 33 msec in Experiment 4, however, facilitatory priming was absent with both orthographically and homophonically mediated word pairs. In addition, with a brief (53-msec) prime exposure duration, direct-priming effects were found with associatively (e.g., frog-toad), orthographically (e.g., toad-told), and homophonically (e.g., toad-towed) related word pairs in Experiment 2. Taken together, these results indicate that following the initial activation of semantic representations, activation automatically feeds back to orthographic, but not phonological, representations during the early stages of word processing. These findings were discussed in the context of current accounts of visual word recognition.     

Looking for meaning: Eye movements are sensitive to overlapping semantic features, not association

Theories of semantic memory differ in the extent to which relationships among concepts are captured via associative or via semantic relatedness. We examined the contributions of these two factors, using a visual world paradigm in which participants selected the named object from a four-picture display. We controlled for semantic relatedness while manipulating associative strength by using the visual world paradigm’s analogue to presenting asymmetrically associated pairs in either their forward or backward associative direction (e.g., ham—eggs vs. eggs—ham). Semantically related objects were preferentially fixated regardless of the direction of presentation (and the effect size was unchanged by presentation direction). However, when pairs were associated but not semantically related (e.g., iceberg—lettuce), associated objects were not preferentially fixated in either direction. These findings lend support to theories in which semantic memory is organized according to semantic relatedness (e.g., distributed models) and suggest that association by itself has little effect on this organization.     

Conceptual similarity effects on working memory in sentence contexts: Testing a theory of anaphora

The degree of semantic similarity between an anaphoric noun phrase (e.g., the bird) and its antecedent (e.g., a robin) is known to affect the anaphor resolution process, but the mechanisms that underlie this effect are not known. One proposal (Almor, 1999) is that semantic similarity triggers interference effects in working memory and makes two crucial assumptions: First, semantic similarity impairs working memory just as phonological similarity does (e.g., Baddeley, 1992), and, second, this impairment interferes with processes of sentence comprehension. We tested these assumptions in two experiments that compared recall accuracy between phonologically similar, semantically similar, and control words in sentence contexts. Our results do not provide support for Almor's claims: Phonological overlap decreased recall accuracy in sentence contexts, but semantic similarity did not. These results shed doubt on the idea that semantic interference in working memory is an underlying mechanism in anaphor resolution.     

The contribution of executive control to semantic cognition: Convergent evidence from semantic aphasia and executive dysfunction

Semantic cognition, as described by the controlled semantic cognition (CSC) framework (Rogers et al., 2015 , Neuropsychologia, 76, 220), involves two key components: activation of coherent, generalizable concepts within a heteromodal ‘hub’ in combination with modality‐specific features (spokes), and a constraining mechanism that manipulates and gates this knowledge to generate time‐ and task‐appropriate behaviour. Executive–semantic goal representations, largely supported by executive regions such as frontal and parietal cortex, are thought to allow the generation of non‐dominant aspects of knowledge when these are appropriate for the task or context. Semantic aphasia (SA) patients have executive–semantic deficits, and these are correlated with general executive impairment. If the CSC proposal is correct, patients with executive impairment should not only exhibit impaired semantic cognition, but should also show characteristics that align with those observed in SA. This possibility remains largely untested, as patients selected on the basis that they show executive impairment (i.e., with ‘dysexecutive syndrome’) have not been extensively tested on tasks tapping semantic control and have not been previously compared with SA cases. We explored conceptual processing in 12 patients showing symptoms consistent with dysexecutive syndrome (DYS) and 24 SA patients, using a range of multimodal semantic assessments which manipulated control demands. Patients with executive impairments, despite not being selected to show semantic impairments, nevertheless showed parallel patterns to SA cases. They showed strong effects of distractor strength, cues and miscues, and probe–target distance, plus minimal effects of word frequency on comprehension (unlike semantic dementia patients with degradation of conceptual knowledge). This supports a component process account of semantic cognition in which retrieval is shaped by control processes, and confirms that deficits in SA patients reflect difficulty controlling semantic retrieval.     

With a letter-searched prime, boat primes float but swim and coat don't: further evidence for automatic semantic activation

Letter search (LS) on the prime typically eliminates semantic priming (swim-float) and orthographic/phonological (O/P) priming (coat-float) but not morphological priming (marked-mark). However, LS on the prime does not reduce semantic priming for low-frequency targets (Tse & Neely, 2007). These findings suggest that semantic activation survives LS but decays during LS to a low level that can be detected only with sensitive measures, which are afforded by low-frequency targets and morphologically related primes and targets. In the present research, we show that LS on the prime results in 0 msec of semantic priming (e.g., swim-float) and 11 msec of O/P priming (e.g., coat-float), both of which are statistically null, whereas the LS semantic+O/P priming effect for primes and targets that do not share a morpheme (e.g., boat-float) is a robust 37 msec. Discussion focuses on the automaticity of semantic activation and whether morphological priming is mediated by (1) a morphemic representation that is separate from semantic representations or (2) activation combined from semantics and orthography/phonology.     

Dissociative effects of phonological vs. semantic associates on recognition memory in the Deese/Roediger-McDermott paradigm

Using a variation of the Deese/Roediger–McDermott paradigm in four experiments, we examined hit rate, false alarm rate, and memory discriminability (d′) for critical items (e.g., sleep) after their semantic associates (e.g., dream, rest, and awake), phonological associates (e.g., bleep, sheep, and cheap) or unrelated items were studied. Replicating previous research (e.g., Neely & Tse, 2007), d′ was lower for critical items than for yoked associates in semantic lists. However, d′ was higher for critical items than for yoked associates in phonological lists, even when the same critical items were used for these two list types. The memory discriminability of critical items was enhanced by phonological lists via a larger increase in their hit rates than in their false alarm rates, relative to the same critical items in lists of unrelated words. These findings (a) could not be fully accounted for by the activation-based theories proposed in the false memory literature, and (b) may suggest that the memory discriminabilities of semantic and phonological lists are modulated by two distinct activation mechanisms.     

With the past behind and the future ahead: Back-to-front representation of past and future sentences

Several studies support the psychological reality of a mental timeline that runs from the left to the right and may strongly affect our thinking about time. Ulrich and Maienborn (Cognition 117:126–138, 2010) examined the linguistic relevance of this timeline during the processing of past- and future-related sentences. Their results indicate that the timeline is not activated automatically during sentence comprehension. While no explicit reference of temporal expressions to the left–right axis has been attested (e.g., *the meeting was moved to the left), natural languages refer to the back–front axis in order to encode temporal information (e.g., the meeting was moved forward). Therefore, the present study examines whether a back–frontal timeline becomes automatically activated during the processing of past- and future-related sentences. The results demonstrate a clear effect on reaction time that emerges from a time–space association along the frontal timeline (Experiment 1). However, this activation seems to be nonautomatic (Experiment 2), rendering it unlikely that this frontal timeline is involved in comprehension of the temporal content of sentences.     

Neuroanatomical distribution of five semantic components of verbs: evidence from fMRI

The Simulation Framework, also known as the Embodied Cognition Framework, maintains that conceptual knowledge is grounded in sensorimotor systems. To test several predictions that this theory makes about the neural substrates of verb meanings, we used functional magnetic resonance imaging (fMRI) to scan subjects' brains while they made semantic judgments involving five classes of verbs-specifically, Running verbs (e.g., run, jog, walk), Speaking verbs (e.g., shout, mumble, whisper), Hitting verbs (e.g., hit, poke, jab), Cutting verbs (e.g., cut, slice, hack), and Change of State verbs (e.g., shatter, smash, crack). These classes were selected because they vary with respect to the presence or absence of five distinct semantic components-specifically, ACTION, MOTION, CONTACT, CHANGE OF STATE, and TOOL USE. Based on the Simulation Framework, we hypothesized that the ACTION component depends on the primary motor and premotor cortices, that the MOTION component depends on the posterolateral temporal cortex, that the CONTACT component depends on the intraparietal sulcus and inferior parietal lobule, that the CHANGE OF STATE component depends on the ventral temporal cortex, and that the TOOL USE component depends on a distributed network of temporal, parietal, and frontal regions. Virtually all of the predictions were confirmed. Taken together, these findings support the Simulation Framework and extend our understanding of the neuroanatomical distribution of different aspects of verb meaning.     

Are individual differences in masked repetition and semantic priming reliable?

Despite the robustness of semantic priming (e.g., cat–DOG), the test-retest and internal reliabilities of semantic priming effects within individuals are surprisingly low. In contrast, repetition priming (e.g., dog–DOG) appears to be far more reliable across a range of conditions. While Stolz and colleagues attribute the low reliability in semantic priming to uncoordinated automatic processes in semantic memory, their use of unmasked priming paradigms makes it difficult to fully rule out the influence of strategic processes. In the present study, we explored the reliability of semantic and repetition priming when primes were heavily masked and cannot be consciously processed. We found that masked repetition, but not semantic, priming effects showed some degree of reliability. Interestingly, skilled lexical processors (as reflected by vocabulary knowledge and spelling ability) also produced larger masked repetition priming effects.     

Redundancy gain for semantic features

In a go/no-go experiment, semantic redundancy gain was assessed for responses to single written words. Specifically, we asked participants to respond only to words whose meaning matched at least one semantic target feature—that is, the target category (e.g., animal), the target color (e.g., gray), or both. On redundant-target trials, the word (e.g., elephant) matched both semantic target features (i.e., gray and animal). On single-target trials, the word (e.g., beaver) matched one target feature (i.e., animal) and a nontarget feature (i.e., brown). We observed shorter reaction times in the redundant-target condition than in the faster single-target condition. Hence, the present study provides the first evidence that redundancy gain is not limited to responses to redundant proximal stimulus features but can also be observed for responses to semantic feature information.     

Well‐Hidden Regularities: Abstract Uses of in and on Retain an Aspect of Their Spatial Meaning

Prepositions name spatial relationships (e.g., book on a table). But they are also used to convey abstract, non‐spatial relationships (e.g., Adrian is on a roll)—raising the question of how the abstract uses relate to the concrete spatial uses. Despite considerable success in delineating these relationships, no general account exists for the two most frequently extended prepositions: in and on. We test the proposal that what is preserved in abstract uses of these prepositions is the relative degree of control between the located object (the figure) and the reference object (the ground). Across four experiments, we find a continuum of greater figure control for on (e.g., Jordan is on a roll) and greater ground control for in (e.g., Casey is in a depression). These findings bear on accounts of semantic structure and language change, as well as on second language instruction.     

The development of morphological representations in young readers: a cross‐modal priming study

The way children organize words in their memory has intrigued many researchers in the past 20 years. Given the large number of morphologically complex words in many languages, the influence of morphemes on this organization is being increasingly examined. The aim of this study was to understand how morphemic information influences English‐speaking children's word recognition. Children in grades 3 and 5 were asked to complete a lexical decision priming task. Prime‐target pairs varied in semantic similarity, with low (e.g., belly‐bell), moderate (e.g., lately‐late), and high similarity relations (e.g., boldly‐bold). There were also word pairs similar in form only (e.g., spinach‐spin) and in semantics only (e.g., garbage‐trash). Primes were auditory and targets were presented visually. Analyses of children's lexical decision times revealed graded priming effects as a function of the convergence of form and meaning. These results indicate that developing readers do not necessarily need to lexicalize morphological units to facilitate word recognition. Their ability to process the morphological structure of words depends on their ability to develop connections between form and meaning.     

Differential prefrontal-temporal neural correlates of semantic processing in children

This study used functional magnetic resonance imaging (fMRI) to examine brain-behavior correlations in a group of 16 children (9- to 12-year-olds). Activation was measured during a semantic judgment task presented in either the visual or auditory modality that required the individual to determine whether a final word was related in meaning to one of two previous words (e.g., found-tank-lost). The main finding was that higher performers (i.e., accuracy) were associated with more activation in posterior representational systems including the inferior and middle temporal gyri, whereas lower performers were associated with more activation in anterior regions including the inferior and middle frontal gyri. This pattern of results was interpreted as reflecting an elaborated semantic representational system in temporal areas for the high accuracy performers that allowed them to efficiently and accurately make meaning based judgments. The low accuracy performers may have an inaccurate or weakly interconnected semantic system that results in greater use of frontal areas in a feature selection process.     

自闭症谱系障碍人群词义加工的脑激活模式：基于fMRI研究的元分析

本研究筛选了11项采用功能性磁共振成像技术探究言语自闭症人群词义加工的研究, 探讨了该人群与典型人群脑激活模式的差异是否具有跨研究的稳定性。结果表明, 差异的脑激活模式稳定存在, 且表现为主要涉及左额上回的典型脑区激活不足。该结果为言语ASD人群语言加工的神经机制提供了来自词义加工的跨研究激活证据, 在明确“减弱的额叶激活”这一稳定差异表现的基础上, 强调了针对不同语言加工任务开展元分析研究的必要性。     

Functional magnetic resonance imaging activation in response to prompts of romantically disillusioning events

To differentiate romantic disillusionment from similar constructs of dissatisfaction and regret, functional Magnetic Resonance Imaging (fMRI) data obtained when romantically involved individuals (N = 39) were reminded of relationship events representing these emotions were analyzed. Whole‐brain activations suggested disillusionment‐linked processes not observed for dissatisfaction or regret. Compared to dissatisfying events, disillusioning ones showed greater activity in regions pertaining to evaluation, reflection, and reconciling conflicting information (e.g., anterior cingulate cortex). No regions showed significantly more activation for dissatisfying than disillusioning events. Compared to regret‐inducing events, disillusioning events showed greater activation in areas thought pertinent to detail processing and decision making (occipital fusiform and lingual gyrus). Regret‐inducing events activated regions suggesting the planning and thoughts of how one could have acted differently (e.g., prefrontal cortex).     

The Role of Sentence Context in Accessing Partial Knowledge of Word Meanings

Two experiments are reported that test the hypothesis that a reader can make use of the size of the semantic domain activated by a sentence context when inferring the meaning of a partially known word. We investigated words at three levels of knowledge: known, frontier, and unknown (e.g., Durso & Shore, 1991). Experiment I demonstrated that participants have knowledge about the meanings of words that they deny are part of the language (the unknown level), and that they make use of relative differences in the size of the semantic domains tapped by two sentences when asked to decide on correct usage of these unknown words. Experiment 2 demonstrated that participants have knowledge about the general semantic constraints operating on their unknown words, even when relative differences in size of semantic domains are controlled. Implications for the role of contextual constraints in vocabulary acquisition are discussed.