Semantic Decision Task Research Articles

Inferior Longitudinal Fasciculus' Role in Visual Processing and Language Comprehension: A Combined MEG-DTI Study.

The inferior longitudinal fasciculus (ILF) is a white matter tract that connects the occipital and the temporal lobes. ILF abnormalities have been associated with deficits in visual processing and language comprehension in dementia patients, thus suggesting that its integrity is important for semantic processing. However, it remains elusive whether ILF microstructural organization per se impacts the visual semantic processing efficiency in the healthy brain. The present study aims to investigate whether there is an association between ILF’s microstructural organization and visual semantic processing at the individual level. We hypothesized that the efficiency of visual semantic processing positively correlates with the degree of anisotropy of the ILF. We studied 10 healthy right-handed subjects. We determined fractional anisotropy (FA) of the ILF using diffusion tensor imaging (DTI). We extracted N400m latency and amplitude from magnetoencephalography (MEG) signals during a visual semantic decision task. N400m and mean FA of the ILF were left lateralized with the higher FA value in the left hemisphere. Inter-individual analysis showed that FA of the ILF negatively correlated with the N400m latency and amplitude, which suggests that high ILF anisotropy is associated with more efficient semantic processing. In summary, our findings provide supporting evidence for a role of the ILF in language comprehension.

Action Semantic Deficits and Impaired Motor Skills in Autistic Adults Without Intellectual Impairment.

Several studies indicate the functional importance of the motor cortex for higher cognition, language and semantic processing, and place the neural substrate of these processes in sensorimotor action-perception circuits linking motor, sensory and perisylvian language regions. Interestingly, in individuals with autism spectrum disorder (ASD), semantic processing of action and emotion words seems to be impaired and is associated with hypoactivity of the motor cortex during semantic processing. In this study, the relationship between semantic processing, fine motor skills and clinical symptoms was investigated in 19 individuals with ASD and 22 typically-developing matched controls. Participants completed two semantic decision tasks involving words from different semantic categories, a test of alexithymia (the Toronto Alexithymia Scale), and a test of fine motor skills (the Purdue Pegboard Test). A significant Group × Word Category interaction in accuracy (p < 0.05) demonstrated impaired semantic processing for action words, but not object words in the autistic group. There was no significant group difference when processing abstract emotional words or abstract neutral words. Moreover, our study revealed deficits in fine motor skills as well as evidence for alexithymia in the ASD group, but not in neurotypical controls. However, these motor deficits did not correlate significantly with impairments in action-semantic processing. We interpret the data in terms of an underlying dysfunction of the action-perception system in ASD and its specific impact on semantic language processing.

The cost of learning new meanings for familiar words

ABSTRACTResearch has shown that adults are skilled at learning new words and meanings. We examined whether learning new meanings for familiar words affects the processing of their existing meanings. Adults learnt fictitious meanings for previously unambiguous words over four consecutive days. We tested comprehension of existing meanings using a semantic relatedness decision task in which the probe word was related to the existing but not the new meaning. Following the training, responses were slower to the trained, but not to the untrained, words, indicating competition between newly-acquired and well-established meanings. This effect was smaller for meanings that were semantically related to existing meanings than for the unrelated counterparts, demonstrating that meaning relatedness modulates the degree of competition. Overall, the findings confirm that new meanings can be integrated into the mental lexicon after just a few days’ exposure, and provide support for current models of ambiguity processing.

How Action Context Modulates the Action-Language Relationship: A Topographic ERP Analysis.

The aim of the present study was to investigate how the context in which an action is presented could modulate the effect of action observation on language processing, an effect that is classically observed in the literature. To address this question, we recorded both behavioral (reaction times) and electrophysiological measures (event-related potentials) of participants performing a semantic decision task involving a verb describing an action that was congruent or incongruent with the action presented in a prime picture that had been observed. The prime picture presented an action performed in a usual or an unusual context. The results revealed different behavioral and topographical pattern responses according to the context in which an action is presented. Importantly, only in the usual context, the congruency between the prime picture and the verb stimulus facilitated the semantic processes, leading to shorter response times in this condition compared to the others. Moreover, the topographic analysis revealed that this facilitation was related to reduced processing times for the semantic access to the verb and for the motor preparation for the answer. Taken together, these findings demonstrate that the context of an action is crucial in the link between action and language.

Does watching Han Solo or C-3PO similarly influence our language processing?

Several studies have demonstrated that perceiving an action influences the subsequent processing of action verbs. However, which characteristics of the perceived action are truly determinant to enable this influence is still unknown. The current study investigated the role of the agent executing an action in this action-language relationship. Participants performed a semantic decision task after seeing a video of a human or a robot performing an action. The results of the first study showed that perceiving a human being executing an action as well as perceiving a robot facilitate subsequent language processing, suggesting that the humanness (The term "humanness" is used as meaning "belonging to human race" and not to refer to a personal quality) of the agent is not crucial in the link between action and language. However, this experiment was conducted with Japanese people who are very familiar with robots; thus, an alternative explanation could be that it is the unfamiliarity with the agent that could perturb the action-language relationship. To assess this hypothesis, we carried out two additional experiments with French participants. The results of the second study showed that, unlike the observation of a human agent, the observation of a robot did not influence language processing. Finally, the results of the third study showed that, after a familiarization phase, French participants too were influenced by the observation of a robot. Overall, the outcomes of these studies indicate that, more than the humanness of the agent, it is the familiarity which we have with this agent that is crucial in the action-language relationship.

Proficiency affects intra- and inter-regional patterns of language control in second language processing

ABSTRACTThis study examines the use of cognitive control during second language (L2) processing by adult language learners. Although cognitive control has been acknowledged as an important component of language processing for years, its conception was as a top-down mechanism of inhibition. Our functional MRI study investigated the correlates of both top-down and bottom-up control as well as semantic decision-making in a group of Spanish learners who varied in proficiency. We observed that multivariate activity patterns were better classified in high proficiency learners during the semantic decision task in regions associated with both top-down and bottom-up control. Additionally, we found that connectivity between these control regions was more organised in high than in low proficiency learners. These findings provide support for the relevance of the distinction between top-down and bottom-up control to language learning. The implications of this distinction are discussed with respect to the current theories of L2 acquisition.

Theta/delta coupling across cortical laminae contributes to semantic cognition

Rhythmic activity in populations of neurons is associated with cognitive and motor function. Our understanding of the neuronal mechanisms underlying these core brain functions has benefitted from demonstrations of cellular, synaptic, and network phenomena, leading to the generation of discrete rhythms at the local network level. However, discrete frequencies of rhythmic activity rarely occur alone. Despite this, little is known about why multiple rhythms are generated together or what mechanisms underlie their interaction to promote brain function. One overarching theory is that different temporal scales of rhythmic activity correspond to communication between brain regions separated by different spatial scales. To test this, we quantified the cross-frequency interactions between two dominant rhythms-theta and delta activity-manifested during magnetoencephalography recordings of subjects performing a word-pair semantic decision task. Semantic processing has been suggested to involve the formation of functional links between anatomically disparate neuronal populations over a range of spatial scales, and a distributed network was manifest in the profile of theta-delta coupling seen. Furthermore, differences in the pattern of theta-delta coupling significantly correlated with semantic outcome. Using an established experimental model of concurrent delta and theta rhythms in neocortex, we show that these outcome-dependent dynamics could be reproduced in a manner determined by the strength of cholinergic neuromodulation. Theta-delta coupling correlated with discrete neuronal activity motifs segregated by the cortical layer, neuronal intrinsic properties, and long-range axonal targets. Thus, the model suggested that local, interlaminar neocortical theta-delta coupling may serve to coordinate both cortico-cortical and cortico-subcortical computations during distributed network activity. NEW & NOTEWORTHY Here, we show, for the first time, that a network of spatially distributed brain regions can be revealed by cross-frequency coupling between delta and theta frequencies in subjects using magnetoencephalography recording during a semantic decision task. A biological model of this cross-frequency coupling suggested an interlaminar, cell-specific division of labor within the neocortex may serve to route the flow of cortico-cortical and cortico-subcortical information to promote such spatially distributed, functional networks.

A lesion and connectivity-based hierarchical model of chronic aphasia recovery dissociates patients and healthy controls.

Traditional models of left hemisphere stroke recovery propose that reactivation of remaining ipsilesional tissue is optimal for language processing whereas reliance on contralesional right hemisphere homologues is less beneficial or possibly maladaptive in the chronic recovery stage. However, neuroimaging evidence for this proposal is mixed. This study aimed to elucidate patterns of effective connectivity in patients with chronic aphasia in light of healthy control connectivity patterns and in relation to damaged tissue within left hemisphere regions of interest and according to performance on a semantic decision task. Using fMRI and dynamic causal modeling, biologically-plausible models within four model families were created to correspond to potential neural recovery patterns, including Family A: Left-lateralized connectivity (i.e., no/minimal damage), Family B: Bilateral anterior-weighted connectivity (i.e., posterior damage), Family C: Bilateral posterior-weighted connectivity (i.e., anterior damage) and Family D: Right-lateralized connectivity (i.e., extensive damage). Controls exhibited a strong preference for left-lateralized network models (Family A) whereas patients demonstrated a split preference for Families A and C. At the level of connections, controls exhibited stronger left intrahemispheric task-modulated connections than did patients. Within the patient group, damage to left superior frontal structures resulted in greater right intrahemispheric connectivity whereas damage to left ventral structures resulted in heightened modulation of left frontal regions. Lesion metrics best predicted accuracy on the fMRI task and aphasia severity whereas left intrahemispheric connectivity predicted fMRI task reaction times. These results are discussed within the context of the hierarchical recovery model of chronic aphasia.

The Differences in Semantic Processing of Pictures and Words between Dyslexic and Typical-Reading University Students

The present study compared the semantic processing of pictures and words by dyslexics to that of typical readers utilizing the electro-physiological (ERP) technique during a semantic categorization decision task. ERPs of 40 university students, 20 typical readers and 20 dyslexic readers were recorded while they participated in a categorization decision task. The subjects were presented with two kinds of stimuli—words and pictures. Results revealed longer reaction times in response to words as compared to pictures in both groups. Electrophysiological measures revealed differences in amplitudes and latencies of ERP components in addition to differences in the mean activity. The results illustrated that the differences between processing words and processing pictures were manifested in timing and in the brain areas involved in the tasks. It also illustrated that although dyslexic and typical readers displayed equal ability to read and understand familiar words, dyslexics could not perform as quickly as typical readers. The semantic domain may be one of the compensatory mechanisms which help compensated dyslexic readers reach and succeed in the higher education system.

Quantifying sensorimotor experience: Body-object interaction ratings for more than 9,000 English words.

Ratings of body-object interaction (BOI) measure the ease with which the human body can interact with a word's referent. Researchers have studied the effects of BOI in order to investigate the relationships between sensorimotor and cognitive processes. Such efforts could be improved, however, by the availability of more extensive BOI norms. In the present work, we collected BOI ratings for over 9,000 words. These new norms show good reliability and validity and have extensive overlap with the words used both in other lexical and semantic norms and in the available behavioral megastudies (e.g., the English Lexicon Project, Balota, Yap, Cortese, Hutchison, Kessler, & Loftis in Behavior Research Methods, 39, 445-459, 2007; and the Calgary Semantic Decision Project, Pexman, Heard, Lloyd, & Yap in Behavior Research Methods, 49, 407-417, 2017). In analyses using the new BOI norms, we found that high-BOI words tended to be more concrete, more graspable, and more strongly associated with sensory, haptic, and visual experience than are low-BOI words. When we used the new norms to predict response latencies and accuracy data from the behavioral megastudies, we found that BOI was a stronger predictor of responses in the semantic decision task than in the lexical decision task. These findings are consistent with a dynamic, multidimensional account of lexical semantics. The norms described here should be useful for future research examining the effects of sensorimotor experience on performance in tasks involving word stimuli.

The kinematics, not the orientation, of an action influences language processing.

Consistent with the embodied view of cognition, several studies have shown a link between action and the processing of action verbs. However, it is largely unknown how action properties can influence semantic activation during word processing. On the basis of the observation of point-light display (PLDs), the present study addressed this issue. Through four experiments, we assessed whether kinematics and orientation, which are two crucial characteristics of human action, can influence the link between action and language. Participants performed a semantic decision task involving action and nonaction verbs after seeing a PLD representing either a biological or a nonbiological human movement, the kinematics (Experiments 1 and 2) or orientation (Experiment 3) of which was modified. Experiment 1 showed that important modifications to the kinematics of actions have a direct influence on the link between action and language. Experiment 2 confirmed this effect and showed that the effect is somatotopic because only modifications to the relevant part of actions affected the link between action and language. In contrast, Experiment 3 showed that modifying the orientation did not disturb the influence of an action on language probably due to the use of a mental rotation strategy. Experiment 4 confirmed this view by demonstrating the use of mental rotation when participants have to recognize rotated point-light actions. These outcomes shed light on how action properties can influence action verbs processing, a crucial step to better understanding the link between action and language. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Weaker semantic language lateralization associated with better semantic language performance in healthy right-handed children.

IntroductionThe relationship between language abilities and language lateralization in the developing brain is important for our understanding of the neural architecture of language development.MethodsWe investigated 35 right‐handed children and adolescents aged 7–16 years with a functional magnetic resonance imaging language paradigm and a comprehensive language and verbal memory examination.ResultsWe found that less lateralized language was significantly correlated with better language performance across areas of the brain and across different language tasks. Less lateralized language in the overall brain was associated with better in‐scanner task accuracy on a semantic language decision task and out‐of‐scanner vocabulary and verbal fluency. Specifically, less lateralized frontal lobe language dominance was associated with better in‐scanner task accuracy and out‐of‐scanner verbal fluency. Furthermore, less lateralized parietal language was associated with better out‐of‐scanner verbal memory across learning, short‐ and long‐delay trials. In contrast, we did not find any relationship between temporal lobe language laterality and verbal performance.ConclusionsThis study suggests that semantic language performance is better with some involvement of the nondominant hemisphere.

Modeling the Structure and Dynamics of Semantic Processing.

The contents and structure of semantic memory have been the focus of much recent research, with major advances in the development of distributional models, which use word co‐occurrence information as a window into the semantics of language. In parallel, connectionist modeling has extended our knowledge of the processes engaged in semantic activation. However, these two lines of investigation have rarely been brought together. Here, we describe a processing model based on distributional semantics in which activation spreads throughout a semantic network, as dictated by the patterns of semantic similarity between words. We show that the activation profile of the network, measured at various time points, can successfully account for response times in lexical and semantic decision tasks, as well as for subjective concreteness and imageability ratings. We also show that the dynamics of the network is predictive of performance in relational semantic tasks, such as similarity/relatedness rating. Our results indicate that bringing together distributional semantic networks and spreading of activation provides a good fit to both automatic lexical processing (as indexed by lexical and semantic decisions) as well as more deliberate processing (as indexed by ratings), above and beyond what has been reported for previous models that take into account only similarity resulting from network structure.

Left frontotemporal effective connectivity during semantic feature judgments in patients with chronic aphasia and age-matched healthy controls

Traditional models of neural reorganization of language skills in patients with chronic stroke-induced aphasia (PWA) propose activation of reperfused or spared left hemisphere tissue results in the most favorable language outcomes. However, these models do not fully explain variable behavioral recovery patterns observed in chronic patients. Instead, investigation of connectivity patterns of critical network nodes may elucidate better-informed recovery models. In the present study, we combined fMRI and dynamic causal modeling (DCM) to examine effective connectivity of a simple three-node left hemisphere network during a semantic feature decision task in 25 PWA and 18 age-matched neurologically intact healthy controls. The DCM model space utilized in Meier, Kapse, & Kiran (2016), which was organized according to exogenous input to one of three regions (i.e., left inferior frontal gyrus, pars triangularis [LIFGtri], left posterior middle temporal gyrus [LpMTG], or left middle frontal gyrus [LMFG]) implicated in various levels of lexical-semantic processing, was interrogated. This model space included all possible combinations of uni- and bidirectional task-modulated connections between LIFGtri, LMFG and LpMTG, resulting in 72 individual models that were partitioned into three separate families (i.e., Family #1: Input to LIFGtri, Family #2: Input to LMFG, Family #3: Input to LpMTG). Family-wise Bayesian model selection revealed Family #2: Input to LMFG best fit both patient and control data at a group level. Both groups relied heavily on LMFG's modulation of the other two model regions. By contrast, between-group differences in task-modulated coupling of LIFGtri and LpMTG were observed. Within the patient group, the strength of activity in LIFGtri and connectivity of LpMTG → LIFGtri were positively associated with lexical-semantic abilities inside and outside of the scanner, whereas greater recruitment of LpMTG was associated with poorer lexical-semantic skills.

Lexical learning in a new language leads to neural pattern similarity with word reading in native language.

Previous neuroimaging studies have suggested similar neural activations for word reading in native and second languages. However, such similarities were qualitatively determined (i.e., overlapping activation based on traditional univariate activation analysis). In this study, using representational similarity analysis and an artificial language training paradigm, we quantitatively computed cross-language neural pattern similarity to examine the modulatory effect of proficiency in the new language. Twenty-four native Chinese speakers were trained to learn 30 words in a logographic artificial language for 12 days and scanned while performing a semantic decision task after 4-day training and after 12-day training. Results showed that higher proficiency in the new language was associated with higher cross-language pattern similarity in select regions of the reading network.

When context modulates the influence of action observation on language processing.

Numerous studies in the field of embodied cognition have shown a crosstalk between language and sensorimotor processes. In particular, it has been demonstrated that perceiving an action influences subsequent language processing. However, when studying the effect of action observation on language processing it has not been considered whether the context of action presentation could modulate this influence. To test this assumption, the participants in our study observed a prime, specifically a cartoon picture of a person performing an action in either a usual or an unusual context, and then had to perform a semantic decision task involving action verbs that could be congruent or incongruent with the action in the prime. Data analyses showed a significant difference on response times for congruent action verbs compared with incongruent action verbs in the usual context, whereas no difference was observed in the unusual context. This finding indicates that the influence of action observation on language appears only with usual actions, suggesting that the context of action presentation is crucial to enable the influence of action observation on action verbs processing.

PB7. Comparison of three different fMRI paradigms for language mapping

Objective Functional magnetic resonance imaging (fMRI) is widely used for mapping of language areas. However, depending on the task design and the region of interest, a clear identification of language relevant areas can be challenging. We, therefore, compared three different fMRI task designs, i.e., picture naming and listening to simple vs. complex sentences followed by a non-verbal semantic decision task, for delineating cortical language areas. Methods 20 right-handed, healthy volunteers were investigated using fMRI (3T) with a sparse-sampling design (controlling for speech-related movement artefacts). In the first task, subjects were asked to name objects which were presented as black-white drawings by speaking out loudly a whole sentence introduced by the phrase ‘That is a/an…’. In the other paradigms, subjects were listening to simple or complex sentences (spoken by a male or female voice) followed by a semantic decision task. Here, three pictures were presented 5s after the sentences and subjects were asked to choose the corresponding item via button press. FMRI activation levels corresponding to the semantic decision after listening to meaningful sentences were compared to a control condition (i.e., listening to reverse sentences). fMRI data were analyzed using SPM12. Results The three language tasks differently activated regions engaged in the language network. Of note, listening to complex sentences led to a significantly higher activation during the semantic decision within the inferior frontal gyrus (IFG) as compared to simple sentences (p Conclusion Our results show that the activation of language-relevant areas depends strongly on the design of the fMRI task and indicate that activation within Broca’s area (IFG) increases with the complexity of the semantic decision.

Assessing neglect dyslexia: Usefulness of a computerized procedure

The neglect syndrome is frequently associated with neglect dyslexia (ND). ND is characterized by omissions or misread initial letters of words. In clinical settings, ND is usually assessed with “paper and pencil” tests. However, without controlling exposure time of items and patients’ response time, ND could be unnoticed. Our computerized procedure consists of four tasks: a single word reading task, a lexical and a semantic decision task and a text reading task. In each task, the time exposure of the items is controlled and we measured both the errors and the participants’ response time. Twenty-eight brain-damaged patients, including 12 neglect patients, and 30 healthy neurological participants carried out this procedure. As expected, neglect patients produced more errors and are slower than brain-damaged patients and healthy volunteers and this especially during the single word reading task. This task shows 256 items: pseudo-words mixed with words (frequent or not, long or short) displaying in different ways (horizontal, vertical without anisometry or with a left or a right anisometry) with or without a spatial index. All this materiel permits error patterns to emerge according to the clinical state (neglect patients, brain-damaged patients or neurological healthy volunteers). Our study aimed at proposing computerized tasks to help the diagnostic of neglect dyslexia. The neglect dyslexia could be observed with or without a severe neglect syndrome. In the case of a light neglect syndrome, having a computerized assessment is important in the ND diagnostic process especially as specific pattern have been observed based on the analyses of the error and the response time in the single word reading task.

Can a lexical decision task predict efficiency in the judgment of ambiguous sentences?

The lexicon plays a fundamental role in reading, but little is known about how it influences reading efficiency. Thus, this study seeks to identify which lexical factors in a lexical decision task are relevant in a semantic decision test. A total of 33 university students were recruited to perform a lexical decision task and a semantic decision task. The results revealed differences between the three types of words in the lexical decision task for all measures, but only in the regressive saccades for the semantic decision task. Ambiguous sentences triggered fewer regressions than sentences related to objects. The only lexical measure found to predict efficiency was average time on regular words, which predicted 24% of the efficiency. We discuss the implications of the use of a lexical decision task and the use of the inverse efficiency score as a semantic measure, and we discuss how the lexicon can predict semantic comprehension.

On understanding creative language: The late positive complex and novel metaphor comprehension

Novel metaphoric sentences have repeatedly evoked larger N400 amplitudes than literal sentences, while investigations of the late positive complex (LPC) have brought inconsistent results, with reports of both increased and reduced amplitudes. In two experiments, we examined novel metaphor comprehension in Polish, using the same set of literal, novel metaphoric, and anomalous sentences. The first aim of the study was to test whether novel metaphors would evoke larger or smaller late positivity complex (LPC) amplitudes compared to literal and anomalous sentences. Some earlier studies have shown that whether increased LPC amplitudes are observed or not may be related to the task participants are asked to perform, with explicit acceptability judgments being more likely to evoke the LPC effect. The second aim of the study was, thus, to test whether the observed LPC pattern would be the same across two tasks, the semantic decision task (Experiment 1) and the reading task (Experiment 2). Our results replicated the N400 effect observed in earlier studies on metaphor in both experiments. Most importantly, a reduction in late positivity to novel metaphors relative to anomalous sentences was found in both experiments. Additionally, this difference was broadly distributed over parietal sites in Experiment 1, and clearly left-lateralized in Experiment 2, which might imply differences in the involvement of recollection and semantic processes. Overall, these results seem to indicate that both conventionality and task demands modulate the LPC pattern.