Listening to Puns Elicits the Co-Activation of Alternative Homophone Meanings during Language Production

Recent evidence suggests that lexical-semantic activation spread during language production can be dynamically shaped by contextual factors. In this study we investigated whether semantic processing modes can also affect lexical-semantic activation during word production. Specifically, we tested whether the processing of linguistic ambiguities, presented in the form of puns, has an influence on the co-activation of unrelated meanings of homophones in a subsequent language production task. In a picture-word interference paradigm with word distractors that were semantically related or unrelated to the non-depicted meanings of homophones we found facilitation induced by related words only when participants listened to puns before object naming, but not when they heard jokes with unambiguous linguistic stimuli. This finding suggests that a semantic processing mode of ambiguity perception can induce the co-activation of alternative homophone meanings during speech planning.     

Cerebral Activations Related to Writing and Drawing with Each Hand

BackgroundWriting is a sequential motor action based on sensorimotor integration in visuospatial and linguistic functional domains. To test the hypothesis of lateralized circuitry concerning spatial and language components involved in such action, we employed an fMRI paradigm including writing and drawing with each hand. In this way, writing-related contributions of dorsal and ventral premotor regions in each hemisphere were assessed, together with effects in wider distributed circuitry. Given a right-hemisphere dominance for spatial action, right dorsal premotor cortex dominance was expected in left-hand writing while dominance of the left ventral premotor cortex was expected during right-hand writing.MethodsSixteen healthy right-handed subjects were scanned during audition-guided writing of short sentences and simple figure drawing without visual feedback. Tapping with a pencil served as a basic control task for the two higher-order motor conditions. Activation differences were assessed with Statistical Parametric Mapping (SPM).ResultsWriting and drawing showed parietal-premotor and posterior inferior temporal activations in both hemispheres when compared to tapping. Drawing activations were rather symmetrical for each hand. Activations in left- and right-hand writing were left-hemisphere dominant, while right dorsal premotor activation only occurred in left-hand writing, supporting a spatial motor contribution of particularly the right hemisphere. Writing contrasted to drawing revealed left-sided activations in the dorsal and ventral premotor cortex, Broca’s area, pre-Supplementary Motor Area and posterior middle and inferior temporal gyri, without parietal activation.DiscussionThe audition-driven postero-inferior temporal activations indicated retrieval of virtual visual form characteristics in writing and drawing, with additional activation concerning word form in the left hemisphere. Similar parietal processing in writing and drawing pointed at a common mechanism by which such visually formatted information is used for subsequent sensorimotor integration along a dorsal visuomotor pathway. In this, the left posterior middle temporal gyrus subserves phonological-orthographical conversion, dissociating dorsal parietal-premotor circuitry from perisylvian circuitry including Broca''s area.     

Effects of TMS on Different Stages of Motor and Non-Motor Verb Processing in the Primary Motor Cortex

The embodied cognition hypothesis suggests that motor and premotor areas are automatically and necessarily involved in understanding action language, as word conceptual representations are embodied. This transcranial magnetic stimulation (TMS) study explores the role of the left primary motor cortex in action-verb processing. TMS-induced motor-evoked potentials from right-hand muscles were recorded as a measure of M1 activity, while participants were asked either to judge explicitly whether a verb was action-related (semantic task) or to decide on the number of syllables in a verb (syllabic task). TMS was applied in three different experiments at 170, 350 and 500 ms post-stimulus during both tasks to identify when the enhancement of M1 activity occurred during word processing. The delays between stimulus onset and magnetic stimulation were consistent with electrophysiological studies, suggesting that word recognition can be differentiated into early (within 200 ms) and late (within 400 ms) lexical-semantic stages, and post-conceptual stages. Reaction times and accuracy were recorded to measure the extent to which the participants'' linguistic performance was affected by the interference of TMS with M1 activity. No enhancement of M1 activity specific for action verbs was found at 170 and 350 ms post-stimulus, when lexical-semantic processes are presumed to occur (Experiments 1–2). When TMS was applied at 500 ms post-stimulus (Experiment 3), processing action verbs, compared with non-action verbs, increased the M1-activity in the semantic task and decreased it in the syllabic task. This effect was specific for hand-action verbs and was not observed for action-verbs related to other body parts. Neither accuracy nor RTs were affected by TMS. These findings suggest that the lexical-semantic processing of action verbs does not automatically activate the M1. This area seems to be rather involved in post-conceptual processing that follows the retrieval of motor representations, its activity being modulated (facilitated or inhibited), in a top-down manner, by the specific demand of the task.     

Shared Brain Lateralization Patterns in Language and Acheulean Stone Tool Production: A Functional Transcranial Doppler Ultrasound Study

Background

The popular theory that complex tool-making and language co-evolved in the human lineage rests on the hypothesis that both skills share underlying brain processes and systems. However, language and stone tool-making have so far only been studied separately using a range of neuroimaging techniques and diverse paradigms.

Methodology/Principal Findings

We present the first-ever study of brain activation that directly compares active Acheulean tool-making and language. Using functional transcranial Doppler ultrasonography (fTCD), we measured brain blood flow lateralization patterns (hemodynamics) in subjects who performed two tasks designed to isolate the planning component of Acheulean stone tool-making and cued word generation as a language task. We show highly correlated hemodynamics in the initial 10 seconds of task execution.

Conclusions/Significance

Stone tool-making and cued word generation cause common cerebral blood flow lateralization signatures in our participants. This is consistent with a shared neural substrate for prehistoric stone tool-making and language, and is compatible with language evolution theories that posit a co-evolution of language and manual praxis. In turn, our results support the hypothesis that aspects of language might have emerged as early as 1.75 million years ago, with the start of Acheulean technology.     

Spatial language processing in the blind: evidence for a supramodal representation and cortical reorganization

Neuropsychological and imaging studies have shown that the left supramarginal gyrus (SMG) is specifically involved in processing spatial terms (e.g. above, left of), which locate places and objects in the world. The current fMRI study focused on the nature and specificity of representing spatial language in the left SMG by combining behavioral and neuronal activation data in blind and sighted individuals. Data from the blind provide an elegant way to test the supramodal representation hypothesis, i.e. abstract codes representing spatial relations yielding no activation differences between blind and sighted. Indeed, the left SMG was activated during spatial language processing in both blind and sighted individuals implying a supramodal representation of spatial and other dimensional relations which does not require visual experience to develop. However, in the absence of vision functional reorganization of the visual cortex is known to take place. An important consideration with respect to our finding is the amount of functional reorganization during language processing in our blind participants. Therefore, the participants also performed a verb generation task. We observed that only in the blind occipital areas were activated during covert language generation. Additionally, in the first task there was functional reorganization observed for processing language with a high linguistic load. As the visual cortex was not specifically active for spatial contents in the first task, and no reorganization was observed in the SMG, the latter finding further supports the notion that the left SMG is the main node for a supramodal representation of verbal spatial relations.     

Interference between sentence processing and probabilistic implicit sequence learning

Background

During sentence processing we decode the sequential combination of words, phrases or sentences according to previously learned rules. The computational mechanisms and neural correlates of these rules are still much debated. Other key issue is whether sentence processing solely relies on language-specific mechanisms or is it also governed by domain-general principles.

Methodology/Principal Findings

In the present study, we investigated the relationship between sentence processing and implicit sequence learning in a dual-task paradigm in which the primary task was a non-linguistic task (Alternating Serial Reaction Time Task for measuring probabilistic implicit sequence learning), while the secondary task were a sentence comprehension task relying on syntactic processing. We used two control conditions: a non-linguistic one (math condition) and a linguistic task (word processing task). Here we show that the sentence processing interfered with the probabilistic implicit sequence learning task, while the other two tasks did not produce a similar effect.

Conclusions/Significance

Our findings suggest that operations during sentence processing utilize resources underlying non-domain-specific probabilistic procedural learning. Furthermore, it provides a bridge between two competitive frameworks of language processing. It appears that procedural and statistical models of language are not mutually exclusive, particularly for sentence processing. These results show that the implicit procedural system is engaged in sentence processing, but on a mechanism level, language might still be based on statistical computations.     

Suggestion-Induced Modulation of Semantic Priming during Functional Magnetic Resonance Imaging

Using functional magnetic resonance imaging during a primed visual lexical decision task, we investigated the neural and functional mechanisms underlying modulations of semantic word processing through hypnotic suggestions aimed at altering lexical processing of primes. The priming task was to discriminate between target words and pseudowords presented 200 ms after the prime word which was semantically related or unrelated to the target. In a counterbalanced study design, each participant performed the task once at normal wakefulness and once after the administration of hypnotic suggestions to perceive the prime as a meaningless symbol of a foreign language. Neural correlates of priming were defined as significantly lower activations upon semantically related compared to unrelated trials. We found significant suggestive treatment-induced reductions in neural priming, albeit irrespective of the degree of suggestibility. Neural priming was attenuated upon suggestive treatment compared with normal wakefulness in brain regions supporting automatic (fusiform gyrus) and controlled semantic processing (superior and middle temporal gyri, pre- and postcentral gyri, and supplementary motor area). Hence, suggestions reduced semantic word processing by conjointly dampening both automatic and strategic semantic processes.     

Effects of Early Bilingual Experience with a Tone and a Non-Tone Language on Speech-Music Integration

We investigated music and language processing in a group of early bilinguals who spoke a tone language and a non-tone language (Cantonese and Dutch). We assessed online speech-music processing interactions, that is, interactions that occur when speech and music are processed simultaneously in songs, with a speeded classification task. In this task, participants judged sung pseudowords either musically (based on the direction of the musical interval) or phonologically (based on the identity of the sung vowel). We also assessed longer-term effects of linguistic experience on musical ability, that is, the influence of extensive prior experience with language when processing music. These effects were assessed with a task in which participants had to learn to identify musical intervals and with four pitch-perception tasks. Our hypothesis was that due to their experience in two different languages using lexical versus intonational tone, the early Cantonese-Dutch bilinguals would outperform the Dutch control participants. In online processing, the Cantonese-Dutch bilinguals processed speech and music more holistically than controls. This effect seems to be driven by experience with a tone language, in which integration of segmental and pitch information is fundamental. Regarding longer-term effects of linguistic experience, we found no evidence for a bilingual advantage in either the music-interval learning task or the pitch-perception tasks. Together, these results suggest that being a Cantonese-Dutch bilingual does not have any measurable longer-term effects on pitch and music processing, but does have consequences for how speech and music are processed jointly.     

Mechanism of case processing in the brain: an FMRI study

In sentence comprehension research, the case system, which is one of the subsystems of the language processing system, has been assumed to play a crucial role in signifying relationships in sentences between noun phrases (NPs) and other elements, such as verbs, prepositions, nouns, and tense. However, so far, less attention has been paid to the question of how cases are processed in our brain. To this end, the current study used fMRI and scanned the brain activity of 15 native English speakers during an English-case processing task. The results showed that, while the processing of all cases activates the left inferior frontal gyrus and posterior part of the middle temporal gyrus, genitive case processing activates these two regions more than nominative and accusative case processing. Since the effect of the difference in behavioral performance among these three cases is excluded from brain activation data, the observed different brain activations would be due to the different processing patterns among the cases, indicating that cases are processed differently in our brains. The different brain activations between genitive case processing and nominative/accusative case processing may be due to the difference in structural complexity between them.     

Activation in a frontoparietal cortical network underlies individual differences in the performance of an embedded figures task

The Embedded Figures Test (EFT) requires observers to search for a simple geometric shape hidden inside a more complex figure. Surprisingly, performance in the EFT is negatively correlated with susceptibility to illusions of spatial orientation, such as the Roelofs effect. Using fMRI, we previously demonstrated that regions in parietal cortex are involved in the contextual processing associated with the Roelofs task. In the present study, we found that similar parietal regions (superior parietal cortex and precuneus) were more active during the EFT than during a simple matching task. Importantly, these parietal activations overlapped with regions found to be involved during contextual processing in the Roelofs illusion. Additional parietal and frontal areas, in the right hemisphere, showed strong correlations between brain activity and behavioral performance during the search task. We propose that the posterior parietal regions are necessary for processing contextual information across many different, but related visuospatial tasks, with additional parietal and frontal regions serving to coordinate this processing in participants proficient in the task.     

Grip Force Reveals the Context Sensitivity of Language-Induced Motor Activity during “Action Words” Processing: Evidence from Sentential Negation

Background

Studies demonstrating the involvement of motor brain structures in language processing typically focus on time windows beyond the latencies of lexical-semantic access. Consequently, such studies remain inconclusive regarding whether motor brain structures are recruited directly in language processing or through post-linguistic conceptual imagery. In the present study, we introduce a grip-force sensor that allows online measurements of language-induced motor activity during sentence listening. We use this tool to investigate whether language-induced motor activity remains constant or is modulated in negative, as opposed to affirmative, linguistic contexts.

Methodology/Principal Findings

Participants listened to spoken action target words in either affirmative or negative sentences while holding a sensor in a precision grip. The participants were asked to count the sentences containing the name of a country to ensure attention. The grip force signal was recorded continuously. The action words elicited an automatic and significant enhancement of the grip force starting at approximately 300 ms after target word onset in affirmative sentences; however, no comparable grip force modulation was observed when these action words occurred in negative contexts.

Conclusions/Significance

Our findings demonstrate that this simple experimental paradigm can be used to study the online crosstalk between language and the motor systems in an ecological and economical manner. Our data further confirm that the motor brain structures that can be called upon during action word processing are not mandatorily involved; the crosstalk is asymmetrically governed by the linguistic context and not vice versa.     

Distinct Effects of Memory Retrieval and Articulatory Preparation when Learning and Accessing New Word Forms

Temporal and frontal activations have been implicated in learning of novel word forms, but their specific roles remain poorly understood. The present magnetoencephalography (MEG) study examines the roles of these areas in processing newly-established word form representations. The cortical effects related to acquiring new phonological word forms during incidental learning were localized. Participants listened to and repeated back new word form stimuli that adhered to native phonology (Finnish pseudowords) or were foreign (Korean words), with a subset of the stimuli recurring four times. Subsequently, a modified 1-back task and a recognition task addressed whether the activations modulated by learning were related to planning for overt articulation, while parametrically added noise probed reliance on developing memory representations during effortful perception. Learning resulted in decreased left superior temporal and increased bilateral frontal premotor activation for familiar compared to new items. The left temporal learning effect persisted in all tasks and was strongest when stimuli were embedded in intermediate noise. In the noisy conditions, native phonotactics evoked overall enhanced left temporal activation. In contrast, the frontal learning effects were present only in conditions requiring overt repetition and were more pronounced for the foreign language. The results indicate a functional dissociation between temporal and frontal activations in learning new phonological word forms: the left superior temporal responses reflect activation of newly-established word-form representations, also during degraded sensory input, whereas the frontal premotor effects are related to planning for articulation and are not preserved in noise.     

Visual Word Recognition in Deaf Readers: Lexicality Is Modulated by Communication Mode

Evidence indicates that adequate phonological abilities are necessary to develop proficient reading skills and that later in life phonology also has a role in the covert visual word recognition of expert readers. Impairments of acoustic perception, such as deafness, can lead to atypical phonological representations of written words and letters, which in turn can affect reading proficiency. Here, we report an experiment in which young adults with different levels of acoustic perception (i.e., hearing and deaf individuals) and different modes of communication (i.e., hearing individuals using spoken language, deaf individuals with a preference for sign language, and deaf individuals using the oral modality with less or no competence in sign language) performed a visual lexical decision task, which consisted of categorizing real words and consonant strings. The lexicality effect was restricted to deaf signers who responded faster to real words than consonant strings, showing over-reliance on whole word lexical processing of stimuli. No effect of stimulus type was found in deaf individuals using the oral modality or in hearing individuals. Thus, mode of communication modulates the lexicality effect. This suggests that learning a sign language during development shapes visuo-motor representations of words, which are tuned to the actions used to express them (phono-articulatory movements vs. hand movements) and to associated perceptions. As these visuo-motor representations are elicited during on-line linguistic processing and can overlap with the perceptual-motor processes required to execute the task, they can potentially produce interference or facilitation effects.     

Congruent embodied representations for visually presented actions and linguistic phrases describing actions

The thesis of embodied semantics holds that conceptual representations accessed during linguistic processing are, in part, equivalent to the sensory-motor representations required for the enactment of the concepts described . Here, using fMRI, we tested the hypothesis that areas in human premotor cortex that respond both to the execution and observation of actions-mirror neuron areas -are key neural structures in these processes. Participants observed actions and read phrases relating to foot, hand, or mouth actions. In the premotor cortex of the left hemisphere, a clear congruence was found between effector-specific activations of visually presented actions and of actions described by literal phrases. These results suggest a key role of mirror neuron areas in the re-enactment of sensory-motor representations during conceptual processing of actions invoked by linguistic stimuli.     

Processing of visually presented sentences in Mandarin and English studied with fMRI.

Comprehension of visually presented sentences in fluent bilinguals was studied with functional magnetic resonance imaging (fMRI) using a set of conceptually similar sentences in two orthographically and phonologically distinct languages, Mandarin and English. Responses were monitored during scanning. Sentence comprehension in each language was compared to fixation in nine subjects and Tamil-like pseudo-word strings in five subjects. Spatially congruent activations in the prefrontal, temporal, and superior parietal regions and in the anterior supplementary motor area were observed for both languages and in both experiments at the individual and group levels of analysis. Proficient bilinguals exposed to both languages early in life utilize common neuroanatomical regions during the conceptual and syntactic processing of written language irrespective of their differences in surface features.     

Studying Memory Encoding to Promote Reliable Engagement of the Medial Temporal Lobe at the Single-Subject Level

The medial temporal lobe (MTL)—comprising hippocampus and the surrounding neocortical regions—is a targeted brain area sensitive to several neurological diseases. Although functional magnetic resonance imaging (fMRI) has been widely used to assess brain functional abnormalities, detecting MTL activation has been technically challenging. The aim of our study was to provide an fMRI paradigm that reliably activates MTL regions at the individual level, thus providing a useful tool for future research in clinical memory-related studies. Twenty young healthy adults underwent an event-related fMRI study consisting of three encoding conditions: word-pairs, face-name associations and complex visual scenes. A region-of-interest analysis at the individual level comparing novel and repeated stimuli independently for each task was performed. The results of this analysis yielded activations in the hippocampal and parahippocampal regions in most of the participants. Specifically, 95% and 100% of participants showed significant activations in the left hippocampus during the face-name encoding and in the right parahippocampus, respectively, during scene encoding. Additionally, a whole brain analysis, also comparing novel versus repeated stimuli at the group level, showed mainly left frontal activation during the word task. In this group analysis, the face-name association engaged the HP and fusiform gyri bilaterally, along with the left inferior frontal gyrus, and the complex visual scenes activated mainly the parahippocampus and hippocampus bilaterally. In sum, our task design represents a rapid and reliable manner to study and explore MTL activity at the individual level, thus providing a useful tool for future research in clinical memory-related fMRI studies.     

Words and Melody Are Intertwined in Perception of Sung Words: EEG and Behavioral Evidence

Language and music, two of the most unique human cognitive abilities, are combined in song, rendering it an ecological model for comparing speech and music cognition. The present study was designed to determine whether words and melodies in song are processed interactively or independently, and to examine the influence of attention on the processing of words and melodies in song. Event-Related brain Potentials (ERPs) and behavioral data were recorded while non-musicians listened to pairs of sung words (prime and target) presented in four experimental conditions: same word, same melody; same word, different melody; different word, same melody; different word, different melody. Participants were asked to attend to either the words or the melody, and to perform a same/different task. In both attentional tasks, different word targets elicited an N400 component, as predicted based on previous results. Most interestingly, different melodies (sung with the same word) elicited an N400 component followed by a late positive component. Finally, ERP and behavioral data converged in showing interactions between the linguistic and melodic dimensions of sung words. The finding that the N400 effect, a well-established marker of semantic processing, was modulated by musical melody in song suggests that variations in musical features affect word processing in sung language. Implications of the interactions between words and melody are discussed in light of evidence for shared neural processing resources between the phonological/semantic aspects of language and the melodic/harmonic aspects of music.     

Emotional States Modulate the Recognition Potential during Word Processing

This study examined emotional modulation of word processing, showing that the recognition potential (RP), an ERP index of word recognition, could be modulated by different emotional states. In the experiment, participants were instructed to compete with pseudo-competitors, and via manipulation of the outcome of this competition, they were situated in neutral, highly positive, slightly positive, highly negative or slightly negative emotional states. They were subsequently asked to judge whether the referent of a word following a series of meaningless character segmentations was an animal or not. The emotional induction task and the word recognition task were alternated. Results showed that 1) compared with the neutral emotion condition, the peak latency of the RP under different emotional states was earlier and its mean amplitude was smaller, 2) there was no significant difference between RPs elicited under positive and negative emotional states in either the mean amplitude or latency, and 3) the RP was not affected by different degrees of positive emotional states. However, compared to slightly negative emotional states, the mean amplitude of the RP was smaller and its latency was shorter in highly negative emotional states over the left hemisphere but not over the right hemisphere. The results suggest that emotional states influence word processing.     

Spontaneous analogising caused by text stimuli in design thinking: differences between higher- and lower-creativity groups

Understanding the cognitive processes used in creative practices is essential to design research. In this study, electroencephalography was applied to investigate the brain activations of visual designers when they responded to various types of word stimuli during design thinking. Thirty visual designers were recruited, with the top third and bottom third of the participants divided into high-creativity (HC) and low-creativity (LC) groups. The word stimuli used in this study were two short poems, adjectives with similar meanings, and adjectives with opposing meanings. The derived results are outlined as follows: (1) the brain activations of the designers increased in the frontal and right temporal regions and decreased in the right prefrontal region; (2) the negative association between the right temporal and middle frontal regions was notable; (3) the differences in activations caused by distinct word stimuli varied between HC and LC designers; (4) the spectral power in the middle frontal region of HC designers was lower than that of LC designers during the short love poem task; (5) the spectral power in the bilateral temporal regions of HC designers was higher than that of LC designers during the short autumn poem task; (6) the spectral power in the frontoparietal region of HC designers was lower than that of LC designers during the similar concept task; and (7) the spectral power in the frontoparietal and left frontotemporal regions of HC designers was higher than that of LC designers during the opposing concept task.     

Reading “Sun” and Looking Up: The Influence of Language on Saccadic Eye Movements in the Vertical Dimension

Traditionally, language processing has been attributed to a separate system in the brain, which supposedly works in an abstract propositional manner. However, there is increasing evidence suggesting that language processing is strongly interrelated with sensorimotor processing. Evidence for such an interrelation is typically drawn from interactions between language and perception or action. In the current study, the effect of words that refer to entities in the world with a typical location (e.g., sun, worm) on the planning of saccadic eye movements was investigated. Participants had to perform a lexical decision task on visually presented words and non-words. They responded by moving their eyes to a target in an upper (lower) screen position for a word (non-word) or vice versa. Eye movements were faster to locations compatible with the word''s referent in the real world. These results provide evidence for the importance of linguistic stimuli in directing eye movements, even if the words do not directly transfer directional information.