The emergence of language in the human mind and brain-Insights from the neurobiology of language, thought and action.

The capacity for language has evolved remarkably quickly in recent human history. Its advent likely coincided with a range of cognitive innovations not found elsewhere at this level of complexity in the rest of the animal kingdom. This late yet near-simultaneous florescence of higher language and cognition is difficult to account for in terms of strictly modular neurocognitive systems, each with its own dedicated function and evolutionary trajectory. Nor does it legitimize the neurocognitive study of language in isolation from other systems of human thought and action. In the wake of emergentist approaches to key human cognitive abilities, the present article considers language as the differentiated product of multiple neural networks dedicated to qualitatively distinct cognitive functions-including (at least) the cortical systems of general semantic cognition and control and the sensorimotor systems supporting language production. A model is proposed to account for how these systems congregate to produce language, featuring a dual-stream architecture of the semantic interface into item-based and item-independent semantic knowledge on the one hand, and a notion of the sensorimotor interface as a key component for the temporal tracking and verbal rehearsal of task-relevant information on the other. Avenues are also offered for enriching this architecture in future versions of the model. Finally, it is proposed that language is an "optimal" combination of these neurocognitive systems, enabling fast and cost-effective transfer of information at the systems level. This last point underpins evidence for the privileged status of language as a tool for adaptive thought and behavior, as well as some important features of brain evolution, development, and functional organization. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Bimodal EEG-fNIRS in Neuroergonomics. Current Evidence and Prospects for Future Research.

Neuroergonomics focuses on the brain signatures and associated mental states underlying behavior to design human-machine interfaces enhancing performance in the cognitive and physical domains. Brain imaging techniques such as functional near-infrared spectroscopy (fNIRS) and electroencephalography (EEG) have been considered key methods for achieving this goal. Recent research stresses the value of combining EEG and fNIRS in improving these interface systems' mental state decoding abilities, but little is known about whether these improvements generalize over different paradigms and methodologies, nor about the potentialities for using these systems in the real world. We review 33 studies comparing mental state decoding accuracy between bimodal EEG-fNIRS and unimodal EEG and fNIRS in several subdomains of neuroergonomics. In light of these studies, we also consider the challenges of exploiting wearable versions of these systems in real-world contexts. Overall the studies reviewed suggest that bimodal EEG-fNIRS outperforms unimodal EEG or fNIRS despite major differences in their conceptual and methodological aspects. Much work however remains to be done to reach practical applications of bimodal EEG-fNIRS in naturalistic conditions. We consider these points to identify aspects of bimodal EEG-fNIRS research in which progress is expected or desired.

A dual architecture for the cognitive control of language: Evidence from functional imaging and language production.

The relation between language processing and the cognitive control of thought and action is a widely debated issue in cognitive neuroscience. While recent research suggests a modular separation between a 'language system' for meaningful linguistic processing and a 'multiple-demand system' for cognitive control, other findings point to more integrated perspectives in which controlled language processing emerges from a division of labor between (parts of) the language system and (parts of) the multiple-demand system. We test here a dual approach to the cognitive control of language predicated on the notion of cognitive control as the combined contribution of a semantic control network (SCN) and a working memory network (WMN) supporting top-down manipulation of (lexico-)semantic information and the monitoring of information in verbal working memory, respectively. We reveal these networks in a large-scale coordinate-based meta-analysis contrasting functional imaging studies of verbal working memory vs. active judgments on (lexico-)semantic information and show the extent of their overlap with the multiple-demand system and the language system. Testing these networks' involvement in a functional imaging study of object naming and verb generation, we then show that SCN specializes in top-down retrieval and selection of (lexico-)semantic representations amongst competing alternatives, while WMN intervenes at a more general level of control modulated in part by the amount of competing responses available for selection. These results have implications in conceptualizing the neurocognitive architecture of language and cognitive control.

Encoding of Novel Verbal Instructions for Prospective Action in the Lateral Prefrontal Cortex: Evidence from Univariate and Multivariate Functional Magnetic Resonance Imaging Analysis.

Verbal instructions are central to humans' capacity to learn new behaviors with minimal training, but the neurocognitive mechanisms involved in verbally instructed behaviors remain puzzling. Recent functional magnetic resonance imaging (fMRI) evidence suggests that the right middle frontal gyrus and dorsal premotor cortex (rMFG-dPMC) supports the translation of symbolic stimulus-response mappings into sensorimotor representations. Here, we set out to (1) replicate this finding, (2) investigate whether this region's involvement is specific to novel (vs. trained) instructions, and (3) study whether rMFG-dPMC also shows differences in its (voxel) pattern response indicative of general cognitive processes of instruction implementation. Participants were shown instructions, which they either had to perform later or merely memorize. Orthogonal to this manipulation, the instructions were either entirely novel or had been trained before the fMRI session. Results replicate higher rMFG-dPMC activation levels during instruction implementation versus memorization and show how this difference is restricted to novel, but not trained, instruction presentations. Pattern similarity analyses at the voxel level further reveal more consistent neural pattern responses in rMFG-dPMC during the implementation of novel versus trained instructions. In fact, this more consistent neural pattern response seemed to be specific to the first instruction presentation and disappeared after the instruction had been applied once. These results further support a role of rMFG-dPMC in the implementation of novel task instructions and highlight potentially important differences in studying this region's gross activation levels versus (the consistency of) its response patterns.

The neural dynamics of competition resolution for language production in the prefrontal cortex.

Previous research suggests a pivotal role of the prefrontal cortex (PFC) in word selection during tasks of confrontation naming (CN) and verb generation (VG), both of which feature varying degrees of competition between candidate responses. However, discrepancies in prefrontal activity have also been reported between the two tasks, in particular more widespread and intense activation in VG extending into (left) ventrolateral PFC, the functional significance of which remains unclear. We propose that these variations reflect differences in competition resolution processes tied to distinct underlying lexico-semantic operations: Although CN involves selecting lexical entries out of limited sets of alternatives, VG requires exploration of possible semantic relations not readily evident from the object itself, requiring prefrontal areas previously shown to be recruited in top-down retrieval of information from lexico-semantic memory. We tested this hypothesis through combined independent component analysis of functional imaging data and information-theoretic measurements of variations in selection competition associated with participants' performance in overt CN and VG tasks. Selection competition during CN engaged the anterior insula and surrounding opercular tissue, while competition during VG recruited additional activity of left ventrolateral PFC. These patterns remained after controlling for participants' speech onset latencies indicative of possible task differences in mental effort. These findings have implications for understanding the neural-computational dynamics of cognitive control in language production and how it relates to the functional architecture of adaptive behavior.

Please say what this word is-Vowel-extrinsic normalization in the sensorimotor control of speech.

The extent to which the adaptive nature of speech perception influences the acoustic targets underlying speech production is not well understood. For example, listeners can rapidly accommodate to talker-dependent phonetic properties-a process known as vowel-extrinsic normalization-without altering their speech output. Recent evidence, however, shows that reinforcement-based learning in vowel perception alters the processing of speech auditory feedback, impacting sensorimotor control during vowel production. This suggests that more automatic and ubiquitous forms of perceptual plasticity, such as those characterizing perceptual talker normalization, may also impact the sensorimotor control of speech. To test this hypothesis, we set out to examine the possible effects of vowel-extrinsic normalization on experimental subjects' interpretation of their own speech outcomes. By combining a well-known manipulation of vowel-extrinsic normalization with speech auditory-motor adaptation, we show that exposure to different vowel spectral properties subsequently alters auditory feedback processing during speech production, thereby influencing speech motor adaptation. These findings extend the scope of perceptual normalization processes to include auditory feedback and support the idea that naturally occurring adaptations found in speech perception impact speech production. (PsycINFO Database Record

A rostro-caudal axis for language in the frontal lobe: the role of executive control in speech production.

The present article promotes a formal executive model of frontal functions underlying speech production, bringing together hierarchical theories of adaptive behavior in the (pre-)frontal cortex (pFC) and psycho- and neurolinguistic approaches to spoken language within an information-theoretic framework. Its biological plausibility is revealed through two Activation Likelihood Estimation meta-analyses carried out on a total of 41 hemodynamic studies of overt word and continuous speech production respectively. Their principal findings, considered in light of neuropsychological evidence and earlier models of speech-related frontal functions, support the engagement of a caudal-to-rostral gradient of pFC activity operationalized by the nature and quantity of speech-related information conveyed by task-related external cues (i.e., cue codability) on the one hand, and the total informational content of generated utterances on the other. In particular, overt reading or repetition and picture naming recruit primarily caudal motor-premotor regions involved in the sensorimotor and phonological aspects of speech; word and sentence generation engage mid- ventro- and dorsolateral areas supporting its basic predicative and syntactic functions; finally, rostral- and fronto-polar cortices subsume domain-general strategic processes of discourse generation for creative speech. These different levels interact in a top-down fashion, ranging representationally and temporally from the most general and extended to the most specific and immediate. The end-result is an integrative theory of pFC as the main executive component of the language cortical network, which supports the existence of areas specialized for speech communication and articulation and regions subsuming internal reasoning and planning. Prospective avenues of research pertaining to this model's principal predictions are discussed.

Lexical-perceptual integration influences sensorimotor adaptation in speech.

A combination of lexical bias and altered auditory feedback was used to investigate the influence of higher-order linguistic knowledge on the perceptual aspects of speech motor control. Subjects produced monosyllabic real words or pseudo-words containing the vowel [ε] (as in "head") under conditions of altered auditory feedback involving a decrease in vowel first formant (F1) frequency. This manipulation had the effect of making the vowel sound more similar to [I] (as in "hid"), affecting the lexical status of produced words in two Lexical-Change (LC) groups (either changing them from real words to pseudo-words: e.g., less-liss, or pseudo-words to real words: e.g., kess-kiss). Two Non-Lexical-Change (NLC) control groups underwent the same auditory feedback manipulation during the production of [ε] real- or pseudo-words, only without any resulting change in lexical status (real words to real words: e.g., mess-miss, or pseudo-words to pseudo-words: e.g., ness-niss). The results from the LC groups indicate that auditory-feedback-based speech motor learning is sensitive to the lexical status of the stimuli being produced, in that speakers tend to keep their acoustic speech outcomes within the auditory-perceptual space corresponding to the task-related side of the word/non-word boundary (real words or pseudo-words). For the NLC groups, however, no such effect of lexical status is observed.