The Sensory Consequences of Speaking: Parametric Neural Cancellation during Speech in Auditory Cortex

When we speak, we provide ourselves with auditory speech input. Efficient monitoring of speech is often hypothesized to depend on matching the predicted sensory consequences from internal motor commands (forward model) with actual sensory feedback. In this paper we tested the forward model hypothesis using functional Magnetic Resonance Imaging. We administered an overt picture naming task in which we parametrically reduced the quality of verbal feedback by noise masking. Presentation of the same auditory input in the absence of overt speech served as listening control condition. Our results suggest that a match between predicted and actual sensory feedback results in inhibition of cancellation of auditory activity because speaking with normal unmasked feedback reduced activity in the auditory cortex compared to listening control conditions. Moreover, during self-generated speech, activation in auditory cortex increased as the feedback quality of the self-generated speech decreased. We conclude that during speaking early auditory cortex is involved in matching external signals with an internally generated model or prediction of sensory consequences, the locus of which may reside in auditory or higher order brain areas. Matching at early auditory cortex may provide a very sensitive monitoring mechanism that highlights speech production errors at very early levels of processing and may efficiently determine the self-agency of speech input

Human Auditory Cortical Activation during Self-Vocalization

During speaking, auditory feedback is used to adjust vocalizations. The brain systems mediating this integrative ability have been investigated using a wide range of experimental strategies. In this report we examined how vocalization alters speech-sound processing within auditory cortex by directly recording evoked responses to vocalizations and playback stimuli using intracranial electrodes implanted in neurosurgery patients. Several new findings resulted from these high-resolution invasive recordings in human subjects. Suppressive effects of vocalization were found to occur only within circumscribed areas of auditory cortex. In addition, at a smaller number of sites, the opposite pattern was seen; cortical responses were enhanced during vocalization. This increase in activity was reflected in high gamma power changes, but was not evident in the averaged evoked potential waveforms. These new findings support forward models for vocal control in which efference copies of premotor cortex activity modulate sub-regions of auditory cortex

Midlife managerial experience is linked to late life hippocampal morphology and function

An active cognitive lifestyle has been suggested to have a protective role in the long-term maintenance of cognition. Amongst healthy older adults, more managerial or supervisory experiences in midlife are linked to a slower hippocampal atrophy rate in late life. Yet whether similar links exist in individuals with Mild Cognitive Impairment (MCI) is not known, nor whether these differences have any functional implications. 68 volunteers from the Sydney SMART Trial, diagnosed with non-amnestic MCI, were divided into high and low managerial experience (HME/LME) during their working life. All participants underwent neuropsychological testing, structural and resting-state functional MRI. Group comparisons were performed on hippocampal volume, morphology, hippocampal seed-based functional connectivity, memory and executive function and self-ratings of memory proficiency. HME was linked to better memory function (p = 0.024), mediated by larger hippocampal volume (p = 0.025). More specifically, deformation analysis found HME had relatively more volume in the CA1 sub-region of the hippocampus (p  <  0.05). Paradoxically, this group rated their memory proficiency worse (p = 0.004), a result correlated with diminished functional connectivity between the right hippocampus and right prefrontal cortex (p  <  0.001). Finally, hierarchical regression modelling substantiated this double dissociation

Identification and characterization of microRNAs expressed in the African malaria vector Anopheles funestus life stages using high throughput sequencing

Background: Over the past several years, thousands of microRNAs (miRNAs) have been identified in the genomes of various insects through cloning and sequencing or even by computational prediction. However, the number of miRNAs identified in anopheline species is low and little is known about their role. The mosquito Anopheles funestus is one of the dominant malaria vectors in Africa, which infects and kills millions of people every year. Therefore, small RNA molecules isolated from the four life stages (eggs, larvae, pupae and unfed adult females) of An. funestus were sequenced using next generation sequencing technology. Results: High throughput sequencing of four replicates in combination with computational analysis identified 107 mature miRNA sequences expressed in the An. funestus mosquito. These include 20 novel miRNAs without sequence identity in any organism and eight miRNAs not previously reported in the Anopheles genus but are known in non-anopheles mosquitoes. Finally, the changes in the expression of miRNAs during the mosquito development were determined and the analysis showed that many miRNAs have stage-specific expression, and are co-transcribed and co-regulated during development. Conclusions: This study presents the first direct experimental evidence of miRNAs in An. funestus and the first profiling study of miRNA associated with the maturation in this mosquito. Overall, the results indicate that miRNAs play important roles during the growth and development. Silencing such molecules in a specific life stage could decrease the vector population and therefore interrupt malaria transmission.IS

Cross-linguistic similarity norms for Japanese–English translation equivalents

Formal and semantic overlap across languages plays an important role in bilingual language processing systems. In the present study, Japanese (first language; L1)–English (second language; L2) bilinguals rated 193 Japanese–English word pairs, including cognates and noncognates, in terms of phonological and semantic similarity. We show that the degree of cross-linguistic overlap varies, such that words can be more or less “cognate,” in terms of their phonological and semantic overlap. Bilinguals also translated these words in both directions (L1–L2 and L2–L1), providing a measure of translation equivalency. Notably, we reveal for the first time that Japanese–English cognates are “special,” in the sense that they are usually translated using one English term (e.g., コール /kooru/ is always translated as “call”), but the English word is translated into a greater variety of Japanese words. This difference in translation equivalency likely extends to other nonetymologically related, different-script languages in which cognates are all loanwords (e.g., Korean–English). Norming data were also collected for L1 age of acquisition, L1 concreteness, and L2 familiarity, because such information had been unavailable for the item set. Additional information on L1/L2 word frequency, L1/L2 number of senses, and L1/L2 word length and number of syllables is also provided. Finally, correlations and characteristics of the cognate and noncognate items are detailed, so as to provide a complete overview of the lexical and semantic characteristics of the stimuli. This creates a comprehensive bilingual data set for these different-script languages and should be of use in bilingual word recognition and spoken language research

Two is better than one: bilingual education promotes the flexible mind

The interest in the influence of bilingualism on our daily life is constantly growing. Speaking two languages (or more) requires people to develop a flexible mindset to rapidly switch back and forth between languages. This study investigated whether and to what extent attending bilingual education benefits cognitive control. We tested two groups of Dutch high-school students who either followed regular classes in Dutch or were taught in both English and Dutch. They performed on a global–local switching paradigm that provides well-established measures of cognitive flexibility and attentional processing style. As predicted, the bilingually educated group showed smaller switching costs (i.e., greater cognitive flexibility) and a decreased global precedence effect than the regular group. Our findings support the idea that bilingual education promotes cognitive flexibility and a bias towards a more focused “scope” of attention.Action Contro