PriMa: A low-cost, modular, open hardware, and 3D-printed fMRI manipulandum.

Motor actions in fMRI settings require specialized hardware to monitor, record, and control the subjects behavior. Commercially available options for such behavior tracking or control are very restricted and costly. We present a novel grasp manipulandum in a modular design, consisting of MRI-compatible, 3D printable buttons and a chassis for mounting. Button presses are detected by the interruption of an optical fiber path, which is digitized by a photodiode and subsequent signal amplification and thresholding. Two feedback devices (manipulanda) are constructed, one for macaques (Macaca mulatta) and one for human use. Both devices have been tested in their specific experimental setting and possible improvements are reported. Design files are shared under an open hardware license.

Shared functional connectivity between the dorso-medial and dorso-ventral streams in macaques.

Manipulation of an object requires us to transport our hand towards the object (reach) and close our digits around that object (grasp). In current models, reach-related information is propagated in the dorso-medial stream from posterior parietal area V6A to medial intraparietal area, dorsal premotor cortex, and primary motor cortex. Grasp-related information is processed in the dorso-ventral stream from the anterior intraparietal area to ventral premotor cortex and the hand area of primary motor cortex. However, recent studies have cast doubt on the validity of this separation in separate processing streams. We investigated in 10 male rhesus macaques the whole-brain functional connectivity of these areas using resting state fMRI at 7-T. Although we found a clear separation between dorso-medial and dorso-ventral network connectivity in support of the two-stream hypothesis, we also found evidence of shared connectivity between these networks. The dorso-ventral network was distinctly correlated with high-order somatosensory areas and feeding related areas, whereas the dorso-medial network with visual areas and trunk/hindlimb motor areas. Shared connectivity was found in the superior frontal and precentral gyrus, central sulcus, intraparietal sulcus, precuneus, and insular cortex. These results suggest that while sensorimotor processing streams are functionally separated, they can access information through shared areas.

ß-glucan-dependent shuttling of conidia from neutrophils to macrophages occurs during fungal infection establishment.

The initial host response to fungal pathogen invasion is critical to infection establishment and outcome. However, the diversity of leukocyte-pathogen interactions is only recently being appreciated. We describe a new form of interleukocyte conidial exchange called "shuttling." In Talaromyces marneffei and Aspergillus fumigatus zebrafish in vivo infections, live imaging demonstrated conidia initially phagocytosed by neutrophils were transferred to macrophages. Shuttling is unidirectional, not a chance event, and involves alterations of phagocyte mobility, intercellular tethering, and phagosome transfer. Shuttling kinetics were fungal-species-specific, implicating a fungal determinant. ß-glucan serves as a fungal-derived signal sufficient for shuttling. Murine phagocytes also shuttled in vitro. The impact of shuttling for microbiological outcomes of in vivo infections is difficult to specifically assess experimentally, but for these two pathogens, shuttling augments initial conidial redistribution away from fungicidal neutrophils into the favorable macrophage intracellular niche. Shuttling is a frequent host-pathogen interaction contributing to fungal infection establishment patterns.

The neural basis of free language choice in bilingual speakers: Disentangling language choice and language execution.

For everyday communication, bilingual speakers need to face the complex task of rapidly choosing the most appropriate language given the context, maintaining this choice over the current communicative act, and shielding lexical selection from competing alternatives from non-target languages. Yet, speech production of bilinguals is typically flawless and fluent. Most of the studies available to date constrain speakers' language choice by cueing the target language and conflate language choice with language use. This left largely unexplored the neural mechanisms underlying free language choice, i.e., the voluntary situation of choosing the language to speak. In this study, we used fMRI and Multivariate Pattern Analysis to identify brain regions encoding the target language when bilinguals are free to choose in which language to name pictures. We found that the medial prefrontal cortex encoded the chosen language prior to speaking. By contrast, during language use, language control recruited a wider brain network including the left inferior frontal lobe, the basal ganglia, and the angular and inferior parietal gyrus bilaterally. None of these regions were involved in language choice. We argue that the control processes involved in language choice are different from those involved in language use. Furthermore, our findings confirm that the medial prefrontal cortex is a domain-general region critical for free choice and that bilingual language choice relies on domain general processes.

Language control in bilinguals: Intention to speak vs. execution of speech.

Bilinguals require a high degree of cognitive control to select the language intended for speaking and inhibit the unintended. Previous neuroimaging studies have not teased apart brain regions for generating the intention to use a given language, and those for speaking in that language. Separating these two phases can clarify at what stage competition between languages occurs. In this fMRI study German-English bilinguals were first cued to use German or English. After a delay, they named a picture in the cued language. During the intention phase, the precuneus, right superior lateral parietal lobule, and middle temporal gyrus were more activated when participants had to update the currently active language. During language execution activation was higher for English compared to German in brain areas associated with cognitive control, most notably the anterior cingulate and the caudate. Our results suggest two different systems enabling cognitive control during bilingual language production.