Experientially grounded language production: Advancing our understanding of semantic processing during lexical selection

Der Prozess der lexikalischen Selektion, d.h. die Auswahl der richtigen Wörter zur Übermittlung einer intendierten Botschaft, ist noch nicht hinreichend verstanden. Insbesondere wurde kaum erforscht, inwiefern Bedeutungsaspekte, welche in sensomotorischen Erfahrungen gründen, diesen Prozess der Sprachproduktion beeinflussen. Die Rolle dieser Bedeutungsaspekte wurde mit zwei Studien untersucht, in denen Probanden Sätze vervollständigten. In Studie 1 wurde der visuelle Eindruck der Satzfragmente manipuliert, so dass die Sätze auf- oder absteigend am Bildschirm erschienen. In Studie 2 mussten die Probanden Kopfbewegungen nach oben oder unten ausführen, während sie die Satzfragmente hörten. Wir untersuchten, ob räumliche Aspekte der produzierten Wörter durch die räumlichen Manipulationen sowie die räumlichen Eigenschaften der präsentierten Satzfragmente beeinflusst werden. Die vertikale visuelle Manipulation in Studie 1 wirkte sich nicht auf die räumlichen Attribute der produzierten Wörter aus. Die Kopfbewegungen in Studie 2 führten zu einem solchen Effekt – bei Kopfbewegungen nach oben waren die Referenten der produzierten Wörter weiter oben im Raum angesiedelt als nach Bewegungen nach unten (und anders herum). Darüber hinaus war dieser Effekt stärker, je ausgeprägter die interozeptive Sensibilität der Probanden war. Zudem beeinflussten die räumlichen Aspekte der Satzfragmente die räumlichen Eigenschaften der produzierten Wörter in beiden Studien. Somit zeigt diese Arbeit, dass in der Erfahrung basierende Bedeutungsanteile, welche entweder in Sprache eingebettet sind oder durch körperliche Aktivität reaktiviert werden, die Auswahl der Wörter beim Sprechen beeinflussen und dass interindividuelle Unterschiede diesen Effekt modulieren. Die Befunde werden in Bezug zu Theorien der Semantik gesetzt. Darüber hinaus wird das Methodenrepertoire erweitert, indem mit Studie 3 ein Ansatz für die Durchführung von Online-Sprachproduktionsexperimenten mit Bildbenennung vorgestellt wird.The process of lexical selection, i.e. producing the right words to get an intended message across, is not well understood. Specifically, meaning aspects grounded in sensorimotor experiences and their role during lexical selection have not been investigated widely. Here, we investigated the role of experientially grounded meaning aspects with two studies in which participants had to produce a noun to complete sentences which described sceneries. In Study 1, the visual appearance of sentence fragments was manipulated and they seemed to move upwards or downwards on screen. In Study 2, participants moved their head up- or downwards while listening to sentence fragments. We investigated whether the spatial properties of the freely chosen nouns are influenced by the spatial manipulations as well as by the spatial properties of the sentences. The vertical visual manipulation used in Study 1 did not influence the spatial properties of the produced words. However, the body movements in Study 2 influenced participants’ lexical choices, i.e. after up-movements the referents of the produced words were higher up compared to after downward movements (and vice verse). Furthermore, there was an increased effect of movement on the spatial properties of the produced nouns with higher levels of participants’ interoceptive sensibility. Additionally, the spatial properties of the stimulus sentences influenced the spatial properties of the produced words in both studies. Thus, experientially grounded meaning aspects which are either embedded in text or reactivated via bodily manipulations may influence which words we chose when speaking, and interindividual differences may moderate these effects. The findings are related to current theories of semantics. Furthermore, this dissertation enhances the methodological repertoire of language production researchers by showing how language production studies with overt articulation in picture naming tasks can be run online (Study 3)

Delta-subunit-containing GABAA-receptors mediate tonic inhibition in paracapsular cells of the mouse amygdala

The intercalated paracapsular cells (pcs) are small GABAergic interneurons that form densely populated clusters surrounding the basolateral (BLA) complex of the amygdala. Their main task in the amygdala circuitry appears to be the control of information flow, as they act as an inhibitory interface between input and output nuclei. Modulation of their activity is thus thought to affect amygdala output and the generation of fear and anxiety. Recent evidence indicates that pcs express benzodiazepine (BZ)-sensitive GABA(A) receptor (GABA(A)R) variants containing the α2- and α3-subunit for transmission of post-synaptic currents, yet little is known about the expression of extrasynaptic GABA(A)Rs, mediating tonic inhibition and regulating neuronal excitability. Here, we show that pcs from the lateral and medial intercalated cell cluster (l- and mITC, respectively) express a tonic GABAergic conductance that could be significantly increased in a concentration-dependent manner by the δ-preferring GABA(A)R agonist THIP (0.5–10 μM), but not by the BZ diazepam (1 μM). The neurosteroid THDOC (300 nM) also increased tonic currents in pcs significantly, but only in the presence of additional GABA (5 μM). Immunohistochemical stainings revealed that both the δ-GABA(A)R and the α4-GABA(A)R subunit are expressed throughout all ITCs, while no staining for the α5-GABA(A)R subunit could be detected. Moreover, 1 μM THIP dampened excitability in pcs most likely by increasing shunting inhibition. In line with this, THIP significantly decreased lITC-generated inhibition in target cells residing in the BLA nucleus by 30%. Taken together these results demonstrate for the first time that pcs express a tonic inhibitory conductance mediated most likely by α4/δ-containing GABA(A)Rs. This data also suggest that δ-GABA(A)R targeting compounds might possibly interfere with pcs-related neuronal processes such as fear extinction

Robotic devices and ICT in long-term care in Japan: Their potential and limitations from a workplace perspective

In light of its rapidly aging society, Japan is pressured to full-heartedly address the labor shortage in long-term care. Among the various policy options currently in discussion, government agencies and business sector representatives agree that robotic devices and information and communication technology (ICT) constitute a suitable countermeasure. However, during our research in Japan in 2019, we found that robotic devices and ICT are only reluctantly being introduced into long-term care facilities. Based on our field visits and interviews as well as supplementary document research, this paper discusses the potential that facility managers ascribe to robotic devices and ICT when it comes to alleviating the labor shortage in the long-term care institutions they run. Of particular interest is the question to what degree the usage of robotic devices and ICT could reduce the physical hardships and mental stress that staff in long-term caregiving experience. This paper will further our understanding of the labor situation in long-term care facilities and contribute to the research field of robotic devices and ICT in Japan’s labor market

Experience-driven meaning affects lexical choices during language production

The role of meaning facets based on sensorimotor experiences is well investigated in comprehension but has received little attention in language production research. In two experiments, we investigated whether experiential traces of space influenced lexical choices when participants completed visually presented sentence fragments (e.g., “You are at the sea and you see a . . .”) with spoken nouns (e.g., “dolphin,” “palm tree”). The words were presented consecutively in an ascending or descending direction, starting from the centre of the screen. These physical spatial cues did not influence lexical choices. However, the produced nouns met the spatial characteristics of the broader sentence contexts such that the typical spatial locations of the produced noun referents were predicted by the location of the situations described by the sentence fragments (i.e., upper or lower sphere). By including distributional semantic similarity measures derived from computing cosine values between sentence nouns and produced nouns using a web-based text corpus, we show that the meaning dimension of “location in space” guides lexical selection during speaking. We discuss the relation of this spatial meaning dimension to accounts of experientially grounded and usage-based theories of language processing and their combination in hybrid approaches. In doing so, we contribute to a more comprehensive understanding of the many facets of meaning processing during language production and their impact on the words we select to express verbal messages.Peer Reviewe

Sulfur Respiration in a Marine Chemolithoautotrophic Beggiatoa Strain

The chemolithoautotrophic strain Beggiatoa sp. 35Flor shows an unusual migration behavior when cultivated in a gradient medium under high sulfide fluxes. As common for Beggiatoa spp., the filaments form a mat at the oxygen–sulfide interface. However, upon prolonged incubation, a subpopulation migrates actively downward into the anoxic and sulfidic section of the medium, where the filaments become gradually depleted in their sulfur and polyhydroxyalkanoates (PHA) inclusions. This depletion is correlated with the production of hydrogen sulfide. The sulfur- and PHA-depleted filaments return to the oxygen–sulfide interface, where they switch back to depositing sulfur and PHA by aerobic sulfide oxidation. Based on these observations we conclude that internally stored elemental sulfur is respired at the expense of stored PHA under anoxic conditions. Until now, nitrate has always been assumed to be the alternative electron acceptor in chemolithoautotrophic Beggiatoa spp. under anoxic conditions. As the medium and the filaments were free of oxidized nitrogen compounds we can exclude this metabolism. Furthermore, sulfur respiration with PHA under anoxic conditions has so far only been described for heterotrophic Beggiatoa spp., but our medium did not contain accessible organic carbon. Hence the PHA inclusions must originate from atmospheric CO2 fixed by the filaments while at the oxygen–sulfide interface. We propose that the directed migration of filaments into the anoxic section of an oxygen–sulfide gradient system is used as a last resort to preserve cell integrity, which would otherwise be compromised by excessive sulfur deposition occurring in the presence of oxygen and high sulfide fluxes. The regulating mechanism of this migration is still unknown

The effects of the frog Eleutherodactylus coqui on invertebrates and ecosystem processes at two scales in the Luquillo Experimental Forest, Puerto Rico

Determining the ubiquity of top-down control effects of predators on their prey and ecosystem processes is important for understanding community and ecosystem-level consequences that may result from predator loss. We conducted experiments at two spatial scales to investigate the effects of terrestrial frogs (Eleutherodactylus coqui) on aerial and litter invertebrates, plant growth and herbivory, and litter decomposition. At both scales, frogs reduced aerial invertebrates and leaf herbivory, but had no effect on litter invertebrates. At the smaller scale, frogs increased foliage production rates, measured as the number of new leaves and new leaf area produced, by 80% and decomposition rates by 20%. The influence of E. coqui on increasing primary productivity and decomposition rates at the smaller scale appeared to be a result of elimination and excretion rather than of controlling prey. While the results provide evidence for frogs controlling herbivorous prey at both scales, species effects on ecosystem processes were only detectable at the smaller scale. The results highlight the difficulties in conducting experiments at large spatial scales. The findings from this study imply that the loss of amphibians and other species of higher trophic levels may affect nutrient cycling rates in tropical forests

Discovery of planetary nebulae using predictive mid-infrared diagnostics

We demonstrate a newly developed mid-infrared planetary nebula (PN) selection technique. It is designed to enable efficient searches for obscured, previously unknown, PN candidates present in the photometric source catalogues of Galactic plane MIR sky surveys. Such selection is now possible via new, sensitive, high-to-medium resolution, MIR satellite surveys such as those from the Spitzer Space Telescope and the all-sky Wide-Field Infrared Survey Explorer (WISE) satellite missions. MIR selection is based on how different colour-colour planes isolate zones (sometimes overlapping) that are predominately occupied by different astrophysical object types. These techniques depend on the reliability of the available MIR source photometry. In this pilot study we concentrate on MIR point source detections and show that it is dangerous to take the MIR GLIMPSE (Galactic Legacy Infrared Mid-Plane Survey Extraordinaire) photometry from Spitzer for each candidate at face value without examining the actual MIR image data. About half of our selected sources are spurious detections due to the applied source detection algorithms being affected by complex MIR backgrounds and the de-blending of diffraction spikes around bright MIR point sources into point sources themselves. Nevertheless, once this additional visual diagnostic checking is performed, valuable MIR selected PN candidates are uncovered. Four turned out to have faint, compact, optical counterparts in our H-alpha survey data missed in previous optical searches. We confirm all of these as true PNe via our follow-up optical spectroscopy. This lends weight to the veracity of our MIR technique. It demonstrates sufficient robustness that high-confidence samples of new Galactic PN candidates can be extracted from these MIR surveys without confirmatory optical spectroscopy and imaging. This is problematic or impossible when the extinction is large.Comment: 14 pages, 7 figures, 7 tables; accepted for publication in MNRA

Internet-based language production research with overt articulation: Proof of concept, challenges, and practical advice

Language production experiments with overt articulation have thus far only scarcely been conducted online, mostly due to technical difficulties related to measuring voice onset latencies. Especially the poor audiovisual synchrony in web experiments (Bridges et al. 2020) is a challenge to time-locking stimuli and participants’ spoken responses. We tested the viability of conducting language production experiments with overt articulation in online settings using the picture–word interference paradigm – a classic task in language production research. In three pre-registered experiments (N = 48 each), participants named object pictures while ignoring visually superimposed distractor words. We implemented a custom voice recording option in two different web experiment builders and recorded naming responses in audio files. From these stimulus-locked audio files, we extracted voice onset latencies offline. In a control task, participants classified the last letter of a picture name as a vowel or consonant via button-press, a task that shows comparable semantic interference effects. We expected slower responses when picture and distractor word were semantically related compared to unrelated, independently of task. This semantic interference effect is robust, but relatively small. It should therefore crucially depend on precise timing. We replicated this effect in an online setting, both for button-press and overt naming responses, providing a proof of concept that naming latency – a key dependent variable in language production research – can be reliably measured in online experiments. We discuss challenges for online language production research and suggestions of how to overcome them. The scripts for the online implementation are made available.Humboldt-Universität zu Berlin (1034)Peer Reviewe

Human germinal center B cells differ from naive and memory B cells by their aggregated MHC class II‐rich compartments lacking HLA‐DO

To generate memory B cells bearing high‐affinity antibodies, naive B cells first encounter antigen in the T cell‐rich areas of secondary lymphoid organs. There, they are activated by antigen‐specific T cells and become germinal center (GC) founder B cells. GC founders enter the GC to become centroblasts that proliferate and mutate their BCR. Centroblasts differentiate into centrocytes that undergo selection, which requires both the recognition/capture of antigen on follicular dendritic cells and the presentation of processed antigen to GC T cells. Because at each stage of differentiation B cells act as antigen‐presenting cells, we analyzed their content of HLA‐DR+‐rich compartments (MIIC), as well as their expression of HLA‐DM, which catalyzes peptide loading of class II molecules, and HLA‐DO, which interacts with HLA‐DM and focuses MHC class II peptide loading on antigens internalized by the BCR. Naive and memory B cells concentrate HLA‐DR, ‐DM and ‐DO into compartments dispersed under the cell surface, which are identified by their expression of lysosome‐associated membrane protein (Lamp)‐1 as late endosomes/lysosomes. GC founders and GC B cells express larger Lamp‐1+DR+ compartments that are concentrated in the juxta‐nuclear region. These compartments express lower levels of HLA‐DM and virtually no HLA‐DO. Upon induction of a GC founder phenotype through the prolonged (days) co‐ligation of BCR and CD40, the naive B cell's peripheral DR+DM+Lamp‐1+ compartments aggregate in a polar fashion close to the nucleus. Furthermore, HLA‐DO expression virtually disappears, whereas low levels of HLA‐DM remain co‐localized with HLA‐DR. Anti‐κ/λ antibodies, used as surrogate antigens, are promptly (minutes) endocytosed in naive, memory and GC B cells. Then, naive and memory B cells target the surrogate antigen to their peripheral HLA‐DO+ MIIC, while GC B cells target it to their HLA‐DO- MIIC aggregates. Taken together, our results show that human GC B cells differ from naive and memory B cells by their aggregated MIIC that lack HLA‐D