Stimulus modality influences session-to-session transfer of training effects in auditory and tactile streaming-based P300 brain–computer interfaces

Despite recent successes, patients suffering from locked-in syndrome (LIS) still struggle to communicate using vision-independent brain–computer interfaces (BCIs). In this study, we compared auditory and tactile BCIs, regarding training effects and cross-stimulus-modality transfer effects, when switching between stimulus modalities. We utilized a streaming-based P300 BCI, which was developed as a low workload approach to prevent potential BCI-inefficiency. We randomly assigned 20 healthy participants to two groups. The participants received three sessions of training either using an auditory BCI or using a tactile BCI. In an additional fourth session, BCI versions were switched to explore possible cross-stimulus-modality transfer effects. Both BCI versions could be operated successfully in the first session by the majority of the participants, with the tactile BCI being experienced as more intuitive. Significant training effects were found mostly in the auditory BCI group and strong evidence for a cross-stimulus-modality transfer occurred for the auditory training group that switched to the tactile version but not vice versa. All participants were able to control at least one BCI version, suggesting that the investigated paradigms are generally feasible and merit further research into their applicability with LIS end-users. Individual preferences regarding stimulus modality should be considered

Modality-specific effects of mental fatigue in multitasking

The mechanisms underlying increased dual-task costs in the comparison of modality compatible stimulus-response mappings (e.g., visual-manual, auditory-vocal) and modality incompatible mappings (e.g., visual-vocal, auditory-manual) remain elusive. To investigate whether additional control mechanisms are at work in simultaneously processing two modality incompatible mappings, we applied a transfer logic between both types of dual-task mappings in the context of a mental fatigue induction. We expected an increase in dual-task costs for both modality mappings after a fatigue induction with modality compatible tasks. In contrast, we expected an additional, selective increase in modality incompatible dual-task costs after a fatigue induction with modality incompatible tasks. We tested a group of 45young individuals (19–30 years) in an online pre-post design, in which participants were assigned to one of three groups. The two fatigue groups completed a 90-min time-on-task intervention with a dual task comprising either compatible or incompatible modality mappings. The third group paused for 90 min as a passive control group. Pre and post-session contained single and dual tasks in both modality mappings for all participants. In addition to behavioral performance measurements, seven subjective items (effort, focus, subjective fatigue, motivation, frustration, mental and physical capacity) were analyzed. Mean dual-task performance during and after the intervention indicated a practice effect instead of the presumed fatigue effect for all three groups. The modality incompatible intervention group showed a selective performance improvement for the modality incompatible mapping but no transfer to the modality compatible dual task. In contrast, the compatible intervention group showed moderately improved performance in both modality mappings. Still, participants reported increased subjective fatigue and reduced motivation after the fatigue intervention. This dynamic interplay of training and fatigue effects suggests that high control demands were involved in the prolonged performance of a modality incompatible dual task, which are separable from modality compatible dual-task demands

Immune targets in the tumor microenvironment treated by radiotherapy.

Radiotherapy (RT), the major anti-cancer modality for more than half of cancer patients after diagnosis, has the advantage of local tumor control with relatively less systematic side effects comparing to chemotherapy. However, the efficacy of RT is limited by acquired tumor resistance leading to the risks of relapse and metastasis. To further enhance the efficacy of RT, with the renaissances of targeted immunotherapy (TIT), increasing interests are raised on RT combined with TIT including cancer vaccines, T-cell therapy, and antibody-based immune checkpoint blockers (ICB) such as anti-CTLA-4 and anti-PD1/PD-L1. In achieving a significant synergy between RT and TIT, the dynamics of radiation-induced response in tumor cells and stromal cells, especially the cross-talk between tumor cells and immune cells in the irradiated tumor microenvironment (ITME) as highlighted in recent literature are to be elucidated. The abscopal effect refereeing the RT-induced priming function outside of ITME could be compromised by the immune-suppressive factors such as CD47 and PD-L1 on tumor cells and Treg induced or enhanced in the ITME. Cell surface receptors temporally or permanently induced and bioactive elements released from dead cells could serve antigenic source (radiation-associated antigenic proteins, RAAPs) to the host and have functions in immune regulation on the tumor. This review is attempted to summarize a cluster of factors that are inducible by radiation and targetable by antibodies, or have potential to be immune regulators to synergize tumor control with RT. Further characterization of immune regulators in ITME will deepen our understanding of the interplay among immune regulators in ITME and discover new effective targets for the combined modality with RT and TIT

Age-Related Interference between the Selection of Input-Output Modality Mappings and Postural Control—a Pilot Study

Age-related decline in executive functions and postural control due to degenerative processes in the central nervous system have been related to increased fall-risk in old age. Many studies have shown cognitive-postural dual-task interference in old adults, but research on the role of specific executive functions in this context has just begun. In this study, we addressed the question whether postural control is impaired depending on the coordination of concurrent response-selection processes related to the compatibility of input and output modality mappings as compared to impairments related to working-memory load in the comparison of cognitive dual and single tasks. Specifically, we measured total center of pressure (CoP) displacements in healthy female participants aged 19–30 and 66–84 years while they performed different versions of a spatial one-back working memory task during semi- tandem stance on an unstable surface (i.e., balance pad) while standing on a force plate. The specific working-memory tasks comprised: (i) modality compatible single tasks (i.e., visual-manual or auditory-vocal tasks), (ii) modality compatible dual tasks (i.e., visual-manual and auditory-vocal tasks), (iii) modality incompatible single tasks (i.e., visual-vocal or auditory- manual tasks), and (iv) modality incompatible dual tasks (i.e., visual-vocal and auditory-manual tasks). In addition, participants performed the same tasks while sitting. As expected from previous research, old adults showed generally impaired performance under high working-memory load (i.e., dual vs. single one-back task). In addition, modality compatibility affected one-back performance in dual-task but not in single-task conditions with strikingly pronounced impairments in old adults. Notably, the modality incompatible dual task also resulted in a selective increase in total CoP displacements compared to the modality compatible dual task in the old but not in the young participants. These results suggest that in addition to effects of working- memory load, processes related to simultaneously overcoming special linkages between input- and output modalities interfere with postural control in old but not in young female adults. Our preliminary data provide further evidence for the involvement of cognitive control processes in postural tasks

The effects of scopolamine upon control of attention and memory in humans

Research into the effects of scopolamine hydrobromide, a post­synaptic cholinergic receptor blocking drug, upon cognition in humans has been conducted for at least two decades. In that time, a distinct pattern of effects has emerged. Within a dose range of 0.3 to 1.2 mg (oral), scopolamine has been found to impair the acquisition of new information in verbal and spatial learning tasks, to reduce stimulus sensitivity in tests of vigilance and to impair selective attention. Generally it is thought that information retrieval, both of newly learned and autobiographical material, is unaffected by this drug. A primary reason for research interest in scopolamine is that the effects have been found to resemble the pattern of impairment found in advanced age, and particularly in Alzheimer's Disease (AD). This is often referred to as the 'Scopolamine model of dementia'. Coupled with the observation of extensive damage to CNS cholinergic neurons in AD, the hypothesis has emerged that acetylcholine activity influences many important cognitive processes. Recent theoretical analyses of cognitive loss in AD have proposed that there is a selective impairment to effortful (i.e. active, conscious) processes, whereas the more automatic (i.e. reflexive, unconscious) aspects of cognition remain intact. If the scopolamine model is to remain valid in this perspective, then it should be possible to show that, in normal humans, the effects of the drug are specific to effortful cognitive control processes. This thesis describes six experiments designed to test this prediction. It is presented in three parts. In Part I, two experiments examined the effects of O. 6mg and O. 9mg oral scopolamine upon the control of attention to targets in visual space. Results confirmed the prediction that the ability to detect stimuli in high probability locations on a VDU is impaired, while detection of stimuli in low probability locations is enhanced. It was argued that the drug broadened the attentional focus, and that this is due to a general reduction in cognitive control. In Part II, two studies sought to find evidence that the drug impairs the active selection of information from semantic memory. Here, subjects were not provided with material to learn, but rather were asked to sustain the retrieval of items from natural semantic categories for extended periods (8 to 12 min). In the second study of this pair, subjects were also constrained as to the type of retrieval strategy they could use. Results failed to confirm the prediction. The drug had no main or interactive effects on active control over semantic memory retrieval. In Part III, two studies tested the prediction that scopolamine would selectively impair the more difficult, controlled aspects of encoding and retrieval following presentation of verbal material (i.e. an episodic memory task) in two sensory modalities (auditory and visual). Subjects were required to recall lists of words, and to actively group their recall on the basis of the items' sensory modality. The first study found that the drug impaired recall, but not recognition, and did not have an effect on more automatic phenomena such as word priming effects and the recall advantage for auditory material. In addition, there was some evidence from statistical interactions that the drug impaired subjects' ability to actively cluster the presented material on the basis of input modality. The second experiment examined effects of scopolamine upon list learning and modality clustering when subjects were given five attempts to recall the same i terns. This experiment introduced two levels of task difficulty, by varying the extent to which item input modality was consistent across learning trials. Pilot testing (non-drug) revealed that list learning and clustering ability were significantly impaired in the variable, as compared to consistent, modality condition. In the full experiment, scopolamine impaired total recall but not recognition. The drug did not directly effect subjects' ability to group items on the basis of modality, and the size of the drug effect on immediate recall was similar for both the easy (i.e. consistent modality) and difficult (i.e. variable modality) learning trials. There were some interactions between drug and task variables which indicated a weak effect upon attention Taken together, these six experiments show the following pattern. Control over visual attention is impaired by scopolamine, and this agrees with some previous research. However, this reduction in cognitive control appears to be specific, rather than general, since the attempts to find an effect of the drug on active control of retrieval from semantic memory and the conscious organisation of material in episodic memory were unsuccessful. In theoretical terms, this series of experiments does not support the view that anticholinergic drug effects are specific to effortful processing. It was argued that the pattern of drug effects observed here is not simply due to low potency of a O. 9mg oral dose. Numerous previous experiments have observed subtle effects of scopolamine 0.9mg oral (and lower doses) on various measures of cognitive function. It was concluded that a low to moderate dose of oral scopolamine does have selective effects on different cognitive processes, but that this selectivity is not related to the amount of cognitive effort involved in the tasks. This work has identified some important limits to the scopolamine model of dementia, and extended research with this drug into several domains of human memory not previously examined. The implications for future research are discussed

Control and controllability of microswimmers by a shearing flow

With the continuing rapid development of artificial microrobots and active particles, questions of microswimmer guidance and control are becoming ever more relevant and prevalent. In both the applications and theoretical study of such microscale swimmers, control is often mediated by an engineered property of the swimmer, such as in the case of magnetically propelled microrobots. In this work, we will consider a modality of control that is applicable in more generality, effecting guidance via modulation of a background fluid flow. Here, considering a model swimmer in a commonplace flow and simple geometry, we analyse and subsequently establish the efficacy of flow-mediated microswimmer positional control, later touching upon a question of optimal control. Moving beyond idealized notions of controllability and towards considerations of practical utility, we then evaluate the robustness of this control modality to sources of variation that may be present in applications, examining in particular the effects of measurement inaccuracy and rotational noise. This exploration gives rise to a number of cautionary observations, which, overall, demonstrate the need for the careful assessment of both policy and behavioural robustness when designing control schemes for use in practice

The impact of auditory working memory training on the fronto-parietal working memory network

Working memory training has been widely used to investigate working memory processes. We have shown previously that visual working memory benefits only from intra-modal visual but not from across-modal auditory working memory training. In the present functional magnetic resonance imaging study we examined whether auditory working memory processes can also be trained specifically and which training-induced activation changes accompany theses effects. It was investigated whether working memory training with strongly distinct auditory materials transfers exclusively to an auditory (intra-modal) working memory task or whether it generalizes to a (across-modal) visual working memory task. We used adaptive n-back training with tonal sequences and a passive control condition. The memory training led to a reliable training gain. Transfer effects were found for the (intra-modal) auditory but not for the (across-modal) visual transfer task. Training-induced activation decreases in the auditory transfer task were found in two regions in the right inferior frontal gyrus. These effects confirm our previous findings in the visual modality and extents intra-modal effects in the prefrontal cortex to the auditory modality. As the right inferior frontal gyrus is frequently found in maintaining modality-specific auditory information, these results might reflect increased neural efficiency in auditory working memory processes. Furthermore, task-unspecific (amodal) activation decreases in the visual and auditory transfer task were found in the right inferior parietal lobule and the superior portion of the right middle frontal gyrus reflecting less demand on general attentional control processes. These data are in good agreement with amodal activation decreases within the same brain regions on a visual transfer task reported previously

Prev Chronic Dis

IntroductionFew studies have prospectively assessed the explanatory effects of demographics, clinical conditions, treatment modality, and general lifestyle behaviors on glycemic control in large heterogeneous samples of middle-aged and older adults with type 2 diabetes. We hierarchically examined these factors, focused especially on the effects of modifiable factors (ie, general lifestyle behaviors), and compared predictive patterns between middle-aged and older adults.MethodsWe used nationally representative data from the 1998 and 2000 Health and Retirement Study (HRS) and the HRS 2003 Diabetes Study. We analyzed data from 379 middle-aged adults (aged 51-64 y) and 430 older adults (aged \ue2\u2030\ua565 y) who self-reported having type 2 diabetes at baseline.ResultsAmong middle-aged adults, demographic factors and clinical conditions were the strongest predictors of hemoglobin A1c (HbA1c) levels. However, among older adults, treatment modality (diet only, oral medication, or insulin only or in combination with other regimens) significantly affected HbA1c levels. Lifestyle (physical activity, smoking, drinking, and body weight control), independent of the effects of demographics, clinical conditions, and treatment modality, significantly affected HbA1c levels. An increase of 1 healthy behavior was associated with a decrease in HbA1c levels of more than 1 percentage point.ConclusionOur findings provide support for current diabetes guidelines that recommend a lifestyle regimen across the entire span of diabetes care and highlight the need to help both sociodemographically and clinically disadvantaged middle-aged adults with type 2 diabetes as well as older adults who exhibit poor adherence to medication recommendations to achieve better glycemic control