Biology subjects

Widmann, A.

Publications and source records attributed to Widmann, A..

9 recordsLinked to original sources

bioRxiv2026

Interaction of involuntary and executive attention during development

Attentional control requires the fine-tuned interaction of attentional networks supporting alertness, orienting and higher-level executive control. This study examined the interaction of executive attention, comprising inhibition, and involuntary orienting towards unexpected deviant sounds in children (6-8-years, N=30), adolescents (10-12-years, N=39) and adults (18-34-years, N=35). An auditory equiprobable Go/Nogo-Oddball paradigm was employed to investigate executive (Go/Nogo) and involuntary (Oddball) attention and their interaction. Event-related potentials (ERP) in the EEG, pupil dilation and behavioral data were analyzed using Bayesian statistics. Deviant sounds evoked an involuntary attentional orienting reflected by the ERP component P3a and decreased performance in all age groups. The distraction effect diminished with age. Pupil dilation in response to deviant and target sounds were modulated by involuntary and executive attention but showed no interaction. In the EEG, frontal Nogo-N2 and Nogo-P3 effects, which reflect response inhibition, appeared in standard trials but not in deviant trials. This interaction suggests that response inhibition is reduced by involuntary attention orienting. While all age groups showed similar amplitudes of the Nogo-N2 effect, the subsequent Nogo- P3 effect, which has been associated to motor inhibition, was absent in the 6-8-year-olds. Age differences observed in latencies of the Nogo-N2 effect but not in the latencies of the Nogo- P3 effect (between adolescents and adults) indicate distinct developmental trajectories of the response inhibition mechanisms underlying the Nogo-N2 and Nogo-P3 effects throughout childhood and adolescence. The present data provide novel insights into the interaction between executive and orienting attention networks in the auditory modality during development.

neuroscience↗

bioRxiv2025

Tuned to explore: Increased phasic responses to auditory targets and novelty in children regardless of induced tonic arousal

The ability to focus on relevant information while ignoring distractions is critical during childhood, as it supports learning, social interaction, and adaptation to changing environments. This attentional balance is thought to depend in part on arousal regulation, mediated by the activity of the locus coeruleus norepinephrine (LC-NE) system. Moderate levels of arousal are typically associated with optimal cognitive performance. However, the interaction between arousal and attention remains poorly understood in humans, especially during development. In this study, we investigated whether experimentally modulating tonic arousal, the baseline level of physiological alertness, affects attentional processing in children (N = 44, aged 6-8) and adults (N = 46, aged 18-35). Participants performed an active auditory three-stimulus (standard, novel, target) oddball task, designed to assess selective attention to target tones and distraction by novel sounds. Prior to each task block, tonic arousal was manipulated using music or videos varying in arousing content. Physiological responses were recorded continuously (skin conductance, pupil dilation, heart rate) to index both tonic arousal and transient, phasic changes in arousal triggered by task events. While tonic arousal modulation was successful, as confirmed by skin conductance levels, Bayesian analyses provided evidence for no effect of this modulation on subsequent attentional processing. Importantly, children generally exhibited stronger phasic arousal responses, particularly to task-irrelevant novel sounds, reflecting less mature regulation of attention and arousal. These findings show developmental differences in physiological responses to unexpected environmental stimuli and provide physiological evidence of increased distractibility during childhood.

neuroscience↗

bioRxiv2025

Eye movements of younger and older adults decrease during story listening in background noise

Assessments of listening effort are increasingly relevant to understanding the speech-comprehension difficulties experienced by older adults. Pupillometry is the most common tool to assess listening effort but has limitations. Recent research has shown that eye movements decrease when listening is effortful and proposed indicators of eye movements as alternative measures. However, much of the work was conducted in younger adults in trial-based sentence-listening paradigm, during concurrent visual stimulation. The extent to which eye movements index listening effort during con tinuous speech listening, independently of visual stimuli, and in older adults, is unknown. In the current study, younger and older adults listened to continuous stories with varying degrees of background noise under free and moving-dot viewing conditions. Eye movements decreased (as indexed by fixation duration, gaze dispersion, and saccade rate) with increasing speech masking. The reduction in eye movements did not depend on age group or viewing conditions, indicating that eye movements can be used to assess effects of speech masking in different visual situations and in people of different ages. The pupil area was only sensitive to speech masking early in the experiment. In sum, the current study suggests that eye movements are a potential tool to assess listening effort during continuous speech listening.

neuroscience↗

bioRxiv2025

Flexibility and Neural Correlates of Action-Sound Predictions

To interact efficiently with our environment, our brain predicts the sensory effects of our actions and compares them with the actual outcomes. This allows us to adapt our actions when predictions and sensory outcomes mismatch. While this process is generally well understood for action-sound predictions, it is an open question how flexibly these predictions can adapt in frequently changing environments, as they occur in real life. To investigate the flexibility of top-down predictions, we asked participants (N = 41) to press one of two buttons, a left-hand and a right-hand button, and switch hands autonomously. One button frequently produced a sound (80%) and rarely no sound. The other button frequently generated no sound (80%) and rarely produced a sound. In a third, separate condition, each button produced a sound in 50% of the trials. Unexpected sounds and unexpected sound omissions elicited a series of error-related brain responses in the electroencephalogram (EEG) at different levels of auditory processing, including a mismatch negativity (MMN) and the P3 complex for unexpected sounds, and the oN1, oN2, and oP3 complex for unexpected omissions. Moreover, unexpected sounds elicited an equivalent MMN--regardless of whether silence was expected (80%) or no reliable expectation was possible (50%), while later P3 components showed different amplitudes. Our results demonstrate flexible action-sound predictions at sensory and higher cortical levels. Furthermore, they indicate that predicted silence does not have an explicit sensory representation at lower levels but emerges at later stages, when higher-level information has been integrated.

neuroscience↗

bioRxiv2024

Critical roles of ERK and Akt signaling in metabolically dependent memory formation in Drosophila larvae.

In the fruit fly Drosophila, memory formation is intricately linked to metabolic state. Our previous findings showed that the preferential support of memory under increased energy levels is mediated by the insulin receptor in the mushroom body (MB), a key memory center in the insect brain. This study analyzed the role of the insulin receptors downstream pathways, Ras-Raf-MEK-ERK and PI3K/Akt, in metabolically dependent memory formation. We evaluated their impact on memory processes by employing RNA interference-mediated downregulation of key components, extracellular signal-regulated kinase (ERK) and protein kinase B (Akt), in the MB of Drosophila larvae. To enhance energy levels, larvae were fed sugar for 60 minutes prior to aversive olfactory conditioning. Our findings revealed that genetically downregulating ERK and Akt in the MB significantly impaired metabolically dependent memory formation, without affecting naive sensory perception or olfactory learning. Immunohistochemical analysis confirmed the presence of active forms of ERK and Akt in the MB, underscoring their roles in modulating memory processes under elevated energy levels. The pivotal roles of these kinases suggest a broader implication of insulin signaling in memory formation under different metabolic conditions, and illuminate the connections between metabolic regulation and memory dynamics in the MB.

neuroscience↗

bioRxiv2024

Enhancing tonic arousal improves voluntary but not involuntary attention in humans

Arousal and attention are fundamental brain functions that play a critical role in optimizing performance. Kahnemans attention model (1973) theorizes a key interplay between attention and arousal, yet this relationship remains poorly understood. Using a multimodal approach, we investigated this interaction in healthy young adults performing an auditory attention task designed to simultaneously assess phasic arousal, voluntary attention, and involuntary attention. Furthermore, tonic arousal was experimentally modulated with low or high arousing music, as confirmed by changes in pupil size and heart rate. Behavioral data confirmed that informative cues enhanced voluntary attention, while unexpected salient task-irrelevant sounds (so-called distractors) produced either shortened or lengthened reaction times depending on their timing relative to target onset. Physiological data indicated that the facilitation effect of distractors on reaction times was driven by increases in phasic arousal. This benefit was further modulated by a dynamic interplay between phasic arousal and voluntary attention over time. Supporting Aston-Jones and Cohens theory, a fronto-central cortical response to distractors revealed that tonic and phasic arousal interact in line with an inverted U-shaped relationship. This study provides empirical evidence, in humans, that tonic arousal can optimize performance by tuning phasic arousal and attentional control.

neuroscience↗

bioRxiv2023

Cognitive limits of larval Drosophila: Testing for conditioned inhibition, sensory preconditioning and second-order conditioning

Drosophila larvae are an established model system for studying the mechanisms of innate and simple forms of learned behaviour. They have about 10 times fewer neurons than adult flies, and it was the low total number of their neurons that allowed for an electron microscopic reconstruction of their brain at synaptic resolution. Regarding the mushroom body, a central brain structure for associative learning in insects, it turned out that more than half of the classes of synaptic connection had previously escaped attention. Understanding the function of these circuit motifs, subsequently confirmed in adult flies, is an important current research topic. In this context, we test larval Drosophila for their cognitive abilities in three tasks that are characteristically more complex than those previously studied. Our data provide evidence for (i) conditioned inhibition, as has previously been reported for adult flies and honeybees. Unlike what is described for adult flies and honeybees, however, our data do not provide evidence for (ii) sensory preconditioning or (iii) second-order conditioning in Drosophila larvae. We discuss methodological features of our experiments as well as four specific aspects of the organisation of the larval brain that may explain why these two forms of learning are observed in honeybees and adult flies, but not in larval Drosophila.

animal behavior and cognition↗

bioRxiv2019

Insulin signaling gates long-term memory formation in Drosophila larvae

The ability to learn new skills and to store them as memory entities is one of the most impressive features of higher evolved organisms. However, not all memories are created equal; some are short-lived forms, and some are longer lasting. Formation of the latter is energetically costly and by the reason of restricted availability of food or fluctuations in energy expanses, efficient metabolic homeostasis modulating different needs like survival, growth, reproduction, or investment in longer lasting memories is crucial. Whilst equipped with cellular and molecular pre-requisites for formation of a protein synthesis dependent long-term memory (LTM), its existence in the larval stage of Drosophila remains elusive. Considering it from the viewpoint that larval brain structures are completely rebuilt during metamorphosis, and that this process depends completely on accumulated energy stores formed during the larval stage, investing in LTM represents an unnecessary expenditure. However, as an alternative, Drosophila larvae are equipped with the capacity to form a protein synthesis independent so-called larval anaesthesia resistant memory (lARM), which is consolidated in terms of being insensitive to cold-shock treatments. Motivated by the fact that LTM formation causes an increase in energy uptake in Drosophila adults, we tested the idea of whether an energy surplus can induce the formation of LTM in the larval stage. Indeed, increasing the metabolic state by feeding Drosophila larvae the disaccharide sucrose directly before aversive olfactory conditioning led to the formation of a larval LTM (lLTM). Moreover, we show that the metabolic state acts as a binary switch between the formation of lARM and lLTM. Based on this finding, we determined that it is the insulin receptor (InR) expressed in the mushroom body Kenyon cells (MB KCs) that mediates this switch to favor the formation of lLTM under energy-rich circumstances and lARM under energy-poor circumstances.

neuroscience↗

bioRxiv2018

Emotion lies in the eye of the listener: emotional arousal to novel sounds is reflected in the sympathetic contribution to the pupil dilation response and the P3

Novel sounds in the auditory oddball paradigm elicit a biphasic dilation of the pupil (PDR) and P3a as well as novelty P3 event-related potentials (ERPs). The biphasic PDR has been hypothesized to reflect the relaxation of the iris sphincter muscle due to parasympathetic inhibition and the constriction of the iris dilator muscle due to sympathetic activation. We measured the PDR and the P3 to neutral and to emotionally arousing negative novels in dark and moderate lighting conditions. By means of principal component analysis (PCA) of the PDR data we extracted two components: the early one was absent in darkness and, thus, presumably reflects parasympathetic inhibition, whereas the late component occurred in darkness and light and presumably reflects sympathetic activation. Importantly, only this sympathetic late component was enhanced for emotionally arousing (as compared to neutral) sounds supporting the hypothesis that emotional arousal specifically activates the sympathetic nervous system. In the ERPs we observed P3a and novelty P3 in response to novel sounds. Both components were enhanced for emotionally arousing (as compared to neutral) novels. Our results demonstrate that sympathetic and parasympathetic contributions to the PDR can be separated and link emotional arousal to sympathetic nervous system activation.\n\nHighlightsO_LIPDR and ERP effects of novel emotional and neutral oddball sounds were studied.\nC_LIO_LIParasympathetic and sympathetic contributions to the PDR were dissociated by PCA.\nC_LIO_LIThe parasympathetic PDR component was absent in darkness.\nC_LIO_LIEmotional arousal enhanced the sympathetic contribution to the PDR and the P3 ERP.\nC_LIO_LIEffects of emotional arousal are mediated by the sympathetic pathway.\nC_LI

neuroscience↗