Biology subjects

Tunnermann, J.

Publications and source records attributed to Tunnermann, J..

3 recordsLinked to original sources

bioRxiv2025

Enhancer control of promoter activity and variability via frequency modulation of clustered transcriptional bursts

Gene expression in mammalian cells is controlled by enhancers that are often dispersed across large cis-regulatory landscapes around a promoter. Yet how enhancers determine transcription of their target genes, and how this depends on their relative position inside a cis-regulatory landscape remains unclear. Here we use live-cell imaging to track the activity of a promoter under the control of the same enhancer, but inserted at different positions across a simplified regulatory landscape with minimal complexity. Combined with mathematical modeling, this reveals that RNA production from the promoter occurs in clusters of transcriptional bursts, with enhancer position controlling the frequency at which such clusters appear. This results in bursts being more frequent and occurring more uniformly across cells when the enhancer is genomically close to the promoter than when it is located at large genomic distance. Mathematical modeling further indicates that the enhancer modulates the promoters ability to transition from its basal transcriptional state to a regime where clusters of bursts become more frequent. Our results challenge existing models of mammalian promoter operation, and reveal that enhancer position within a cis-regulatory landscape critically controls the timing and variability of transcriptional output in single cells.

molecular biology↗

bioRxiv2024

Trade-off between search costs and accuracy in oculomotor and manual search tasks

Humans must weigh various factors when choosing between competing courses of action. In case of eye movements, for example, a recent study demonstrated that the human oculomotor system trades off the temporal costs of eye movements against their perceptual benefits, when choosing between competing visual search targets. Here, we compared such trade-offs between different effectors. Participants were shown search displays with targets and distractors from two stimulus sets. In each trial, they chose which target to search for, and, after finding it, discriminated a target feature. Targets differed in their search costs (how many target-similar distractors were shown) and discrimination difficulty. Participants were rewarded or penalized based on whether the targets feature was discriminated correctly. Additionally, participants were given limited time to complete trials. Critically, they inspected search items either by eye movements only or by manual actions (tapping a stylus on a tablet). Results show that participants traded off search costs and discrimination difficulty of competing targets for both effectors, allowing them to perform close to the predictions of an ideal observer model. However, behavioral analysis and computational modelling revealed that oculomotor search performance was more strongly constrained by decision-noise (what target to choose) and sampling-noise (what information to sample during search) than manual search. We conclude that the trade-off between search costs and discrimination accuracy constitutes a general mechanism to optimize decision-making, regardless of the effector used. However, slow-paced manual actions are more robust against the detrimental influence of noise, compared to fast-paced eye movements. New & NoteworthyHumans trade off costs and perceptual benefits of eye movements for decision-making. Is this trade-off effector-specific or does it constitute a general decision-making principle? Here, we investigated this question by contrasting eye movements and manual actions (tapping a stylus on a tablet) in a search task. We found evidence for a costs-benefits trade-off in both effectors, however, eye movements were more strongly compromised by noise at different levels of decision-making.

neuroscience↗

bioRxiv2024

Self-association enhances early attentional selection through automatic prioritization of socially salient signals

Efficiently processing self-related information is critical for cognition, yet the earliest mechanisms enabling this self-prioritization remain unclear. By combining a temporal order judgement task with computational modelling based on the Theory of Visual Attention (TVA), we show how mere, arbitrary associations with the self can fundamentally alter attentional selection of sensory information into short-term memory/awareness, by enhancing the attentional weights and processing capacity devoted to encoding socially loaded information. This self-prioritization in attentional selection occurs automatically at early perceptual stages but reduces when active social decoding is required. Importantly, the processing benefits obtained from attentional selection via self-relatedness and via physical salience were additive, suggesting that social and perceptual salience captured attention via separate mechanisms. Furthermore, intra-individual correlations revealed an obligatory self-prioritization effect, whereby self-relatedness overpowered the contribution of perceptual salience in guiding attentional selection. Together, our findings provide evidence for the influence of self-relatedness during earlier, automatic stages of attentional section at the gateway to perception, distinct from later post-attentive processing stages.

neuroscience↗