Nils B. Kroemer

Stronger brain responses to acute stress reflect greater everyday stress variability

The paper links acute stress brain responses to everyday stress variability, finding greater variability correlates with stronger neural stress responses in specific brain regions.

Non-invasive vagus nerve stimulation modulates Pavlovian bias in a state-dependent manner

This study shows that non-invasive vagus nerve stimulation reduces Pavlovian response biases only after a caloric load, suggesting state-dependent modulation related to metabolic interoception.

Effects of non-invasive vagus nerve stimulation on pupil dilation are dependent on sensory matching

This study investigates how non-invasive vagus nerve stimulation affects pupil dilation and finds that effects depend on differences in perceived sensation between stimulation and sham conditions.

Higher glucose levels buffer against everyday stress load

This study finds that higher glucose levels are associated with lower self-reported stress and can predict subsequent stress changes in healthy individuals.

From stomach to striatum: Ghrelin infusions increase work for rewards

This paper investigates the effects of ghrelin infusions on motivation and brain activity in humans, finding increased effort for rewards and enhanced striatal connectivity.

Glucose levels are associated with mood, but the association is mediated by ratings of metabolic state

This study shows that glucose levels are linked to mood, but this link is fully mediated by conscious ratings of metabolic state, not subconscious processes.

Metabolic state shapes cortisol reactivity to acute stress: A systematic review and meta-analysis of metabolic and hormonal modulators

This study examines how metabolic and hormonal factors influence cortisol reactivity to acute stress through a systematic review and meta-analysis of 21 studies.

Does transcutaneous vagus nerve stimulation alter pupil dilation? A living Bayesian meta-analysis

This paper performs a Bayesian meta-analysis comparing continuous and pulsed tVNS protocols on pupil dilation, finding stronger evidence for pulsed tVNS effects.

Stress-induced brain responses are associated with BMI in women

The paper examines how stress-induced brain responses relate to BMI in women, finding that specific brain regions predict BMI and that endocrine factors, not inflammation, are linked to these changes.

Non-invasive vagus nerve stimulation decreases vagally mediated heart rate variability

This study investigates the effects of transcutaneous auricular vagus nerve stimulation (taVNS) on heart rate and variability, finding that it decreases HRV without altering HR.

How gut hormones shape reward: a systematic review of the role of ghrelin and GLP-1 in human fMRI

This paper reviews the role of ghrelin and GLP-1 in human reward systems using fMRI, finding ghrelin increases reward responses while GLP-1 effects are less consistent.

Vagus nerve stimulation increases stomach-brain coupling via a vagal afferent pathway

This study shows that vagus nerve stimulation increases stomach-brain coupling in specific brain regions and correlates with changes in hunger ratings.

Spatio-temporal dynamics of stress-induced network reconfigurations reflect negative affectivity

The paper identifies spatio-temporal brain network reconfigurations during stress that predict negative affectivity but not disorder diagnosis.

Acute vagus nerve stimulation does not affect liking or wanting ratings of food in healthy participants

Brain signaling dynamics after vagus nerve stimulation

This study investigates the effects of transcutaneous vagus nerve stimulation (tVNS) on brain signaling using fMRI, finding increased NTS activation but no changes in dynamic functional connectivity or gastric motility.

Influenca: a gamified assessment of value-based decision-making for longitudinal studies

Influenca is a gamified app for repeated assessment of reward learning, showing moderate reliability in reinforcement learning parameters over time.

Non-invasive vagus nerve stimulation boosts mood recovery after effort exertion

This study shows that non-invasive vagus nerve stimulation improves positive mood after physical and cognitive exertion, with effects dependent on baseline mood.

Can't decide how much to EAT? Effort variability for reward is associated with cognitive restraint

The paper examines the relationship between variability in reward seeking and eating behaviors, finding that greater effort variability is linked to lower cognitive restraint.

Threat-induced hippocampal connectivity fingerprints do not generalize to psychosocial stress

This paper tests if a machine learning model predicting stress from hippocampal connectivity generalizes to psychosocial stress, finding limited generalizability.

Localized prediction of glutamate from whole-brain functional connectivity of the pregenual anterior cingulate cortex

The paper uses machine learning to predict local glutamate levels from functional connectivity in the pregenual anterior cingulate cortex, showing better prediction for p32 than p24.

Evidence for modulation of EEG microstate sequence by vigilance level

This study shows that EEG microstate parameters are associated with vigilance levels, with different effects on microstate class durations and transitions.

Vagus nerve stimulation increases vigor to work for rewards

This study shows that transcutaneous auricular vagus nerve stimulation (taVNS) increases vigor for rewards, particularly for food, but not effort maintenance, with left-side stimulation having a stronger effect.

Stimulation of the vagus nerve reduces learning in a go/no-go reinforcement learning task

This study shows that vagus nerve stimulation impairs reinforcement learning by reducing the learning rate, particularly after punishment, in a go/no-go task.

Non-invasive stimulation of vagal afferents reduces gastric frequency

This study shows that non-invasive vagus nerve stimulation reduces gastric frequency without affecting resting energy expenditure.

Individual differences in dopamine function underlying the balance between model-based and model-free control

This study investigates how baseline dopamine levels influence the effect of L-DOPA on model-based and model-free control in decision-making tasks.

The anterior insula channels prefrontal expectancy signals during affective processing

This study investigates how the anterior insula modulates prefrontal cortex responses to emotional stimuli based on expectancy signals using fMRI and cross-correlation analyses.

Addressing the reliability fallacy: Similar group effects may arise from unreliable individual effects

The paper shows that reliable group brain activation patterns do not guarantee reliable individual measurements and provides a toolbox to assess fMRI contrast reliability.

L-DOPA reduces model-free control of behavior by attenuating the transfer of value to action

This study shows that L-DOPA reduces model-free control of behavior by decreasing the influence of reward on choices and increasing choice randomness, as measured by fMRI.