Petra Hermann

YNIMG Journal 2025 Journal Article

Slow-wave sleep is associated with nucleus accumbens volume in elderly adults

• Kitti Bán
• Ádám Nárai
• Noémi Báthori
• Éva M. Bankó
• Adél Bihari
• Vivien Tomacsek
• Tibor Kovács
• Béla Weiss

Slow-wave sleep (SWS) is essential for restorative neural processes and its decline is associated with both healthy and pathological ageing. Building on previous rodent research, this longitudinal study identified a significant association between nucleus accumbens (NAcc) volume and SWS duration in cognitively unimpaired older adults, whilst no significant link was observed between NAcc volume and N2 or rapid eye movement (REM) sleep percentage. Our findings support the involvement of the NAcc in ageing-related modulation of SWS and thus suggest the NAcc as a potential neural marker or therapeutic target for improving SWS.

YNIMG Journal 2024 Journal Article

The effect of head motion on brain age prediction using deep convolutional neural networks

• Pál Vakli
• Béla Weiss
• Dorina Rozmann
• György Erőss
• Ádám Nárai
• Petra Hermann
• Zoltán Vidnyánszky

Deep learning can be used effectively to predict participants' age from brain magnetic resonance imaging (MRI) data, and a growing body of evidence suggests that the difference between predicted and chronological age-referred to as brain-predicted age difference (brain-PAD)-is related to various neurological and neuropsychiatric disease states. A crucial aspect of the applicability of brain-PAD as a biomarker of individual brain health is whether and how brain-predicted age is affected by MR image artifacts commonly encountered in clinical settings. To investigate this issue, we trained and validated two different 3D convolutional neural network architectures (CNNs) from scratch and tested the models on a separate dataset consisting of motion-free and motion-corrupted T1-weighted MRI scans from the same participants, the quality of which were rated by neuroradiologists from a clinical diagnostic point of view. Our results revealed a systematic increase in brain-PAD with worsening image quality for both models. This effect was also observed for images that were deemed usable from a clinical perspective, with brains appearing older in medium than in good quality images. These findings were also supported by significant associations found between the brain-PAD and standard image quality metrics indicating larger brain-PAD for lower-quality images. Our results demonstrate a spurious effect of advanced brain aging as a result of head motion and underline the importance of controlling for image quality when using brain-predicted age based on structural neuroimaging data as a proxy measure for brain health.

YNIMG Journal 2021 Journal Article

Neural basis of distractor resistance during visual working memory maintenance

• Petra Hermann
• Béla Weiss
• Balázs Knakker
• Petra Madurka
• Annamária Manga
• Ádám Nárai
• Zoltán Vidnyánszky

Visual working memory representations must be protected from the intervening irrelevant visual input. While it is well known that interference resistance is most challenging when distractors match the prioritised mnemonic information, its neural mechanisms remain poorly understood. Here, we identify two top-down attentional control processes that have opposing effects on distractor resistance. We reveal an early selection negativity in the EEG responses to matching as compared to non-matching distractors, the magnitude of which is negatively associated with behavioural distractor resistance. Additionally, matching distractors lead to reduced post-stimulus alpha power as well as increased fMRI responses in the object-selective visual cortical areas and the inferior frontal gyrus. However, the congruency effect found on the post-stimulus periodic alpha power and the inferior frontal gyrus fMRI responses show a positive association with distractor resistance. These findings suggest that distractor interference is enhanced by proactive memory content-guided selection processes and diminished by reactive allocation of top-down attentional resources to protect memorandum representations within visual cortical areas retaining the most selective mnemonic code.

YNICL Journal 2019 Journal Article

Efficacy of weight loss intervention can be predicted based on early alterations of fMRI food cue reactivity in the striatum

• Petra Hermann
• Viktor Gál
• István Kóbor
• C. Brock Kirwan
• Péter Kovács
• Tamás Kitka
• Zsuzsanna Lengyel
• Eszter Bálint

Increased fMRI food cue reactivity in obesity, i.e. higher responses to high- vs. low-calorie food images, is a promising marker of the dysregulated brain reward system underlying enhanced susceptibility to obesogenic environmental cues. Recently, it has also been shown that weight loss interventions might affect fMRI food cue reactivity and that there is a close association between the alteration of cue reactivity and the outcome of the intervention. Here we tested whether fMRI food cue reactivity could be used as a marker of diet-induced early changes of neural processing in the striatum that are predictive of the outcome of the weight loss intervention. To this end we investigated the relationship between food cue reactivity in the striatum measured one month after the onset of the weight loss program and weight changes obtained at the end of the six-month intervention. We observed a significant correlation between BMI change measured after six months and early alterations of fMRI food cue reactivity in the striatum, including the bilateral putamen, right pallidum, and left caudate. Our findings provide evidence for diet-induced early alterations of fMRI food cue reactivity in the striatum that can predict the outcome of the weight loss intervention.

YNIMG Journal 2014 Journal Article

Repetition probability effects for inverted faces

• Mareike Grotheer
• Petra Hermann
• Zoltán Vidnyánszky
• Gyula Kovács