Biology subjects

Horvath, K.

Publications and source records attributed to Horvath, K..

9 recordsLinked to original sources

bioRxiv2026

Fires attract and fuel hunting success of Australian pyrophilic birds

Changes in fire regimes negatively impact biodiversity worldwide1,2. The immediate behavioral responses of animals to fire, however, are largely unknown. Despite presenting obvious dangers, fire can also attract animals by providing unique foraging opportunities3. Such attraction to fire (pyrophilia) has already been observed in some bird species, yet its underlying motivation remains unidentified. Here, we examined the abundance and behavior of 16 bird species before, during, and after prescribed burns in the northern Australian savanna. Eight species were on average 3 to 23 times more abundant during fires. Raptors caught on average ten times more prey per hour during burns than in the absence of fire, and their foraging success increased with fire size. Black kites, the most pyrophilic birds observed, were more numerous during larger fires and foraged more efficiently on the ground than in the air. These results underscore the importance of investigating animal behavior in response to active fire and the effects of shifting fire regimes on the foraging ecology of pyrophilic animals.

animal behavior and cognition↗

bioRxiv2025

ADHD-like traits reshape the balance between inhibitory control and predictive processes

Adaptive behavior relies on a dynamic balance between flexible, goal-directed control and efficient, automatic processes. This equilibrium is often disrupted in Attention-Deficit/Hyperactivity Disorder (ADHD), a condition understood to exist along a continuum of traits in the general population. While ADHD is consistently linked to response inhibition deficits, its relationship with statistical learning (a mechanism for habit learning) and, crucially, the interaction between these functions, remains underexplored. Here, using a novel paradigm in a non-clinical sample of university students (n = 226), we investigated how ADHD-like traits modulate the interplay between response inhibition and statistical learning. We found that higher ADHD-like traits were associated with poorer response inhibition, confirming previous research. Importantly, we uncovered an antagonistic relationship between inhibition and statistical learning, where weaker inhibitory control typically led to enhanced learning of environmental regularities. However, this learning advantage progressively diminished across the ADHD trait continuum, becoming markedly reduced in individuals with high symptom prevalence. These findings provide novel evidence that ADHD-like traits influence not only isolated neurocognitive processes but also their dynamic interaction, highlighting a spectrum-based mechanism that may underlie the transition from adaptive variability to maladaptive behavioral patterns. This work advocates for a dimensional approach to ADHD, emphasizing early detection and targeted interventions for individuals with varying levels of symptomatic expression, broadening support beyond traditional diagnostic boundaries.

neuroscience↗

bioRxiv2023

Persistently increased post-stress activity of paraventricular thalamic neurons is essential for the emergence of stress-induced maladaptive behavior

ABSTRACTTraumatic events can immediately lead to debilitating symptoms collectively called Acute Stress Disorder (ASD), however the mechanisms of ASD are poorly understood. Using a rodent model of ASD here we identify a crucial communication bottleneck between the brainstem and the forebrain, the calretinin-positive neurons in the paraventricular thalamus (PVT/CR+), that controls ASD. We show that following a single acute stress event, the pre-sleep behavior of the mice is altered for several days in parallel with a persistent increase in the firing rate of PVT/CR+ cells. Optogenetic inhibition of PVT/CR+ neuronal activity after the stress event for one hour was sufficient to rescue both the ASD symptoms and the prolonged increase in PVT/CR+ firing rate. Inhibition applied 5 days later was still able to ameliorate some of the symptoms. These data suggest that post-stress activity of PVT/CR+ neurons play a critical role in mediating the acute forms of stress-related affective dysfunctions. One-Sentence SummaryPost-stress inhibition of paraventricular thalamic neurons prevents the emergence of acute stressed phenotype.

neuroscience↗

bioRxiv2022

Recruitment of Corticotropin-releasing Hormone CRH Neurons in response ton Categorically Distinct Stress Challenges in the Mouse Brain

1.Corticotropin-releasing hormone (CRH) neurons in the paraventricular hypothalamic nucleus (Pa) are in the position to integrate stress-related information and initiate adaptive neuroendocrine-, autonomic-, metabolic- and behavioral responses. In addition to hypophyseotropic cells, CRH is widely expressed in the CNS, however their involvement in organization of the stress response is not fully understood. In these experiments, we took the advantage of recently available Crh-IRES-Cre; Ai9 mouse line to study the recruitment of hypothalamic and extrahypothalamic CRH neurons in categorically distinct, acute stress reactions. Reporter mice were exposed to restraint, ether, high salt and lipopolisacharide stress. The induced activation of CRH neurons was detected by colocalization of immediate early gene c-Fos in Td tomato expressing cells. We found differential activation of CRH neurons in central amygdaloid nucleus (Ce), bed nucleus stria terminalis lateral division, ventral posterior (BSTLVP), medial preoptic nucleus (MPO), ventromedial hypothalamic nucleus (VMH), premammillary nucleus (PM) and prepositus hypoglossal nucleus (Pr) in response to physiological (ether, high salt and LPS) and psychological (restraint) stressors. CRH positive cells in Pa became activated, however in the Barringtons nucleus and locus coeruleus no actiovation could be observed due to most tested stressors. Furthermore no CRH neuron activation occured in dorsal (BSTLD) and posterior (BSTLP) region of lateral division of bed nucleus stria terminalis after restraint stress. In the inferior olive only ether exposition resulted in CRH neuron activation. These results confirm activation of CRH neurons in the Pa, reveals new subset of stress-related CRH cells through the mouse brain and disprove the recruitment of CRH cells in the SOL and in the Barringtons nucleus to acute psychological stress in mice.

neuroscience↗

bioRxiv2020

Neurophysiological coding of statistical and deterministic rule information

Humans are capable of acquiring multiple types of information presented in the same visual information stream. It has been suggested that at least two parallel learning processes are important during learning of sequential patterns - statistical learning and rule-based learning. Yet, the neurophysiological underpinnings of these parallel learning mechanisms in visual sequences are not fully understood. To differentiate between the simultaneous mechanisms at the single trial level, we apply a temporal EEG signal decomposition approach together with sLORETA source localization method to delineate whether distinct statistical and rule-based learning codes can be distinguished in EEG data and can be related to distinct functional neuroanatomical structures. We demonstrate that concomitant but distinct aspects of information coded in the N2 time window play a role in these mechanisms: mismatch detection and response control underlie statistical learning and rule-based learning, respectively, albeit with different levels of time-sensitivity. Moreover, the effects of the two learning mechanisms in the different temporally decomposed clusters of neural activity also differed from each other in neural sources. Importantly, the right inferior frontal cortex (BA44) was specifically implicated in statistical learning, confirming its role in the acquisition of transitional probabilities. In contrast, rule-based learning was associated with the prefrontal gyrus (BA6). The results show how simultaneous learning mechanisms operate at the neurophysiological level and are orchestrated by distinct prefrontal cortical areas. The current findings deepen our understanding on the mechanisms how humans are capable of learning multiple types of information from the same stimulus stream in a parallel fashion.

neuroscience↗

bioRxiv2020

Implicit anticipation of probabilistic regularities: Larger CNV emerges for unpredictable events

Anticipation of upcoming events plays a crucial role in automatic behaviors. It is, however, still unclear whether the event-related brain potential (ERP) markers of anticipation could track the implicit acquisition of probabilistic regularities that can be considered as building blocks of automatic behaviors. Therefore, in a four-choice reaction time (RT) task performed by young adults (N = 36), the contingent negative variation (CNV) as an ERP marker of anticipation was measured from the onset of a cue stimulus until the presentation of a target stimulus. Due to the probability structure of the task, target stimuli were either predictable or unpredictable, but this was unknown to participants. The cue did not contain predictive information on the upcoming target. Results showed that the CNV amplitude during response preparation was larger before the unpredictable than before the predictable target stimuli. In addition, although RTs increased, the P3 amplitude decreased for the unpredictable as compared with the predictable target stimuli, possibly due to the stronger response preparation that preceded stimulus presentation. These results suggest that enhanced attentional resources are allocated to the implicit anticipation and processing of unpredictable events. This might originate from the formation of internal models on the probabilistic regularities of the stimulus stream, which primarily facilitates the processing of predictable events. Overall, we provide ERP evidence that supports the role of implicit anticipation and predictive processes in the acquisition of probabilistic regularities.

neuroscience↗

bioRxiv2019

Perceiving structure in unstructured stimuli: Implicitly acquired prior knowledge impacts the processing of unpredictable transitional probabilities

It is unclear how implicit prior knowledge is involved and remains persistent in the extraction of the statistical structure underlying sensory input. Therefore, this study investigated whether the implicit knowledge of 2nd order transitional probabilities characterizing a stream of visual stimuli impacts the processing of unpredictable transitional probabilities embedded in a similar input stream. Young adults (N = 50) performed a four-choice reaction time (RT) task that consisted of structured and unstructured blocks. In the structured blocks, more probable and less probable short-range nonadjacent transitional probabilities were present. In the unstructured blocks, the unique combinations of the short-range transitional probabilities occurred with equal probability; therefore, they were unpredictable. All task blocks were visually identical at the surface level. While one-half of the participants completed the structured blocks first followed by the unstructured blocks, this was reversed in the other half of them. The change in the structure was not explicitly denoted, and no feedback was provided on the correctness of each response. Participants completing the structured blocks first showed faster RTs to more probable than to less probable short-range transitional probabilities in both the structured and unstructured blocks, indicating the persistent effect of prior knowledge. However, after extended exposure to the unstructured blocks, they updated this prior knowledge. Participants completing the unstructured blocks first showed the RT difference only in the structured blocks, which was not constrained by the preceding exposure to unpredictable stimuli. The results altogether suggest that implicitly acquired prior knowledge of predictable stimuli influences the processing of subsequent unpredictable stimuli. Updating this prior knowledge seems to require a longer stretch of time than its initial acquisition.

neuroscience↗

bioRxiv2018

Explicit instruction differentially affects subcomponents of procedural learning and consolidation

Procedural memory facilitates the efficient processing of complex environmental stimuli and contributes to the acquisition of automatic behaviours and habits. Learning can occur intentionally or incidentally, yet, how the mode of learning affects procedural memory is still poorly understood. Importantly, procedural memory is a complex cognitive function composed of different subprocesses, including the acquisition and consolidation of statistical, frequency-based and sequential, order-based knowledge. Therefore, we tested how statistical and sequence knowledge develops during incidental versus intentional procedural memory formation and during consolidation. Seventy-four young adults performed either the uncued, incidental (N = 37) or the cued, intentional (N = 37) version of a probabilistic sequence learning task. Performance was retested after a 12-hour offline period, enabling us to test the effect of sleep on consolidation; therefore, half of the participants slept during the delay, while the other half had normal daily activity (PM-AM versus AM-PM design). The mode of learning (incidental versus intentional) had no effect on the acquisition of statistical knowledge, while intention to learn increased sequence learning performance. Consolidation was not affected by intention to learn: Both statistical and sequence knowledge was retained over the 12-hour delay, irrespective of the mode of learning and whether the delay included sleep or wake activity. These results suggest a time-dependent instead of sleep-dependent consolidation of both statistical and sequence knowledge. Our findings could contribute to a better understanding of how the mode of learning (intentional or incidental) affects procedural memory formation and consolidation.

neuroscience↗

bioRxiv2017

Deconstructing Procedural Memory: Different Learning Trajectories and Consolidation of Sequence and Statistical Learning

Procedural learning is a fundamental cognitive function that facilitates efficient processing of and automatic responses to complex environmental stimuli. Here, we examined training-dependent and off-line changes of two sub-processes of procedural learning: namely, sequence learning and statistical learning. Whereas sequence learning requires the acquisition of order-based relationships between the elements of a sequence, statistical learning is based on the acquisition of probabilistic associations between elements. Seventy-eight healthy young adults (58 females and 20 males) completed the modified version of the Alternating Serial Reaction Time task that was designed to measure Sequence and Statistical Learning simultaneously. After training, participants were randomly assigned to one of three conditions: active wakefulness, quiet rest, or daytime sleep. We examined off-line changes in Sequence and Statistical Learning as well as further improvements after extended practice. Performance in Sequence Learning increased during training, while Statistical Learning plateaued relatively rapidly. After the off-line period, both the acquired sequence and statistical knowledge was preserved, irrespective of the vigilance state (awake, quiet rest or sleep). Sequence Learning further improved during extended practice, while Statistical Learning did not. Moreover, within the sleep group, cortical oscillations and sleep spindle parameters showed differential associations with Sequence and Statistical Learning. Our findings can contribute to a deeper understanding of the dynamic changes of multiple parallel learning and consolidation processes that occur during procedural memory formation.

neuroscience↗