Biology subjects

Szczepanik, M.

Publications and source records attributed to Szczepanik, M..

4 recordsLinked to original sources

bioRxiv2022

Emotion schema effects on associative memory differ across emotion categories at the behavioural, physiological and neural level

Previous behavioural and neuroimaging studies have consistently reported that our memory is enhanced for associations congruent or incongruent with the structure of our prior knowledge, termed as schemas. However, it remains unclear if similar effects exist if encoded associations are emotional. Do emotional schemas also facilitate learning and subsequent retrieval? Does it depend on the type of experienced emotions? Using a novel face-word pair association paradigm combined with fMRI and eye-tracking techniques, we demonstrated and replicated in two independent studies that congruency with emotion schemas and emotion category interact to affect associative memory. Overall, emotion schemas facilitated memory for associative context, paralleled by the recruitment of left inferior frontal gyrus (IFG) during successful encoding of emotionally congruent vs. incongruent pairs. However, emotion schema effects differed across two negative emotion categories: disgust and fear, with disgust remembered better than fear. The IFG engagement was higher during successful encoding of congruent vs. incongruent pairs, but only in the case of disgust, suggestive of more semantic processing involved in learning disgust-related associations. On the contrary, the encoding of congruent vs. incongruent fear-related pairs was supported by activity in right fusiform gyrus (FG), suggesting greater sensory processing of faces. Successful memory formation for congruent disgust-related pairs was associated with a higher loading of pupil dilation component related to sympathetic activation, longer gaze time on words compared to faces, and more gaze switches between the two. This was reversed for fear-related pairs where the faces attracted more attention, as reflected by longer gaze time (compared to words). Overall, our results at the behavioural, physiological, and neural level converge to suggest that emotional congruency influences memory similar to semantic schemas. However, encoding processes and neural effects vary depending on emotion category, reflecting the differential role of semantic processing and visual attention processes in the modulation of memory by disgust and fear.

neuroscience↗

bioRxiv2021

Learning about threat from friends and strangers is equally effective: an fMRI study on observational fear conditioning

Humans often benefit from social cues when learning about the world. For instance, learning about threats from others can save the individual from dangerous first-hand experiences. Familiarity is believed to increase the effectiveness of social learning, but it is not clear whether it plays a role in learning about threats. Using functional magnetic resonance imaging, we undertook a naturalistic approach and investigated whether there was a difference between observational fear learning from friends and strangers. Participants (observers) witnessed either their friends or strangers (demonstrators) receiving aversive (shock) stimuli paired with colored squares (observational learning stage). Subsequently, participants watched the same squares, but without receiving any shocks (direct-expression stage). We observed a similar pattern of brain activity in both groups of observers. Regions related to threat responses (amygdala, anterior insula, anterior cingulate cortex) and social perception (fusiform gyrus, posterior superior temporal sulcus) were activated during the observational phase, reflecting the fear contagion process. The anterior insula and anterior cingulate cortex were also activated during the subsequent stage, indicating the expression of learned threat. Because there were no differences between participants observing friends and strangers, we argue that social threat learning is independent of the level of familiarity with the demonstrator. HighlightsO_LIWe compared observational learning of fear from friends and strangers C_LIO_LIFamiliarity does not enhance social learning of fear in humans C_LIO_LIBayesian statistics confirm absence of differences between friends and strangers C_LIO_LIObservational fear learning activates social and fear networks including amygdala C_LIO_LIAmygdala activations are absent when learned fear is recalled C_LI

neuroscience↗

bioRxiv2020

AI aided design of epitope-based vaccine for the induction of cellular immune responses against SARS-CoV-2

The heavy burden imposed by the COVID-19 pandemic on our society triggered the race towards the development of therapies or preventive strategies. Among these, antibodies and vaccines are particularly attractive because of their high specificity, low probability of drug-drug interaction, and potentially long-standing protective effects. While the threat at hand justifies the pace of research, the implementation of therapeutic strategies cannot be exempted from safety considerations. There are several potential adverse events reported after the vaccination or antibody therapy, but two are of utmost importance: antibody-dependent enhancement (ADE) and cytokine storm syndrome (CSS). On the other hand, the depletion or exhaustion of T-cells has been reported to be associated with worse prognosis in COVID-19 patients. This observation suggests a potential role of vaccines eliciting cellular immunity, which might simultaneously limit the risk of ADE and CSS. Such risk was proposed to be associated with FcR-induced activation of proinflammatory macrophages (M1) by Fu et al. 2020 and Iwasaki et al. 2020. All aspects of the newly developed vaccine (including the route of administration, delivery system, and adjuvant selection) may affect its effectiveness and safety. In this work we use a novel in silico approach (based on AI and bioinformatics methods) developed to support the design of epitope-based vaccines. We evaluated the capabilities of our method for predicting the immunogenicity of epitopes. Next, the results of our approach were compared with other vaccine-design strategies reported in the literature. The risk of immuno-toxicity was also assessed. The analysis of epitope conservation among other Coronaviridae was carried out in order to facilitate the selection of peptides shared across different SARS-CoV-2 strains and which might be conserved in emerging zootic coronavirus strains. Finally, the potential applicability of the selected epitopes for the development of a vaccine eliciting cellular immunity for COVID-19 was discussed, highlighting the benefits and challenges of such an approach.

bioinformatics↗

bioRxiv2020

Observed but Never Experienced - Vicarious Learning of Fear Under Ecological Conditions

Learning to avoid threats often occurs by observing the behavior of others. Most previous research on observational fear learning in humans has used pre-recorded stimuli as social cues. Here, we aimed to enhance the ecological validity of the learning situation: the observer watched their friend ( demonstrator) performing a differential fear-conditioning task in real time. During the task, one conditioned stimulus (CS+) was repeatedly linked with electric stimulation (US) while another one (CS-) was always safe. Subsequently, the observer was presented with the CS+ and CS- directly but without receiving any shocks. Skin conductance (SCR) and fear-potentiated startle (FPS) responses were measured in observers throughout the whole experiment. While the US applied to the demonstrator elicited strong SCR in the observers, subsequent differential SCR to CSs (CS+ vs. CS-) presented directly were dependent on declarative knowledge of the CS+/US contingency. Contingency-aware observers also showed elevated FPS during both CS+ and CS- compared to intertrial intervals. We conclude that observational fear learning involves two components: an automatic emotional reaction to the response of the demonstrator and learning to predict stimulus contingency (CS+/US pairing). Ecological modifications proposed offer new perspectives on studying social learning of emotions.

neuroscience↗