Biology subjects

Markiewicz, R.

Publications and source records attributed to Markiewicz, R..

4 recordsLinked to original sources

bioRxiv2023

Brain-to-brain coupling forecasts future joint action outcomes

In this study, we investigated whether brain-to-brain coupling patterns could predict performance in a time-estimation task which requires two players to cooperate. The participant pairs, were tasked with synchronising button presses after converging on a shared representation of short, medium, and long time intervals while utilizing feedback to adjust responses. We employed EEG-hyperscanning and focused on post-feedback brain activity. We found that negative feedback led to increased frontal mid-line theta activity across individuals. Moreover, a correlation in post-feedback theta power between players forecasted failed joint action, while an anti-correlation forecasted success. These findings suggest that temporally coupled feedback related brain activity between two individuals serves as an indicator of redundancy in adjustment of a common goal representation. Additionally, the anti-correlation of this activity reflects cognitive strategic mechanisms that ensure optimal joint action outcomes. Rather than a paired overcompensation, successful cooperation requires flexible strategic agility from both partners.

neuroscience↗

bioRxiv2022

Cross-modal alterations of Alpha Activity do not reflect inhibition of early sensory processing: A frequency tagging study

Selective attention involves prioritizing relevant sensory input while suppressing irrelevant stimuli. It has been proposed that oscillatory alpha-band activity ([~]10 Hz) aids this process by functionally inhibiting early sensory regions. However, recent studies have challenged this notion. Our EEG and MEG studies aimed to investigate whether alpha oscillations serve as a gatekeeper for downstream signal transmission. We first observed these effects in an EEG study and then replicated them using MEG, which allowed us to localize the sources. We employed a cross-modal paradigm where visual cues indicated whether upcoming targets required visual or auditory discrimination. To assess inhibition, we utilized frequency-tagging, simultaneously flickering the fixation cross at 36 Hz and playing amplitude-modulated white noise at 40 Hz during the cue-to-target interval. Consistent with prior research, we observed an increase in posterior alpha activity following cues signalling auditory targets. However, remarkably, both visual and auditory frequency tagged responses amplified in anticipation of auditory targets, correlating with alpha activity amplitude. Our findings suggest that when attention shifts to auditory processing, the visual stream remains responsive and is not hindered by occipital alpha activity. This implies that alpha modulation does not solely regulate gain control in early visual areas but rather orchestrates signal transmission to later stages of the processing stream.

neuroscience↗

bioRxiv2021

Bilingual speakers' enhanced monitoring can slow them down

Performance differences between bilinguals and monolinguals on conflict tasks can be affected by the balance of various sub-processes such as conflict monitoring and allocation of attentional resources for stimulus categorisation. Here we investigated the effect of bilingualism on these sub-processes during a conflict task with medium monitoring demand. We examined the behavioural responses and evoked potentials from bilinguals and monolinguals during a flanker task with 25% incongruent trials. We analysed behavioural differences by means of averaged response times and ex-Gaussian analyses of response time distributions. For the evoked potentials we focused on N2 (reflecting conflict monitoring) and P3 responses (reflecting allocation of attentional resources for cognitive control). We found that bilinguals had significantly longer response distribution tails compared to monolinguals. Additionally, bilinguals exhibited a more pronounced N2 and smaller P3 components compared to monolinguals, independent of experimental condition, suggesting a different balance of sub-processes for the two groups. It is suggested that bilinguals engaged more strongly in monitoring processes, leading to the allocation of fewer attentional resources during stimulus categorisation. Importantly, N2 amplitudes were positively and P3 amplitudes negatively related to the length of response distribution tails. We postulate that these results reflect an overactive monitoring system in bilinguals. This enhanced monitoring led to reduced engagement of attentional resources for stimulus categorisation, but also occasionally to slow responses. These results suggest that changes of the cognitive control system due to bilingual experience can change the balance of processes during conflict tasks, potentially leading to a small behavioural disadvantage.

neuroscience↗

bioRxiv2021

How the healthy ageing brain supports semantic binding during language comprehension

Semantic binding refers to constructing complex meaning based on elementary building blocks. Using EEG, we investigated the age-related changes in modulations of oscillatory brain activity supporting lexical retrieval and semantic binding. Young and older adult participants were visually presented two-word phrases, which for the first word revealed a lexical retrieval signature (e.g. swift vs. swrfeq) and for the second word revealed a semantic binding signature (e.g. horse in a semantic binding "swift horse" vs. no binding "swrfeq horse" context). The oscillatory brain activity associated with lexical retrieval as well as semantic binding significantly differed between healthy older and young adults. Specifically for lexical retrieval, we found that different age groups exhibited opposite patterns of theta and alpha modulation, which as a combined picture suggest that lexical retrieval is associated with different and delayed signatures in older compared to young adults. For semantic binding, in young adults we found a signature in the low-beta range centred around the target word onset (i.e. a smaller low-beta increase for binding relative to no binding), while in healthy older adults we found an opposite binding signature about ~500ms later in the low- and high-beta range (i.e. a smaller low- and high-beta decrease for binding relative to no binding). The novel finding of a different and delayed oscillatory signature for semantic binding in healthy older adults reflects that the integration of word meaning into the semantic context takes longer and relies on different mechanisms in healthy older compared to young adults.

neuroscience↗