Biology subjects

Eimer, M.

Publications and source records attributed to Eimer, M..

6 recordsLinked to original sources

bioRxiv2026

The 2-feature Simultaneous Type/ Serial Token Model of temporal feature conjunctions: Successes are merely fortunate conjunctions.

Resolving the binding problem, i.e., how we integrate perceptual features in space and time to perceive objects, people and events as coherent wholes instead of masses of free-floating features, has been a central goal of cognitive scientists for decades. Conjunction errors occur whenever features are mis-bound leading to illusory percepts that were not actually presented. A specific kind of Rapid Serial Visual Presentation experiment induces temporal illusory conjunctions, called distractor intrusion errors. Despite these errors being well-established, current theories and models provide limited explanations. We present the 2-feature Simultaneous Type/Serial Token (2f-ST2) Model, the latest addition to the family of ST2-models, which simulates the most important behavioural and electrophysiological distractor intrusion findings. These include response distributions, reaction time patterns, and evoked electrophysiology responses. Importantly, we simulate these results across diverse empirical paradigms, implementing a range of stimulus sets, temporal dynamics, and involving multiple responses after each trial, without needing to modify our model's architecture or core parameters. Our findings are discussed in relation to theories of selective attention and working-memory binding. We argue that the 2f-ST2 model is more parsimonious than the leading theory of distractor-intrusions (the focussed-attention/sophisticated-guessing model), since it uses only a single binding mechanism, implying that correct bindings are simply fortunate conjunctions. The 2f-ST2 model further makes predictions for stimulus-competition, subjective-visibility and human electrophysiology. In summary, the ST2-model is a general framework for understanding how perception, temporal attention and working-memory interact, and the 2f-ST2 model extends the framework to distractor intrusions, thus explaining temporal feature binding.

neuroscience↗

bioRxiv2026

Paradoxical influences of prediction are resolved across time

It is widely thought that our brains use expectations to optimise perception, yet theoretical accounts disagree about the form of this optimisation. Bayesian accounts propose that perception is biased towards expected events, rapidly generating more veridical experiences, whereas cancellation accounts argue that unexpected inputs are perceptually prioritised as they are more informative. A recent opposing process theory reconciles these views by proposing a temporal reversal in prioritisation: perceptual processing is pre-emptively biased towards what is expected, followed by later enhancement of only particularly surprising inputs that are informative for learning and model updating. Here, we tested this account using time-resolved decoding of EEG data, while participants observed avatar action outcomes that were either expected or unexpected based on their own movements. Expectation effects on the neural representations of these action outcomes indeed unfolded over time in such a manner, with higher decoding for task-relevant expected outcomes starting before stimulus onset, followed by a later post-stimulus advantage for unexpected outcomes. These findings support the opposing process theory, demonstrating a reversal in prioritisation that is not predicted by current Bayesian or cancellation accounts. By exerting distinct influences across time, expectations can thus render perception veridical, while still allowing for the accurate perception of particularly unexpected events that are important for updating our beliefs or ongoing courses of action. Significance statementHow we perceive the world is shaped by our expectations. Yet it remains unclear how the brain can use these expectations to make perception both more accurate and more informative, given these demands require opposite influences of expectation on processing - upweighting versus downweighting the expected, respectively. Here, we show that this apparent conflict is resolved across time. The expected is enhanced before a stimulus appears by pre-activating what we expect, whereas unexpected inputs are enhanced later. This temporal reversal allows expectations to support both demands, rapidly generating generally more accurate perceptual experiences, while also remaining sensitive to unexpected information that is critical for learning and adaptive behaviour.

neuroscience↗

bioRxiv2024

The impact of language proficiency on task-dependent neural activity and functional connectivity: Insights from deafness

Our study aimed to investigate the impact of differences in language proficiency on the neural correlates of cognitive processing in deaf adults. In congenitally and early deaf individuals, individual differences in language proficiency reflect the degree of language access during critical developmental periods and significantly influence cognitive function. By studying the neural substrates of cognition in a population with diverse language backgrounds and skills, we can explore the influence of early language experience on the formation of cognitive networks in the brain. We used functional MRI in a group of deaf adults with varying language experience backgrounds and a control group of hearing participants. In this study, we investigated the hypothesis that differences in language skills modulate neural response and functional connectivity during the execution of demanding cognitive tasks tapping into working memory and planning. Our study revealed that differences in language proficiency, independently of language modality (signed or spoken), are positively correlated with neural activity and functional connectivity within regions of the task-positive network during working memory in deaf adults. Furthermore, compared to hearing participants, the deaf group showed distinctive patterns of neural activity and connectivity during working memory task performance in task-dependent regions of the brain. Taken together, our findings emphasise the profound impact of early environmental experiences on brain responses during cognitive processing. Specifically, they highlight the role of language proficiency in shaping and supporting high-order cognition in the brain. Significance statementHigher-order cognitive abilities, such as working memory and planning, are essential for human activity. They enable the coordination of mental processes and goal-directed behaviour. When successfully executing cognitive tasks, the human brain exhibits systematic patterns of neural activity and connectivity in the frontal and parietal regions. In this study, we investigated whether the control of nonverbal cognition is influenced by differences in language proficiency at the level of the functional organisation of the brain. Our study showed that differences in language proficiency in deaf individuals are positively associated with neural activity and functional connectivity within the task-positive brain regions during working memory. These findings offer compelling evidence for the critical role of access to a natural language in scaffolding the neural mechanisms that support higher-order cognition. Our results provide a deeper understanding of the relationship between language proficiency and cognitive processing, highlighting the importance of early language access in modulating and shaping brain function. Revealing the contribution of a developed language system to the formation of cognitive networks has implications not only for understanding the processes underlying cognitive development and functioning but also for informing policy and practice in relation to education and language access.

neuroscience↗

bioRxiv2021

Sensory experience modulates the reorganisation of temporal auditory regions for executive processing

Crossmodal plasticity refers to the reorganisation of sensory cortices in the absence of their main sensory input. Understanding this phenomenon provides insights into brain function and its potential for change and enhancement. Using fMRI, we investigated how early deafness influences crossmodal plasticity and the organisation of executive functions in the adult human brain. Results from a range of visual executive function tasks (working memory, task switching, planning, inhibition) show that deaf individuals specifically recruit "auditory" regions during task switching. Neural activity in superior temporal regions, most significantly in the right hemisphere, are good predictors of behavioural performance during task switching in the deaf group, highlighting the functional relevance of the observed cortical reorganisation. Our results show executive processing in typically sensory regions, suggesting that the development and ultimate role of brain regions are influenced by perceptual environmental experience.

neuroscience↗

bioRxiv2019

Humans can efficiently look for, but not select multiple visual objects

The human brain recurrently prioritizes task-relevant over task-irrelevant visual information. A central, question is whether multiple objects can be prioritized simultaneously. To answer this, we let observers search for two colored targets among distractors. Crucially, we independently varied the number of target colors that observers anticipated, and the number of target colors actually used to distinguish the targets in the display. This enabled us to dissociate the preparation of selection mechanisms from the actual engagement of such mechanisms. Multivariate classification of electroencephalographic activity allowed us to track selection of each target separately across time. The results revealed only small neural and behavioral costs associated with preparing for selecting two objects, but substantial costs when engaging in selection. Further analyses suggest this cost is the consequence of neural competition resulting in limited parallel processing, rather than a serial bottleneck. The findings bridge diverging theoretical perspectives on capacity limitations of feature-based attention.

neuroscience↗

bioRxiv2016

Multivariate EEG analyses support high-resolution tracking of feature-based attentional selection

The primary electrophysiological marker of feature-based selection is the N2pc, a lateralized posterior negativity emerging around 180-200 ms. As it relies on hemispheric differences, its ability to discriminate the locus of focal attention is severely limited. Here we demonstrate that multivariate analyses of raw EEG data provide a much more fine-grained spatial profile of feature-based target selection. When training a pattern classifier to determine target position from EEG, we were able to decode target positions on the vertical midline, which cannot be achieved using standard N2pc methodology. Next, we used a forward encoding model to construct a channel tuning function that describes the continuous relationship between target position and multivariate EEG in an eight-position display. This model can spatially discriminate individual target positions in these displays and is fully invertible, enabling us to construct hypothetical topographic activation maps for target positions that were never used. When tested against the real pattern of neural activity obtained from a different group of subjects, the constructed maps from the forward model turned out statistically indistinguishable, thus providing independent validation of our model. Our findings demonstrate the power of multivariate EEG analysis to track feature-based target selection with high spatial and temporal precision.\n\nSignificance StatementFeature-based attentional selection enables observers to find objects in their visual field. The spatiotemporal profile of this process is difficult to assess with standard electrophysiological methods, which rely on activity differences between cerebral hemispheres. We demonstrate that multivariate analyses of EEG data can track target selection across the visual field with high temporal and spatial resolution. Using a forward model, we were able to capture the continuous relationship between target position and EEG measurements, allowing us to reconstruct the distribution of cortical activity for target locations that were never shown during the experiment. Our findings demonstrate the existence of a temporally and spatially precise EEG signal that can be used to study the neural basis of feature-based attentional selection.

neuroscience↗