Biology subjects

Kaltenmaier, A.

Publications and source records attributed to Kaltenmaier, A..

3 recordsLinked to original sources

bioRxiv2025

Tracking visual rhythms: a concert of sensory and motor simulation

When will I see something and what will it be? Temporal predictions are crucial for adaptive interaction with the environment and are typically accompanied by predictions about sensory content, yet these two types of what and when predictions are usually studied separately. Specifically, oscillatory phase-coupling (or entrainment) has been proposed to align our neural sensitivity with likely moments of stimulus appearance, however these accounts ignore that predictions about when something will appear are usually accompanied by predictions about what it will be. Thus, temporal predictions may not enhance all sensory processing but rather modulate particular channels encoding predicted content. We here demonstrate oscillatory phase-coupling in vision and show how it relates to content-specific encoding. In a magnetoencephalography (MEG) study, participants observed rhythmic Gabors at 1.33 or 2 Hz with predictable orientations. They judged the timing or orientation of a delayed probe which manipulated the requirement to covertly maintain the sequence rhythm. We found sustained oscillatory phase-coupling to the entrained rhythm in motor areas specifically when participants judged stimulus timing, where its extent was associated with perceptual performance. Meanwhile, neural decoding revealed content predictions in early visual areas ( what) that fluctuated in line with temporal predictions ( when). These temporally-specific content predictions appeared regardless of task instruction but were correlated and phase-aligned with the motor phase-coupling during timing judgements. These findings suggest that temporal predictions may be derived from motor readouts of temporally-specific sensory predictions, with broad implications for our understanding of entrainment and prediction, and how we represent time more generally.

neuroscience↗

bioRxiv2024

The "Ocular Response Function" for encoding and decoding oculomotor related neural activity

Oculomotor activity provides critical insights into cognition and health, with growing evidence demonstrating its involvement in various cognitive functions such as attention, memory, and sensory processing, and that it is a significant indicator of psychopathologies and neurological disorders. Despite its crucial importance across domains, the neural mechanisms supporting oculomotion have been underexplored, largely because eye movements are typically treated as artefacts to be removed from the neural signal. While useful for data cleaning, this approach risks discarding valuable information about oculomotor control, and there has been recent interest in modelling these signals instead to understand them. Using time-resolved regression methods with magnetoencephalography (MEG) and eye tracking during the resting state, we thus here sought to model Ocular Response Functions (ORFs), that characterise the neural signatures of distinct oculomotor events, specifically saccades, blinks, and pupil dilation. We demonstrate the relationships between ocular action and neural activity (encoding), revealing a range of sensory cortical, cerebellar and frontal signatures preceding and following such ocular events. We conversely show how we can reconstruct ocular events from brain activity, and further apply resting-state derived ORFs to a passive listening task - demonstrating how some neural markers interpreted as directly related to sensation may in principle indirectly result from oculomotor contributions to task-related neural processing. By providing an accessible framework for examining the interplay between eye movements and neural processes, we offer a range of insights with potential applications across cognitive and clinical neuroscience.

neuroscience↗

bioRxiv2024

Expectations about presence enhance the influence of content-specific expectations on low-level orientation judgements

Will something appear and if so, what will it be? Perceptual expectations can concern both the presence and content of a stimulus. However, it is unclear how these different types of expectations interact with each other in biasing perception. Here, we tested how expectations about stimulus presence and content differently affect perceptual inference. Across separate online discovery (N=110) and replication samples (N=218), participants were asked to judge both the presence and content (orientation) of noisy grating stimuli. Crucially, preceding compound cues simultaneously and orthogonally predicted both whether a grating was likely to appear as well as what its orientation would be. We found that expectations of presence interacted with expectations of content, such that the latters effect on discrimination was larger when a stimulus was expected to appear than when it was not. This interaction was observed both when a grating was truly presented and when participants falsely perceived one. Confidence in having seen a grating on the other hand was independently affected by presence and content expectations. Further, modelling revealed higher sensitivity in distinguishing between grating presence and absence following absence cues than presence cues, demonstrating an asymmetry between gathering evidence in favour of stimulus presence and absence. Finally, evidence for overweighted predictions being associated with hallucination-like perception was inconclusive. In sum, our results provide nuance to popular predictive processing accounts of perception by showing that expectations of presence and content have distinct but interacting roles in shaping conscious perception.

neuroscience↗