Biology subjects

Sachgau, C.

Publications and source records attributed to Sachgau, C..

3 recordsLinked to original sources

bioRxiv2025

Metacognitive Reactivity and Temporal Perception: The Influence of Confidence Ratings on the Temporal Binding Window

The influence of confidence in assessing the perceived timing of sensory events on perceptual decision-making remains poorly understood. Metacognition--the ability to reflect on ones thought processes -- is often assessed through confidence ratings in perceptual tasks. However, accessing metacognitive information can influence task performance, a phenomenon known as the reactivity effect. This study examines metacognitive reactivity by examining the impact of confidence ratings on the temporal binding window (TBW) in two multisensory time perception tasks that use identical stimuli but require different judgments: Temporal Order Judgment (TOJ) and Simultaneity Judgment (SJ). Thirty-five participants (aged 18-39) completed TOJ and SJ tasks with and without confidence ratings via Prolific, an online participant recruitment platform. Psychometric functions were fitted to response and confidence data to determine TBW and the point of subjective simultaneity (PSS). Both tasks exhibited reactivity effects, with the effect being stronger in the SJ task. TBW significantly differed between TOJ and SJ tasks, regardless of confidence ratings. Additionally, TBWs from TOJ and SJ tasks were strongly correlated, as were the width parameters of confidence curves, suggesting shared underlying mechanisms in both perceptual and metacognitive processes. These findings highlight the utility of confidence ratings in evaluating TOJ and SJ performance, revealing both task differences and commonalities. We also discuss the potential for training interventions to enhance temporal perception, particularly in older adults. Finally, we reflect on the advantages and challenges of online data collection via Prolific, including its diverse participant pool and timing precision limitations.

neuroscience↗

bioRxiv2018

Perceived timing of active head movement at different speeds

The central nervous system must determine which sensory events occur at the same time. Actively moving the head corresponds with large changes in the relationship between the observer and the environment, sensorimotor processing, and spatiotemporal perception. Numerous studies have shown that head movement onset must precede the onset of other sensory events in order to be perceived as simultaneous, indicating that head movement perception is slow. Active head movement perception has been shown to be slower than passive head movement perception and dependent on head movement velocity, where participants who move their head faster than other participants require the head to move even earlier than comparison stimuli to be perceived as simultaneous. These results suggest that head movement perception is slower (i.e., suppressed) when the head moves faster. The present study used a within-subjects design to measure the point of subjective simultaneity (PSS) between active head movement speeds and a comparison sound stimulus. Our results clearly show that i) head movement perception is faster when the head moves faster within-subjects, ii) active head movement onset must still precede the onset of other sensory events (Average PSS: -123 to -52 ms) in order to be perceived as occurring simultaneously even at the fastest speeds (Average peak velocity: 76{degrees}/s to 257{degrees}/s). We conclude that head movement perception is slow, but that this delay is minimized with increased speed. While we do not provide evidence against sensory suppression, which requires active versus passive head movement comparison, our results do rule out velocity-based suppression.

neuroscience↗

bioRxiv2017

Simultaneous spike-time locking to multiple frequencies

Phase locking of neural firing is ubiquitously observed in the brain and occurs when neurons fire at a particular phase of a periodic signal. Here we study in detail how spikes of single neurons can simultaneously lock to multiple distinct frequencies at the example of p-type electroreceptor afferents in the electrosensory system of the Gymnotiform weakly electric fish Apteronotus leptorhynchus. We identify key elements for multiple frequency locking, study its determining factors and limits, and provide concise mathematical models reproducing our main findings. Our findings provide another example how rate and temporal codes can coexist and complement each other in single neurons, and demonstrate that sensory coding in p-type electroreceptor afferents provides a much richer representation of the sensory environment than commonly assumed. Since the underlying mechanisms are not specific to the electrosensory system, our results could provide the basis for studying multiple-frequency locking in other systems.

neuroscience↗