Rats rely on airflow cues for self-motion perception.

Self-motion perception is a vital skill for all species. It is an inherently multisensory process that combines inertial (body-based) and relative (with respect to the environment) motion cues. Although extensively studied in human and non-human primates, there is currently no paradigm to test self-motion perception in rodents using both inertial and relative self-motion cues.

Modality-specific effects of threat on self-motion perception.

Background: Threat and individual differences in threat-processing bias perception of stimuli in the environment. Yet, their effect on perception of one's own (body-based) self-motion in space is unknown. Here, we tested the effects of threat on self-motion perception using a multisensory motion simulator with concurrent threatening or neutral auditory stimuli.

Multisensory Calibration: A Variety of Slow and Fast Brain Processes Throughout the Lifespan.

From before we are born, throughout development, adulthood, and aging, we are immersed in a multisensory world. At each of these stages, our sensory cues are constantly changing, due to body, brain, and environmental changes. While integration of information from our different sensory cues improves precision, this only improves accuracy if the underlying cues are unbiased.

Multisensory decisions from self to world.

Classic Bayesian models of perceptual inference describe how an ideal observer would integrate 'unisensory' measurements (multisensory integration) and attribute sensory signals to their origin(s) (causal inference). However, in the brain, sensory signals are always received in the context of a multisensory bodily state-namely, in combination with other senses. Moreover, sensory signals from both interoceptive sensing of one's own body and exteroceptive sensing of the world are highly interdependent and never occur in isolation.

Modality-specific sensory and decisional carryover effects in duration perception.

Background: The brain uses recent history when forming perceptual decisions. This results in carryover effects in perception. Although separate sensory and decisional carryover effects have been shown in many perceptual tasks, their existence and nature in temporal processing are unclear.

Contrary neuronal recalibration in different multisensory cortical areas.

The adult brain demonstrates remarkable multisensory plasticity by dynamically recalibrating itself based on information from multiple sensory sources. After a systematic visual-vestibular heading offset is experienced, the unisensory perceptual estimates for subsequently presented stimuli are shifted toward each other (in opposite directions) to reduce the conflict. The neural substrate of this recalibration is unknown.

The dynamic boundaries of the Self: Serial dependence in the Sense of Agency.

The feeling of control over one's actions, termed the Sense of Agency (SoA), delineates one's experience as an embodied self. Although this embodied experience is typically perceived as stable over time, recent theoretical accounts highlight the experience-dependent and dynamic nature of the embodied self. In this study we examined how recent experiences modulate SoA (i.

Rapid cross-sensory adaptation of self-motion perception.

Perceptual adaptation is often studied within a single sense. However, our experience of the world is naturally multisensory. Here, we investigated cross-sensory (visual-vestibular) adaptation of self-motion perception.

Supervised Multisensory Calibration Signals Are Evident in VIP But Not MSTd.

Multisensory plasticity enables our senses to dynamically adapt to each other and the external environment, a fundamental operation that our brain performs continuously. We searched for neural correlates of adult multisensory plasticity in the dorsal medial superior temporal area (MSTd) and the ventral intraparietal area (VIP) in 2 male rhesus macaques using a paradigm of supervised calibration. We report little plasticity in neural responses in the relatively low-level multisensory cortical area MSTd.

Increased influence of prior choices on perceptual decisions in autism.

Autism spectrum disorder (ASD) manifests sensory and perceptual atypicalities. Recent theories suggest that these may reflect a reduced influence of prior information in ASD. Some studies have found reduced adaptation to recent sensory stimuli in ASD.

Perceptual decisions are biased toward relevant prior choices.

Perceptual decisions are biased by recent perceptual history-a phenomenon termed 'serial dependence.' Here, we investigated what aspects of perceptual decisions lead to serial dependence, and disambiguated the influences of low-level sensory information, prior choices and motor actions. Participants discriminated whether a brief visual stimulus lay to left/right of the screen center.

Overconfidence in visual perception in parkinson's disease.

Increased dependence on visual cues in Parkinson's disease (PD) can unbalance the perception-action loop, impair multisensory integration, and affect everyday function of PD patients. It is currently unknown why PD patients seem to be more reliant on their visual cues. We hypothesized that PD patients may be overconfident in the reliability (precision) of their visual cues.

Visual self-motion cues are impaired yet overweighted during visual-vestibular integration in Parkinson's disease.

Parkinson's disease is prototypically a movement disorder. Although perceptual and motor functions are highly interdependent, much less is known about perceptual deficits in Parkinson's disease, which are less observable by nature, and might go unnoticed if not tested directly. It is therefore imperative to seek and identify these, to fully understand the challenges facing patients with Parkinson's disease.

Self-motion perception in Parkinson's disease.

Parkinson's disease (PD), best characterized by its classic motor symptoms, also manifests non-motor symptoms including perceptual impairments. Normal motor and perceptual brain functions interact continuously in an action-perception loop; hence, perceptual and motor dysfunction in PD are likely also intertwined. A vital skill in order to maintain balance, and to move around in the environment is the ability to perceive one's own motion in space (self-motion perception).

Better than Optimal.

Using a novel visual-tactile paradigm in rats, Nikbakht et al. (2018) describe multisensory behavior that outperformed predictions of optimal cue combination (indicating cross-modal synergy) and exposed encoding in PPC neurons (of stimulus and choice signals) that was independent of stimulus modality.

Decoupled choice-driven and stimulus-related activity in parietal neurons may be misrepresented by choice probabilities.

Trial-by-trial correlations between neural responses and choices (choice probabilities) are often interpreted to reflect a causal contribution of neurons to task performance. However, choice probabilities may arise from top-down, rather than bottom-up, signals. We isolated distinct sensory and decision contributions to single-unit activity recorded from the dorsal medial superior temporal (MSTd) and ventral intraparietal (VIP) areas of monkeys during perception of self-motion.

Self-motion perception in autism is compromised by visual noise but integrated optimally across multiple senses.

Perceptual processing in autism spectrum disorder (ASD) is marked by superior low-level task performance and inferior complex-task performance. This observation has led to theories of defective integration in ASD of local parts into a global percept. Despite mixed experimental results, this notion maintains widespread influence and has also motivated recent theories of defective multisensory integration in ASD.

Supervised calibration relies on the multisensory percept.

Multisensory plasticity enables us to dynamically adapt sensory cues to one another and to the environment. Without external feedback, "unsupervised" multisensory calibration reduces cue conflict in a manner largely independent of cue reliability. But environmental feedback regarding cue accuracy ("supervised") also affects calibration.

Microelectrode recording duration and spatial density constraints for automatic targeting of the subthalamic nucleus.

Background: Accurate detection of the boundaries of the subthalamic nucleus (STN) in deep brain stimulation (DBS) surgery using microelectrode recording (MER) is considered to refine localization and may therefore improve clinical outcome. However, MER tends to extend operation time and its cost-utility balance has been debated.

Objectives: To quantify the tradeoff between accuracy of STN localization and the spatial and temporal parameters of MER that effect the operation time using an automated detection method.

The use of macroelectrodes in recording cellular spiking activity.

Microelectrode recording (MER) is an important navigational and investigational tool, specifically with regard to deep brain stimulation (DBS) surgery. MER is often utilized when targeting the subthalamic nucleus (STN) and other deep brain nuclei in the management of Parkinson's disease (PD), tremor, dystonia and other emerging applications. Microelectrodes are used to detect and measure cellular spiking activity while macroelectrodes are considered more suitable for measuring the collective sum of slow potentials from multiple cells near the electrode, the local field potential (LFP).

Multisensory calibration is independent of cue reliability.

Multisensory calibration is fundamental for proficient interaction within a changing environment. Initial studies suggested a visual-dominant mechanism. More recently, a cue-reliability-based model, similar to optimal cue integration, has been proposed.

Propofol decreases neuronal population spiking activity in the subthalamic nucleus of Parkinsonian patients.

Background: Implantation of deep brain stimulation (DBS) electrodes in the subthalamic nucleus (STN) for the treatment of Parkinson disease is often performed using microelectrode recording (MER) of STN population spike activity. The extent to which sedative drugs interfere with MER is unknown. We recorded the population activity of STN neurons during propofol sedation and examined its effect on neuronal activity.

Levodopa and subthalamic deep brain stimulation responses are not congruent.

There is a consensus that in Parkinson's disease, the extent of preoperative levodopa responsiveness predicts the efficacy of subthalamic nucleus deep brain stimulation (STN DBS). However, this may be the result of statistical methods and primary assumptions. We were able to reproduce previously published correlation results on our data (N = 49 patients).

Subthalamic span of beta oscillations predicts deep brain stimulation efficacy for patients with Parkinson's disease.

The significance of oscillations that characterize the subthalamic nucleus in Parkinson's disease is still under debate. Here, we analysed the spectral and spatial characteristics of 314 microelectrode trajectories from 128 patients undergoing subthalamic nucleus deep brain stimulation surgery for Parkinson's disease. We correlated the subthalamic nucleus pathophysiology with the outcome of surgery, as evaluated by the third section of the Unified Parkinson's Disease Rating Scale (motor score), which was subdivided into tremor, rigidity, limb-bradykinesia and axial-bradykinesia subscores.

Delimiting subterritories of the human subthalamic nucleus by means of microelectrode recordings and a Hidden Markov Model.

Positive therapeutic response without adverse side effects to subthalamic nucleus deep brain stimulation (STN DBS) for Parkinson's disease (PD) depends to a large extent on electrode location within the STN. The sensorimotor region of the STN (seemingly the preferred location for STN DBS) lies dorsolaterally, in a region also marked by distinct beta (13-30 Hz) oscillations in the parkinsonian state. In this study, we present a real-time method to accurately demarcate subterritories of the STN during surgery, based on microelectrode recordings (MERs) and a Hidden Markov Model (HMM).