The Many Roles of Precision in Action.

Active inference describes (Bayes-optimal) behaviour as being motivated by the minimisation of surprise of one's sensory observations, through the optimisation of a generative model (of the hidden causes of one's sensory data) in the brain. One of active inference's key appeals is its conceptualisation of precision as biasing neuronal communication and, thus, inference within generative models. The importance of precision in perceptual inference is evident-many studies have demonstrated the importance of ensuring precision estimates are correct for normal (healthy) sensation and perception.

Seeing Through Each Other's Hearts: Inferring Others' Heart Rate as a Function of Own Heart Rate Perception and Perceived Social Intelligence.

Unlabelled: Successful social interactions require a good understanding of the emotional states of other people. This information is often not directly communicated but must be inferred. As all emotional experiences are also imbedded in the visceral or interoceptive state of the body (i.

Active tactile discrimination is coupled with and modulated by the cardiac cycle.

Perception and cognition are modulated by the phase of the cardiac signal in which the stimuli are presented. This has been shown by locking the presentation of stimuli to distinct cardiac phases. However, in everyday life sensory information is not presented in this passive and phase-locked manner, instead we actively move and control our sensors to perceive the world.

People can identify the likely owner of heartbeats by looking at individuals' faces.

For more than a century it has been proposed that visceral and vasomotor changes inside the body influence and reflect our experience of the world. For instance, cardiac rhythms (heartbeats and consequent heart rate) reflect psychophysiological processes that underlie our cognition and affective experience. Yet, considering that we usually infer what others do and feel through vision, whether people can identify the most likely owner of a given bodily rhythm by looking at someone's face remains unknown.

Emotional representations of space vary as a function of peoples' affect and interoceptive sensibility.

Most research on people's representation of space has focused on spatial appraisal and navigation. But there is more to space besides navigation and assessment: people have different emotional experiences at different places, which create emotionally tinged representations of space. Little is known about the emotional representation of space and the factors that shape it.

Reduced differentiation of emotion-associated bodily sensations in autism.

More research has been conducted on how autistic people understand and interpret other people's emotions, than on how autistic people experience their own emotions. The experience of emotion is important however, because it can relate to difficulties like anxiety and depression, which are common in autism. In neurotypical adults and children, different emotions have been associated with unique maps of activity patterns in the body.

Active sampling in visual search is coupled to the cardiac cycle.

Recent research has demonstrated that perception and reasoning vary according to the phase of internal bodily signals such as heartbeat. This has been shown by locking the presentation of sensory events to distinct phases of the cardiac cycle. However, task-relevant information is not usually encountered in such a phase-locked manner nor passively accessed, but rather actively sampled at one's own pace.

Dopaminergic Modulation of Sensory Attenuation in Parkinson's Disease: Is There an Underlying Modulation of Beta Power?

Pathological high amplitude of beta oscillations is thought as the underlying mechanism of motor symptoms in Parkinson's disease (PD), in particular with regard to bradykinesia. In addition, abnormality in a neurophysiological phenomenon labeled sensory attenuation has been found in patients with PD. The current study explored the hypothesis that the abnormal sensory attenuation has a causal link with the typical abnormality in beta oscillations in PD.

Voluntary tic suppression and the normalization of motor cortical beta power in Gilles de la Tourette syndrome: an EEG study.

Gilles de la Tourette syndrome (GTS) is a neurological condition characterized by motor and vocal tics. Previous studies suggested that this syndrome is associated with abnormal sensorimotor cortex activity at rest, as well as during the execution of voluntary movements. It has been hypothesized that this abnormality might be interpreted as a form of increased tonic inhibition, probably to suppress tics; however, this hypothesis has not been tested so far.

The functional neuroanatomy of emotion processing in frontotemporal dementias.

Impaired processing of emotional signals is a core feature of frontotemporal dementia syndromes, but the underlying neural mechanisms have proved challenging to characterize and measure. Progress in this field may depend on detecting functional changes in the working brain, and disentangling components of emotion processing that include sensory decoding, emotion categorization and emotional contagion. We addressed this using functional MRI of naturalistic, dynamic facial emotion processing with concurrent indices of autonomic arousal, in a cohort of patients representing all major frontotemporal dementia syndromes relative to healthy age-matched individuals.

Sensorimotor beta power reflects the precision-weighting afforded to sensory prediction errors.

It has been proposed that accurate motor control relies on Bayesian inference that integrates sensory input with prior contextual knowledge (Bays and Wolpert, 2007; Körding and Wolpert, 2004; Wolpert et al., 1995). Recent evidence has suggested that modulations in beta power (∼12-30 Hz) measured over sensorimotor cortices using electroencephalography (EEG) may represent parameters of Bayesian inference.

Emotional facedness in Parkinson's disease.

People with Parkinson's disease (PD) have a deficit of facial expression. Previous studies indicate that hemispheric dominance for emotional processing can give rise to an asymmetric pattern of facial expression of emotion. In this study, we aimed to evaluate possible asymmetry in facial emotion expressivity in PD.

Alexithymia mediates the relationship between interoceptive sensibility and anxiety.

A number of empirical and theoretical reports link altered interoceptive processing to anxiety. However, the mechanistic understanding of the relationship between the two remains poor. We propose that a heightened sensibility for interoceptive signals, combined with a difficulty in attributing these sensations to emotions, increases an individual's vulnerability to anxiety.

Cardiac responses to viewing facial emotion differentiate frontotemporal dementias.

Objective: To establish proof-of-principle for the use of heart rate responses as objective measures of degraded emotional reactivity across the frontotemporal dementia spectrum, and to demonstrate specific relationships between cardiac autonomic responses and anatomical patterns of neurodegeneration.

Methods: Thirty-two patients representing all major frontotemporal dementia syndromes and 19 healthy older controls performed an emotion recognition task, viewing dynamic, naturalistic videos of facial emotions while ECG was recorded. Cardiac reactivity was indexed as the increase in interbeat interval at the onset of facial emotions.

High-frequency peripheral vibration decreases completion time on a number of motor tasks.

A recent theoretical account of motor control proposes that modulation of afferent information plays a role in affecting how readily we can move. Increasing the estimate of uncertainty surrounding the afferent input is a necessary step in being able to move. It has been proposed that an inability to modulate the gain of this sensory information underlies the cardinal symptoms of Parkinson's disease (PD).

Neurophysiological Changes Measured Using Somatosensory Evoked Potentials.

Measurements of somatosensory evoked potentials (SEPs), recorded using electroencephalography during different phases of movement, have been fundamental in understanding the neurophysiological changes related to motor control. SEP recordings have also been used to investigate adaptive plasticity changes in somatosensory processing related to active and observational motor learning tasks. Combining noninvasive brain stimulation with SEP recordings and intracranial SEP depth recordings, including recordings from deep brain stimulation electrodes, has been critical in identifying neural areas involved in specific temporal stages of somatosensory processing.

Motor signatures of emotional reactivity in frontotemporal dementia.

Automatic motor mimicry is essential to the normal processing of perceived emotion, and disrupted automatic imitation might underpin socio-emotional deficits in neurodegenerative diseases, particularly the frontotemporal dementias. However, the pathophysiology of emotional reactivity in these diseases has not been elucidated. We studied facial electromyographic responses during emotion identification on viewing videos of dynamic facial expressions in 37 patients representing canonical frontotemporal dementia syndromes versus 21 healthy older individuals.

Impaired Interoceptive Accuracy in Semantic Variant Primary Progressive Aphasia.

Background: Interoception (the perception of internal bodily sensations) is strongly linked to emotional experience and sensitivity to the emotions of others in healthy subjects. Interoceptive impairment may contribute to the profound socioemotional symptoms that characterize frontotemporal dementia (FTD) syndromes, but remains poorly defined.

Methods: Patients representing all major FTD syndromes and healthy age-matched controls performed a heartbeat counting task as a measure of interoceptive accuracy.

Facial Emotion Recognition and Expression in Parkinson's Disease: An Emotional Mirror Mechanism?

Background And Aim: Parkinson's disease (PD) patients have impairment of facial expressivity (hypomimia) and difficulties in interpreting the emotional facial expressions produced by others, especially for aversive emotions. We aimed to evaluate the ability to produce facial emotional expressions and to recognize facial emotional expressions produced by others in a group of PD patients and a group of healthy participants in order to explore the relationship between these two abilities and any differences between the two groups of participants.

Methods: Twenty non-demented, non-depressed PD patients and twenty healthy participants (HC) matched for demographic characteristics were studied.

Physiological and Perceptual Sensory Attenuation Have Different Underlying Neurophysiological Correlates.

Unlabelled: Sensory attenuation, the top-down filtering or gating of afferent information, has been extensively studied in two fields: physiological and perceptual. Physiological sensory attenuation is represented as a decrease in the amplitude of the primary and secondary components of the somatosensory evoked potential (SEP) before and during movement. Perceptual sensory attenuation, described using the analogy of a persons' inability to tickle oneself, is a reduction in the perception of the afferent input of a self-produced tactile sensation due to the central cancellation of the reafferent signal by the efference copy of the motor command to produce the action.

A Causal Role for Primary Motor Cortex in Perception of Observed Actions.

It has been proposed that motor system activity during action observation may be modulated by the kinematics of observed actions. One purpose of this activity during action observation may be to predict the visual consequence of another person's action based on their movement kinematics. Here, we tested the hypothesis that the primary motor cortex (M1) may have a causal role in inferring information that is present in the kinematics of observed actions.

Grasp-specific motor resonance is influenced by the visibility of the observed actor.

Motor resonance is the modulation of M1 corticospinal excitability induced by observation of others' actions. Recent brain imaging studies have revealed that viewing videos of grasping actions led to a differential activation of the ventral premotor cortex depending on whether the entire person is viewed versus only their disembodied hand. Here we used transcranial magnetic stimulation (TMS) to examine motor evoked potentials (MEPs) in the first dorsal interosseous (FDI) and abductor digiti minimi (ADM) during observation of videos or static images in which a whole person or merely the hand was seen reaching and grasping a peanut (precision grip) or an apple (whole hand grasp).