Self-generated Movements Research Articles

Interparticle Adhesion Regulates the Surface Roughness of Growing Dense Three-Dimensional Active Particle Aggregates.

Activity and self-generated motion are fundamental features observed in many living and nonliving systems. Given that interparticle adhesive forces can regulate particle dynamics, we investigate how interparticle adhesion strength controls the boundary growth and roughness of active particle aggregates. Using particle based simulations incorporating both activity (birth, death, and growth) and systematic physical interactions (elasticity and adhesion), we establish that interparticle adhesion strength (fad) controls the surface roughness of a densely packed three-dimensional(3D) active particle aggregate expanding into a highly viscous medium. We discover that the surface roughness of a 3D active particle aggregate increases in proportion to the interparticle adhesion strength (fad) and show that asymmetry in the radial and transverse active particle mean-squared displacement (MSD) suppresses 3D surface roughness at lower adhesion strengths. By analyzing the statistical properties of particle displacements at the aggregate periphery, we determine that the 3D surface roughness is driven by the movement of active particle toward the core at high interparticle adhesion strengths. Our results elucidate the physics controlling the expansion of adhesive 3D active particle collectives into a highly viscous medium, with implications into understanding stochastic interface growth in active matter systems characterized by self-generation of particles.

Reduced readiness potential and post-movement beta synchronization reflect self-disorders in early course schizophrenia

Disturbances of conscious awareness, or self-disorders, are a defining feature of schizophrenia. These include symptoms such as delusions of control, i.e. the belief that one’s actions are controlled by an external agent. Models of self-disorders point at altered neural mechanisms of source monitoring, i.e. the ability of the brain to discriminate self-generated stimuli from those driven by the environment. However, evidence supporting this putative relationship is currently lacking. We performed electroencephalography (EEG) during self-paced, brisk right fist closures in ten (M = 9; F = 1) patients with Early-Course Schizophrenia (ECSCZ) and age and gender-matched healthy volunteers. We measured the Readiness Potential (RP), i.e. an EEG feature preceding self-generated movements, and movement-related EEG spectral changes. Self-disorders in ECSCZ were assessed with the Examination of Anomalous Self-Experience (EASE). Patients showed a markedly reduced RP and altered post-movement Event-Related Synchronization (ERS) in the beta frequency band (14–24 Hz) compared to healthy controls. Importantly, smaller RP and weaker ERS were associated with higher EASE scores in ECSCZ. Our data suggest that disturbances of neural correlates preceding and following self-initiated movements may reflect the severity of self-disorders in patients suffering from ECSCZ. These findings point towards deficits in basic mechanisms of sensorimotor integration as a substrate for self-disorders.

Sensory attenuation in the absence of movement: Differentiating motor action from sense of agency

Sensory attenuation is the phenomenon that stimuli generated by willed motor actions elicit a smaller neurophysiological response than those generated by external sources. It has mostly been investigated in the auditory domain, by comparing ERPs evoked by self-initiated (active condition) and externally-generated (passive condition) sounds. The mechanistic basis of sensory attenuation has been argued to involve a duplicate of the motor command being used to predict sensory consequences of self-generated movements. An alternative possibility is that the effect is driven by between-condition differences in participants’ sense of agency over the sound. In this paper, we disambiguated the effects of motor-action and sense of agency on sensory attenuation with a novel experimental paradigm. In Experiment 1, participants watched a moving, marked tickertape while EEG was recorded. In the active condition, participants chose whether to press a button by a certain mark on the tickertape. If a button-press had not occurred by the mark, then a tone would be played 1 s later. If the button was pressed prior to the mark, the tone was not played. In the passive condition, participants passively watched the animation, and were informed about whether a tone would be played on each trial. The design for Experiment 2 was identical, except that the contingencies were reversed (i.e., a button-press by the mark led to a tone). The results were consistent across the two experiments: while there were no differences in N1 amplitude between the active and passive conditions, the amplitude of the Tb component was suppressed in the active condition. The amplitude of the P2 component was enhanced in the active condition in both Experiments 1 and 2. These results suggest that motor-actions and sense of agency have differential effects on sensory attenuation to sounds and are indexed with different ERP components.

Sleep as a window on the sensorimotor foundations of the developing hippocampus.

The hippocampal formation plays established roles in learning, memory, and related cognitive functions. Recent findings also suggest that the hippocampus integrates sensory feedback from self-generated movements to modulate ongoing motor responses in a changing environment. Such findings support the view of Bland and Oddie (Behavioural Brain Research, 2001, 127, 119-136) that the hippocampus is a site of sensorimotor integration. In further support of this view, we review neurophysiological evidence in developing rats that hippocampal function is built on a sensorimotor foundation and that this foundation is especially evident early in development. Moreover, at those ages when the hippocampus is first establishing functional connectivity with distant sensory and motor structures, that connectivity is preferentially expressed during periods of active (or REM) sleep. These findings reinforce the notion that sleep, as the predominant state of early infancy, provides a critical context for sensorimotor development, including development of the hippocampus and its associated network.

The growing sensory suppression on visual perception during head-rotation preparation.

Sensory perception is often impaired by self-generated movements. This effect of sensory suppression has been commonly observed in voluntary hand-movement-induced tactile sensation during the period of motor preparation and execution. However, it remains unclear whether such suppression also occurs in the visual domain and if it can be induced by the preparation of other body movements. To extend our knowledge about sensory suppression, the present study investigated visual sensitivity during the preparation of head rotation. Participants wore virtual reality goggles and rotated their heads horizontally according to a visual cue presented on the goggles screens. Before the start of head rotation, a target of Landolt C was displayed at a peripheral location that was directed by the head-rotation cue or a symmetric location in the opposite visual field. After each head rotation, participants reported the target's orientation, allowing the measurement of the discrimination threshold. Besides, the discrimination sensitivity was also measured in two head-still conditions with or without the presentation of a visual cue. The results showed that the discrimination performance was largely impaired by the preparation of head rotation. This effect of sensory attenuation increased with the approach of head-motion onset. However, the attenuation was not found on the discrimination of auditory stimuli during the preparation of head rotation, thus excluding the account of general dual-task requirement. In contrast to the previous findings of improved perception by preparation of saccade or reach, our findings indicate that sensory suppression rather than attention shift plays a major role during the preparation of head movement.

An Electrically-Coupled Pioneer Circuit Enables Motor Development Via Proprioceptive Feedback

Precocious movements are widely seen in embryos of various animal species. Whether such movements via proprioceptive feedback play instructive roles in motor development or are mere reflection of activities in immature motor circuits is a long-standing question. Here we image the emerging motor activities in Drosophila embryos that lack proprioceptive feedback, and show that proprioceptive experience is essential for the development of locomotor central pattern generators (CPGs). Downstream of proprioceptive inputs, we identify a pioneer premotor circuit composed of two pairs of segmental interneurons, whose gap-junctional transmission requires proprioceptive experience and plays a crucial role in CPG formation. The circuit autonomously generates rhythmic plateau potentials via IP3-mediated Ca2+ release from internal stores, which contribute to muscle contractions and hence produce proprioceptive feedback. Our findings demonstrate the importance of self-generated movements in instructing motor development, and identify the cells, circuit, and physiology at the core of this proprioceptive feedback.

The influence of Friedrich Engels on Alexander Bogdanov’s Basic Elements of the Historical View of Nature

Alexander Bogdanov’s first work of philosophy, Basic Elements of the Historical View of Nature, was fundamentally influenced by Friedrich Engels. As a Marxist philosopher seeking to elaborate a comprehensive, systematic, and scientific worldview appropriate for worker–students, Bogdanov found inspiration in Engels’s Anti-Duhring, which provided him with his monist conception of being and his ‘historical view of nature’ and pointed him toward three critical elements of his work: the monism of motion (energy), Spinoza’s naturalist and determinist system, and Charles Darwin’s conception of natural selection. Bogdanov’s overall goal was to demonstrate that in nature, life, the psyche, and society there is no such thing as self-generated motion; all change occurs because of external action. For the individual and for society this means that existence determines consciousness, and societies evolve as a result of their struggle for existence, which is manifested first and foremost in labor.

Sensory Neurobiology: A New Crossroads Deep in the Cortex

Self-generated movements elicit concomitant sensory responses that are beneficial to ignore. Combining state-of-the-art physiology, behavior, and anatomy, a new study discovers a neural crossroads in the deepest layer of auditory cortex where pre-lick ramping activity suppresses peri-lick sound responses across layers.

Motion parallax via head movements modulates visuo-motor control in pigeons.

Although it has been proposed that birds acquire visual depth cues through dynamic head movements, behavioral evidence on how birds use motion parallax depth cues caused by self-motion is lacking. This study investigated whether self-generated motion parallax modulates pecking motor control and visual size perception in pigeons (Columba livia). We trained pigeons to peck a target on a touch monitor and to classify it as small or large. To manipulate motion parallax of the target, we changed the target position on the monitor according to the bird's head position in real time using a custom-built head tracker with two cameras. Pecking motor control was affected by the manipulation of motion parallax: when the motion parallax signified the target position farther than the monitor surface, the head position just before pecking to target was near the monitor surface, and vice versa. By contrast, motion parallax did not affect how the pigeons classified target sizes, implying that motion parallax might not contribute to size constancy in pigeons. These results indicate that motion parallax via head movements modulates pecking motor control in pigeons, suggesting that head movements of pigeons have the visual function of accessing motion parallax depth cues.

The Significance of ‘Home’ in Seamus Heaney

The Significance of ‘Home’ in Seamus Heaney Romy Dawson Home has always been more than mere domestic setting in Seamus Heaney’s work. The people, traditions, values, sounds, noises, and smells that emerged from his Ulster farmstead and surrounding landscape have been not only central to his identity as a Northern Irish poet, but absolutely integral to his creative well-spring. This essay will assess the abiding impact of Mossbawn, Heaney’s first and arguably most influential home, on his work. Looking at poems from four different collections – Death of a Naturalist (1966), Wintering Out (1972), North (1975), and Station Island (1984) – will allow for a widespread consideration of Mossbawn’s legacy. We find an interesting interweaving of fondness, warmth, fear, sometimes even disgust, when Heaney recollects life (and death) on the farm: an intermittently destabilized pastoral idyll. He was, in William Wordsworth’s words, ‘Foster’d alike by beauty and by fear’,1 both cradled and confined by the landscape, and community, that raised him. The Death of a Naturalist One of Heaney’s earliest memories of home is ‘Churning Day’. The sixth poem in Death of a Naturalist, it concerns the almost alchemic process by which his family convert milk into butter. Its early stages are arduous and chaotic: A thick crust, coarse-grained as limestone rough-cast, hardened gradually on top of the four crocks … After the hot brewery of gland, cud and udder, … …the hooped churn was scoured with plumping kettles and the busy scrubber echoed daintily[.]2 Studies • volume 110 • number 439 322 Harsh guttural consonants welcome us into the Heaney home, bringing withthemallthecommotionandmalodourofmilkfermentation.The‘clamour and clang of the opening’,3 as Neil Corcoran puts it, is intensified by the use of molossus (‘crust, coarse-grained’), obstructing smooth readings of the line. The ‘hot brewery’ of the cow’s stomach is a melting-pot of bodily juices: ‘gland, cud and udder’. Internal rhyme between these last two words acts to emphasize the organic, rancid origins of the milk. Any potential undertones of grubbiness, however, are quickly ousted by Heaney, who reports of two cleaning methods undertaken: both abrasively hot (‘plumping’) water and ‘busy’, dainty human hands are used to prepare the old-fashioned equipment for butter-making (21). Movement picks up as the ‘four crocks’ are removed from their restingplaces and assembled for the main event.Young Heaney watches, spellbound, as pots ‘spilled their heavy lip/of cream, their white insides, into the sterile churn’. Mild disgust and sanitation collide yet again as buttermilk, equated with innards, enters the disinfected wooden churn. Sibilance established in these two lines is maintained throughout the stanza: ‘The staff, like a great whisky muddle … mother took first turn … slugged … blistered … spattered’, carrying in its sputter the slipping and sliding of ‘flabby milk’ (21). At last, exhausted muscles (‘Arms’), sore skin (‘blistered’) and ruined ‘clothes bear fruit, and nuggets of butter are seen magically floating to the surface: ‘finally gold flecks/began to dance’. Just like the crocks that ‘spil[l]’ themselves into the churn, these ‘flakes’ dance of their own accord. A sort of mystical harmony is achieved through these self-generated movements. ‘[H]eavy and rich’, this butter is extracted from the milk in a gold rush of excitement: ‘fished’ and ‘straine[d]’ by dexterous hands until it sits like ‘gilded gravel’ in the bowl (21–2). The scene is almost otherworldly, a fairytale memoir of Mossbawn and its rituals. The unpleasant aftermath of churning day is accepted with a perverse satisfaction: ‘The house would stink long after churning day, / acrid as a sulphur mine’. Like lucky beneficiaries whose risks have paid off, the family ‘mov[e] with gravid ease, / [their] brains turned crystals full of clean deal churns’. With the ‘plash and gurgle … pat and slap’ still reverberating in his mind, young Heaney is now ‘gravid’ with inspiration; his poetic intentions rendered paradoxically ‘crysta[l]’ clear by the frenzy of yesterday’s ventures (22). ‘[W]et lumps’ close the poem, completing the string of jugular assonance throughout: ‘cud … udder … butter … scrubber … muddler … plunged … Studies • volume 110 • number 439 323 The Significance of ‘Home’ in Seamus Heaney slugged … thumped’. Heaney has dug into ‘the very cud of...

The Rapid Developmental Rise of Somatic Inhibition Disengages Hippocampal Dynamics From Self-Motion

Early electrophysiological brain oscillations recorded in preterm babies and newborn rodents are initially mostly ignited by bottom-up sensorimotor activity and only later can detach from external inputs. This is a hallmark of most developing brain areas including the hippocampus, which in the adult brain, functions in integrating external inputs onto internal dynamics. Such developmental disengagement from external inputs is likely a fundamental step for the proper development of cognitive internal models. Despite its importance, the exact timing and circuit basis for this disengagement remain unknown. To address this issue, we have investigated the daily evolution of CA1 dynamics and underlying circuits during the first and second postnatal week of mouse development using a combination of two-photon calcium imaging of neuronal somata and axons in non-anesthetized pups, viral tracing and chemogenetics. We show that the first postnatal week ends with an abrupt switch in the representation of self-motion in CA1. Indeed, most CA1 pyramidal cells switch from activated to inhibited by self-generated movements at the end of the first postnatal week whereas GABAergic neurons remain positively modulated throughout this period. This rapid switch occurs within two days and is mediated by the rapid anatomical and functional surge of somatic inhibition. The observed dynamics is consistent with a two-population model undergoing strengthening inhibition. Remarkably, a transient silencing of local somatostatin-expressing interneurons both prevents the emergence of the perisomatic GABAergic coverage and the disengagement of CA1 hippocampal dynamics from self-motion. We propose that such activity-dependent emergence of feedback inhibitory circuits critically inaugurates the development of internal cognitive models. Funding Information: This work was supported by the European Research Council under the European Union’s, Horizon 2020 research and innovation program Grant#646925, the Fondation Bettencourt Schueller, and a NWB seed grant # R20046AA. Declaration of Interest: None to declare. Ethics Approval Statement: All experiments were performed under the guidelines of the French National Ethics Committee for Sciences and Health report on Ethical Principles for Animal Experimentation in agreement with the European Community Directive 86/609/EEC (Apafis#18-185 and #30-959).

Movement errors during skilled motor performance engage distinct prediction error mechanisms

The brain detects deviations from intended behaviors by estimating the mismatch between predicted and actual outcomes. Axiomatic to these computations are salience and valence prediction error signals, which alert the brain to the occurrence and value of unexpected events. Despite the theoretical assertion of these prediction error signals, it is unknown whether and how brain mechanisms underlying their computations support error processing during skilled motor behavior. Here we demonstrate, with functional magnetic resonance imaging, that internal detection, i.e., without externally-provided feedback, of self-generated movement errors evokes instantaneous activity increases within the salience network and delayed lingering decreases within the nucleus accumbens – a key structure in the reward valuation pathway. A widespread suppression within the sensorimotor network was also observed. Our findings suggest that neural computations of salience and valence prediction errors during skilled motor behaviors operate on different time-scales and, therefore, may contribute differentially to immediate and longer-term adaptive processes.

Predicting the Sensory Consequences of Self-Generated Actions: Pre-Supplementary Motor Area as Supra-Modal Hub in the Sense of Agency Experience.

Sense of agency refers to the feeling that one’s self-generated action caused an external environment event. In a previous study, we suggested that the supplementary motor area (SMA), in its anterior portion (pre-SMA), is a key structure for attributing the sense of agency for the visual consequences of self-generated movements. However, real-life actions can lead to outcomes in different sensory modalities, raising the question of whether SMA represents a supra-modal hub for the sense of agency. Here, we compared the agency experience for visual and auditory outcomes by taking advantage of the intentional binding effect (IB). We observed discrete time-windows for the agency manifestation across different sensory modalities: While there was an IB at 200 ms delay between the action and the visual outcome, a time compression was observed when the auditory outcome followed the action by 400 ms. The magnitude of the IB was mirrored by meaningful brain activity in the pre-SMA but only at the specific delay when a sizeable IB was seen. We conclude that attributing consequences of self-generated movements to one’s action is based on similar mechanisms across sensory modalities and that those mechanisms are related to the functioning of the motor system.

The impact of motion gain on egocentric distance judgments from motion parallax

For self-generated motion parallax, a sense of head velocity is needed to estimate distance from object motion. This information can be obtained from proprioceptive and visual sources. If visual and kinesthetic information are incongruent, the visual motion of objects will not match the sensed physical velocity of the head, resulting in a distortion of perceived distances. We assessed this prediction by varying the gain between physical observer head motion and the simulated motion. Given that the relative and absolute motion parallax would be greater than expected from head motion when gain was greater than 1.0, we anticipated that this manipulation would result in objects appearing closer to the observer. Using an HMD, we presented targets 1 to 3 meters away from the observer within a cue rich environment with textured walls and floors. Participants stood and swayed laterally at a rate of 0.5 Hz paced using a metronome. Lateral gain was applied by amplifying their real position by factors of 1.0 to 3.0, then using that to set the instantaneous viewpoint within the virtual environment. After presentation, the target disappeared and the participant performed a blind walk and reached for it. Their hand position was recorded and we computed positional errors relative to the target. We found no effect of motion parallax gain manipulation on binocular reaching accuracy. In a second study we evaluated the role of stereopsis in counteracting the anticipated distortion in perceived space by testing observers monocularly. In this case, distances were perceived as nearer as gain increased, but the effects were relatively small. Taken together our results suggest that observers are flexible in their interpretation of observer produced motion parallax during active head movement. This provides considerable tolerance of spatial perception to mismatches between physical and virtual motion in rich virtual environments.

Contributions of Retinal Direction Selectivity to Central Visual Processing

The brain monitors the sensory environment via signals from the sensory periphery, such as the olfactory epithelium, the inner ear, and the retina. Understanding how sensory stimuli are processed throughout the sensory hierarchy, and how this relates to behavior, is a central outstanding question in the field of neuroscience. The processing of visual motion in mice offers unique opportunities for addressing these questions thanks to a rich literature on the anatomical and physiological properties of motion-sensitive neurons across the visual system, paired with recent developments of cutting-edge genetic and imaging approaches. A visual scene typically contains motion originating from either moving objects or optic flow caused by self-generated movements. Neurons encoding the direction of visual motion are said to be 'direction-selective'. It was historically believed the circuits responsible for creating direction selectivity de novo exist within the visual cortex. Yet, in mice, direction-selective responses can be found already in the retina, suggesting in this model organism visual motion analysis starts at the earliest stage of the visual hierarchy. This minireview presents emerging literature demonstrating how retinal direction-selective cells make causal contributions to central visual motion processing and visually guided behaviors in mice, and their potential clinical relevance, and outlines experiments for testing remaining questions. Research in this field will undoubtedly continue to advance our understanding of the basic principles of the visual system and how sensory neurons extract fundamental features of the world.

Availability of synchronous information in an additional sensory modality does not enhance the full body illusion

The Full body illusion (FBI) is an illusion in which participants experience a change in self-location to a body that is perceived from a third-person perspective. The FBI is usually induced through experimenter generated stroking but can also be induced through self-generated stroking. In four experiments (three preregistered) we compared a self-generated stroking induction condition to a self-generated movement condition, where the only difference between conditions was the presence or absence of touch. We investigated whether the illusion reflects an all-or-nothing phenomenon or whether the illusion is influenced by the availability of synchronous information in an additional sensory modality. As a prerequisite, we investigated whether the FBI can also be induced using just self-generated movement in the absence of synchronous touch. Illusion strength was measured through illusion statements. Participants reported an equally strong illusion for both induction methods in Experiments 1, 2 and 3. In the third experiment, we additionally measured the time of illusion onset. Like the illusion strength measures, the illusion onset times did not differ between the two induction methods. In the fourth experiment participants only completed the self-generated movement condition. Again, they reported the FBI, demonstrating that the findings of Experiments 1, 2 and 3 were not dependent on the presence of a condition that used synchronous touch. Together, these findings confirm the hypothesis that the FBI is an all-or-nothing phenomenon and that adding additional multisensory synchronicity does not help to enhance the strength, onset time or onset probability of the illusion.

Rediscovering Richard Held: Activity and Passivity in Perceptual Learning.

Understanding the role of self-generated movements in perceptual learning is central to action-based theories of perception. Pioneering work on sensory adaptation by Richard M. Held during the 1950s and 1960s can still shed light on this question. In a variety of rich experiments Held and his team demonstrated the need for self-generated movements in sensory adaptation and perceptual learning. This body of work received different critical interpretations, was then forgotten for some time, and saw a surge of revived interest within embodied cognitive science. Through a brief review of Held’s work and reactions to it, we seek to contribute to discussions on the role of activity and passivity in perceptual learning. We classify different positions according to whether this role is considered to be contextual (facilitatory, but not necessary), enabling (causally necessary), or constitutive (an inextricable part of the learning process itself). We also offer a critique of the notions of activity and passivity and how they are operationalized in experimental studies. The active-passive distinction is not a binary but involves a series of dimensions and relative degrees that can make it difficult to interpret and replicate experimental results. We introduce three of these dimensions drawing on work on the sense of agency: action initiation, control, and monitoring. These refinements in terms of causal relations and dimensions of activity-passivity should help illuminate open questions concerning the role of activity in perception and perceptual learning and clarify the convergences and differences between enaction and ecological psychology.

Self-Generated Whisker Movements Drive State-Dependent Sensory Input to Developing Barrel Cortex

Cortical development is an activity-dependent process [1-3]. Regarding the role of activity in the developing somatosensory cortex, one persistent debate concerns the importance of sensory feedback from self-generated movements. Specifically, recent studies claim that cortical activity is generated intrinsically, independent of movement [3, 4]. However, other studies claim that behavioral state moderates the relationship between movement and cortical activity [5-7]. Thus, perhaps inattention to behavioral state leads to failures to detect movement-driven activity [8]. Here, we resolve this issue by associating local field activity (i.e., spindle bursts) and unit activity in the barrel cortex of 5-day-old rats with whisker movements during wake and myoclonic twitches of the whiskers during active (REM) sleep. Barrel activity increased significantly within 500ms of whisker movements, especially after twitches. Also, higher-amplitude movements were more likely to trigger barrel activity; when we controlled for movement amplitude, barrel activity was again greater after a twitch than a wake movement. We then inverted the analysis to assess the likelihood that increases in barrel activity were preceded within 500ms by whisker movements: at least 55% of barrel activity was attributable to sensoryfeedback from whisker movements. Finally, when periods with and without movement were compared, 70%-75% of barrel activity was movement related. These results confirm the importance of sensory feedbackfrom movements in driving activity in sensorimotor cortex and underscore the necessity of monitoring sleep-wake states to ensure accurate assessments of the contributions of the sensory periphery to activity in developing somatosensory cortex.

The Active Sensing of Control Difference.

SummaryIn everyday life, people control objects in the world around them to varying degrees. The processes people actively use to establish their control, while interacting with an environment containing large ambiguity, remain unknown. This study examines how people explore their control over the environment and how they detect small differences in control among objects. In the experimental task, participants moved three dots on a screen and identified one dot over which the level of control is different from that of the other two. The results support a two-step behavior mechanism underlying the sensing of control difference: People first explore their overall control in the environment, and then the results of the initial exploration are used to selectively tune the direction (i.e., either more or less) of the detected control difference, ensuring efficient and rapid detection of the type of control difference that is potentially important for further action selections.

Learning to find spatially reversed sounds

Adaptation to systematic visual distortions is well-documented but there is little evidence of similar adaptation to radical changes in audition. We use a pseudophone to transpose the sound streams arriving at the left and right ears, evaluating the perceptual effects it provokes and the possibility of learning to locate sounds in the reversed condition. Blindfolded participants remain seated at the center of a semicircular arrangement of 7 speakers and are asked to orient their head towards a sound source. We postulate that a key factor underlying adaptation is the self-generated activity that allows participants to learn new sensorimotor schemes. We investigate passive listening conditions (very short duration stimulus not permitting active exploration) and dynamic conditions (continuous stimulus allowing participants time to freely move their heads or remain still). We analyze head movement kinematics, localization errors, and qualitative reports. Results show movement-induced perceptual disruptions in the dynamic condition with static sound sources displaying apparent movement. This effect is reduced after a short training period and participants learn to find sounds in a left-right reversed field for all but the extreme lateral positions where motor patterns are more restricted. Strategies become less exploratory and more direct with training. Results support the hypothesis that self-generated movements underlie adaptation to radical sensorimotor distortions.