Expert players accurately detect an opponent's movement intentions through sound alone

Sounds offer a rich source of information about events taking place in our physical and social environment. However, outside the domains of speech and music, little is known about whether humans can recognize and act upon the intentions of another agent's actions detected through auditory information alone. In this study we assessed whether intention can be inferred from the sound an action makes, and in turn, whether this information can be used to prospectively guide movement. In 2 experiments experienced and novice basketball players had to virtually intercept an attacker by listening to audio recordings of that player's movements. In the first experiment participants had to move a slider, while in the second one their body, to block the perceived passage of the attacker as they would in a real basketball game. Combinations of deceptive and nondeceptive movements were used to see if novice and/or experienced listeners could perceive the attacker's intentions through sound alone. We showed that basketball players were able to more accurately predict final running direction compared to nonplayers, particularly in the second experiment when the interceptive action was more basketball specific. We suggest that athletes present better action anticipation by being able to pick up and use the relevant kinematic features of deceptive movement from event-related sounds alone. This result suggests that action intention can be perceived through the sound a movement makes and that the ability to determine another person's action intention from the information conveyed through sound is honed through practice. (PsycINFO Database Recor

An exploration on whole-body and foot-based vibrotactile sensitivity to melodic consonance

Consonance is a distinctive attribute of musical sounds, for which a psychophysical explanation has been found leading to the critical band perceptual model. Recently this model has been hypothesized to play a role also during tactile perception. In this paper the sensitivity to vibrotactile consonance was subjectively tested in musicians and non-musicians. Before the test, both such groups listened to twelve melodic intervals played with a bass guitar. After being acoustically isolated, participants were exposed to the same intervals in the form of either a whole-body or foot-based vibrotactile stimulus. On each trial they had to identify whether an interval was ascending, descending or unison. Musicians were additionally asked to label every interval using standard musical nomenclature. The intervals identification as well as their labeling was above chance, but became progressively more uncertain for decreasing consonance and when the stimuli were presented underfoot. Musicians\u2019 labeling of the stimuli was incorrect when dissonant vibrotactile intervals were presented underfoot. Compared to existing literature on auditory, tactile and multisensory perception, our results reinforce the idea that vibrotactile musical consonance plays a perceptual role in both musicians and non-musicians. Might this role be the result of a process occurring at central and/or peripheral level, involving or not activation of the auditory cortex, concurrent reception from selective somatosensory channels, correlation with residual auditory information reaching the basilar membrane through bone conduction, is a question our preliminary exploration leaves open to further research work

To hear or not to hear: sound availability modulates sensory-motor integration

When we walk in place with our eyes closed after a few minutes of walking on a treadmill, we experience an unintentional forward body displacement (drift), called the sensory-motor aftereffect. Initially, this effect was thought to be due to the mismatch experienced during treadmill walking between the visual (absence of optic flow signaling body steadiness) and proprioceptive (muscle spindles firing signaling body displacement) information. Recently, the persistence of this effect has been shown even in the absence of vision, suggesting that other information, such as the sound of steps, could play a role. To test this hypothesis, six cochlear-implanted individuals were recruited and their forward drift was measured before (Control phase) and after (Post Exercise phase) walking on a treadmill while having their cochlear system turned on and turned off. The relevance in testing cochlear-implanted individuals was that when their system is turned off, they perceive total silence, even eliminating the sounds normally obtained from bone conduction. Results showed the absence of the aftereffect when the system was turned off, underlining the fundamental role played by sounds in the control of action and breaking new ground in the use of interactive sound feedback in motor learning and motor development

HEALTHCARE EXPENDITURE AND THE INCOME EFFECT: A CAUSAL ANALYSIS

The rate of healthcare expenditures as a share of GDP in the United States is growing at an alarmingly fast rate. A leading economic theory that explains this phenomenon is the income effect, which claims that the rise in per capita income is the main reason for increases in healthcare expenditure. This paper seeks to estimate the causal effect of per capita income on per capita health expenditures at the state level by instrumenting for income using time-series variation in global oil prices interacted with cross-sectional variation in state level oil reserves in the United States. The benefit of using an instrumental variable approach is that it can effectively separate the potentially exogenous sources of variation in income, allowing for a cleaner analysis. I run an ordinary least squares regression as well as an instrumental variable regression in order to compare the results between the two. I refine and improve past economic models in order to achieve an accurate study of the causal relationship between increases in income and healthcare expenditure in the United States in the years 2000-2009

The Sound in Action: The link between sound perception and human behavior.

I suoni fanno parte della nostra vita. Nonostante essi siano soltanto onde che arrivano al nostro orecchio stimolandone i recettori, siamo comunque in grado di ricavare informazioni rilevanti rispetto all\u2019ambiente che ci circonda. Siamo in grado, infatti, di riconoscere se un\u2019automobile si muove verso di noi, se una persona sta correndo o camminando, ma anche che tipo di superficie stiamo calpestando o il movimento che stiamo eseguendo solo attraverso il loro suono.Poiche\u301 l\u2019elaborazione delle informazioni sensoriali e\u300 funzionale all\u2019interazione con l\u2019ambiente circostante, lo scopo di questa tesi e\u300 far luce sulla relazione esistente tra elaborazione sonora e il tipo di movimento evocato da quest\u2019ultima. Attraverso cinque diversi esperimenti abbiamo indagato la pianificazione dei movimenti in funzione della distanza di approccio di un suono rispetto allo spazio peripersonale, alla relazione tra suono prodotto da un movimento (es. suono di passi) e l\u2019organizzazione conseguente del movimento ed infine come si sviluppa la capacita di comprendere le intenzioni degli altri ascoltando il suono prodotto dai loro movimenti. I risultati ottenuti dimostrano per la prima volta che: 1) lo spazio peripersonale e\u300 funzionale alla pre-pianificazione e anticipazione di un\u2019azione difensiva (quando, per esempio, percepiamo un agente estero diretto verso di noi); 2) ascoltare il suono di passi su diverse superfici evoca illusioni pseudo-tattili che richiamano la rappresentazione interna del piano motorio del cammino; 3) la rimozione del feedback sonoro durante il cammino porta a una riduzione del processo d\u2019integrazione sensitivo motorio e della rappresentazione interna del movimento; 4) l\u2019abilita\u300 di richiamare tale rappresentazione interna del movimento dipende dal livello di esperienza sensitivo motoria che una persona ha rispetto al suono ascoltato; 5) possiamo capire le intenzioni di un\u2019altra persona solo ascoltando il suono prodotto dalla sua azione, questa abilita\u300 dipende dall\u2019esperienza rispetto al movimento ascoltato. Inoltre dimostra come considerando le componenti in frequenza, intensita\u300 e durata si possono ricavare informazioni rilevanti per guidare le azioni. I suoni non sono nient\u2019altro che onde, ma per gli esseri umani sono ricchi di informazioni e possono guidare le loro azioni.Sounds are part of our life. In principle they are just waves that reach our ears and stimulate inner receptors; nevertheless humans are able to extract relevant environmental information. Just through the sounds we can understand whether a car is approaching us, or if someone is walking or running. Since the elaboration of the information that comes from our senses is functional to plan an action for interacting within the surroundings, the aim of this thesis is to shed light on the link between sounds and the movements produced and evoked by them. By means of five experiments we investigated the relationship between action planning and sound distance evaluation; the connection between the sound produced by a movement (e.g. the footsteps' sound) and the related motor planning and finally how humans develop the ability to infer the intention of another person just by listening to the sound he/she produces. The results showed for the first time that: 1) sounds approaching the surroundings of our body (the so called peripersonal space) areperceivedandenactedin a highly specific and detailed way 2) sounds produced by movements can evoke pseudo-haptic illusions that recall the internal movement representation of that movement; 3) the absence of the sound of a movement degrades the sensory-motor integration process along with the internal movement representation; 4) the ability to re-call this internal representation depends on the level of motor experience on the heard movement; 5) from the sound of an action performed by another person, people can infer his/her intentions, but, again, this ability is experience related. In conclusion our experiments strongly sustain the fundamental role that the sound of actions play in action control and learning. We showed that from the different sound\u2019s components as frequencies, intensity and time humans can specifically extract relevant information to guide their movements

Interactive footstep sounds modulate the perceptual-motor aftereffect of treadmill walking

In this study, we investigated the role of interactive auditory feedback in modulating the inadvertent forward drift experienced while attempting to walk in place with closed eyes following a few minutes of treadmill walking. Simulations of footstep sounds upon surface materials such as concrete and snow were provided by means of a system composed of headphones and shoes augmented with sensors. In a control condition, participants could hear their actual footstep sounds. Results showed an overall enhancement of the forward drift after treadmill walking independent of the sound perceived, while the strength of the aftereffect, measured as the proportional increase (posttest/pretest) in forward drift, was higher under the influence of snow compared to both concrete and actual sound. In addition, a higher knee angle flexion was found during the snow sound condition both before and after treadmill walking. Behavioral results confirmed those of a perceptual questionnaire, which showed that the snow sound was effective in producing strong pseudo-haptic illusions. Our results provide evidence that the walking in place aftereffect results from a recalibration of haptic, visuo-motor but also sound-motor control systems. Self-motion perception is multimodal

Might as Well Jump: Sound Affects Muscle Activation in Skateboarding

The aim of the study is to reveal the role of sound in action anticipation and performance, and to test whether the level of precision in action planning and execution is related to the level of sensorimotor skills and experience that listeners possess about a specific action. Individuals ranging from 18 to 75 years of age - some of them without any skills in skateboarding and others experts in this sport - were compared in their ability to anticipate and simulate a skateboarding jump by listening to the sound it produces. Only skaters were able to modulate the forces underfoot and to apply muscle synergies that closely resembled the ones that a skater would use if actually jumping on a skateboard. More importantly we showed that only skaters were able to plan the action by activating anticipatory postural adjustments about 200 ms after the jump event. We conclude that expert patterns are guided by auditory events that trigger proper anticipations of the corresponding patterns of movements