1,804 research outputs found
Manual action affect vocalization of infants
No full textUpper limb gestures, as well as transitive actions (i.e. acted upon an object) when either executed or observed aVect speech. Broca’s area seems to be involved in integration between the two motor representations of arm and mouth (Bernardis and Gentilucci, Neuropsychologia, 44:178–190, 2006, Gentilucci etal., Eur J Neurosci, 19:190–202, 2004a, Neuropsychologia, 42:1554–1567, 2004b, J Cogn Neurosci, 18:1059–1074, 2006). The rele- vance of these data is in relation with the hypothesis that language evolved from manual gestures, and was gradually transformed in speech by means of a system of dual motor commands to hand and mouth (Gentilucci and Corballis, Neurosci Biobehav, Rev 30:949–960, 2006). The present study aimed to verify whether this system of integration between gestures (and transitive actions) and speech is involved also in the language development of infants. Vocalizations of infants aged between 11 and 13 months were recorded during both manipulation of objects of diVerent size and request arm gestures towards the same objects presented by the experimenter. Frequency in voice spectra increased when the infants manipulated or gestured to large objects in comparison with the same activities directed to small objects. These data suggest that intrinsic properties of an object evoking commands of manual inter- action are used to identify that object, and to communicate
How does action resist visual illusion? Uncorrected oculomotor information does not account for accurate pointing in peripersonal space
No full textInteraction of two sources of information in spatio-temporal occlusions
No full textINVESTIGATIVE OPHTALMOLOGY & VISUAL SCIENC
Visually guided pointing and the Mueller-Lyer illusion: why are the data so contradictory?
No full textImitation during phoneme production
No full textDoes listening to and observing the speaking interlocutor influence phoneme production? In two experiments female participants were required to recognize and, then, to repeat the string-of-phonemes /aba/ presented by actors visually, acoustically and audiovisually. In experiment 1 a male actor presented the string-of-phonemes and the participants’ lip kinematics and voice spectra were compared with those of a reading control condition. In experiment 2 female and male actors presented the string-of-phonemes and the lip kinematics and the voice spectra of the participants’ responses to the male actors were compared with those to the female actors (control condition). In both experiments 1 and 2, the lip kinematics in the visual presentations and the voice spectra in the acoustical presentations changed in the comparison with the control conditions approaching the male actors’ values, which were different from those of the female participants and actors. The variation in lip kinematics induced changes also in voice formants but only in the visual presentation. The data suggest that both features of the lip kinematics and of the voice spectra tend to be automatically imitated when repeating a string-of-phonemes presented by a visible and/or audible speaking interlocutor. The use of imitation, in place of the usual lip kinematics and vocal features, suggests an automatic and unconscious tendency of the perceiver to interact closely with the interlocutor. This is in accordance with the idea that resonant circuits are activated by the activity of the mirror system, which relates observation to execution of arm and mouth gestures
Speech and gesture share the same communication system
No full textHumans speak and produce symbolic gestures. Do these two forms of communication interact, and how? First, we tested whether the two communication signals influenced each other when emitted simultaneously. Participants either pronounced words, or executed symbolic gestures, or emitted the two communication signals simultaneously. Relative to the unimodal conditions, multimodal voice spectra were enhanced by gestures, whereas multimodal gesture parameters were reduced by words. In other words, gesture reinforced word, whereas word inhibited gesture. In contrast, aimless arm movements and pseudo-words had no comparable effects. Next, we tested whether observing word pronunciation during gesture execution affected verbal responses in the same way as emitting the two signals. Participants responded verbally to either spoken words, or to gestures, or to the simultaneous presentation of the two signals. We observed the same reinforcement in the voice spectra as during simultaneous emission. These results suggest that spoken word and symbolic gesture are coded as single signal by a unique communication system. This signal represents the intention to engage a closer interaction with a hypothetical interlocutor and it may have a meaning different from when word and gesture are encoded singly
Emotional and cognitive information processing in obstacle negotiation in patient with Parkinson’s disease and freezing
No full textObjective: We used emotional (images from the International Affective Picture System - IAPS)1 and cognitive inputs (visual perturbation in a stepping-over-the-obstacle task) with the aim to investigate the hypothesis of a cognitive and affective processing overload in the genesis of freezing of gait (FoG) in Parkinson’s disease (PD).
Background: FoG is one of the most severe symptoms in PD. It appears as an unpredictable stopping phenomenon during gait and locomo- tor tasks. The underlying mechanism of freezing is still largely unknown. An emerging hypothesis explores freezing as an information processing overload problem produced by a basal ganglia faulty output control in cognitive, limbic and motor neural networks2
Methods: We recruited 12 PD patients with FoG, 11 patients without FoG, and 15 healthy elderly controls. Participants underwent neurological, neuropsychological, and affective state assessments. The emotional stimuli were 20 different images taken from the IAPS system (10 with positive valence, 10 with negative valence, all with a medium level of rating in the arousal). The cognitive stimulus was the obstacle with a light placed on the top.
Participants were placed at the beginning of a walkway and were asked to look at a screen placed at the other end, where the IAPS images were presented. The obstacle was positioned in the middle of the walkway (set at 10% of participants’ height). The participants were asked to walk and step over the obstacle, and in half of the trials, when the subject began the last step before overcoming the obstacle, the light on the top was turned on randomly.
Results: In PD with FoG, the clearance (vertical distance between the foot and the obstacle during the crossing step) was modulated by the valence of the emotional image when the light was off (lower step clear- ance in response to unpleasant images p=0.020), but not when the light was on.
Moreover, results showed slower reaction times in response to unpleas- ant images (p=0.028), and longer times to approach (p=0.012) and cross (p=0.023) the obstacle when unpleasant images were presented. A similar slowing is present in the mean velocity of the crossing step in response to unpleasant images ((p=0.044).
Conclusions: Our data support the hypothesis that the increase of cog- nitive and emotional information processing3, could be relevant in the gen- esis of freezing episodes during planning and motor control
Electophysiological evidence of cross-modal priming between the meaning system of gesture and language
No full textBehavioral results showed an interference effect between the meaning of iconic gestures and that of unrelated words. ERPs analyses showed a greater P200 component for nouns than for verbs,
which was modulated by the relation with the preceding gesture,
and a clear N400 with greater negative values for verbs than for
nouns
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