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New Research in Developmental Science

Congratulations to David and Monica, whose latest paper has just been published in Developmental Science!


Vercillo, T., Burr, D., Sandini, G. & Gori, M. (2014). Children do not recalibrate motor-sensory temporal order after exposure to delayed sensory feedback,Dev Sci,
PDF

Prolonged adaptation to delayed sensory feedback to a simple motor act (such as pressing a key) causes recalibration of sensory-motor synchronization, so instantaneous feedback appears to precede the motor act that caused it (Stetson, Cui, Montague & Eagleman, 2006). We investigated whether similar recalibration occurs in school-age children. Although plasticity may be expected to be even greater in children than in adults, we found no evidence of recalibration in children aged 8-11 years. Subjects adapted to delayed feedback for 100 trials, intermittently pressing a key that caused a tone to sound after a 200 ms delay. During the test phase, subjects responded to a visual cue by pressing a key, which triggered a tone to be played at variable intervals before or after the keypress. Subjects judged whether the tone preceded or followed the keypress, yielding psychometric functions estimating the delay when they perceived the tone to be synchronous with the action. The psychometric functions also gave an estimate of the precision of the temporal order judgment. In agreement with previous studies, adaptation caused a shift in perceived synchrony in adults, so the keypress appeared to trail behind the auditory feedback, implying sensory-motor recalibration. However, school children of 8 to 11 years showed no measureable adaptation of perceived simultaneity, even after adaptation with 500 ms lags. Importantly, precision in the simultaneity task also improved with age, and this developmental trend correlated strongly with the magnitude of recalibration. This suggests that lack of recalibration of sensory-motor simultaneity after adaptation in school-age children is related to their poor precision in temporal order judgments. To test this idea we measured recalibration in adult subjects with auditory noise added to the stimuli (which hampered temporal precision). Under these conditions, recalibration was greatly reduced, with the magnitude of recalibration strongly correlating with temporal precision.

New Research in Trends in Cognitive Science

Congratulations to Paola and Scott , whose latest paper has just been accepted in Trends in Cognitive Science!

Binda, P. & Murray, S. O. (2014). Keeping a large-pupilled eye on high-level visual processing,Trends Cogn Sci, PDF

The pupillary light response has long been considered an elementary reflex. However, evidence now shows that it integrates information from such complex phenomena as attention, contextual processing, and imagery. These discoveries make pupillometry a promising tool for an entirely new application: the study of high-level vision.

New Research in Current Biology

Congratulations to David and Marco, whose latest paper has just been published in Current Biology!

Burr, D. & Cicchini, G. M. (2014). Vision: efficient adaptive coding,Curr Biol, 22 (24), R1096-1098.
PDF

Recent studies show that perception is driven not only by the stimuli currently impinging on our senses, but also by the immediate past history. The influence of recent perceptual history on the present reflects the action of efficient mechanisms that exploit temporal redundancies in natural scenes.

New Research in EBR

Congratulations to David and Monica, whose latest paper has just been published in Experimental Brain Research!

Development of context-dependency in human space perception, PDF

Sciutti, A., Burr, D., Saracco, A., Sandini G. & Gori, M.

Perception is a complex process, where prior knowledge exerts a fundamental influence over what we see. The use of priors is at the basis of the well-known phenomenon of central tendency: Judgments of almost all quantities (such as length, duration, and number) tend to gravitate toward their mean magnitude. Although such context-dependency is universal in adult perceptual judgments, how it develops with age remains unknown. We asked children from 7 to 14 years of age and adults to reproduce lengths of stimuli drawn from different distributions and evaluated whether judgments were influenced by stimulus context. All participants reproduced the presented length differently depending on the context: The same stimulus was reproduced as shorter, when on average stimuli were short, and as longer, when on average stimuli were long. Interestingly, the relative importance given to the current sensory signal and to priors was almost constant during childhood. This strategy, which in adults is optimal in Bayesian terms, is apparently successful in holding the sensory noise at bay even during development. Hence, the influence of previous knowledge on perception is present already in young children, suggesting that context-dependency is established early in the developing brain.


New Research in Proceedings of the Royal Society

Congratulations to Roberto
Irene and David, whose latest paper has just been published in Proceedings of the Royal Society!

Arrighi, R., Togoli, I. & Burr, D. C. (2014). A generalized sense of number, Proc R Soc B (2014) PDF

Much evidence has accumulated to suggest that many animals, including young human infants, possess an abstract sense of approximate quantity, a number sense. Most research has concentrated on apparent numerosity of spatial arrays of dots or other objects, but a truly abstract sense of number should be capable of encoding the numerosity of any set of discrete elements, however displayed and in whatever sensory modality. Here, we use the psychophysical technique ofadaptation to study the sense of number for serially presented items. We show that numerosity of both auditory and visual sequences is greatly affected by prior adaptation to slow or rapid sequences of events. The adaptation to visual stimuli was spatially selective (in external, not retinal coordinates), pointing to a sensory rather than cognitive process. However, adaptation generalized across modalities, from auditory to visual and vice versa. Adaptation also generalized across formats: adapting to sequential streams of flashes affected the perceived numerosity of spatial arrays. All these results point to a perceptual system that transcends vision and audition to encode an abstract sense of number in space and in time.

SFX 2014 – Serial effects in perception: prediction, priming and adaptation – Workshop

Pisa, 11th -12th December 2014

Recent studies show that perception is driven not only by the stimuli currently impinging on our senses, but also by the immediate past history. The current studies show that perception most often is dragged towards the past stimulus history. This feature, which is reminiscent of priming, is an optimizing strategy in an environment where things change slowly over time and the future is correlated with the present.

However this opens the question as to when it is beneficial to assume continuity between past and present and when is it beneficial to emphasize any differences between past and present, as occurs with sensory adaptation. The workshop aims at encouraging discussion in the field gathering more than 10 distinguished researchers worldwide. The workshop begins on Thursday the 11th in the afternoon and ends Friday 12th in the evening. The meeting will be hosted in the Seminar room of the Institute of Neuroscience - CNR in Pisa.

Confirmed speakers are:

Geoff Boynton, David Burr, Gianluca Campana, Marco Cicchini, Floris de Lange, József Fiser, Peter Foldiak, Aldo Genovesio, Árni Kristjánsson, Larry Maloney, Pascal Mamassian, Isabelle Mareschal, Lars Muckli, Samuel Solomon, Peter Thompson, David Whitney

Here is the programme (PDF) and the abstract book (PDF)

Here there are a large map and an enlargement of Pisa City Center. A zoomed version of CNR premises can be found here


For travel and accomodation, visit the following links: http://www.pisa-airport.com/ and http://www.hotelleonardopisa.it/azienda.aspx?idm=12&idl=2

Wi-fi connection with Eduroam login will be available on the workshop premises and in the lab.

For any detailed information contact us (David Burr, Guido Marco Cicchini).

Special Issues on Multisensory Research

Multisensory research is calling for papers to appear in four special issues due publishing by mid-2015

Special Issue on Multimodality of Early Sensory Processing
Guest Editors: Paola Binda, Guido Marco Cicchini and Roberto Arrighi
Deadline is extended to 30 November 2014. Click here for more details.

Special Issue on Multisensory Development and Plasticity
Guest Editors: Monica Gori and Ileana Hanganu-Opatz
Deadline is 30 September 2014. Click here for more details.

Special Issue on Vestibular Cognition
Guest Editors:  Laurence Harris and Elisa Ferrè
Deadline is 1 October 2014. Click here for more details.

Special Issue on Understanding the Correspondences
Guest Editors:  Charles Spence, Ophelia Deroy and Cesare V. Parise,
Deadline is 1 October 2014. Click here for more details.

Online submission: Articles for publication in Multisensory Research can be submitted online through Editorial Manager, please click here.


Multisensory Research is an interdisciplinary archival journal covering all aspects of multisensory processing including the control of action, cognition and attention. Research using any approach to increase our understanding of multisensory perceptual, behavioural, neural and computational mechanisms is encouraged. Empirical, neurophysiological, psychophysical, brain imaging, clinical, developmental, mathematical and computational analyses are welcome. Research will also be considered covering multisensory applications such as sensory substitution, crossmodal methods for delivering sensory information or multisensory approaches to robotics and engineering. Short communications and technical notes that draw attention to new developments will be included, as will reviews and commentaries on current issues. Special issues dealing with specific topics will be announced from time to time. Multisensory Research is a continuation of Seeing and Perceiving and of Spatial Vision.

New Research in Journal of Vision

Congratulations to
EckartConcetta and David, whose latest paper has just been published in Journal of Vision!

Zimmermann, E., Morrone, M. C. & Burr, D. C. (2014). The visual component to saccadic compression,J Vis, 12 (14), PDF

Visual objects presented around the time of saccadic eye movements are strongly mislocalized towards the saccadic target, a phenomenon known as "saccadic compression." Here we show that perisaccadic compression is modulated by the presence of a visual saccadic target. When subjects saccaded to the center of the screen with no visible target, perisaccadic localization was more veridical than when tested with a target. Presenting a saccadic target sometime before saccade initiation was sufficient to induce mislocalization. When we systematically varied the onset of the saccade target, we found that it had to be presented around 100 ms before saccade execution to cause strong mislocalization: saccadic targets presented after this time caused progressively less mislocalization. When subjects made a saccade to screen center with a reference object placed at various positions, mislocalization was focused towards the position of the reference object. The results suggest that saccadic compression is a signature of a mechanism attempting to match objects seen before the saccade with those seen after.

New Research in Behaioural Brain Research

Congratulations to Eckart, Concetta and David, whose latest paper has just been accepted for publication in Behavioural Brain Research!

Zimmermann, E., Morrone, M. C. & Burr, D. C. (2014). Buildup of spatial information over time and across eye-movements,Behavioural brain research, PDF

To interact rapidly and effectively with our environment, our brain needs access to a neural represen-tation of the spatial layout of the external world. However, the construction of such a map poses majorchallenges, as the images on our retinae depend on where the eyes are looking, and shift each time wemove our eyes, head and body to explore the world. Research from many laboratories including ourown suggests that the visual system does compute spatial maps that are anchored to real-world coordi-nates. However, the construction of these maps takes time (up to 500 ms) and also attentional resources.We discuss research investigating how retinotopic reference frames are transformed into spatiotopicreference-frames, and how this transformation takes time to complete. These results have implicationsfor theories about visual space coordinates and particularly for the current debate about the existence ofspatiotopic representations.

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