Workshop at Monash University December 16th 2011

This workshop is an interdisciplinary effort to broaden our understanding of sensory integration and its relations to theoretical issues in cognitive science and philosophy of mind. Topics for discussion will include multimodal sensory integration, unimodal integration, the types of factors that may influence integration, theories of integration, sensory integration in mental and neurological disorder, assumptions of unity and disunity, and more. The aim will be to understand and expand the issues into areas such as perceptual unity, binding and consciousness. The lofty goal is for interaction to flow both ways: philosophy and theoretical cognitive science will benefit from the wonderful findings on sensory integration and perhaps science can be inspired to approach integration in new ways by seeing how it connects with deep theoretical issues. Talks will thus be a mixture of empirical results exemplifying different aspects of sensory integration, and theoretical and philosophical approaches.

Venue: Monash University Conference Center, Level 7, 30 Collins Street, Melbourne CBD. [Notice: this is not Clayton or Caulfield but city; Parliament Station is closest]

Date and time: Friday 16th December 2011; 9.30-18.00, followed by dinner.

Organisers: Jakob Hohwy (Monash) and Tim Bayne (Oxford)

Registration: Please email Jakob Hohwy (jakob.hohwy@monash.edu) if you wish to participate.

Price: $30 for staff and $15 for students to cover costs for coffee, tea and lunch, please pay in cash on the day.

Dinner: The workshop will be followed by dinner at Wagamama (83 Flinders Lane) at participants' own cost. Please let Jakob know if you wish to come for dinner.

Program
[Some details yet to be finalised: speaker order may change and some titles still to come]
 Time    Speaker Title
 9.00-9.30 Venue open - Coffee/tea 
 9.30-11.00 Casey O'Callaghan (Rice University)
 Multimodality in Perception
 11.00-11.15 Break 
 11.15-11.45 Ayla Barutchu (Florey Neuroscience Institutes) Top-down influences in multisensory integration
 11.45-12.15 Bryan Paton (Monash University)
 The rubber hand illusion in autism: precision and accuracy in  visuotactile-proprioceptive integration
 12.15-12.45 Olivia Carter (University of Melbourne)
 Perceptual rivalry and the senses
 12.45-13.30 Lunch 
 13.30-14.00 Anastasia Gorbunova (Monash University)
Perceptual inference and cross-modal modulation
 14.00-14.30 Philip Gerrans (University of Adelaide)
 Passivity or externality? Sensory integration and the
  experience of alien control.
 14.30-15.00 Jacqui Howell (Monash University)
 The misperception of length in vision, haptics and audition
 15.00-15.15 Break 
 15.15-15.45 Jakob Hohwy (Monash University)  Cutaneous capture of kinesthetics
 15.45-16.15 Ramesh Rajan (Monash University)
 Dissociable and transferable processes in extracting signal from noise in hearing
 16.15-16.25 Break
 
 16.25-17.50 Tim Bayne (University of Oxford) Multisensory objects
 17.50-18.00 Close
 
 18.00- Drinks and dinner


Abstracts

Ayla Barutchu (Florey Neuroscience Institutes)
Top-down influences in multisensory integration
Historically, it has been commonly accepted that multisensory integration (MSI) is predominantly driven by bottom-up inputs. Indeed irrelevant multisensory stimuli and irrelevant cross-sensory cues have been shown to modulate integrative activity at both a behavioral and neural level highlighting the importance of bottom-up inputs in sensory integration. However, recent evidence has suggested that MSI is not immune to top-down influences. The development of integrative processes is dependent on prolonged environmental experience throughout childhood and adolescence, and, in adults, prior experience and cross-sensory associative learning have been shown to influence the integration of sensory inputs. Attention as a top-down modulator of MSI has also received much empirical support. What remains as a contentious topic of debate is the role stimulus relevance plays in MSI. In this talk, I will present new behavioral and neural evidence stressing the important role top-down influences play in the inhibition of MSI to irrelevant auditory and visual signals. Knowledge of the relevance of sensory stimuli can inhibit behavioral enhancements by MSI, and influence neural activity during early processing in primary sensory brain regions. The interplay between bottom-up drivers of MSI and top-down influences guided by the relevance of sensory stimuli will be discussed.

Bryan Paton (Monash University)
The rubber hand illusion in autism: precision and accuracy in visuotactile-proprioceptive integration
Autism spectrum disorder (ASD) is characterised by differences in unimodal and multimodal sensory and proprioceptive processing, with complex biases towards local over global processing. Many of these elements are implicated in versions of the rubber hand illusion (RHI), which were therefore studied (with J Hohwy and P Enticott, Monash) in high-functioning individuals with ASD and a typically developing control group. Both groups experienced the illusion. A number of differences were found, related to proprioception and sensorimotor processes. The ASD group showed reduced sensitivity to visuotactile-proprioceptive discrepancy but more accurate proprioception. This group also differed on acceleration in subsequent reach trials. Results are discussed in terms of weak top-down integration and precision-accuracy trade-offs.

Jakob Hohwy (Monash University)
Cutaneous capture of kinesthetics
A study of intrahaptic conflict (conducted with G Van Doorn and M Symmons, Monash) suggests capture of kinesthetic cues by cutaneous cues. Participants were unaware of how they actually moved and instead mapped their movement according to a cutaneous cue. This study is used to begin a taxonomy of different types of capture/suppression phenomena in sensory integration. The roles of attention, forward modelling and stimulus reliability are discussed and related to the "unity assumption" of co-location of the causal sources of sensory input.

Anastasia Gorbunova (Monash University)
Perceptual inference and cross-modal modulation
Preliminary data is presented from a study (conducted with J Hohwy and B Paton, Monash) investigating crossmodal modulation of perceptual inference. The findings and other studies are reviewed and discussed in terms of perceptual mechanisms influencing sensory integration.

Philip Gerrans (University of Adelaide)
Passivity or externality? Sensory integration and the experience of alien control.
Schizophrenics with delusions of alien control say that they are performing actions intended by someone else. One very interesting question here concerns the phenomenology. Do these patients actually feel as if someone else is controlling their body (feelings of externality)? What would that feel like? Or do they merely feel as though they did not intend the action (feelings of passivity)? Can the distinction between feelings of passivity and externality be empirically vindicated?
    I will argue that modest progress can be made. Predictive coding models of motor control help explain the phenomenology in terms of anomalous integration of visual and proprioceptive information about the trajectories of bodily movement. Philosophical theories of action such as that of Elisabeth Pacherie help distinguish contents and conceptual levels of explicitness at which the relevant information is represented by the neural circuitry implicated in these delusions by cognitive neuroscience.
    I will conclude that the relevant feeling is of passivity not externality.

Jacqui Howell (Monash University)
Title: The misperception of length in vision, haptics and audition.
In a darkened room, participants felt, saw and heard stimuli travel over predetermined distances in three orientations – gravitational-vertical, radial-vertical and horizontal. On all trials they were required to judge the length of the distance travelled. Judgments based on visual information over-estimated length in the radial-vertical direction, while those based on haptic information overestimated length in the gravitational-vertical direction. Length estimates based on auditory information were similar across the three orientations. Results are interpreted in light of the horizontal-vertical illusion.