i-Perception

Scottish Vision Group Meeting.

Pion

The Scottish Vision Group (SVG) Meeting is an annual event. The meeting was held 25-27 March 2011 on the Isle of Skye, Scotland. Previous meetings took place in:

2001 The Burn, Glenesk, Brechin, Angus
2002 The Burn, Glenesk, Brechin, Angus
2003 The Burn, Glenesk, Brechin, Angus
2004 The Burn, Glenesk, Brechin, Angus
2005 The Log Cabin Hotel, Kirkmichael, Perthshire
2006 The University of Aberdeen, Aberdeen
2007 Kinloch Hotel, Blackwaterfoot, Isle of Arran
2008 Dundarach Hotel, Pilochry, Perthshire
2009 Western Isles Hotel, Tobermory, Isle of Mull
2010 The Royal Dunkeld Hotel, Dunkeld, Perthshire

The meeting organiser was Martin Lages, and the committee included Paul Hibbard, Martin Lages, Phil MacAleer, David Simmons, and Roger Watt. The meeting was supported by Suzanne Heron and Katarzyna Jaworska. The following are the abstracts of that meeting.

Asia-Pacific Conference on Vision.

Pion

The Asia-Pacific Conference on Vision (APCV) is an annual meeting devoted to vision research. The 2011 meeting was held 15–18 July in the exciting city of Hong Kong. The conference aims to facilitate vision research throughout the Asia-Pacific by bringing together scientists from the broad range of disciplines contributing to modern vision science, including visual psychophysics, neuroscience, computational vision, and cognitive psychology. William Hayward was the chair of the organizing committee, which included members from the University of Hong Kong, the Chinese University of Hong Kong, Hong Kong Polytechnic University, Hong Kong University of Science and Technology, and Hong Kong Shue Yan University. The following are the abstracts of keynote speakers, talks, and posters from the conference.

12th International Multisensory Research Forum Abstracts.

Pion

The International Multisensory Research Forum (IMRF) is an annual meeting. The 2011 meeting was held 17‒20 October in Fukuoka, Japan. The conference provides a platform for scientists who are interested in how different senses interact with each other and are integrated. Researchers from many different disciplines, including neuroscience, psychophysics, cognitive psychology, computational modeling, developmental research, and engineering, participate. This year, Yôiti Suzuki was the general chair of the organizing committee, which included members from universities and research institutes in Japan. The following are the abstracts of keynote speakers, symposia, talks, and posters from the conference.

AVA Christmas Meeting 2011.

Pion

The AVA Christmas Meeting was held 19 December at the University of York and celebrated 16 years of AVA Christmas Meetings. It was a one-day meeting held in the Department of Psychology at the University of York. The meeting welcomed presentations concerning any aspects of vision and visual perception and their applications. Invited talks included: Matteo Carandini (Institute of Ophthalmogy, UCL), Karl Gegenfurtner CRS Guest lecture (Giessen University), and Hannah Smithson 2011 Marr Medal winner (University of Durham). The following are the abstracts of meeting presentations.

Perceptual organization of shape, color, shade, and lighting in visual and pictorial objects. Baingio Pinna

Pion

The main questions we asked in this work are the following: Where are representations of shape, color, depth, and lighting mostly located? Does their formation take time to develop? How do they contribute to determining and defining a visual object, and how do they differ? How do visual artists use them to create objects and scenes? Is the way artists use them related to the way we perceive them? To answer these questions, we studied the microgenetic development of the object perception and formation. Our hypothesis is that the main object properties are extracted in sequential order and in the same order that these roles are also used by artists and children of different age to paint objects. The results supported the microgenesis of object formation according to the following sequence: contours, color, shading, and lighting.

Looking at Op Art: Gaze stability and motion illusions. Frouke Hermens, Johannes Zanker

Pion

Various Op artists have used simple geometrical patterns to create the illusion of motion in their artwork. One explanation for the observed illusion involves retinal shifts caused by small involuntary eye movements that observers make while they try to maintain fixation. Earlier studies have suggested a prominent role of the most conspicuous of these eye movements, small rapid position shifts called microsaccades. Here, we present data that could expand this view with a different interpretation. In three experiments, we recorded participants’ eye movements while they tried to maintain visual fixation when being presented with variants of Bridget Riley’s Fall, which were manipulated such as to vary the strength of induced motion. In the first two experiments, we investigated the properties of microsaccades for a set of stimuli with known motion strengths. In agreement with earlier observations, microsaccade rates were unaffected by the stimulus pattern and, consequently, the strength of induced motion illusion. In the third experiment, we varied the stimulus pattern across a larger range of parameters and asked participants to rate the perceived motion illusion. The results revealed that motion illusions in patterns resembling Riley’s Fall are perceived even in the absence of microsaccades, and that the reported strength of the illusion decreased with the number of microsaccades in the trial. Together, the three experiments suggest that other sources of retinal image instability than microsaccades, such as slow oculomotor drift, should be considered as possible factors contributing to the illusion.

How simultaneous is the perception of binocular depth and rivalry in plaid stimuli?. Athena Buckthought, Janine D Mendola

Pion

Psychophysical experiments have demonstrated that it is possible to perceive both binocular depth and rivalry in plaids (Buckthought and Wilson 2007, Vision Research 47 2543-2556). In a recent study, we investigated the neural substrates for depth and rivalry processing with these plaid patterns, when either a depth or rivalry task was performed (Buckthought and Mendola 2011, Journal of Vision 11 1-15). However, the extent to which perception of the two stimulus aspects was truly simultaneous remained somewhat unclear. In the present study, we introduced a new task in which subjects were instructed to perform both depth and rivalry tasks concurrently. Subjects were clearly able to perform both tasks at the same time, but with a modest, symmetric drop in performance when compared to either task carried out alone. Subjects were also able to raise performance levels for either task by performing it with a higher priority, with a decline in performance for the other task. The symmetric declines in performance are consistent with the interpretation that the two tasks are equally demanding of attention (Braun and Julesz 1998, Perception & Psychophysics 60 1-23). The results demonstrate the impressive combination of binocular features that supports coincident depth and rivalry in surface perception, within the constraints of presumed orientation and spatial frequency channels.

Crossmodal correspondences: Innate or learned?. Charles Spence, Ophelia Deroy

Pion

“Are Chimpanzees synaesthetic?” An affirmative answer to this question appeared recently in a Nature commentary on a study by Ludwig, Adachi, and Matzuzawa (2011) that demonstrated crossmodal correspondences in both chimpanzees and humans. Here we question the claim that chimpanzees are synaesthetic. We also question the claim that certain crossmodal correspondences are innate. We suggest an alternative account for the crossmodal correspondence between auditory pitch and visual lightness in terms of the internalization of correlations present in the environment. We highlight the limitations of such natural correlation approaches to the study of crossmodal correspondences as well as how such claims could potentially be tested in future research.