Spatial and temporal aspects of visual backward masking in children and young adolescents

We thank Marc Repnow for his help setting up the experiments. In addition, we thank two anonymous reviewers for their very thoughtful and helpful comments. This work was supported by the Volkswagen Foundation project “Between Europe and the Orient—A Focus on Research and Higher Education in/on Central Asia and the Caucasus” and by the VELUX Foundation project “Perception, Cognition and Healthy Brain Aging.”Peer reviewedPublisher PD

Local form interference in biological motion perception

Peer reviewedPublisher PD

An advantage for horizontal motion direction discrimination

We would like to thank Cosmin Manulescu, Aureja Balatkaite, Alisa Dambe, Hilary Mccall, Sorin Spataru, and Emily Williams for help collecting data for this project. In addition, we would like to thank Sebastiaan Mathôt for helpful discussions on the Bayesian analysis.Peer reviewedPostprin

Idiosyncratic body motion influences person recognition

Person recognition is an important human ability. The main source of information we use to recognize people is the face. However, there is a variety of other information that contributes to person recognition, and the face is almost exclusively perceived in the presence of a moving body. Here, we used recent motion capture and computer animation techniques to quantitatively explore the impact of body motion on person recognition. Participants were familiarized with two animated avatars each performing the same basic sequence of karate actions with slight idiosyncratic differences in the body movements. The body of both avatars was the same, but they differed in their facial identity and body movements. In a subsequent recognition task, participants saw avatars whose facial identity consisted of morphs between the learned individuals. Across trials, each avatar was seen animated with sequences taken from both of the learned movement patterns. Participants were asked to judge the identity of the avatars. The avatars that contained the two original heads were predominantly identified by their facial identity regardless of body motion. More importantly however, participants identified the ambiguous avatar primarily based on its body motion. This clearly shows that body motion can affect the perception of identity. Our results also highlight the importance of taking into account the face in the context of a body rather than solely concentrating on facial information for person recognition.peer-reviewe

Motion coherence and direction discrimination in healthy aging

This work was supported by a BBSRC grant to KSP (BB/K007173/1). Commercial relationships: none. Corresponding author: Karin S. Pilz. Email: [email protected]. Address: School of Psychology, William Guild Building, University of Aberdeen, Scotland, UK.Peer reviewedPublisher PD

Selective age-related changes in orientation perception

Orientation perception is a fundamental property of the visual system and an important basic processing stage for visual scene perception. Neurophysiological studies have found broader tuning curves and increased noise in orientation-selective neurons of senescent monkeys and cats, results that suggest an age-related decline in orientation perception. However, behavioral studies in humans have found no evidence for such decline, with performance being comparable for younger and older participants in orientation detection and discrimination tasks. Crucially, previous behavioral studies assessed performance for cardinal orientation only, and it is well known that the human visual system prefers cardinal over oblique orientations, a phenomenon called the oblique effect. We hypothesized that age-related changes depend on the orientation tested. In two experiments, we investigated orientation discrimination and reproduction for a large range of cardinal and oblique orientations in younger and older adults. We found substantial age-related decline for oblique but not for cardinal orientations, thus demonstrating that orientation perception selectively declines for oblique orientations. Taken together, our results serve as the missing link between previous neurophysiological and human behavioral studies on orientation perception in healthy aging.</p

Effects of cue validity on attentional selection

Visual attention can be allocated to locations or objects, leading to enhanced processing of information at the specific location (space-based effects) or specific object (object-based effects). Previous studies have observed object-based effects to be smaller and less robust than space-based effects, with large individual differences in their temporal occurrence. Studies on space- and object-based effects are often based on a two-rectangle paradigm in which targets appear at cued locations more often than uncued locations. It is, however, unclear whether and how the target's spatial probability affects the temporal occurrence of these effects. In three experiments with different cue validities (80%, 50% and 33%), we systematically changed the interval between the cue and the target from 50 to 600 ms. On a group level and for individuals, we examined how cue validity affects the occurrence of object- and space-based effects. We observed that the magnitude and the prevalence of space-based effects heavily decreased with reduced cue validity. Object-based effects became even more sparse and turned increasingly negative with decreasing cue validity, representing a different-object rather than a same-object advantage. These findings indicate that changes in cue-validity affect both space- and object-based effects, but it does not account for the low prevalence and magnitude of object-based effects

Behavioural evidence for distinct mechanisms related to global and biological motion perception

This work was supported by a Biotechnology and Biological Sciences Research Council grant to KSP (BB/K007173/1).Peer reviewedPublisher PD

Visual attention, biological motion perception and healthy ageing

Open Access via Springer Compact Agreement This study was funded by a grant from the Development Trust to Karin S. Pilz and Louise H. Phillips.Peer reviewedPublisher PD

Effects of aging on identifying emotions conveyed by point-light walkers

M.G. was supported by EC FP7 HBP (grant 604102), PITN-GA-011-290011 (ABC) FP7-ICT-2013-10/ 611909 (KOROIBOT), and by GI 305/4-1 and KA 1258/15-1, and BMBF, FKZ: 01GQ1002A. K.S.P. was supported by a BBSRC New Investigator Grant. A.B.S. and P.J.B. were supported by an operating grant (528206) from the Canadian Institutes for Health Research. The authors also thank Donna Waxman for her valuable help in data collection for all experiments described here.Peer reviewedPostprin