The weight of expectation: Implicit,rather than explicit,prior expectations drive the size–weight illusion

In the size–weight illusion, small objects feel heavier than identically weighted larger objects. This illusion is thought to be a consequence of how one's prior expectations can influence conscious perception—lifters expect the large object to outweigh the small object and subsequently experience it as feeling lighter than they expected it to be. Here, we directly examined how a familiar object's identity can affect how heavy someone expects it to be, and how these expectations will influence subsequent perceptions of heaviness. We describe two novel weight illusions induced with familiar objects. In one condition, participants judged the weight of a set of similar-size objects with very different natural weights (a polystyrene sphere, a tennis ball, and a cricket ball), which had all been adjusted to weigh the same amount as one another. In this condition, participants experienced a small, but reliable, weight illusion, with the lightest looking ball feeling heavier than the heaviest looking ball. In the other condition, participants judged the weights of a different set of balls, which were different sizes, but similar natural weights, to one another (a golf ball, a foam soccer ball, and an inflated beach ball). Again, participants experienced a perceptual illusion, but in the opposite direction. Surprisingly, participant's perceptions matched, rather than contrasted with, their explicit expectations such that, even though they expected the golf ball to outweigh the beach ball they perceived the golf ball as feeling heavier than the beach ball. The effect of object mass appeared to dominate the effect of conscious expectations, suggesting that contrasting expectations of heaviness are not necessary to experience weight illusions and that current models of this robust perceptual effect must be revised.     

Early Verb Learning: How Do Children Learn How to Compare Events?

An important problem verb learners must solve is how to extend verbs. Children could use cross-situational information to guide their extensions; however, comparing events is difficult. In 2 studies, researchers tested whether children benefit from initially seeing a pair of similar events (“progressive alignment”) while learning new verbs and whether this influence changes with age. In Study 1, 2.5- and 3.5-year-old children participated in an interactive task. Children who saw a pair of similar events and then varied events were able to extend verbs at test and differed from a control group; children who saw 2 pairs of varied events did not differ from the control group. In Study 2, events were presented on a monitor. Following the initial pair of events that varied by condition, a Tobii x120 eye tracker recorded 2.5-, 3.5-, and 4.5-year-olds’ fixations to specific elements of events (areas of interest) during the 2nd pair of events, which were the same across conditions. After seeing the pair of events that were highly similar, 2.5-year-olds showed significantly longer fixation durations to agents and to affected objects as compared with the all-varied condition. At test, 3.5-year-olds were able to extend the verb, but only in the progressive alignment condition. These results are important because they show children’s visual attention to relevant elements in dynamic events is influenced by their prior comparison experience, and they show that young children benefit from seeing similar events as they learn to compare events to each other.     

Inaccuracy of Affordance Judgments for Firefighters Wearing Personal Protective Equipment

In order to safely negotiate cluttered and dangerous environments, firefighters must efficiently and effectively make affordance judgments. Failure to do so could put them at risk for slips, trips, and falls, which are major causes of injuries for firefighters. We examined how well firefighters were able to perceive their obstacle crossing abilities while wearing firefighting protective equipment. Firefighters were asked to judge whether they could cross over, under, and through different obstacles that simulated idealized fireground situations. Perceptual judgment errors were found for each obstacle type, the largest occurring with an overestimation of ability to pass under an obstacle. Years of experience had a moderate positive correlation with absolute judgment error in the “over” and “under” obstacles. Overall, a general lack of awareness of their personal protective equipment for obstacle crossing ability was observed. A better understanding of how to reduce judgment error while wearing firefighter protective gear would likely decrease the risk of injuries on the fireground.     

Rapid decrement in the effects of the Ponzo display dissociates action and perception

It has been demonstrated that pictorial illusions have a smaller influence on grasping than they do on perceptual judgments. Yet to date this work has not considered the reduced influence of an illusion as it is measured repeatedly. Here we studied this decrement in the context of a Ponzo illusion to further characterize the dissociation between vision for perception and for action. Participants first manually estimated the lengths of single targets in a Ponzo display with their thumb and index finger, then actually grasped these targets in another series of trials, and then manually estimated the target lengths again in a final set of trials. The results showed that although the perceptual estimates and grasp apertures were equally sensitive to real differences in target length on the initial trials, only the perceptual estimates remained biased by the illusion over repeated measurements. In contrast, the illusion’s effect on the grasps decreased rapidly, vanishing entirely after only a few trials. Interestingly, a closer examination of the grasp data revealed that this initial effect was driven largely by undersizing the grip aperture for the display configuration in which the target was positioned between the diverging background lines (i.e., when the targets appeared to be shorter than they really were). This asymmetry between grasping apparently shorter and longer targets suggests that the sensorimotor system may initially treat the edges of the configuration as obstacles to be avoided. This finding highlights the sensorimotor system’s ability to rapidly update motor programs through error feedback, manifesting as an immunity to the effects of illusion displays even after only a few trials.     

Understanding Chinese university student conceptions of assessment: cultural similarities and jurisdictional differences between Hong Kong and China

Hong Kong (HK) and the People’s Republic of China (PRC), while sharing historic cultural roots, have different policies for and practices of educational assessment. Student conceptions of assessment function to guide individual behaviour in response to the functions, purposes, and consequences of assessments. A new self-report questionnaire was developed to account for attitudes and beliefs detected in qualitative and pilot survey studies. In a two-group confirmatory factor analysis, an eight-factor solution, in which seven factors were dependent on a higher order factor (i.e., School Quality), was found with good fit. The seven factors were named: Societal Uses, Class Benefits, Accuracy, Negative Aspects, Teacher Use, Family Effects, and Competition. Invariance testing showed that regression weights were not equivalent between the PRC and HK students, though they were among PRC pre-degree and postgraduate students. There were statistically significant differences in factor mean scores between the HK and PRC groups. Conventional Chinese cultural norms were less explanatory of results than the effect of institutional assessment policies and practices in each jurisdiction.     

Book notes

The Divine Matrix: Creativity as Link between East and West Joseph A. Bracken, S. J., 1995 Maryknoll, NY: Orbis 177 pp., US$21.00 (pb) ISBN 1–57075–004–1

Glaubenswelt Islam: Eine Einführung Series: Religionswissenschaftliche Texte und Studien, Vol. 7 UDO SCHAEFER, 1996 Hildesheim: Georg Olms Verlag 149 pp, DM 24.80 ISBN 3–487–10159–9

Islam: The View from the Edge Richard Bulliet, 1995 New York: Columbia University Press 236 pp., US$16.95, £11.95 ISBN 0–231–08219–3

Living Faiths in South Africa Martin Prozesky & John De Gruchy, eds, 1995 London: Hurst & Company 241 pp., £35.00 (hb), £12.95 (pb) ISBN 1–85065–249‐X (hb), ISBN 1–85065–244–9 (pb)

Signs of the Times: The New Religious Movements in Theological Perspective John A. Sauba, 1996 Sherbrooke, Québec, Canada: Librairie Médiaspaul 119 pp., CDN$13.95, US$10.00 ISBN 2–89420–326–8

The Body and Society: Explorations in Social Theory Bryan S. Turner, Sage 1996, 2nd edition London 254 pp., £13.95 (pb) ISBN 0–8039–8809–5

Revolutionary Brotherhood: Freemasonry and the Transformation of the American Social Order, 1730–1840 Steven C Bullock, 1996 Chapel Hill, London: University of North Carolina Press. Published for the Institute of Early American History and Culture, Williamsburg, Virginia 421 pp., US$49.95 (hb) ISBN 0–8078–2282–5

Two Masters: The Buddha and Jesus J. D. M. Derrett, 1995 Yelvertoft Manor, Northamptonshire: Pilkington Press 143 pp., £17.50 ISBN 1–899044–09–4

Autobiography of an Aspiring Saint Cecilia Ferrazzi, 1996 Transcribed, translated & edited by Anne Jacobson Schutte Chicago, El., London: The University of Chicago Press 101 pp., US$30.00 (hb), US$14.95 (pb) ISBN 0–226–24447–4 (pb)

Sacred World: A Guide to Shambhala Waniorship in Daily Life Jeremy Hayward with Karen Hayward, 1995 London: Rider 262 pp., £10.99 (pb) ISBN 0–7126–7240–0     

Organizational tenure,work environment perceptions,and employee mental health

The mediating effect of organizational “time investments” on the relationship between work environment perceptions and mental health was explored in two work settings. Participants were 257 managerial-level employees in a line organization and 214 in a staff setting. Results support the hypothesis of greater “responsivity” to perceived organizational stimuli for longer tenured employees, but only in the line setting. The mixed findings in the staff organization suggest that other characteristics of the environment (e.g., systems function) and of its members (e.g., organizational versus occupational identification) need to be considered. Implications for the social responsibilities of organizations to their members are offered in conclusion.