Dolphin pointing is linked to the attentional behavior of a receiver

In 2001, Xitco et al. (Anim Cogn 4:115–123) described spontaneous behaviors in two bottlenose dolphins (Tursiops truncatus) that resembled pointing and gaze alternation. The dolphins spontaneous behavior was influenced by the presence of a potential receiver, and the distance between the dolphin and the receiver. The present study adapted the technique of Call and Tomasello [(1994) J Comp Psychol 108:307–317], used with orangutans to test the effect of the receivers orientation on pointing in these same dolphins. The dolphins directed more points and monitoring behavior at receivers whose orientation was consistent with attending to the dolphins. The results demonstrated that the dolphins pointing and monitoring behavior, like that of apes and infants, was linked to the attentional behavior of the receiver.     

The role of vision in the on-line correction of illusion effects on action.

In this study, participants reached out and picked up a bar placed on a background grating that induced an illusion in the perceived orientation of the bar. The illusion had a large effect on the orientation of the hand early in the reaches, but this effect decreased continuously as the hand approached the target. This pattern occurred whether or not participants were allowed vision of the hand and target while reaching. These results are consistent with a "planning/control" model of action, in which actions are planned using a context-dependent visual representation but monitored and corrected on-line using a context-independent visual representation. The hypothesized neural bases of these representations are discussed.     

Imagined body orientation and perception of the visual vertical

The existence of body orientation mental imagery was tested by examining whether self roll tilt imagery affects the subjective visual vertical (SVV). Twenty healthy subjects judged the orientation of a dim luminous bar with respect to gravitational vertical, while normally seated in complete darkness with their head firmly restrained earth vertically. SVV was measured in three conditions: a reference condition with no imagery, and a left and a right imagery condition, during which the bar orientation was to be judged while the subjects imagine themselves roll-tilted towards left or right, respectively. The imagined roll tilts were of the same magnitude as roll tilts which generally induce an E- effect, i.e., an SVV lean toward the side opposite to those of body tilt. If imagery and perception of self roll tilt share common processes, self roll tilt imagery should induce an E-like effect. Results show an imagery- induced E-like effect, which strongly supports the idea that humans can perform mental imagery of body orientation about gravity. Received: 4 April 2000 / Accepted: 1 September 2000     

The role of balance dynamics in the active perception of orientation.

The Stoffregen and Riccio (1988) hypothesis that perceived orientation is determined primarily by balance dynamics was tested. Perception of orientation was evaluated in the context of a task that required Ss to control the roll orientation of a device in which they were seated. The device's direction of balance was manipulated across trials and thus was independent of gravity. Eighteen Ss participated in the investigation. After each trial, Ss estimated their mean tilt with respect to upright. Correlations of perceived tilt with tilt from balance were consistently higher than the correlations with gravity tilt. The dominance of balance over gravity depended on the magnitude of tilt from balance.     

To pass or not to pass: More a question of body orientation than visual cues

This study investigated the influence of pitch body tilt on judging the possibility of passing under high obstacles in the presence of an illusory horizontal self-motion. Seated subjects tilted at various body orientations were asked to estimate the possibility of passing under a projected bar (i.e., a parking barrier), while imagining a forward whole-body displacement normal to gravity. This task was performed under two visual conditions, providing either no visual surroundings or a translational horizontal optic flow that stopped just before the barrier appeared. The results showed a main overestimation of the possibility of passing under the bar in both cases and most importantly revealed a strong influence of body orientation despite the visual specification of horizontal self-motion by optic flow (i.e., both visual conditions yielded a comparable body tilt effect). Specifically, the subjective passability was proportionally deviated towards the body tilt by 46% of its magnitude when facing a horizontal optic flow and 43% without visual surroundings. This suggests that the egocentric attraction exerted by body tilt when referring the subjective passability to horizontal self-motion still persists even when anchoring horizontally related visual cues are displayed. These findings are discussed in terms of interaction between spatial references. The link between the reliability of available sensory inputs and the weight attributed to each reference is also addressed.     

Time,quantum mechanics,and decoherence

State-reduction and the notion of actuality are compared to passage through time and the notion of the present; already in classical relativity the latter give rise to difficulties. The solution proposed here is to treat both tense and value-definiteness as relational properties or facts as relations; likewise the notions of change and probability. In both cases essential characteristics are absent: temporal relations are tenselessly true; probabilistic relations are deterministically true.The basic ideas go back to Everett, although the technical development makes use of the decoherent histories theory of Griffiths, Omnès, and Gell-Mann and Hartle. Alternative interpretations of the decoherent histories framework are also considered.I would like to thank Abner Shimony for valuable criticism.     

Spatio-temporal differentiation and integration in visual motion perception

Summary Perceptual organization during short tachistoscopic presentation of stimulus patterns formed by ten moving bright spots, representing a human body in walking, running, etc. was investigated. Exposure times were .1 sec to .5 sec.The results reveal that in all Ss the dot pattern is perceptually organized to a gestalt, a walking, running, etc., person at an exposure time of .2 sec. 40% of Ss perceived a human body in such motion at presentation times as short as 0.1 sec. Under the experimental conditions used the track length of the bright spots at the threshold of integration to a moving unit was of the size order 10 visual angle.This result is regarded as indicating that a complex vector analysis of the proximal motion pattern is accomplished at the initial stage of physiological signal recording and that it is a consequence of receptive field organization. It is discussed in terms of vector calculus.     

The role of surface attraction in perceiving volumetric shape

Rock [1973, Orientation and Form (New York: Academic Press)] showed that form perception generally depends more on the orientation of a stimulus in world coordinates than on its orientation in retinal coordinates. He suggested that the assignment of an object's 'environmental orientation' depends on gravity, visual frame of reference, and the observer's ability to impose orientation along one axis or another. This paper shows that the assignment of environmental orientation and perceived 3-D form also depends on the relationship between an object and retinally adjacent surfaces in the scene to which it might be attached. Whereas previous examples have demonstrated effects of orientation on 2-D form, we show that orientation can affect the perceived intrinsic 3-D shape of a volume.     

Scaling space with the mirror illusion: The influence of body plasticity on perceived affordances

How do body representations influence decisions about action? We developed a novel paradigm using the mirror illusion (Holmes, Crozier, & Spence, in Cognitive, Affective, & Behavioral Neuroscience, 4, 193–200, 2004) to examine two ways of evoking body plasticity—extension of body capabilities and visual capture—and its influence on perceived affordances. In two experiments, we manipulated the action capabilities of a seen left hand by lengthening the arm with a rod (Exp. 1) or enlarging the hand with a glove (Exp. 2). The right hand was unaltered physically and was occluded by placement in a mirror box. We induced visual capture through synchronous finger movements of both hands. Right-hand estimates of reaching and of fitting through apertures increased relative to actual capabilities during visual capture, supporting the claim that visual capture can induce the incorporation of an apparent body extension into action decisions. The results suggest that both perceptual and cognitive influences on bodily awareness underlie perceived affordances.     

Modernity and Identity: Themes and Perspectives in the Study of Older Adults

Developments in social gerontology have led to an increased awareness of the relationship between political economy, culture, and personal narrative as influences on social identity in later life. Central to this debate has been a growing interest in lifestyle choice as evidence of a change from modern to postmodern forms of aging. A key component of this process has been the erosion of a predictable framework for an aging identity, previously supplied by the welfare state. It is argued that, alongside the emergence of no-care zones in health and welfare, postmodern ideas on consumerism and the body have led to an assault on identity in old age. As a result, we may be seeing the emergence of no-identity zones which fail to sustain an authentic framework for supporting experiences in old age. A critical gerontology should include the study of identity as central to understanding the disjunction between aging from within and aging within society.     

On finite approximability of ψ-intermediate logics

The aim of this note is to show (Theorem 1.6) that in each of the cases: = {, }, or {, , }, or {, , } there are uncountably many -intermediate logics which are not finitely approximable. This result together with the results known in literature allow us to conclude (Theorem 2.2) that for each : either all -intermediate logics are finitely approximate or there are uncountably many of them which lack the property.     

Players’ Gender and Male Referees’ Decisions About Aggression in French Soccer: A Preliminary Study

The aim of this study was to examine (a) aggression displayed by players and (b) referees decisions about these behaviors as a function of the gender of the players in French soccer. Twenty-six games (13 for women and 13 for men) were videotaped. Instrumental aggressive acts and referees decisions were then observed. The findings indicated a significant effect of gender on instrumental aggression and referees decisions related to these behaviors. Male players displayed more instrumental aggressive acts than female players did. Nevertheless, relative to the total number of aggressive acts displayed, referees penalized women more than men. Gender stereotypes might be a relevant explanation for these results, as soccer is generally perceived as a masculine-type sport, particularly in France, and aggression as a masculine characteristic.     

The effect of body posture on long-range time-to-contact estimation

On Earth, gravity accelerates freely moving objects downward, whereas upward-moving objects are being decelerated. Do humans take internalised knowledge of gravity into account when estimating time-to-contact (TTC, the time remaining before the moving object reaches the observer)? To answer this question, we created a motion-prediction task in which participants saw the initial part of an object's trajectory moving on a collision course prior to an occlusion. Observers had to judge when the object would make contact with them. The visual scene was presented with a head-mounted display. Participants lay either supine (looking up) or prone (looking down), suggestive of the ball either rising up or falling down toward them. Results showed that body posture had a significant effect on time-to-contact estimation, but only when occlusion times were long (2.5 s). The effect was also rather small. This lack of immediacy in the posture effect suggests that TTC estimation is initially robust toward the effect of gravity, which comes to bear only as more time is allowed for post-processing of the visual information.     

Orientation Constancy in Neurons of Monkey Visual Cortex

We studied the effect of body tilt on the orientation selectivity of single neurons in the visual cortex of an alert monkey. The monkey performed a visual fixation task either in the upright position or with its whole body tilted about the naso-occipital (roll) axis by ±25° or ±30°. We determined the preferred stimulus orientation for 51 of 117 neurons in two or, if possible, three body positions (i.e. with the whole body upright, and tilted either left ear or right ear down). In striate cortex, most of the neurons were of a non-compensatory type, showing a change in the preferred orientation according to the body tilt and the estimated counterrolling of the eye. By contrast, about 40% of the neurons in prestriate cortex were of a compensatory type, preferring similar orientations in all body positions. This suggests that mechanisms which produce orientation constancy with respect to the direction of gravity are implemented at an early stage of cortical processing.     

The relationship between allocentric and egocentric frames of reference and categorical and coordinate spatial information processing

We report two experiments on the relationship between allocentric/egocentric frames of reference and categorical/coordinate spatial relations. Jager and Postma (2003) suggest two theoretical possibilities about their relationship: categorical judgements are better when combined with an allocentric reference frame and coordinate judgements with an egocentric reference frame (interaction hypothesis); allocentric/egocentric and categorical/coordinate form independent dimensions (independence hypothesis). Participants saw stimuli comprising two vertical bars (targets), one above and the other below a horizontal bar. They had to judge whether the targets appeared on the same side (categorical) or at the same distance (coordinate) with respect either to their body-midline (egocentric) or to the centre of the horizontal bar (allocentric). The results from Experiment 1 showed a facilitation in the allocentric and categorical conditions. In line with the independence hypothesis, no interaction effect emerged. To see whether the results were affected by the visual salience of the stimuli, in Experiment 2 the luminance of the horizontal bar was reduced. As a consequence, a significant interaction effect emerged indicating that categorical judgements were more accurate than coordinate ones, and especially so in the allocentric condition. Furthermore, egocentric judgements were as accurate as allocentric ones with a specific improvement when combined with coordinate spatial relations. The data from Experiment 2 showed that the visual salience of stimuli affected the relationship between allocentric/egocentric and categorical/coordinate dimensions. This suggests that the emergence of a selective interaction between the two dimensions may be modulated by the characteristics of the task.     

Priming of reach and grasp actions by handled objects

Pictures of handled objects such as a beer mug or frying pan are shown to prime speeded reach and grasp actions that are compatible with the object. To determine whether the evocation of motor affordances implied by this result is driven merely by the physical orientation of the object's handle as opposed to higher-level properties of the object, including its function, prime objects were presented either in an upright orientation or rotated 90° from upright. Rotated objects successfully primed hand actions that fit the object's new orientation (e.g., a frying pan rotated 90° so that its handle pointed downward primed a vertically oriented power grasp), but only when the required grasp was commensurate with the object's proper function. This constraint suggests that rotated objects evoke motor representations only when they afford the potential to be readily positioned for functional action.     

The speed of visual processing in children and adults: Effects of backward and forward masking

Children, 4-5 and 9-10 years old, and college-age adults were tested on two visual masking tasks. The first task required the Ss to identify whether a tachistoscopically presented bar was horizontal or vertical The second task, also using tachistoscopic presentation of stimuli, required Ss to locate a horizontal (or vertical) bar in a matrix of vertical (or horizontal) bars. In both tasks, backward masking produced greater disruption than did forward masking, and the amount of disruption induced by both backward and forward masking decreased as age increased. An Age by Masking Condition interaction was found only in the location task and reflected a much greater difference between backward- and forward-masking conditions for the youngest group than for the older groups. On the basis of these findings and other considerations, it was concluded that only in the location task, which presumably required visual search, was the speed of visual processing slower in the younger group.     

Advertising's misinformation effect

This research explores whether post-experience advertising alters information learned in a consumer's direct experience. An advertising misinformation effect was obtained for colour memory of a previously seen candy bar wrapper upon both visual and verbal misinformation. However, the misleading visual information produced more ‘remember’ judgements than misleading verbal information. This advertising misinformation effect did not dissipate when the source was discredited. We found that such memory changes can be directly linked to consumer subjective judgements and choices when the misleading information is particularly salient. Not only do these findings constitute a novel generalizability of the misinformation effect, they also have implications for social policy research on deceptive advertising. Copyright © 1998 John Wiley & Sons, Ltd.     

The relationship between allocentric and egocentric frames of reference and categorical and coordinate spatial information processing

We report two experiments on the relationship between allocentric/egocentric frames of reference and categorical/coordinate spatial relations. Jager and Postma (2003) suggest two theoretical possibilities about their relationship: categorical judgements are better when combined with an allocentric reference frame and coordinate judgements with an egocentric reference frame (interaction hypothesis); allocentric/egocentric and categorical/coordinate form independent dimensions (independence hypothesis). Participants saw stimuli comprising two vertical bars (targets), one above and the other below a horizontal bar. They had to judge whether the targets appeared on the same side (categorical) or at the same distance (coordinate) with respect either to their body-midline (egocentric) or to the centre of the horizontal bar (allocentric). The results from Experiment 1 showed a facilitation in the allocentric and categorical conditions. In line with the independence hypothesis, no interaction effect emerged. To see whether the results were affected by the visual salience of the stimuli, in Experiment 2 the luminance of the horizontal bar was reduced. As a consequence, a significant interaction effect emerged indicating that categorical judgements were more accurate than coordinate ones, and especially so in the allocentric condition. Furthermore, egocentric judgements were as accurate as allocentric ones with a specific improvement when combined with coordinate spatial relations. The data from Experiment 2 showed that the visual salience of stimuli affected the relationship between allocentric/egocentric and categorical/coordinate dimensions. This suggests that the emergence of a selective interaction between the two dimensions may be modulated by the characteristics of the task.     

Balance Theory Applied to Service Quality: A Focus on the Organization, Provider, and Consumer Triad

As quality experts have focused primarily on manufacturing, theoretical frameworks for examining quality in the service sector are lacking. In order to fill this gap, Heider's (1958) balance theory is applied to explain how service organization, service provider, and consumer interrelationships influence service quality. Propositions are offered pertaining to: (a) how and why positive or negative relationships among the parties in this triad are developed, and (b) the consequences of these relationships on service quality, affective outcomes, and withdrawal behaviors. Examination of the service triangle within this framework can enhance understanding of quality service delivery and guide future research efforts in the continuous improvement domain.