Cognitive suppression of tilt sensations during linear horizontal self-motion in the dark

On the basis of models of otolith functioning, one would expect that, during sinusoidal linear self-motion in darkness, percepts of body tilt are experienced. However, this is normally not the case, which suggests that the otoliths are not responsive to small deviations from the vertical of the gravito-inertial force vector acting on them. Here we show that this is incorrect. Subjects usually know on what kind of linear motion device they are (going to be) moved, having seen it prior to experimentation. This may result in a cognitive suppression of such otolith responses. In the present study, subjects were kept completely unaware of how they were moved and were asked to report on how they thought they moved. About 50% of the reports included tilt percepts almost immediately. It is concluded that this reveals the presence of otolith responsiveness to even small and short-lived deviations of the gravito-inertial force vector from verticality, a responsiveness which is suppressed when (prior) cognitions exist that the motion path is purely in the horizontal plane.     

Perceiving self-motion in depth: The role of stereoscopic motion and changing-size cues

During self-motions, different patterns of optic flow are presented to the left and right eyes. Previous research has, however, focused mainly on the self-motion information contained in a single pattern of optic flow. The present experiments investigated the role that binocular disparity plays in the visual perception of self-motion, showing that the addition of stereoscopic cues to optic flow significantly improves forward linear vection in central vision. Improvements were also achieved by adding changingsize cues to sparse (but not dense) flow patterns. These findings showed that assumptions in the heading literature that stereoscopic cues facilitate self-motion only when the optic flow has ambiguous depth ordering do not apply to vection. Rather, it was concluded that both stereoscopic and changingsize cues provide additional motion-in-depth information that is used in perceiving self-motion.     

Coordination modes in sensorimotor synchronization of whole-body movement: a study of street dancers and non-dancers

This study investigated whole-body sensorimotor synchronization (SMS) in street dancers and non-dancers. Two kinds of knee bending movement in a standing position to a metronome beat were explored in terms of stability under different movement frequencies: down-movement condition (knee flexion on the beat) and up-movement condition (knee extension on the beat). Analyses of phase relation between movement and beat revealed several distinct differences between the down- and up-movement conditions, and between dancers and non-dancers. In both groups under the up-movement condition, deviation from intended phase relation at higher beat rates, and enhanced fluctuations were observed. The deviation from intended phase relation under up-movement condition, and movement fluctuations were greater in non-dancers than in dancers. Moreover, subjective difficulty rating revealed that both groups felt that the up-movement condition was more difficult at higher beat rates. These findings suggest that down and up movements are two distinguishable coordination modes in whole-body coordination, and that street dancers have superior whole-body SMS ability.     

The role of central and peripheral vision in perceiving the direction of self-motion

Three experiments were performed to examine the role that central and peripheral vision play in the perception of the direction of translational self-motion, or heading, from optical flow. When the focus of radial outflow was in central vision, heading accuracy was slightly higher with central circular displays (10°–25° diameter) than with peripheral annular displays (40° diameter), indicating that central vision is somewhat more sensitive to this information. Performance dropped rapidly as the eccentricity of the focus of outflow increased, indicating that the periphery does not accurately extract radial flow patterns. Together with recent research on vection and postural adjustments, these results contradict theperipheral dominance hypothesis that peripheral vision is specialized for perception of self-motion. We propose afunctional sensitivity hypothesis—that. self-motion is perceived on the basis of optical information rather than the retinal locus of stimulation, but that central and peripheral vision are differentially sensitive to the information characteristic of each retinal region.     

Consensus in work role requirements: the influence of discrete occupational context on role expectations

Although role theory has long described how expectations shape role behavior, little empirical research has examined differences among work role requirements and how features of the discrete occupational context may influence the extent to which role expectations are shared among role holders. The authors examined consensus in work role requirements from a sample of over 20,000 incumbents across 98 occupations. They found that consensus systematically decreased as work role requirements ranged from molecular tasks to responsibilities to molar traits. In addition, they found that consensus in these work role requirements was significantly influenced by the amount of interdependence, autonomy, and routinization present in the surrounding task and social contexts.     

The role of context specificity in learning: the effects of training context on explosives detection in dogs

Various experiments revealed that if an animal learns a stimulus–response–reinforcer relationship in one context and is then tested in another context there is usually a lessening of stimulus control, and the same discriminative stimuli that reliably controlled the behavior in the first context will have less effect in the new context. This reduction in performance is known as the context shift effect. The effect of changing context on the probability of detecting explosives was investigated in seven highly trained explosives detection dogs (EDDs). In experiment 1 the dogs were trained alternately on path A, which always had five hidden explosives, and on a very similar path B, which never had any explosives. Within a few sessions the dogs showed a significant decrease in search behavior on path B, but not on path A. In experiment 2 the same dogs were trained only on path B with a target density of one explosive hidden every 4th day. The probability of the dogs now detecting the explosive was found to be significantly lower than in experiment 1. In experiment 3 the effect of the low target density as used in experiment 2 was investigated on a new but very similar path C. Both the detection probability for the one explosive every 4th day on the new path and the motivation to search were significantly higher than found in experiment 2. Finally, in experiment 4, an attempt was made to recondition the dogs to search on path B. Although trained for 12 daily sessions with one explosive hidden every session, the dogs failed to regain the normal levels of motivation they had shown on both new paths and on the paths that they knew usually contained explosives. The findings reveal that even a very intensively trained EDD will rapidly learn that a specific stretch of path does not contain explosives. The dog will then be less motivated to search and will miss newly placed targets. This learning is specific to the formerly always-clean path and is to some extent irreversible. However, the dog will search and detect normally on new paths even if they are very similar to the always-clean path. The data are discussed in terms of variables affecting renewal. The results suggest that following training designed to make a behavior context independent, any extinction training will not generalize beyond that specific context used during the extinction training. In addition, if the behavior is extinguished in a specific context, it will be very difficult to restore that behavior in that context. These conclusions should be considered by anyone attempting to extinguish well-established trans-context behaviors.This research reports portions of a doctoral dissertation submitted by Irit Gazit to Tel Aviv University.     

The role of context on boundary extension

Boundary extension (BE) is a memory error in which observers remember more of a scene than they actually viewed. This error reflects one’s prediction that a scene naturally continues and is driven by scene schema and contextual knowledge. In two separate experiments we investigated the necessity of context and scene schema in BE. In Experiment 1, observers viewed scenes that either contained semantically consistent or inconsistent objects as well as objects on white backgrounds. In both types of scenes and in the no-background condition there was a BE effect; critically, semantic inconsistency in scenes reduced the magnitude of BE. In Experiment 2 when we used abstract shapes instead of meaningful objects, there was no BE effect. We suggest that although scene schema is necessary to elicit BE, contextual consistency is not required.     

The role of central and peripheral vision in perceiving the direction of self-motion.

Three experiments were performed to examine the role that central and peripheral vision play in the perception of the direction of translational self-motion, or heading, from optical flow. When the focus of radial outflow was in central vision, heading accuracy was slightly higher with central circular displays (10 degrees-25 degrees diameter) than with peripheral annular displays (40 degrees diameter), indicating that central vision is somewhat more sensitive to this information. Performance dropped rapidly as the eccentricity of the focus of outflow increased, indicating that the periphery does not accurately extract radial flow patterns. Together with recent research on vection and postural adjustments, these results contradict the peripheral dominance hypothesis that peripheral vision is specialized for perception of self-motion. We propose a functional sensitivity hypothesis--that self-motion is perceived on the basis of optical information rather than the retinal locus of stimulation, but that central and peripheral vision are differentially sensitive to the information characteristic of each retinal region.     

From anticipation to integration: the role of integrated action-effects in building sensorimotor contingencies

Ideomotor approaches to action control have provided evidence that the activation of an anticipatory image of previously learned action-effects plays a decisive role in action selection. This study sought for converging evidence by combining three previous experimental paradigms: the response–effect compatibility protocol introduced by Kunde (Journal of Experimental Psychology: Human Perception and Performance, 27(2), 387–394, 2001), the acquisition-test paradigm developed by Elsner and Hommel (Journal of Experimental Psychology: Human Perception and Performance, 27(1), 229, 2001), and the object-action compatibility manipulation of Tucker and Ellis (Visual Cognition, 8(6), 769–800, 2001). Three groups of participants first performed a response–effect compatibility task, in which they carried out power and precision grasps that produced either grasp-compatible or grasp-incompatible pictures, or no action effects. Performance was better in the compatible than in the incompatible group, which replicates previous observations and extends them to relationships between grasps and objects. Then, participants were to categorize object pictures by carrying out grasp responses. Apart from replicating previous findings of better performance in trials in which object size and grasp type was compatible, we found that this stimulus–response compatibility effect depended on previous response-effect learning. Taken together, these findings support the assumption that the experience of action–effect contingencies establishes durable event files that integrate representations of actions and their effects.     

Arrhenius vs. Ehrlich on immunochemistry: Decisions about scientific progress in the context of the Nobel prize

This study forms part of a larger research project examining the election process for the Nobel prizes for Physiology or Medicine at the Karolinska Institute in Stockholm, and the role and function of the prizes in early 20th century Swedish and international medicine. The purpose of the study is to clarify the decision-making process which led to the Nobel prize for Paul Ehrlich in 1908, ‘for work on immunity’. His award was preceded by the most dramatic conflict within the prize authority concerning any prizewinner prior to World War I, and thus is apt to illuminate both the implicit and explicit criteria and the strategies used in the prize deliberations. Ehrlich's chemical ideas on the immune response were criticized by the physical chemist Svante Arrhenius who recommended the application of his disciplines's methods and principles on immunological problems. This criticisms were brought into the Nobel prize debate by J.E. Johansson, a physiologist who asserted that Ehrlich's research was of little scientific value and therefore not worthy of a prize. Yet the majority of the Institute, led by its chairmam, the chemist K.A.H. Mörner, succeeded in awarding Ehrlich. An analysis of the controversy shows it to be primarily based upon (1) a difference of scientific styles between the antagonists, resulting in incongruous definitions of immunology as a research field, and of the proper aims and methods of immunological studies. Other factors influencing the final decision were (2) the Institute's negative reaction to what was considered an intrusion in medical Nobel prize matters by a chemist, (3) Arrhenius' and Johansson's diverging views on what kind of work should be awarded a prize, and (4) Johansson's position as a non-conformist at the Karolinska.     

Environmental context and recognition: the role of recollection and familiarity

Evidence for effects of changed environmental context on recognition has been equivocal. Using 3 experiments, the author investigated the role of environmental context from a dual-processing approach. Experiment 1 showed that testing word recognition in a novel context led to a reliable decrement but only for recognition accompanied by conscious recollection, with familiarity-based recognition judgments being unaffected. This was replicated in Experiment 2 using stimuli that were novel to the participants (nonwords). Experiment 3 showed that the decrement in recollection also occurred when the changed-context condition involved presenting items in a different but familiar context. The results suggest that effects of environmental context will only be found when recognition is accompanied by conscious recollection and that this effect is due to a specific item-context association.     

Episodic memory updating: The role of context familiarity

We previously demonstrated that spatial context is a powerful reminder that can trigger memory updating (Hupbach, Hardt, Gomez, & Nadel in Learning & Memory, 15, 574–579 2008). In the present study, we asked whether the familiarity of the spatial context modulates the role of spatial context as a reminder. Since context familiarity can be easily manipulated in children, we chose 5-year-olds as study participants. In two experiments, we demonstrated robust memory-updating effects in children. Spatial context triggered incorporation of new information into old memories only when the context was unfamiliar. In highly familiar spatial environments (children’s homes), spatial context did not initiate memory updating. Other reminders (the experimenter and a reminder question) became highly effective in familiar contexts. These findings shed further light on the specific conditions that trigger memory updating and support the view that the mechanisms underlying it are similar in children and adults.     

Pronouncing novel graphemes: The role of consonantal context

In three experiments, we examined how readers learn and generalize new pronunciations for vowel graphemes. Children ages 6 1/2 to 9 (n = 97) and college students (n = 21) were taught a nonword that included a novel vowel pronunciation in the middle position (e.g., zuop is pronounced /zup/). They were then asked to pronounce other nonwords that contained the same vowel grapheme. Participants were more likely to use the taught pronunciation when the target item and the training item shared a consonant as well as a vowel than when they shared only the vowel. The new pronunciation was not significantly more likely to appear when the target shared the vowel and final consonant (rime) of the training stimulus than when it shared the initial consonant and vowel. We discuss implications for views of reading and its development.     

Ambiguous figures: role of context and critical features

Context and attention to critical features as factors in determining the perceptual organization of ambiguous figures were investigated in the present two studies. In the first study, a fixation point directed attention to a critical or to a neutral feature of an ambiguous figure. Placement of the fixation point on different features of an ambiguous figure did not affect the figure-ground organization of the figure, but it did influence the speed of the identification response. In the second study, presentation of an ambiguous figure was preceded by a biased figure or by features of the figure. Results indicated that the interpretation of the ambiguous figure was overwhelmingly influenced by the advanced presentation of a biased drawing but only slightly influenced by the advanced presentation of a critical feature. These findings support analysis-by-synthesis (Neisser, 1967) as an explanation of the perception of ambiguous figures over other contemporary attention theories.     

Influences of the perception of self-motion on postural parameters.

We examined how spatial and temporal characteristics of the perception of self-motion, generated by constant velocity visual motion, was reflected in orientation of the head and whole body of young adults standing in a CAVE, a virtual environment that presents wide field of view stereo images with context and texture. Center of pressure responses from a force plate and perception of self-motion through orientation of a hand-held wand were recorded. The influence of the perception of self-motion on postural kinematics differed depending upon the plane and complexity of visual motion. Postural behaviors generated through the perception of self-motion appeared to contain a confluence of the cortically integrated visual and vestibular signals and of other somatosensory inputs. This would suggest that spatial representation during motion in the environment is modified by both ascending and descending controls. We infer from these data that motion of the visual surround can be used as a therapeutic tool to influence posture and spatial orientation, particularly in more visually sensitive individuals following central nervous system (CNS) impairment.     

The role of faith in the psychotherapeutic context

The focus of this article is the role of faith in psychotherapy. It is suggested that the psychotherapeutic endeavor may be fruitfully informed by insights from other disciplines. The theologian Paul Tillich's view of faith is discussed as it applies to the psychotherapeutic endeavor. The relation between faith and anxiety is explored in the context of the problem of resistance and change in psychotherapy. The work of theorists from various perspectives (existential, analytic) is discussed in the light of Tillich's view of faith.     

An observation on the role of context variability in free recall

The authors conducted 3 experiments investigating the effect of context variability and word frequency on free recall. Context variability refers to the number of pre-experimental contexts in which a given word is experienced. Both between-subjects and within-subjects manipulations of context variability demonstrated a distinct advantage for low context variability words. Standard word frequency effects were obtained in 2 of the 3 experiments, but the common finding of no word frequency differences in mixed lists of high and low word frequency may depend on the level (low vs. high) of context variability. The authors speculate that the advantage for low context variability items may accrue from better item-to-list context associations or better storage of contextual information as a consequence of the smaller pre-experimental contextual fan that these items possess.     

The effect of context on the silver ceiling: a role congruity perspective on prejudiced responses

Three studies examined role incongruity as a source of age bias in hiring decisions. Building on previous research demonstrating contextual variation in prejudice, the authors predicted that prejudiced responses emerge particularly in contexts where group stereotypes misalign with the requirements of social roles. Findings indicate that (a) older workers are particularly penalized in occupational contexts that are quickly changing, (b) older workers are perceived as less adaptable than younger workers, and (c) the tendency to prefer younger than older workers more for a dynamic than a stable company is mediated by perceptions of adaptability. Finally, adaptability perceptions better predicted hiring bias than did global evaluations of older people and levels of contact with older people. These experiments provide initial evidence that perceived fit to roles is a determinant of contextual variation in prejudiced responses.     

Impact of an individualist vs. collectivist context on the social valorization of internal explanations

The theory of the norm of internality emphasizes the role of Western individualism in the normativity of internal explanations. The present study examines the link between the social value accorded to targets expressing internal vs. external explanations and individualist vs. collectivist contexts. Sixty-three male and female French management sciences students evaluated two targets (internal vs. external) in a simulated recruitment situation. The job vacancy was partially manipulated to create individualist vs. collectivist contexts. Participants were asked to state whether or not they would recruit the targets and to describe the targets on traits relating to social utility (market value) and social desirability (likeability). As expected, the results showed that the effect of the targets' internality on recruitment judgments and perceived social utility was stronger in the individualist context than in the collectivist context. However, the analysis also revealed that the participant's gender moderated the impact of the context on the evaluation of the targets. The results showed that the context strongly affected the men's judgments, whereas it had no effect on the women's judgments.