Dissociating position and heading estimations: Rotated visual orientation cues perceived after walking reset headings but not positions

This project examined the roles of idiothetic cues due to individuals’ movement and allothetic cues independent of individuals’ movement in individuals’ estimations of their position and heading during locomotion. In an immersive virtual environment, participants learned the locations of five objects and then moved along two legs of a path before positioning the origin and the objects. Participants’ estimations of their test position and their test heading were calculated based on the responded objects’ locations, using a method of dissociating position estimation and heading estimation developed in this project. Results showed that when a conflicting visual orientation cue was presented after walking, participants relied on the allothetic cues (i.e., the visual orientation cue) for their heading estimation, but on idiothetic cues for their position estimation. These results indicate that after participants updated their position in terms the origin of the path (homing vector) via path integration, they estimated their heading. These results are inconsistent with the theoretical models stipulating that homing vectors are specified in terms of participants’ body coordinate systems, but are consistent with the models stipulating that both homing vectors and participants’ heading are specified in terms of a fixed reference direction in the environment.     

Auditory memory and the irrelevant sound effect: Further evidence for changing-state disruption

Four experiments investigate the hypothesis that irrelevant sound interferes with serial recall of auditory items in the same fashion as with visually presented items. In Experiment 1 an acoustically changing sequence of 30 irrelevant utterances was more disruptive than 30 repetitions of the same utterance (the changing-state effect; Jones, Madden, & Miles, 1992) whether the to-be-remembered items were visually or auditorily presented. Experiment 2 showed that two different utterances spoken once (a heterogeneous compound suffix; LeCompte & Watkins, 1995) produced less disruption to serial recall than 15 repetitions of the same sequence. Disruption thus depends on the number of sounds in the irrelevant sequence. In Experiments 3a and 3b the number of different sounds, the "token-set" size (Tremblay & Jones, 1998), in an irrelevant sequence also influenced the magnitude of disruption in both irrelevant sound and compound suffix conditions. The results support the view that the disruption of memory for auditory items, like memory for visually presented items, is dependent on the number of different irrelevant sounds presented and the size of the set from which these sounds are taken. Theoretical implications are discussed.     

Emotionally meaningful targets enhance orienting triggered by a fearful gazing face

Studies investigating the effect of emotional expression on spatial orienting to a gazed-at location have produced mixed results. The present study investigated the role of affective context in the integration of emotion processing and gaze-triggered orienting. In three experiments, a face gazed non-predictively to the left or right, and then its expression became fearful or happy. Participants identified (Experiments 1 and 2) or detected (Experiment 3) a peripheral target presented 225 or 525 ms after the gaze cue onset. In Experiments 1 and 3 the targets were either threatening (a snarling dog) or non-threatening (a smiling baby); in Experiment 2 the targets were neutral. With emotionally valenced targets, the gaze-cuing effect was larger when the face was fearful compared to happy—but only with the longer cue–target interval. With neutral targets, there was no interaction between gaze and expression. Our results indicate that a meaningful context optimises attentional integration of gaze and expression information.     

Categorizing a moving target in terms of its speed,direction, or both

Pigeons categorized a moving target in terms of its speed and direction in an adaptation of the randomization procedure used to study human categorization behavior (Ashby & Maddox, 1998). The target moved according to vectors that were sampled with equal probabilities from two slightly overlapping bivariate normal distributions with the dimensions of speed and direction. On the average, pigeons categorized optimally in that they attended to either speed or direction alone, or divided attention between them, as was required by different reinforcement contingencies. Decision bounds were estimated for individual pigeons for each attentional task. Average slopes and y intercepts of these individually estimated decision bounds closely approximated the corresponding values for optimal decision bounds. There is therefore at least one task in which pigeons, on the average, display flexibility and quantitative precision in allocating attention to speed and direction when they categorize moving targets.     

Partner Orientation and Speaker's Knowledge as Conflicting Parameters in Language Production

Two parameters of language production, the partner model and the mentally represented knowledge about a spatial constellation, are investigated with respect to their influence on spatial reference. At issue is whether the verbally expressed point of view in route directions is primarily influenced by the needs of the partner or by the underlying mental representation of the speaker stemming from his or her own experience with an object. Two experiments in which participants (N = 90) were asked to produce a set of route directions are reported. The experimental situation was such that the point of view of the speaker did not correspond to the point of view of the partner. The results show that more participants localize from their own point of view than from the point of view of the partner. Discussion centers on the fact that speakers do not always behave in a truly partner-oriented manner.     

Individual temporal differences in precompetition anxiety and hormonal concentration

This investigation explored individual differences in hormonal concentration and directional perception of anxiety 24hrs, 2hrs and 1 hr before an important competition. Those who perceived their anxiety level as positive to performance (i.e. facilitators) showed an increase in testosterone concentration as time-to-event approached that contrasted markedly with those who perceived their anxiety intensity as negative to performance (i.e. debilitators). The facilitatory group also exhibited a lower cortisol response 2 hrs and 1 hr, relative to 24 hrs before the event, whilst the response of the debilitatory group was elevated as time-to-event approached. Finally, the facilitatory group evidenced a trend towards rapid elevations in all of the catecholamines, whilst the concentration amongst the debilitatory group remained stable as the event approached. The findings add further substance to the veracity of the directional construct in acting as the important distinguishing variable which accounts for significant individual differences. Additionally it addresses the mechanism by which the relationship between anxiety direction and performance may be brought about. Such underpinning biochemical mechanisms offer one possible yet long awaited explanation to aid our understanding of the pre-event anxiety direction response of competitive individuals.     

想象空间中物体搜索的阶段模型的证实

用因素实验证明,在故事阅读产生的想象场景中,位于其中的观察者对身体四周物体的搜索分为两个阶段：第一阶段是目标方位的判断,认知加工时间的模式是前＜后＜左＝右;第二阶段是注意指向目标方位,从而辨别目标物体,认知加工时间的模式是注意点＜注意点对面＜注意点左侧＝注意点右侧。这两个阶段没有交互作用。反应时依赖于被试的视点。     

医疗费用在医疗制度改革中的变化趋势及政策取向

医疗费用的水准及其变化过程主要取决于一个国家的经济发展水平。我们预测其变化趋势可能经历三个新阶段。因此,在宏观管理上要注意四个方面的政策取向：重效率轻收入、重效果轻价格、重科学管理轻粗放经营、重长远利益轻眼前利益。