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A sudden touch on one hand can improve vision near that hand, revealing crossmodal links in spatial attention. It is often assumed that such links involve only multimodal neural structures, but unimodal brain areas may also be affected. We tested the effect of simultaneous visuo-tactile stimulation on the activity of the human visual cortex. Tactile stimulation enhanced activity in the visual cortex, but only when it was on the same side as a visual target. Analysis of effective connectivity between brain areas suggests that touch influences unimodal visual cortex via back-proJections from multimodal parietal areas. This provides a neural explanation for crossmodal links in spatial attention., Spatial attention picks out particular locations for further sensory processing. Most studies of spatial attention have considered only a single sensory modality at a time (1, 2), but crossmodal links [...]

Three experiments examine whether spatial attention and visual word recognition processes operate independently or interactively in a spatially cued lexical-decision task. Participants responded to target strings that had been preceded first by a prime word at fixation and then by an abrupt onset cue either above or below fixation. Targets appeared either in the cued (i.e., valid) or uncued (i.e., invalid) location. The proportion of validly cued trials and the proportion of semantically related prime--target pairs were manipulated independently. It is concluded that spatial attention and visual word recognition processes are best seen as interactive. Spatial attention affects word recognition in 2 distinct ways: (a) it affects the uptake of orthographic information, possibly acting as 'glue' to hold letters in their proper places in words, and (b) it (partly) determines whether or not activation from the semantic level feeds down to the lexical level during word recognition.

ABSTRACT. The participants were 360 Canadian undergraduates. After receiving written scenarios involving a campus visitor seeking direction to a nearby destination (simple route) or a distant destination (complex route), they [...]

We performed six experiments in order to examine the ability of rats to use moving beacons and landmarks as cues to the location of reward on an eight-arm radial maze. In Experiments 1-4, the cues and goals were moved before each trial, and groups in which a single beacon was placed on the rewarded arm, a single landmark indicated that reward was on the arm immediately to the left of a landmark, or two landmarks were placed on each side of the reward arm were compared. The rats rapidly learned to track the reward in the beacon condition, failed to find the reward sooner than chance expectation with a single landmark, and did only slightly better than chance with two landmarks. In Experiments 5 and 6, the rats were trained in five trials per day, with the landmark and goal locations constant over daily rewarded trials, and in two extinction trials that were inserted among the rewarded trials. The rats found the goal arm at substantially better than chance expectancy with both one and two landmarks. Our results, in agreement with data from recent swimming pool experiments (A. D. L. Roberts & Pearce, 1998), show that rats will use the relationship between moving landmarks and a goal in order to find reward.

Experiments were designed in which some properties of spatial representations in rats could be examined. Adult subjects were trained to escape through a hole at a fixed position in a large circular arena (see Schenk, 1989). The experiments were conducted in the dark, with a limited number of controlled visual light cues, in order to assess the minimal cue requirement for place learning. Three light cues identical in shape, height, and distance from the table were used. Depending on the condition, they were either permanently on or alternatively on or off, contingent on the position of the rat in the field. Two questions were asked: (1) How many identical visual cues were necessary for spatial discrimination in the dark, and (2) could rats integrate the relative positions of separate cues, under conditions in which the rat was never allowed to perceive all three cues simultaneously. The results suggest that rats are able to achieve a place discrimination task even if the three cues necessary for efficient orientation can never be seen simultaneously. A dissociation between the discrimination of the spatial position of the goal and the capacity to reach it by a direct path suggests that, with a reduced number of cues, prolonged locomotion might be required for accurate orientation in the environment.

ABSTRACT. In 2 experiments, spatial error detection capability and movement accuracy were investigated in both single and bimanual rapid aiming movements. In both experiments, right-handed college-age participants (N = 40 [...]

ABSTRACT. In this study, the authors examined how task, informational, and sensorimotor system constraints influence postural control. Postural behavior of subjects with (n = 15) and without (n = 15) [...]

ABSTRACT. In 3 experiments, the authors examined movement space-time variability as a function of the force-time properties of the initial impulse in a movement timing task. In the range of [...]

Abstract * Behavioral studies indicate that spatial and object working memory are computed by dissociable subsystems. We investigated the neural bases of this dissociation with a whole-brain fMRI design and [...]

Two quite different concepts of space are important in geography and environmental psychology. One is the concept of macro-environment, of space as geographical scale. The other is the concept of form-at-a-timeless-instant: of naive geometry. Confusing these two concepts leads to serious errors. This paper examines some methodological and philosophical sources of this confusion, and points to a number of research problems in geography and psychology that can benefit from an untangling of the two concepts of space. One such problem is the need to understand the development of mapping abilities in very young children. Another is the larger question of building a body of theory to explain the development of macro-environmental cognition and behavior. Key Words: macro-environment, spatial form, scale, children's mapping.

A survey of 421 children and 165 parents from three suburban primary schools in Newcastle, New South Wales, Australia has provided information on the nature and location of children's play, both at present and a generation ago. Although modern children have greater access to individual transport in the form of higher bicycle ownership, other constraints appear to have restricted their play space. These include the availability of home-based leisure technology such as computer games and greater parental restriction on where children might play. The results of the survey would appear to indicate that children prefer to play at home. However, analysis of the children's stories and drawings suggests that, given the chance, a majority of children would choose to engage in outdoor activities in the bush, in parks or on the beach. Their actual choice of play space may thus be determined by a knowledge of parental constraints.

This study investigated gender differences in wayfinding and representation of an unfamiliar building. Thirty-two white German adults (undergraduates, graduates, academic staff, carpenters, social workers) carried out three wayfinding runs, each followed by a representation task either of drawing a map or of writing a description of the environment. Self-estimation of spatial anxiety and environmental competencies was assessed before the task. Men recalled more route directions in maps and descriptions than women. Independent from element quantity, women preferred landmarks to route directions under both conditions. Men preferred mixed representations with similar proportions of landmarks and route directions in their first and second representation and showed a weak landmark preference only in the last representation. Route direction preferences related to higher speed in wayfinding (more men) and higher self-estimation of wayfinding competence. Landmark preferences related, in women only, to higher self-estimated levels of spatial anxiety. Speed in wayfinding, self-estimation of competencies, and spatial anxiety overlapped predictability of gender on differences in environmental representation.

This paper investigates the determinants of spatial knowledge and how our knowledge of space varies according to geographic location. By using data on U.S. city names recalled at 22 test locations, a multivariate model of the information surface specific to each test location is calibrated. This model links the probability of a city being recalled from memory to its distance from the test site, its population size, its location with respect to other cities, and whether or not it is a state capital. The paper then suggests that these recall data provide information on spatial knowledge surfaces from which large-scale spatial choices, such as migration destinations, are made. Results from the analysis lend further evidence to the idea that spatial knowledge is stored and processed hierarchically and that individuals underrepresent information in large clusters. Consequently, the results have important implications for modeling any spatial behavior based on individuals' spatial information surfaces. In particular, the results cast further doubt on the validity of traditional large-scale spatial choice frameworks and lend support to the competing destinations hypothesis. Key Words: spatial cognition, spatial choice, city name recalls, hierarchical information processing.

Byline: NORA S. NEWCOMBE Some years ago, when my younger child was about 5 years old, a friend of mine was pregnant. Because she was having premature contractions, she was [...]

The biblical story of locusts sweeping across Egypt is a classic example of a traveling population wave. Periodically, an organism becomes so numerous that an outbreak emerges, which spreads not [...]

Shepard's (1994) choice of kinematic geometry to support his theory is questioned by Todorovic, Schwartz, and Hecht. His theoretical framework, however, can be applied to another domain that may be less susceptible to some of their concerns. The domain is the representation of spatial layout. [HECHT; SCHWARTZ; SHEPARD; TODOROVIC]

This collection of comments summarises an attempt to evaluate the usefulness of Spatial Divisions of Labour in the contributors' own theoretical and empirical work. Several comments illustrate the manner in which Massey's work can be applied in contexts which differ markedly from that of Britain. Others are more critical, claiming that the relations between space, class, and gender are inadequately theorised in Massey's book. Neither the applications nor the vision about advances required would have been possible without Spatial Divisions of Labour.

Sex differences on Piaget's water-level (horizontality) test are well established but poorly understood. In this article, correlates of female horizontality performance are systematically explored. Across the five experiments reported, it was found that female subjects who failed the water-level test (poor-horizontality female subjects) were selectively impaired on tasks that required processing information from the otolith organs. In Experiment 1, poor-horizontality female subjects were found to be impaired relative to good-horizontality subjects on the rod-and-frame test. In Experiment 2, a relation was found between female horizontality performance and the ability to process vestibular information in a passive transport task. Experiment 3 ruled out poor spatial updating as a mediating factor in this relation. The results of Experiments 4 and 5 indicated that poor-horizontality female subjects perform randomly on vestibular navigation because they cannot judge linear displacement under conditions of passive transport. The linear transport task is similar to the rod-and-frame task in that both require the central processing of otolith signals. It is proposed that one way to solve the water-level test is to imagine, on the basis of prior perceptual experiences, what the water level looks like inside titled containers. Because of complex visual-otolish interactions, poor-horizontality female subjects may experience these events differently than good-horizontality subjects.

Analyses of human object recognition abilities led to the hypothesis that 2 kinds of spatial relation representations are used in human vision. Evidence for the distinction between abstract categorical spatial relation representations and specific coordinate spatial relation representations was provided in 4 experiments. These results indicate that Ss make categorical judgments--on/ off, left/right, and above/below--faster when stimuli are initially presented to the left cerebral hemisphere, whereas they make evaluations of distance--in relation to 2 mm, 3 mm, or 1 in. (2.54 cm)--faster when stimuli are initially presented to the right cerebral hemisphere. In addition, there was evidence that categorical representations developed with practice.

Transformed spatial mappings were used to perturb normal visual-motor processes and reveal the structure of internal spatial representations used by the motor control system. In a 2-D discrete aiming task performed under rotated visual-motor mappings, the pattern of spatial movement error was the same for all Ss: peak error between 90[degrees] and 135[degrees] of rotation and low error for 180[degrees] rotation. A two-component spatial representation, based on oriented bidirectional movement axes plus direction of travel along such axes, is hypothesized. Observed reversals of movement direction under rotations greater than 90[degrees] are consistent with the hypothesized structure. Aiming error under reflections, unlike rotations, depended on direction of movement relative to the axis of reflection (see Cunningham & Pavel, in press). Reaction time and movement time effects were observed, but a speed-accuracy tradeoff was found only for rotations for which the direction-reversal strategy could be used. Finally, adaptation to rotation operates at all target locations equally but does not alter the relative difficulty of different rotations. Structural properties of the representation are invariant under learning.

If a right-left spatial compatibility effect is observed, it can be maintained that the space has been segmented into right- and left-side parts. The present study aimed at showing a spatial compatibility effect (and, by implication, a right-left subdivision of space) solely attributable to the orienting of attention. Five groups of 8 normal subjects were required to give right-left discriminative responses to stimuli presented within one of six empty boxes arranged in a horizontal row. Reaction times and errors were recorded. The first two experiments showed that a right-left grouping of the boxes occurred regardless of whether subjects' fixation was kept at the intermediate position (Experiement 1) or at one extremity (Experiment 2) of the row. In Experiments 3 and 4, subjects' attention was not aligned with a fixed position but was moved, through peripheral cues, from trial to trial and positioned between different pairs of adjacent boxes. The results showed that the display was again subdivided into two regions and that the reference point for the right-left subdivision was the focus of attention. In Experiment 5, eye position was instrumentally monitored, and subjects' attention was directed by central cues. The results confirmed that the focusing of attention leads to a right-left partitioning of space, with the boundary at the locus of focal attention. In conclusion, we demonstrated, by employing a right-left spatial compatibility paradigm, that directing attention to a position in space brings about a right-left perceptual organization that predominates over that provided by the other egocentric reference axes.

Three studies investigated the factors that lead spatial information to be stored in an orientation-specific versus orientation-free manner. In Experiment 1, we replicated the findings of Presson and Hazelrigg (1984) that learning paths from a small map versus learning the paths directly from viewing a world leads to different functional characteristics of spatial memory. Whether the route display was presented as the path itself or as a large map of the path did not affect how the information was stored. In Experiment 2, we examined the effects of size of stimulus display, size of world, and scale transformations on how spatial information in maps is stored and available for use in later judgments. In Experiment 3, we examined the effect of size on the orientation specificity of the spatial coding of paths that are viewed directly. The major determinant of whether spatial information was stored and used in an orientation-specific or an orientation-free manner was the size of the display. Small displays were coded in an orientation-specific way, whereas very large displays were coded in a more orientation-free manner. These data support the view that there are distinct spatial representations, one more perceptual and episodic and one more integrated and model-like, that have developed to meet different demands faced by mobile organisms.

In eight experiments we investigated spatial and semantic priming effects. In Experiments 1 and 2, subjects made judgments about the locations of buildings on their campus and locations of states in the United States. We found that location judgments were faster when preceded by judgments about geographically near locations than by judgments about relatively far locations. In Experiments 3a, 3b, and 3c, subjects judged words as names of states of the United States or as nonstate words. No spatial priming effect was found in any experiment, now was a priming effect found for nonstate words preceded by semantically related words. Experiment 4 compared spatial priming in a state-nonstate classification with a state-plus-location classification task. Spatial priming was found in the latter but not the former. These results are interpreted with an account that treats spatial and nonspatial knowledge as separate structures. Using the nonstate words of Experiment 3c, Experiments 5a and 5b together demonstrated semantic priming in a lexical decision task. The semantic priming results are interpreted with a postlexical checking-strategy account of semantic priming.

Three predictions were derived from the hypothesis that adult age differences in certain measures of cognitive functioning are attributable to age-related reductions in a processing resource such as working-memory capacity. Each prediction received at least some degree of empirical support in a study involving 120 males ranging between 20 and 79 years of age. First, older adults exhibited greater impairments of performance than did young adults when task complexity increased and more demands were placed on the limited processing resources; second, the magnitudes of these complexity effects were highly correlated across verbal (reasoning) and spatial (paper folding) tasks. Finally, statistical control of an index of a working-memory processing resource attenuated the effects of age on the measures of cognitive performance. It was concluded that further progress in understanding the mechanisms of the relation between age and cognitive functioning will require improved conceptualizations of the nature of working memory or other hypothesized mediating constructs.

Two experiments investigated the structure of spatial memories. Subjects learned locations of objects in spatial layouts (Experiment 1) or locations of object anmes on maps (Experiment 2). Physical and perceptual boundaries were absent in these spatial arrays. Subjects then participated in three tasks: item recognition, in which the variable of interest was spatial priming; free and cued recall; and Euclidean distance estimation. Ordered-tree analysis of individual subjects' recall protocols produced hierarchical trees consistent with regularities in output order. Spatial priming and distance estimations depended on whether pairs of objects appeared in the same subtree or in different subtrees. These findings indicate that spatial memories have a hierarchical component, even when physical and perceptual boundaries are nonexistent. Priming also increased with depth of clustering in ordered trees. This result supports spreading-activation theories of retrieval but provides evidence against several 'non-spreading-activation' theories.

Adults were asked to judge the self-to-object directions in a room from novel points of observation that differed from their actual point at times only by a rotation and at other times only by a translation. The results show for the rotation trials that the errors and latencies when a novel point was imagined were worse than the baseline responses from their actual points of observation, and the latencies varied as a function of the magnitude of the to-be-imagined rotation. For the translation trials, on the other hand, the erros and latencies when a novel point was imagined were comparable to the baseline responses from their actual point and did not vary significantly across the different imagined station points. The evidence indicates that subjects know the object-to-object relations directly, without going through the origin of a coordinate system. In addition, similarities in processing during imagination on the one hand, and perception and action on the other are discussed.

We carried out two experiments to investigate how people reason about the spatial relations among objects. The experiments were designed to test a theory of spatial inference based on mental models. The theory predicts that problems requiring only one model of the spatial layout to be constructed should be easier than those requiring more than one model to be constructed, even when the multiple-model problems have valid conclusions. A contrasting theory, based on rules of inference, predicts that problems based on fewer inferential steps should be easier than problems based on more steps. The first experiment held constant the number of inferential steps specified by the inference-rule theory, but varied the number of models required to make a valid response: the one-model problems were reliably easier than the problems requiring more than one model. The second experiment contrasted opposing predictions from the two theories, and once again the results supported the model-based theory.

Sex-related differences in spatial ability, favoring males, have frequently been reported in the literature. Recent analyses, however, have found indications of a convergence in the scores of men and women on spatial tests over the years. This research examined the evidence for such a secular trend in a German population using data of 18 samples that had completed the Cube Perspectives Test, a measure of spatial visualization ability. The largest effect size (d = .77) was found for a sample tested in 1978, the smallest difference (d = .38) was observed for a sample tested in 1987. There was a clear trend narrowing the sex-related differences; the correlation between the recency of the data and the respective d-value was -.926. The convergence of the scores of men and women proved to be stronger than in the previous studies.

Different expressions of spatial knowledge were examined by having groups of first-, fourth-, and sixth-grade children perform model construction, verbal description, and route reversal tasks after they learned the correct path through a pedestrian maze. Age-related improvement was found in the rate of learning the maze and in the accuracy of verbal descriptions, suggesting that maze learning may be verbally mediated. All children performed well in sequencing intersections in the model but performed poorly in choosing path options in the model. Route reversal after learning was accurate and equivalent across groups. Overall, results suggest that both general and task-specific skills are involved in different products of spatial knowledge.

A detailed computational model for learning spatial networks is presented. Information is kept in a distributed, modular format: 'condition-actions pairs.' Knowledge of individual routes consists in chaining this piecemeal information. The model, called the Traveller, was fully implemented, and some sample runs are discussed. In learning a new network, the model displays the well-known transition from route level to survey level knowledge. No special mechanisms are needed to achieve the transition, as the Traveller's interactions with the environment gradually structure its emerging cognitive map. The Traveller is compared with some of the main competing computational models, and evidence from empirical research is adduced to support the suggested representational format.

A series of studies tested for distractor compatibility effects across wide target/distractor distances (0.6 [degrees] to 20 [degrees] of visual angle). The effects of precue condition, constant/varied target location, horizontal/vertical distractor distance, and foveal/peripheral presentation were studied. Results show strong compatibility effects across wide distances when distractors are at peripheral retinal locations. When both stimuli were presented at the same peripheral location in opposite hemifields, compatibility effects were evident within an area of at least 2.5 [degrees] of visual angle. In contrast, when foveally placed distractors were used, compatibility effects were found primarily with target letters positioned near. The findings suggest that distance effects are not homogeneous across retinal location., Space-based theories of visual attention suggest that attention can be covertly allocated to an extrafoveal location, but there is some disagreement as to the width of the attended area. Some [...]

In previous research (D. J. Bryant, B. Tversky, & N. Franklin, 1992; N. Franklin & B. Tversky, 1990), the authors showed that spatial knowledge conveyed by descriptions and direct experience induces participants to take the perspective of a character surrounded by objects. In this study, the authors used models and diagrams to convey the same information. With models, as with descriptions and experience, participants adopted the character's perspective (the spatial framework analysis). With diagrams, participants took an outside perspective (the intrinsic computation analysis). Even when informationally equivalent, different depictions made salient different aspects of the world. When instructed, however, participants were able to take either the inside or the outside perspective in memory for both diagrams and models. Depth cues in depictions also govern participants' perspective. When diagrams contained rich pictorial depth cues, participants used the spatial framework analysis, and when models were viewed without access to depth cues, participants relied on the intrinsic computation analysis.

Gender differences in pointing accuracy in computer-simulated mazes were studied as a function of maze complexity and training effects. College students (primarily White) were led through mazes with different numbers of turns; at the end of each maze, they were asked to indicate the direction of the maze origin (starting point). Pointing accuracy declined with the number of turns, but men were consistently more accurate than women by about 120 [degrees], regardless of maze complexity. Training participants to track the relative position of the maze origin while moving through the maze produced equivalent benefits in pointing accuracy for both women and men. Thus, although pointing accuracy of men remained higher than that of women, the results suggest that pointing performance can be modified by experience.

Most studies of the relationship between spatial learning and long-term potentiation (LTP) using genetically-engineered mice have been carried out with hippo-campal slice preparation techniques. The conditions necessary to obtain LCP in vitro may not be compared to those in animals that are awake. Techniques developed to measure LTP in the awake mouse show that the conclusions from earlier experiments that LTP in the dentate gyrus may be unnecessary for spatial learning could be inaccurate.