Cognitive map formation supported by auditory, haptic, and multimodal information in persons with blindness

For efficient navigation, the brain needs to adequately represent the environment in a cognitive map. In this review, we sought to give an overview of literature about cognitive map formation based on non-visual modalities in persons with blindness (PWBs) and sighted persons. The review is focused on the auditory and haptic modalities, including research that combines multiple modalities and real-world navigation. Furthermore, we addressed implications of route and survey representations. Taking together, PWBs as well as sighted persons can build up cognitive maps based on non-visual modalities, although the accuracy sometime somewhat differs between PWBs and sighted persons. We provide some speculations on how to deploy information from different modalities to support cognitive map formation. Furthermore, PWBs and sighted persons seem to be able to construct route as well as survey representations. PWBs can experience difficulties building up a survey representation, but this is not always the case, and research suggests that they can acquire this ability with sufficient spatial information or training. We discuss possible explanations of these inconsistencies.

Cognitive map formation through tactile map navigation in visually impaired and sighted persons

The human brain can form cognitive maps of a spatial environment, which can support wayfinding. In this study, we investigated cognitive map formation of an environment presented in the tactile modality, in visually impaired and sighted persons. In addition, we assessed the acquisition of route and survey knowledge. Ten persons with a visual impairment (PVIs) and ten sighted control participants learned a tactile map of a city-like environment. The map included five marked locations associated with different items. Participants subsequently estimated distances between item pairs, performed a direction pointing task, reproduced routes between items and recalled item locations. In addition, we conducted questionnaires to assess general navigational abilities and the use of route or survey strategies. Overall, participants in both groups performed well on the spatial tasks. Our results did not show differences in performance between PVIs and sighted persons, indicating that both groups formed an equally accurate cognitive map. Furthermore, we found that the groups generally used similar navigational strategies, which correlated with performance on some of the tasks, and acquired similar and accurate route and survey knowledge. We therefore suggest that PVIs are able to employ a route as well as survey strategy if they have the opportunity to access route-like as well as map-like information such as on a tactile map.

Spatial Knowledge via Auditory Information for Blind Individuals: Spatial Cognition Studies and the Use of Audio-VR

Spatial cognition is a daily life ability, developed in order to be able to understand and interact with our environment. Even if all the senses are involved in mental representation of space elaboration, the lack of vision makes it more difficult, especially because of the importance of peripheral information in updating the relative positions of surrounding landmarks when one is moving. Spatial audio technology has long been used for studies of human perception, particularly in the area of auditory source localisation. The ability to reproduce individual sounds at desired positions, or complex spatial audio scenes, without the need to manipulate physical devices has provided researchers with many benefits. We present a review of several studies employing the power of spatial audio virtual reality for research in spatial cognition with blind individuals. These include studies investigating simple spatial configurations, architectural navigation, reaching to sounds, and sound design for improved acceptability. Prospects for future research, including those currently underway, are also discussed.

Mental Maps and the Use of Sensory Information by Blind and Partially Sighted People

This article aims to fill an important gap in the literature by reporting on blind and partially sighted people's use of spatial representations (mental maps) from their perspective and when travelling on real routes. The results presented here were obtained from semi-structured interviews with 100 blind and partially sighted people in five different countries. They are intended to answer three questions about the representation of space by blind and partially sighted people, how these representations are used to support travel, and the implications for the design of travel aids and orientation and mobility training. They show that blind and partially sighted people do have spatial representations and that a number of them explicitly use the term mental map. This article discusses the variety of approaches to spatial representations, including the sensory modalities used, the use of global or local representations, and the applications to support travel. The conclusions summarize the answers to the three questions and include a two-level preliminary classification of the spatial representations of blind and partially sighted people.

Visual Experience and Access to Spatial Knowledge

Persons who were congenitally blind, late blind, and blindfold sighted learned an object-array by being guided within it in cardinal directions towards walls. Subjects then judged the near, far, left, and right locations of objects from different points of observation (PO). One-half of the subjects were guided to POs and at spot informed about their orientation (actual condition). The rest were first asked to imagine being at POs (imaginal condition). Group and task condition did not interact, but group and PO did: Visual experience speeded up judgments, especially in corners. The sequence imaginal-actual speeded up judgments in all groups.

Can Visually Impaired Children Use Tactile Maps to Estimate Directions?

This article reports on three experiments in which totally blind children and children with residual vision were asked to estimate directions between landmarks in a large-scale layout of objects. The children experienced the layout either directly, by walking around it, or indirectly by examining a tactile map. The authors found that the use of tactile maps considerably facilitated the performance of the totally blind children. The theoretical and practical implications of these findings are discussed.

Effects of Orientation on Braille Reading by People who are Visually Impaired: The Role of Context

Research by Heller suggested that speed and accuracy of reading may be seriously compromised by the inclusion of noncanonical (tilted) braille text. The study presented here extended that research by including characters other than those used by Heller and whole words. Similar results were found for Heller's original character set ( B–J), but the effect of orientation was reduced with other letters and whole words. The authors conclude that braille readers, especially experienced ones, have more facility with noncanonical braille than would be inferred from Heller's results.

Updated Tactile Feedback with a Pin Array Matrix Helps Blind People to Reduce Self-Location Errors

Autonomous navigation in novel environments still represents a challenge for people with visual impairment (VI). Pin array matrices (PAM) are an effective way to display spatial information to VI people in educative/rehabilitative contexts, as they provide high flexibility and versatility. Here, we tested the effectiveness of a PAM in VI participants in an orientation and mobility task. They haptically explored a map showing a scaled representation of a real room on the PAM. The map further included a symbol indicating a virtual target position. Then, participants entered the room and attempted to reach the target three times. While a control group only reviewed the same, unchanged map on the PAM between trials, an experimental group also received an updated map representing, in addition, the position they previously reached in the room. The experimental group significantly improved across trials by having both reduced self-location errors and reduced completion time, unlike the control group. We found that learning spatial layouts through updated tactile feedback on programmable displays outperforms conventional procedures on static tactile maps. This could represent a powerful tool for navigation, both in rehabilitation and everyday life contexts, improving spatial abilities and promoting independent living for VI people.

Way-finding strategies of blind persons in urban scale

The aim of this study was to determine whether urban environments with different prominent sensory inputs have an impact on the way-finding strategies of blind people and to identify these impacts, where applicable. We specifically investigated how blind people use their senses to compensate for the lack of visual information and how the priority of senses changes according to the urban context. The participants of the study consisted of nine congenitally blind individuals and the study took place in two urban settings: a dense urban district, Kemeralti district in İzmir; and an urban park, the İzmir Fair Park. During the learning phase, a first trial along the selected routes was conducted for each participant individually along with one of the researchers. In the test phase, the participants were requested to re-walk the route and verbally report the environmental cues they attended to. The participants' verbal reports were recorded and transcripts of the recordings were coded according to the environmental sensory inputs. In addition, the short-term memory of each participant was also evaluated. The results show that the characteristics of the urban environment seem to have an impact on way-finding strategies of blind individuals. It was found that the sound of the city and the echo from the environment are the most important factors for blind participants in the dense urban environment. Environmental boundaries provided echoes and gave a sense of enclosure that helped them orient themselves, whereas, in the park environment, the sense of enclosure was not enhanced due to a lack of boundaries in the environment.

Maternal Self-Critical and Dependent Personality Styles and Mother-Infant Communication

This study investigated mother-infant communication in relation to Blatt's measures of adult personality organization, namely, interpersonal relatedness and self-definition, defining the higher ends of these two measures as dependency and self-criticism, respectively. A nonclinical sample of 126 mother-infant dyads provided the data. An evaluation of maternal self-criticism and dependency was made six weeks postpartum; four months postpartum, mother-infant self- and interactive contingencies during face-to-face play were studied and analyzed in conjunction with the earlier evaluation. Self- and interactive contingencies were defined by the predictability within, and between, the behaviors of each partner. This approach assesses the process of relating from moment to moment within a dyad. Self-contingency measures the degree of stability/variability of one person's ongoing rhythms of behavior; interactive contingency measures the likelihood that one person's behavior is influenced by the behavior of the partner. Infant and mother facial affect, gaze, and touch, and infant vocal affect, were coded second by second from split-screen videotape. Maternal self-criticism and dependency had strikingly different effects on mother-infant communication. Self-critical mothers showed lowered attention and emotion coordination, staying more "separate" from infants in these realms, compromising infant interactive efficacy. This finding is consistent with Blatt and colleagues' descriptions of self-critical individuals as preoccupied with self-definition, compromising relatedness. Dependent mothers and their infants showed reciprocal emotional vigilance, consistent with Blatt and colleague's description of dependent individuals as "empty" and "needy" of emotional supplies from their partner. The study documents that the influence of the mother's personality organization operates through both infant and maternal contributions, a co-created process rather than a direct unilateral transmission from mother to infant.

Orientation and mobility aids for individuals with blindness: Verbal description vs. audio-tactile map

Individuals with visual impairment face significant challenges traveling in the physical environment. Independent movement is directly connected to the quality of someone's life, and thus, orientation and mobility issues are always listed among the top priorities of research in the field. The aim of the present research was to examine the level of accuracy of the cognitive map developed through the use of a verbal description versus the cognitive map developed using an audio-tactile map. A comparison of the effectiveness of the two mobility aids in detecting specific points of interest in the physical environment was an objective of the research. The procedure involved the study of a map using the two mobility aids, and an assessment through the transfer to the corresponding physical environment. The results suggest that an individual with visual impairment can acquire and use a functional cognitive map through the use of an audio-tactile map, while relying on a verbal description entails greater difficulty in detecting specific points of interest when he/she comes into the physical environment.

Blind and Sighted Children's Spatial Knowledge of Their Home Environments

The development of spatial knowledge of the home environment was longitudinally studied in three groups of school-age children who varied in their visual ability: totally blind, visually impaired, and normally sighted. The children were asked to judge which of three locations in their homes was the closest to a designated position: (1) judging by the routes necessary to get to the locations; and (2) judging by straight-line distances to the locations. Locations were either on the same floor as the designed position, on a different floor, or in the yard. Totally blind children were delayed in mastery of the tasks compared to the other children, particularly in judging straight-line distances between familiar locations. Their mistakes suggest that their spatial understanding of their home environments is based on their knowledge of routes between places rather than on their knowledge of the overall layout of the familiar space.

Movement Imagery in Young and Congenitally Blind Children: Mental Practice without Visuo-spatial Information

The study explored whether young children and congenitally totally blind children show mental practice effects for blind movements which cross the body midline. Experiment 1 tested blindfolded sighted children, with a mean age of 7 years and 11 months, on recall of a linear movement. Prior to recall, subjects either had to perform, or to imagine irrelevant (larger/smaller/same) movements. Irrelevant movements produced significant bias (CE/Constant Errors), whether carried out or imaged, although bias from imagined movements was smaller. The VE (variance/consistency) scores improved with (actual and mental) rehearsal. Articulatory suppression during delays had no effect. Experiment 2 used the same paradigm to test three groups of congenitally totally blind children with respective mean Mental Ages (MA) of 10 years and 7 months, 13 years and 7 months, and 16 years and 4 months, based on IO scores on the Williams Intelligence Test (1956) for visually handicapped children. Irrelevant movements during delays produced bias (CE) in recall, whether the movements were carried out or imagined, although bias was smaller in imagery conditions. The (CE) bias effects did not interact with MA. Mental Age interacted significantly with Delay Tasks in VE scores. The lowest MA group was less efficient (more variable) than the others, particularly in (actual and imagined) rehearsal. Articulatory suppression had no effect. The results suggest that young children can show mental practice effects in the absence of current visual cues, and that visuospatial imagery is not a necessary condition, because imagined movements also biased recall by the congenitally totally blind. It was argued that movement as well as cognitive factors can be involved in mental practice effects, and that the nature of mediation depends on the available information.

Is there any relationship between a child's body image and spatial skills?

This paper reports on a study designed to evaluate whether or not the relationship between body image and spatial skills, generally assumed to be fundamental, does in fact exist Using both the Cratty and Sams (1968) test, and a modification of it, we found no relationship between spatial skills and either overall body image or any of its components.

Effects of Hand Orientation and Delay on the Verbal Judgment of Haptically Perceived Orientation

We examined the haptic perception of orientations of a single bar throughout the horizontal plane using a verbal response: participants were to assign a number of minutes to the orientation of a bar defined with respect to the stimulus table. Performance was found to be systematically biased. Deviations were consistent with, yet much smaller than, those resulting from haptic motor matching tasks. The size and direction of the deviations were found to correlate with hand orientation, and not to depend on spatial location per se, suggesting a role for hand-centred reference frames in biasing performance. Delaying the response by 10 s led to a small improvement only of right-hand perceptions, indicating different hemispheric involvement in processes involved in retaining and/or recoding of haptic orientation information. Also the haptic oblique effect was found with the current verbal response. Importantly, it was affected neither by hand orientation nor by delay, suggesting that the oblique effect is independent of the aforementioned deviations in orientation perception.

Spatial navigation by congenitally blind individuals

Spatial navigation in the absence of vision has been investigated from a variety of perspectives and disciplines. These different approaches have progressed our understanding of spatial knowledge acquisition by blind individuals, including their abilities, strategies, and corresponding mental representations. In this review, we propose a framework for investigating differences in spatial knowledge acquisition by blind and sighted people consisting of three longitudinal models (i.e., convergent, cumulative, and persistent). Recent advances in neuroscience and technological devices have provided novel insights into the different neural mechanisms underlying spatial navigation by blind and sighted people and the potential for functional reorganization. Despite these advances, there is still a lack of consensus regarding the extent to which locomotion and wayfinding depend on amodal spatial representations. This challenge largely stems from methodological limitations such as heterogeneity in the blind population and terminological ambiguity related to the concept of cognitive maps. Coupled with an over‐reliance on potential technological solutions, the field has diffused into theoretical and applied branches that do not always communicate. Here, we review research on navigation by congenitally blind individuals with an emphasis on behavioral and neuroscientific evidence, as well as the potential of technological assistance. Throughout the article, we emphasize the need to disentangle strategy choice and performance when discussing the navigation abilities of the blind population. WIREs Cogn Sci 2016, 7:37–58. doi: 10.1002/wcs.1375

For further resources related to this article, please visit the WIREs website.

Allocentric Spatial Performance Higher in Early-Blind and Sighted Adults Than in Retinopathy-of-Prematurity Adults

The question as to whether people totally blind since infancy process allocentric or external spatial information like the sighted has caused considerable debate within the literature. Due to the extreme rarity of the population, researchers have often included individuals with retinopathy of prematurity (RoP--over oxygenation at birth) within the sample. However, RoP is inextricably confounded with prematurity per se. Prematurity, without visual disability, has been associated with spatial processing difficulties. In this experiment, blindfolded sighted participants and two groups of functionally totally blind participants heard text descriptions from a survey (allocentric) or route (egocentric) perspective. One blind group lost their sight due to RoP and a second group before 24 months of age. The accuracy of participants' mental representations derived from the text descriptions was assessed via questions and maps. The RoP participants had lower scores than the sighted and early blind, who performed similarly. In other words, it was not visual impairment alone that resulted in impaired allocentric spatial performance in this task but visual impairment together with RoP. This finding may help explain the contradictions within the existing literature on the role of vision in allocentric spatial processing.

The impact of vision in spatial coding

The aim of this study is to examine the performance in coding and representing of near-space in relation to vision status (blindness vs. normal vision) and sensory modality (touch vs. vision). Forty-eight children and teenagers participated. Sixteen of the participants were totally blind or had only light perception, 16 were blindfolded sighted individuals, and 16 were non-blindfolded sighted individuals. Participants were given eight different object patterns in different arrays and were asked to code and represent each of them. The results suggest that vision influences performance in spatial coding and spatial representation of near space. However, there was no statistically significant difference between participants with blindness who used the most effective haptic strategy and blindfolded sighted participants. Thus, the significance of haptic strategies is highlighted.

Tactile maze solving in congenitally blind individuals

Vision is undoubtedly important for navigation although not essential as blind individuals outperform their blindfolded seeing counterparts in a variety of navigational tasks. It is believed that the blind's superior performance is because of their efficient use of proprioceptive signals and environmental cues such as temperature and echolocation. We hypothesize that by limiting these cues, blind individuals will lose their advantage compared with controls in spatial navigation tasks. We therefore evaluated the performance of blind and sighted individuals in small-scale, tactile multiple T mazes. Our results show that blindfolded sighted controls outperformed blind participants in the route-learning tasks. This suggests that, contrary to indoor large-scale spaces, navigational skills inside small-scale spaces benefit from visual experience.

The role of visual experience in mental scanning of actual pathways: evidence from blind and sighted people

In this research we compare blind and normally sighted people in mental scanning of spatial maps using locomotor or visual/locomotor exploration of a real 3-D environment. Different types of visual experience were tested: early (congenital) and late (adventitious) onset of blindness, short-term deprivation (blindfolded-sighted), and full vision (sighted). Participants were asked to learn six positions in a large parking area with movement alone (congenital, adventitious, blindfolded-sighted) or with vision plus movement (sighted), and then to mentally scan between positions in the path. Finally, they had to describe how they imagined scanning the learned pathway. We found a significant linear relation between space and time, ie the classic mental scanning effect, in all tested groups. However, the linear component was lower in blind participants, especially congenital. Instead, short-term visual deprivation had minimal impact on mental scanning. Overall, blind participants had shorter scanning times than both sighted groups, and the effect was particularly evident with farther distances. These results suggest that there is a quantitative rather than a qualitative difference between the blind and the sighted. In addition, the mental scanning strategies reported by participants also affected mental scanning times. The theoretical implications of these findings are discussed.

Using the voice of the child who is blind as a tool for exploring spatial perception

Researchers from different disciplines have attempted to investigate the way in which people who are blind conceptualize and perceive elements of the spatial environment. Most of the studies that are reported in the literature use an experimental approach based on measurements of the performance in test situations of people who are blind or people who are sighted but who are blindfolded. The findings from these studies are important and have shed light on the process of understanding spatial relations in both small- and large-scale space. However, they have sometimes produced contrasting findings. The study the authors are currently involved in diverges from other studies in this key area in that the method used is essentially qualitative and participatory in character. This article gives an example of using the child’s voice to explore spatial understanding and involves a narrative account from a 13-year-old student who was blind from birth about the strategies he uses to overcome the challenges he faces in making sense of space. The results suggest that the child’s voice can provide insights into spatial understanding that can be used to help triangulate the findings and understandings achieved from the experimental approaches that dominate the literature.

Differences between early-blind, late-blind, and blindfolded-sighted people in haptic spatial-configuration learning and resulting memory traces

The roles of visual and haptic experience in different aspects of haptic processing of objects in peripersonal space are examined. In three trials, early-blind, late-blind, and blindfolded-sighted individuals had to match ten shapes haptically to the cut-outs in a board as fast as possible. Both blind groups were much faster than the sighted in all three trials. All three groups improved considerably from trial to trial. In particular, the sighted group showed a strong improvement from the first to the second trial. While superiority of the blind remained for speeded matching after rotation of the stimulus frame, coordinate positional-memory scores in a non-speeded free-recall trial showed no significant differences between the groups. Moreover, when assessed with a verbal response, categorical spatial-memory appeared strongest in the late-blind group. The role of haptic and visual experience thus appears to depend on the task aspect tested.

Haptic orientation perception: Sex differences and lateralization of functions

The present study examined sex differences in haptic orientation representation using three tasks: a bimanual parallel-setting task comprising haptic orientation perception and motor matching action, and two unimanual tasks focusing on the perception and action elements separately. A verbal judgment task focused on haptic orientation perception: participants were to assign a number of minutes to a felt orientation. An orientation production task required the rotation of a bar to match a verbally presented number of minutes. Although both male and female performance was systematically biased we found that males are more accurate in parallel-setting and verbal judgment of orientation, suggesting differences in haptic orientation perception, in particular. Increasing allocentric reference frame involvement by delaying the action in the parallel-setting task did not affect the sex difference found. In addition to a male advantage over tasks, performance on both unimanual tasks suggests sex differences in lateralization of haptic orientation processing; a dependence on hand orientation was found only for right hand performance in males.

External and body-centered frames of reference in spatial memory: Evidence from touch

The study reports independent effects of external and body-centered reference cues on spatial coding of an irregular sequence of haptic locations. The aim was to investigate the nature of spatial coding by using a modality that does not provide distal cues routinely. Our method isolates and combines body-centered and external spatial reference cues for irregularly placed locations, scanned along a raised-line route. Disrupting body-centered reference for the locations, by orienting the map differently to the body in the test phase than in the presentation phase, doubled errors in positioning the locations along the route in recall. Adding external reference, by giving instructions to use a surrounding frame for reference when body-centered coding was disrupted, reduced errors to near baseline (no-rotation) levels. Adding external reference cues to intact (not displaced) body-centered reference halved errors, as compared with the baseline. The results are consistent with the hypothesis that accurate spatial coding is determined by the congruence of potential reference cues from diverse sources. The new findings suggest that external and body-centered reference cues have independent additive effects on spatial coding. The sequence of locations had a significant effect in all the reference conditions, suggesting the additional use of fortuitous but distinctive local touch cues on the route. The discussion considers theoretical and practical implications of the results.

Improved Mental Rotation by Near-Sighted Subjects

Several studies have shown significant correlations among factors such as sex, age, and hormone levels with performance on mental rotation tasks. To perform spatial rotation also seems to be related to cognitive abilities such as musical skills. The present experiment investigated a possible relationship for enhanced spatial abilities, as observed in near-sighted subjects, with mental rotation performance. 39 near-sighted and 21 normal-sighted subjects were tested on a mental rotation task using two-dimensional representations of three-dimensional objects. Near-sighted subjects displayed fewer errors in possible rotations than normal-sighted subjects. There was no difference in errors between groups in identification of mirror images (“impossible rotations”). Results were interpreted in terms of a relation between enhanced reliance on nonvisual information by near-sighted subjects and improved spatial representation.

Delay improves performance on a haptic spatial matching task

Systematic deviations occur when blindfolded subjects set a test bar parallel to a reference bar in the horizontal plane using haptic information (Kappers and Koenderink 1999, Perception 28:781-795; Kappers 1999, Perception 28:1001-1012). These deviations are assumed to reflect the use of a combination of a biasing egocentric reference frame and an allocentric, more cognitive one (Kappers 2002, Acta Psychol 109:25-40). In two experiments, we have examined the effect of delay between the perception of a reference bar and the parallel setting of a test bar. In both experiments a 10-s delay improved performance. The improvement increased with a larger horizontal (left-right) distance between the bars. This improvement was interpreted as a shift from the egocentric towards the allocentric reference frame during the delay period.

Mental rotation of a tactile layout by young visually impaired children

Mental rotation tasks have been used to probe the mental imagery both of sighted and of visually impaired people. People who have been blind since birth display a response pattern which is qualitatively similar to that of sighted people but tend to respond more slowly or with a higher error rate. It has been suggested that visually impaired people code the stimulus and its (or their own) motion in a different way from sighted people-in particular, congenitally blind people may ignore the external reference framework provided by the stimulus and surrounding objects, and instead use body-centred or movement-based coding systems. What has not been considered before is the relationship between different strategies for tactually exploring the stimulus and the response pattern of congenitally blind participants. Congenitally blind and partially sighted children were tested for their ability to learn and recall a layout of tactile symbols. Children explored layouts of one, three, or five shapes which they then attempted to reproduce. On half the trials there was a short pause between exploring and reproducing the layouts. In an aligned condition children reproduced the array from the same position at which they had explored it; in a rotated condition children were asked to move 90 degrees round the table between exploring and reproducing the layout. Both congenitally blind and partially sighted children were less accurate in the rotated condition than in the aligned condition. Five distinct strategies used by the children in learning the layout were identified. These strategies interacted with both visual status and age. We suggest that the use of strategies, rather than visual status or chronological age, accounts for differences in performances between children.

The haptic 'oblique effect' in children's and adults' perception of orientation

The haptic perception of vertical, horizontal, and diagonal orientations was studied in children (aged 7 and 9 years) and in adults. The purpose was to test the hypothesis that the haptic oblique effect results from the different scanning movements at work when one hand explores an oblique standard and the other hand sets the response rod. In experiment 1, blindfolded subjects reproduced the orientation of a standard rod presented in either the frontal, the horizontal, or the sagittal plane, and this task was achieved either ipsilaterally (the same hand explored the standard and set the response rod) or contralaterally (one hand explored the standard and the other hand set the response rod). Since, in the sagittal plane, scanning movements are analogous when the left and right hands explore oblique orientations, no oblique effect should be observed in this condition if the hypothesis is valid. Moreover, a development effect should be observed, since young children generally rely more on movement coding than do older children and adults. Results did not support these predictions: the same oblique effect appeared in the frontal and the sagittal planes both in the ipsilateral and in the contralateral condition, and the effect of age was not in the direction predicted by the hypothesis. The results were consistent with the hypothesis in the horizontal plane only. Experiments 2 and 3 provided further tests of this hypothesis but both failed to support it. Taken together, the results of these three experiments did not support the assumption and it is suggested that the haptic oblique effect may be linked to the gravitational cues provided by the arm-hand system when it acts in the three spatial planes.

Perspective taking, pictures, and the blind

Congenitally blind, late blind, and blindfolded sighted controls attempted a Piagetian perspective-taking (three-mountain) task. Piaget used the term perspective to mean point of view (Piaget & Inhelder, 1967, p. 210), and the present usage does not imply linear perspective. Subjects used raised-line drawings to depict alternative points of view of an array of three geometric solid forms (cube, cone, and ball). They then identified the point of view of raised-line drawings. The effect of visual status on accuracy was nonsignificant for both response measures. Using alternating vision of the array and drawings, sighted subjects in a control condition performed like the congenitally blind. However, congenitally blind individuals did require more time than the other subjects for the perspective-taking task. In an additional experiment, no difference was found between the three groups in the accuracy or speed of tactile shape matching. The results suggest that visual imagery and visual experience are not necessary for tactile perspective taking.

Understanding maps as symbols: the development of map concepts in children

We expect that many readers encountered this article with the beliefs that maps are highly specialized devices primarily used for wayfinding; that they represent the spatial world in a single, correct form; that they are readily transparent; and that their sole contribution to psychology is their role in externalizing environmental cognition. By discussing the myriad functions and forms of maps, by highlighting their symbolic nature, and by considering some of the misconceptions about maps, we have attempted to demonstrate the value of maps for addressing a wide range of developmental questions. Our review of past research literature suggests that research conducted within individual disciplines has both strengths and limitations. Work in the psychological tradition is characterized by attention to important subject characteristics and to carefully described and implemented research designs, procedures, coding, and analyses. At the same time, this work reveals, at best, highly restricted views about maps, and at worst, fundamental misconceptions about maps. Work in the geographic and environmental traditions, in contrast, samples a broader range of map forms and functions, but it suffers from inattention to procedural details that makes the conclusions less compelling than they might otherwise be. A conventional wisdom is emerging from the work in both traditions: That children's map understanding occurs extremely early and extremely easily. The limitations of both research traditions, however, suggest the need for caution in accepting this view. Developmental and cartographic theories provide a compelling reason to reexamine the early and easy view and suggest the need for alternative conceptual and empirical approaches. We have argued that future work should integrate the traditions of psychology and geography. Illustrative data from an interdisciplinary program of research were presented. We described work demonstrating the gradual and difficult process of mastering the representational and geometric correspondences that link the map to its referent in the world. Our data suggest that there are significant achievements in map conceptualization (the understanding of the concept of a map), map identification (understanding the formal components of a map), and map utilization (the ability to use maps). Our data support the view that maps are not transparent and that children's abilities to understand, use, and create maps are linked to their developing representational and spatial skills. In concluding, we should acknowledge that we have deliberately pushed interpretations about understanding maps as symbolic representations to the extreme. The reason for this strategy is simple: We believe that work on maps--both in the public schools and in academia--is assumed to be an expendable and irrelevant luxury.(ABSTRACT TRUNCATED AT 400 WORDS)