Evidence against integration of spatial maps in humans

A dynamic 3-D virtual environment was constructed for humans as an open-field analogue of Blaisdell and Cook's (2005) pigeon foraging task to determine if humans, like pigeons, were capable of integrating separate spatial maps. Participants used keyboard keys and a mouse to search for a hidden goal in a 4×4 grid of raised cups. During Phase 1 training, a goal was consistently located between two landmarks (Map 1: blue T and red L). During Phase 2 training, a goal was consistently located down and left of a single landmark (Map 2: blue T). Transfer trials were then conducted in which participants were required to make choices in the presence of the red L alone. Cup choices during transfer assessed participants’ strategies: association (from Map 1), generalization (from Map 2), or integration (combining Map 1 and 2). During transfer, cup choices increased to a location which suggested an integration strategy and was consistent with results obtained with pigeons. However, additional analyses of the human data suggested participants initially used a generalization strategy followed by a progressive shift in search behavior away from the red L. This shift in search behavior during transfer was responsible for the changes in cup choices across transfer trials and was confirmed by a control condition. These new analyses offer an alternative explanation to the spatial integration account proposed for pigeons.Electronic Supplementary Material Supplementary material is available for this article at     

Getting the big picture: Development of spatial scaling abilities

Spatial scaling is an integral aspect of many spatial tasks that involve symbol-to-referent correspondences (e.g., map reading, drawing). In this study, we asked 3–6-year-olds and adults to locate objects in a two-dimensional spatial layout using information from a second spatial representation (map). We examined how scaling factor and reference features, such as the shape of the layout or the presence of landmarks, affect performance. Results showed that spatial scaling on this simple task undergoes considerable development, especially between 3 and 5 years of age. Furthermore, the youngest children showed large individual variability and profited from landmark information. Accuracy differed between scaled and un-scaled items, but not between items using different scaling factors (1:2 vs. 1:4), suggesting that participants encoded relative rather than absolute distances.     

Evidence against integration of spatial maps in humans: generality across real and virtual environments

A real-world open-field search task was implemented with humans as an analogue of Blaisdell and Cook’s (Anim Cogn 8:7–16, 2005) pigeon foraging task and Sturz, Bodily, and Katz’s (Anim Cogn 9:207–217, 2006) human virtual foraging task to 1) determine whether humans were capable of integrating independently learned spatial maps and 2) make explicit comparisons of mechanisms used by humans to navigate real and virtual environments. Participants searched for a hidden goal located in one of 16 bins arranged in a 4 × 4 grid. In Phase 1, the goal was hidden between two landmarks (blue T and red L). In Phase 2, the goal was hidden to the left and in front of a single landmark (blue T). Following training, goal-absent trials were conducted in which the red L from Phase 1 was presented alone. Bin choices during goal-absent trials assessed participants’ strategies: association (from Phase 1), generalization (from Phase 2), or integration (combination of Phase 1 and 2). Results were inconsistent with those obtained with pigeons but were consistent with those obtained with humans in a virtual environment. Specifically, during testing, participants did not integrate independently learned spatial maps but used a generalization strategy followed by a shift in search behavior away from the test landmark. These results were confirmed by a control condition in which a novel landmark was presented during testing. Results are consistent with the bulk of recent findings suggesting the use of alternative navigational strategies to cognitive mapping. Results also add to a growing body of literature suggesting that virtual environment approaches to the study of spatial learning and memory have external validity and that spatial mechanisms used by human participants in navigating virtual environments are similar to those used in navigating real-world environments.     

Exploring the effects of similarity on mapping spatial relations

Solving a map task requires transferring information acquired in one spatial context to another context, an ability that marks an important step in cognitive development. This study investigated how preschoolers’ mapping performance was affected by the extent of similarity between spaces. Whereas prior work examined effects of similarity in tasks involving matching individual objects, our tasks required considering spatial relations among objects. We found that the accuracy of mapping between two spaces with somewhat different perceptual features was higher than the accuracy of mapping between spaces with identical features. Yet, a further increase in differences between the two spaces had a detrimental effect on mapping. The results suggest that some degree of similarity between spaces is beneficial to children’s ability to transfer relational information. However, when the spaces have the same surface features, it may draw children’s attention to individual objects and inhibit their ability to focus on common relations across contexts.     

The spatial specificity of sensory attenuation for self-touch

Self-touch is sensed less intense as touch produced by another person. According to the standard explanation, if predicted and actual sensations match, the intensity of the touch will be reduced. Here, we asked whether sensory attenuation is spatially specific. To this end, participants laid their left hand under a metal arc on which a force sensor was mounted. Pressing the sensor caused one of two motors to rotate a lever that either touched the index or the ring finger. We took care that no cues would reveal in advance which of the motors would move in order to leave participants uninformed about the finger that will be stimulated. Any reduction in felt intensity of the touch could therefore be induced only by the efference copy of the touching movement. We found strong spatial specificity of sensory attenuation of self-touch, selecting between two fingers of the same hand.     

Integration of spatial information across vision and language

Three experiments investigated whether spatial information acquired from vision and language is maintained in distinct spatial representations on the basis of the input modality. Participants studied a visual and a verbal layout of objects at different times from either the same (Experiments 1 and 2) or different learning perspectives (Experiment 3) and then carried out a series of pointing judgments involving objects from the same or different layouts. Results from Experiments 1 and 2 indicated that participants pointed equally fast on within- and between-layout trials; coupled with verbal reports from participants, this result suggests that they integrated all locations in a single spatial representation during encoding. However, when learning took place from different perspectives in Experiment 3, participants were faster to respond to within- than between-layout trials and indicated that they kept separate representations during learning. Results are compared to those from similar studies that involved layouts learned from perception only.     

The role of spatial attention and other processes on the magnitude and time course of cueing effects

We are quite often exposed to multiple objects present in the visual scene, thus attentional selection is necessary in order to selectively respond to the relevant information. Objects can be selected on the basis of the location they occupy by orienting attention in space. In this paper, we review the evidence showing that attention can be oriented in space either endogenously, on the basis of central cues, predictive of the relevant location, or exogenously, automatically triggered by the salient properties of visual stimuli (peripheral cues). Several dissociations observed between orienting on the basis of the two types of cues have led to the conclusion that they do not represent just two modes of triggering the orienting of the very same attentional mechanism, but rather they modulate processing differently. We present a theoretical framework according to which endogenous predictive cues facilitate target processing by orienting attention, thus amplifying processing at the attended location. In contrast, apart from attentional orienting, peripherally presented discrepant cues might trigger additional cue-target event-integration and event-segregation processes, which modulate processing in a different way, thus leading to cueing effects that are exclusively triggered by peripheral cues.     

Realism in confidence judgements of performance based on implicit learning

In two experiments we employed calibration methods to investigate the realism of participants' confidence ratings of their own classification performance based on knowledge acquired after training on an artificial grammar. In Experiment 1 participants showed good realism (but overconfidence) for grammatical strings but very poor realism for non-grammatical strings. Method of training (string repetition in writing or mere exposure) did not affect the realism. Furthermore, the participants underestimated their overall performance. In Experiment 2, using a more complex grammar and controlling for two types of associative chunk-strength, participants showed good realism (but still overconfidence) for both letter and symbol strings, irrespective of grammaticality. Together, these experiments show that implicit learning can give rise to knowledge products that are associated with fairly realistic meta-knowledge. It is argued that both the zero-correlation criterion and the guessing criterion are misplaced when used to define implicit knowledge; two reasons being that confidence judgements may be affected both by implicit knowledge and by inferences.     

Local rather than global processing of visual arrays in numerosity discrimination by pigeons (Columba livia)

A series of experiments investigated which stimulus properties pigeons use when they discriminate pairs of visual arrays that differ in numerosity. Transfer tests with novel stimuli confirmed that the birds’ choices were based on relative differences in numerosity. However, pigeons differed from other species in the non-numerical cues that affected their choices. In human and non-human primates, numerical discrimination is often influenced by continuous variables such as surface area or overall stimulus brightness. Pigeons showed little evidence of using those cues, even when summed area and brightness had been correlated with numerosity differences and reward outcome. But when array-element sizes were asymmetrically distributed across numerosities, the birds readily utilized information about item sizes as an additional discriminative cue. These novel results are discussed in relation to pigeons’ tendency to focus on local, rather than global dimensions when they process other non-numerical complex visual stimuli. The findings suggest there may be inter-specific differences in the type of perceptual information that provides the input stage for mechanisms underlying numerical processing. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

How to separate coordinate and categorical spatial relation components in integrated spatial representations: A new methodology for analysing sketch maps

Spatial relations between landmarks can be represented by means of categories and coordinates. In the present research, this paradigm was applied to sketch maps based on information acquired in goal-directed behaviour of exploration of a university campus area. The first aim was to investigate whether categorical and coordinate information can be considered conceptually independent in sketch maps. The second aim was to assess which kind of distance measure served better to represent coordinate information in the present case study, and finally to assess the factorial structure of coordinate and categorical data. Analytic methodology as well as statistical analysis were found to confirm that separating coordinate and categorical components was formally as well as empirically appropriate. A series of confirmatory factor analyses showed the best fit for the model with two correlated components, as well as an acceptable reliability of measures emerged. The two components were moderately correlated. Moreover, the adoption of Manhattan distance seemed to be the most effective method to represent coordinate spatial relations in spatial sketch maps of areas acquired through navigation.     

Transfer of avoidance responding to a sensory preconditioned cue: Evidence for the role of S-S and R-S knowledge in avoidance learning

In avoidance learning studies, a warning signal (Sd) is directly paired with an aversive unconditioned stimulus (US) unless a particular response is performed. Research by Augustson and Dougher (1997) demonstrated that not only warning signals but also stimuli that are indirectly paired with the aversive event are capable of affecting the avoidance response. In the present study, we extended these results by incorporating a sensory preconditioning paradigm in an avoidance learning procedure. Sensory preconditioning training influenced the selection of avoidance responses in the presence of warning signals that were never paired directly with the aversive events. Moreover, results suggest that the selection of the avoidance responses was based on an integration of knowledge about the relation between the Sd and the US (S-S knowledge) and knowledge about the relation between the avoidance response and the US (R-S knowledge). As the expectancy-based theory of Lovibond (2006) is the only theory of avoidance that incorporates both knowledge structures, the results provide unique support for this theory.     

Grounding spatial language in the motor system: Reciprocal interactions between spatial semantics and orienting

Shifts of attention that are directed by spatial words are thought to be mediated by a spatial frame of reference. Previous studies have documented a selection cost when visual attention is directed along the left/right axis relative to the above/below axis due to the greater ambiguity of the horizontal endpoints. The present study investigated whether the horizontal endpoints may be more fully disambiguated when “left/right” cues are first enacted by nondivisible, more discrete, modes of orienting such as directional motor responses. This issue was investigated using a repetition priming paradigm in which the effects of prior enactments were measured on the subsequent conceptual control of visual attention. The results of four experiments showed that grounding spatial language in the motor system can enhance the focus of visual attention by disambiguating the endpoints of the horizontal axis. In so doing, the present study extends previous research demonstrating that spatial concepts can influence the spatial distribution of attention by demonstrating that different modes of orienting can also influence the semantics of space. Implications for the premotor theory of attention and grounded theories of cognition are also discussed.     

Frames of reference in spatial language acquisition

Languages differ in how they encode spatial frames of reference. It is unknown how children acquire the particular frame-of-reference terms in their language (e.g., left/right, north/south). The present paper uses a word-learning paradigm to investigate 4-year-old English-speaking children’s acquisition of such terms. In Part I, with five experiments, we contrasted children’s acquisition of novel word pairs meaning left-right and north-south to examine their initial hypotheses and the relative ease of learning the meanings of these terms. Children interpreted ambiguous spatial terms as having environment-based meanings akin to north and south, and they readily learned and generalized north-south meanings. These studies provide the first direct evidence that children invoke geocentric representations in spatial language acquisition. However, the studies leave unanswered how children ultimately acquire “left” and “right.” In Part II, with three more experiments, we investigated why children struggle to master body-based frame-of-reference words. Children successfully learned “left” and “right” when the novel words were systematically introduced on their own bodies and extended these words to novel (intrinsic and relative) uses; however, they had difficulty learning to talk about the left and right sides of a doll. This difficulty was paralleled in identifying the left and right sides of the doll in a non-linguistic memory task. In contrast, children had no difficulties learning to label the front and back sides of a doll. These studies begin to paint a detailed account of the acquisition of spatial terms in English, and provide insights into the origins of diverse spatial reference frames in the world’s languages.     

Individual differences in spatial mental imagery

In this article, we report a new image-scanning paradigm that allowed us to measure objectively individual differences in spatial mental imagery—specifically, imagery for location. Participants were asked to determine whether an arrow was pointing at a dot using a visual mental image of an array of dots. The degree of precision required to discriminate “yes” from “no” trials was varied. In Experiment 1, the time to scan increasing distances, as well as the number of errors, increased when greater precision was required to make a judgement. The results in Experiment 2 replicated those results while controlling for possible biases. When greater precision is required, the accuracy of the spatial image becomes increasingly important—and hence the effect of precision in the task reflects the accuracy of the image. In Experiment 3, this measure was shown to be related to scores on the Paper Folding test, on the Paper Form Board test, and on the visuospatial items on Raven's Advanced Progressive Matrices—but not to scores on questionnaires measuring object–based mental imagery. Thus, we provide evidence that classical standardized spatial tests rely on spatial mental imagery but not object mental imagery.     

Short-term memory for temporal intervals: Contrasting explanations of the choose-short effect in pigeons

To better understand short-term memory for temporal intervals, we re-examined the choose-short effect. In Experiment 1, to contrast the predictions of two models of this effect, the subjective shortening and the coding models, pigeons were exposed to a delayed matching-to-sample task with three sample durations (2, 6 and 18 s) and retention intervals ranging from 0 to 20 s. Consistent with the coding model, the results suggested a sudden forgetting of memories for duration. In Experiment 2, to test the confusion hypothesis, the characteristics of the ITI and the retention interval differed. Contrary to the confusion hypothesis, a choose-short effect was obtained. In both experiments, a test with only two of the three comparison keys was performed. The results suggest three effects that may be controlling the birds’ responses: stimulus generalization when no retention interval is present; an increase in random responding at longer retention intervals; and, similarly, an increase in preference for the “short-sample” key at longer retention intervals.     

Sex differences in spatial ability: a lateralization of function approach

The current study was designed to examine whether the extent of the male advantage in performance on a spatial task was determined by the extent to which the task was right-hemisphere dependent. Participants included 108 right-handed men and women who completed the mental rotation, waterlevel, and paperfolding tasks, all of which were presented bilaterally. The results partially supported the hypothesis. On the mental rotation task, men showed a right-hemisphere advantage, whereas women showed no hemispheric differences; however, no overall sex differences were observed. On the waterlevel task, men outperformed women, and both men and women showed a right-hemisphere advantage. On the paperfolding task, no sex or hemispheric differences were observed. Although the findings of the current study were mixed, the study provides a framework for examining sex differences across different types of spatial ability.     

Modularity and spatial reorientation in a simple mind: encoding of geometric and nongeometric properties of a spatial environment by fish

When disoriented in environments with distinctive geometry, such as a closed rectangular arena, human infants and adult rats reorient in accord with the large-scale shape of the environment, but not in accord with nongeometric properties such as the colour of a wall. Human adults, however, conjoined geometric and nongeometric information to reorient themselves, which has led to the suggestion that spatial processing tends to become more flexible over development and evolution. We here show that fish tested in the same tasks perform like human adults and surpass rats and human infants. These findings suggest that the ability to make use of geometry for spatial reorientation is an ancient evolutionary tract and that flexibility and accessibility to multiple sources of information to reorient in space is more a matter of ecological adaptations than phylogenetic distance from humans.     

Auditory spatial concepts in blind football experts

ObjectivesWe compared the spatial concepts given to sounds' directions by blind football players with both blind non-athletes and sighted individuals.MethodParticipants verbally described the directions of sounds around them by using predefined spatial concept labels, under two blocked conditions: 1) facing front, 2) pointing with the hand towards the stimulus.ResultsBlind football players categorized the directions more precisely (i.e., they used simple labels for describing the cardinal directions and combined labels for the intermediate ones) than the other groups, and their categorization was less sensitive to the response conditions than blind non-athletes. Sighted participants' categorization was similar to previous studies, in which the front and back regions were generally more precisely described than the sides, where simple labels were often used for describing directions around the absolute left and right.ConclusionsThe differences in conceptual categorization of sound directions are a) in sighted individuals, influenced by the representation of the visual space b) in blind individuals, influenced by the level of expertise in action and locomotion based on non-visual information, which can be increased by auditive stimulation provided by blind football training.