Influence of mapping complexity on negative priming for incompatible spatial mappings

For tasks with an incompatible stimulus-response mapping, whether the compatible response must be inhibited paradigm for four-choice tasks with three different incompatible spatial mappings. For a mapping that did not follow a simple rule, reaction time was lengthened when the corresponding response on the preceding trial became the required response on the current trial, as compared with when it did not, showing a negative priming effect. However, for mappings that followed a simple rule, negative priming was not evident. The present study extends this research to a more complex mapping. On the basis of a two-process model adopted from the negative priming literature, we hypothesized that high mapping complexity should also diminish the negative priming effect for incompatible mappings, because the balance of cognitive resources is allocated to identification of the correct response. Two experiments are reported in which mappings of different complexity were used in six-choice spatial tasks. Analyses of reaction times showed that negative priming diminished with increased mapping complexity, apparently due to increased dominance of response identification processes, rather than inhibition of the corresponding response.     

Switching between spatial stimulus-response mappings: a developmental study of cognitive flexibility

Four different age groups (8-9-year-olds, 11-12-year-olds, 13-15-year-olds and young adults) performed a spatial rule-switch task in which the sorting rule had to be detected on the basis of feedback or on the basis of switch cues. Performance errors were examined on the basis of a recently introduced method of error scoring for the Wisconsin Card Sorting Task (WCST; Barcelo & Knight, 2002). This method allowed us to differentiate between errors due to failure-to-maintain-set (distraction errors) and errors due to failure-to-switch-set (perseverative errors). The anticipated age differences in performance errors were most pronounced for perseverative errors between 8-9 years and 11-12 years, but for distraction errors adult levels were not reached until 13-15 years. These findings were interpreted to support the notion that set switching and set maintenance follow distinct developmental trajectories.     

Determinants of the benefit for consistent spatial mappings in dual-task performance of three-choice tasks

Performance of pairs of three-choice tasks shows a consistency benefit for which reaction times are shorter when the stimulus-response mappings for each task are consistent (both corresponding or both mirrored) than when they are inconsistent. In the present study, we examined whether this consistency benefit is reduced at long stimulus onset asynchronies, as it is for pairs of two-choice tasks, or is relatively unaffected, as it is for pairs of four-choice tasks. The consistency benefit was evident for both corresponding and mirrored mappings, at all intervals. For consistent mirrored mappings, the benefit was found for the side stimulus positions (for which responses are crossed) but not for the center position, whereas for consistent corresponding mappings, a benefit was evident for the center position as well. The results for both mappings are in agreement with an emergent mapping-choice account. The consistent corresponding mapping also benefits from subjects’ ability to apply a respond-corresponding rule across tasks. An emergent perceptual-feature process that contributes to the consistency benefit for two-choice tasks does not seem to play a role in tasks with three or more choices.     

Two spatial maps for perceived visual space: Evidence from relative mislocalizations

When observers are asked to localize the peripheral position of a target with respect to the midposition of a spatially extended comparison stimulus, they tend to mislocalize the target as being more outer than the midposition of the comparison stimulus (cf. Müsseler, Van der Heijden, Mahmud, Deubel, & Ertsey, 1999). For explaining this finding, we examined a model that postulates that in the calculation of perceived positions two sources are involved, a sensory map and a motor map. The sensory map provides vision and the motor map contains information for saccadic eye movements. The model predicts that errors in location judgements will be observed when the motor map has to provide the information for the judgements. In four experiments we examined, and found evidence for, this prediction. Localization errors were found in all conditions in which the motor map had to be used but not in conditions in which the sensory map could be used.     

Aiming at a far target under different viewing conditions: visual control in basketball jump shooting

Most research on visual search in aiming at far targets assumes preprogrammed motor control implying that relevant visual information is detected prior to the final shooting or throwing movements. Eye movement data indirectly support this claim for stationary tasks. Using the basketball jump shot as experimental task we investigated whether in dynamic tasks in which the target can be seen until ball release, continuous, instead of preprogrammed, motor control is possible. We tested this with the temporal occlusion paradigm: 10 expert shooters took shots under four viewing conditions, namely, no vision, full vision, early vision (vision occluded during the final +/-350 ms before ball release), and late vision (vision occluded until these final +/-350 ms). Late-vision shooting appeared to be as good as shooting with full vision while early-vision performance was severely impaired. The results imply that the final shooting movements were controlled by continuous detection and use of visual information until ball release. The data further suggest that visual and movement control of aiming at a far target develop in close correspondence with the style of execution.     

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.     

Minimizing error in measurement of error: a proposed method for calculation of error in a two-dimensional motor task

Traditional one-dimensional error scores are still consistently used in research on motor learning to quantify two-dimensional error; however, the inherent differences in two-dimensional tasks render that application inappropriate and often misleading. Consequently, the purpose of this paper was to propose a novel method of presenting errors, which more precisely represents the accuracy, direction, and variability of error in two-dimensional settings. Although closely related to several alternatives for representing errors, the methodology used and the results obtained provide a more accurate procedure for pinpointing critical trends in what have been commonly referred to as AE (absolute error), VE (variable error), CE (constant error), and E (total variability). The proposed measurements of AVE (adjusted variable error), DE (directional error), TSE (total spread of error), and RE (radial error) provide composite error scores carrying a variety of information about performance on two-dimensional tasks. Formulas and examples are provided to facilitate computation and enhance understanding of the proposed scores.     

Representation of spatial structure in reaching to a visual target.

Reaches made without feedback to positions on an object's surface reflect the spatial form of the surface. In Experiment 1, the reaching pattern varied with the stimulus surface's spatial attributes, consistent with a point-by-point perceptual representation of the surface. In Experiment 2, systematic reaching errors were determined solely by target position regardless of surface structure, implying a highly consistent representation of location. In Experiment 3, illusory slant was imparted to a surface by an aniseikonic lens. Individual variations in directly judged slant were reflected in the reaching pattern, implying organization of local perceptual representation of location and global perception of spatial attributes of the stimulus into a coherent structure.     

A facilitative role for corticosterone in the acquisition of a spatial task under moderate stress

Emotionally charged experiences alter memory storage via the activation of hormonal systems. Previously, we have shown that compared with rats trained for a massed spatial learning task in the water maze in warm water (25°C), animals that were trained in cold water (19°C) performed better and showed higher levels of the stress hormone corticosterone. Here, we examined whether manipulating the levels of corticosterone can determine the strength of spatial information acquisition and retention. Rats were injected with metyrapone (25, 50, and 75 mg/kg, i.p.) or with corticosterone (10 and 25 mg/kg, i.p.) and trained in a massed spatial task in either cold (19°C) or warm (25°C) water. We found that whereas animals injected with vehicle performed well in the spatial task in cold water (moderate stress), rats injected with the intermediate metyrapone dose showed impairment in performance. Moreover, whereas animals injected with vehicle on average did not perform well in warm water (mild stress), rats injected with the lower corticosterone dose showed improvement in performance in warm water. These two mirror experiments of corticosterone blockade and enhancement strongly suggest that corticosterone is instrumental in the acquisition and retention of the spatial learning task.     

Intrinsic orientation and study viewpoint in recognizing spatial structure of a shape

Two experiments dissociated the roles of intrinsic orientation of a shape and participants’ study viewpoint in shape recognition. In Experiment 1, participants learned shapes with a rectangular background that was oriented differently from their viewpoint, and then recognized target shapes, which were created by splitting study shapes along different intrinsic axes, at different views. Results showed that recognition was quicker when the study shapes were split along the axis parallel to the orientation of the rectangular background than when they were split along the axis parallel to participants’ viewpoint. In Experiment 2, participants learned shapes without the rectangular background. The results showed that recognition was quicker when the study shape was split along the axis parallel to participants’ viewpoint. In both experiments, recognition was quicker at the study view than at a novel view. An intrinsic model of object representation and recognition was proposed to explain these findings.     

Olfactory perception as a compass for olfactory neural maps

The mammalian brain commonly uses structural proximity to reflect proximity in stimulus and perceptual space. Objects or object features that are near each other in physical structure or perception are also near each other in the brain. This generates sensory maps. The topography of olfactory connectivity implies a rudimentary map in the olfactory epithelium, a more intricate map in the olfactory bulb, but no ordered topography is evident in piriform cortex. Currently, we are largely unable to link the ordered topography in epithelium and bulb to meaningful olfactory axes within a strong predictive framework. We argue that the path to uncovering such a predictive framework depends on systematically characterizing olfactory perception, and we describe initial efforts in this direction.     

Estimation of true score and error variance for tests under various equivalence assumptions

Maximum-likelihood estimators of true score variance and error variance for mental tests are derived for six different models of equivalent measurements. Statistical properties of the estimators are examined. Main emphasis is placed upon essentially-equivalent measurements. A statistical criterion for this type of measurement is given. The solution of the comparatively simple maximum-likelihood equations is effected by means of a rapid Newton-Raphson procedure. Two different initial estimators are considered and their relative merits in terms of second moments evaluated. Four numerical examples are appended by way of illustration.Paper read at the Mathematical Psychology Meeting, August 28, 1968, at Stanford, Calfornia.This research was supported in part by the National Institute of Child Health and Human Development, Research Grant 1 P01 HD01762.     

Imposing structure on a Corsi-type task: evidence for hierarchical organisation based on spatial proximity in serial-spatial memory

Structure was imposed on a tapping task by requiring participants to reproduce sequences of responses to icons organised in spatial clusters. A first experiment featured sequences either segregated or not segregated by clusters. Accuracy was higher for sequences segregated by clusters. Moreover, inter-response times were longer at cluster boundaries than within cluster boundaries. To rule out possible confounding effects of movement length, this temporal pattern was replicated in a second experiment requiring a single response indicating the next sequential step, following the presentation of a portion of a previously practised sequence. These results suggest that sequence reproduction can be sustained by a hierarchical representation based on spatial proximity and provide a first indication of the role of spatial structure in serial-spatial memory.     

Interference between auditory and visual duration judgements suggests a common code for time

Auditory stimuli usually have longer subjective durations than visual ones for the same real duration, although performance on many timing tasks is similar in form with different modalities. One suggestion is that auditory and visual stimuli are initially timed by different mechanisms, but later converted into some common duration code which is amodal. The present study investigated this using a temporal generalization interference paradigm. In test blocks, people decided whether comparison durations were or were not a 400-ms standard on average. Test blocks alternated with interference blocks where durations were systematically shorter or longer than in test blocks, and interference was found, in the direction of the durations in the interference blocks, even when the interfering blocks used stimuli in a different modality from the test block. This provides what may be the first direct experimental evidence for a “common code” for durations initially presented in different modalities at some level of the human timing system.     

Intrinsic array structure is neither necessary nor sufficient for nonegocentric coding of spatial layouts

Mou and McNamara (2002) have recently theorized that nonegocentric reference frames (viz., intrinsic reference frames, based on the spatial structure of a configuration of objects) are used to organize spatial relationships in memory. The theory has not made claims about whether the intrinsic structure of a stimulus array is necessary or sufficient for such nonegocentric coding. We demonstrate that salient intrinsic axes in a layout of objects are neither necessary nor sufficient for people to use a nonegocentric reference frame in organizing spatial memory. In Experiment 1, participants were successfully instructed to adopt a nonegocentric preferred direction in memory for an array of objects with no salient intrinsic reference axes. In Experiment 2, with no instructions, participants adopted an egocentric preferred direction for an array with a salient intrinsic axis. These results suggest that physically salient array structure exerts a minimal influence in the coding of spatial memory through nonegocentric reference frames.     

Evidence for long-term spatial memory in a parid

Many animals use spatial memory. Although much work has examined the accuracy of spatial memory, few studies have explicitly focused on its longevity. The importance of long-term spatial memory for foraging has been demonstrated in several cases. However, the importance of such long-term memory for all animals is unclear. In this study, we present the first evidence that a parid species (the black-capped chickadee, Poecile atricapillus) can remember the location of a single food item for at least 6 months under an associative-learning spatial memory paradigm with multiple reinforcements. We did not detect a significant difference in memory longevity between two populations of chickadees shown previously to differ in short-term spatial memory and hippocampal morphology, an area of the brain involved in spatial memory. Our study showed that small birds such as parids can maintain spatial memories for long periods, a feat shown previously only in corvids. Moreover, we were able to demonstrate this longevity within the context of only 16 repeated trials. We speculate that this ability may potentially be useful in relocating caches if reinforced by repeated visits. Future studies are necessary to test whether our results were specifically due to multiple reinforcements of the food-containing location and whether parids may have similar memory longevity during food-caching experiences in the wild.     

Evaluating the temporal structure and correlates of daily self-esteem using a trait state error framework (TSE)

This study evaluates the temporal structure of daily self-esteem and the relative contribution of a range of theoretically motivated predictors of daily self-esteem. To assess self-esteem stability, a daily version of the Rosenberg Self-Esteem scale (RSE, Rosenberg, 1965) was administered to 278 undergraduates for five consecutive days. These short-term longitudinal data were analysed using the Trait State Error (TSE) modelling framework. The TSE decomposes multi-wave data into three components: (1) a stable trait component, (2) a state component, and (3) an error component. Significant predictors of the trait component of self-esteem observed across five days were: (1) emotional stability, and (2) the congruence between implicit and explicit self-esteem. Significant predictors of the state components of self-esteem were daily positive and negative events. We discuss the implications of these results for future research concerning self-esteem stability.     

Neural evidence supports a novel framework for spatial navigation

The spatial knowledge used for human navigation has traditionally been separated into three categories: landmark, route, and survey knowledge. While behavioral research has retained this framework, it has become increasingly clear from recent neuroimaging studies that such a classification system is not adequate for understanding the brain. This review proposes a new framework, with a taxonomy based on the cognitive processes and subprocesses involved in spatial navigation. The neural correlates of spatial memory can inform our understanding of the cognitive processes involved in human navigation, and conversely, the specific task demands of an experiment can inform the interpretation of neuroimaging results. This review examines the neural correlates of each cognitive process separately, to provide a closer inspection of each component of spatial navigation. While landmark, route, and survey knowledge are still important components of human navigation, the neural correlates are not neatly ascribed to these three categories. The present findings provide motivation for a more detailed examination of the cognitive processes engaged during wayfinding.