Object-goal positioning influences spatial representation in rats

Three tests investigated how the geometric relation between object/landmarks and goals influenced spatial choice behavior in rats. Two groups searched for hidden food in an object-filled circular arena containing 24 small poles. For the “Proximal” group, four distinct objects in a square configuration were placed close to four baited poles. For the “Distal” group, the identical configuration of objects was rotated 45° relative to the poles containing the hidden food. The Proximal group learned to locate the baited poles more quickly than the Distal group. Tests with removed and rearranged landmarks indicated that the two groups learned to use the objects differently. The results suggested that close proximity of objects to goals encouraged their use as beacons, while greater distance of objects from goals resulted in the global encoding of the geometric properties of the arena and the use of the objects as landmarks. Received: 22 June 1998 / Accepted after revision: 23 January 1999     

Gaining perspective on spatial perspective taking

Spatial perspective taking is a term that encompasses a class of phenomena that assess the extent to which a perceiver can access spatial information relative to a viewpoint different from the perceiver’s egocentric viewpoint (e.g. something on my right is on the left of someone facing me). We investigated whether spatial perspective taking that involves judging how objects are oriented around an agent is susceptible to alterations in social motivations. In all experiments, participants saw a picture of two objects and asked to judge the relationship between the objects when there was, or was not, an agent between them. Results from Experiment 1 showed that participants spontaneously described the objects from the agent’s perspective when he was present. Experiments 2 and 3 explored whether this effect was altered by prior participant exposure to manipulations of social inclusion or social exclusion. Results from these two studies demonstrated that socially included participants and socially excluded participants did not differ in their tendencies to adopt the spatial perspective of another. These results are discussed in the context of the results of other studies showing that perspective taking can be influenced by social motivations.     

Forming a stable spatial representation

The visual system sometimes fails, partially or completely, to encode and/or retrieve spatial relations among parts of an object. For example, targets can easily be confused with their mirror images, especially when they must be retained in memory. In the current experiments we ask whether our representations of spatial relations can be amended by information from different cognitive domains. Specifically, we ask whether failure to form a stable representation of spatial relations among parts can be overcome by the use of linguistic information. Four year-olds saw squares split by color and matched them after delay. In Experiment 1, children saw the target and were told either “Look, this is a blicket” (Label Condition) or “Look!” (NoLabel Condition). Then, three choices appeared: the target (e.g. vertical split with red left, green right), its mirror image, and another square that had a different internal split (e.g. horizontal). Overall, children performed better than chance. However, their errors were almost exclusively mirror image confusions, suggesting that children failed to bind color and location (e.g. red left, green right). There was no difference between the NoLabel and Label conditions, suggesting the whole-object novel label did not help children form a stable representation of the spatial relation among the parts. Experiment 2 tested whether color–location binding can be improved by providing language that might bind these features. Children were shown a target and were told, e.g. “The red is on the left.” Performance was reliably better than in Experiment 1, suggesting language did help children bind color and location. Experiments 3 and 4 explored whether the same performance improvement could be accomplished by increasing non-linguistic attention to the target (i.e. flashing the red part, Experiment 3) or by using neutral relational language (e.g. “The red is touching the green”). Neither experiment showed enhanced performance, suggesting that language can augment visual–spatial representations only if it conveys very specific information (e.g. direction). Generally, the results suggest that specific linguistic information can help form a stable representation of spatial relationship and that this effect is not attributable to general attentional effects.     

Usefulness and limitation of spatial representation

What discussed herein is not an “open problem” in the sense of mathematics. It is a problem that psychologists should keep in mind when presenting a formal model. A model will be useful for phenomena on which the model has been formulated. However, the model may contain a number of remaining properties that not necessarily represent related psychological phenomena adequately. The situation is analogous to that the particle model of light does not represent diffraction whereas the wave model of light is not adequate for the Compton effect. When presenting a model, mathematical psychologists should be especially keen about this point. The problem is discussed with a concrete example.     

Lexical-semantic body knowledge in 5- to 11-year-old children: How spatial body representation influences body semantics

This study addresses the relation between lexico-semantic body knowledge (i.e., body semantics) and spatial body representation (i.e., structural body representation) by analyzing naming performances as a function of body structural topography. One hundred and forty-one children ranging from 5 years 2 months to 10 years 5 months old were asked to provide a lexical label for isolated body part pictures. We compared the children’s naming performances according to the location of the body parts (body parts vs. head features and also upper vs. lower limbs) or to their involvement in motor skills (distal segments, joints, and broader body parts). The results showed that the children’s naming performance was better for facial body parts than for other body parts. Furthermore, it was found that the naming of body parts was better for body parts related to action. These findings suggest that the development of a spatial body representation shapes the elaboration of semantic body representation processing. Moreover, this influence was not limited to younger children. In our discussion of these results, we focus on the important role of action in the development of body representations and semantic organization.     

Transthyretin influences spatial reference memory

Transthyretin (TTR) is a plasma and cerebrospinal fluid carrier for thyroxine and retinol, described also to sequester the amyloid beta peptide. TTR levels have been described as decreased in the cerebrospinal fluid of patients with Alzheimer's disease. In order to investigate the role of TTR in learning and memory, we studied young adult and old TTR-null 129/Sv mice for cognitive performance. In the absence of TTR, 5-month-old mice display spatial reference memory impairment when compared to age-matched wild-type mice. Interestingly, while aging in wild-type mice is associated with a worsening reference memory performance, TTR-null mice show no further impairment with increasing age. As a result, no significant differences were found in this spatial reference task in old mice. Our data show that the absence of TTR seems to accelerate the poorer cognitive performance normally associated with aging.     

Embodied representation of the body contains veridical spatial information

In two experiments, the extent to which mental body representations contain spatial information was examined. Participants were asked to compare distances between various body parts. Similar to what happens when people compare distances on a real visual stimulus, they were faster as the distance differences between body parts became larger (Experiment 1), and this effect could not (only) be explained by the crossing of major bodily categories (umbilicus to knee vs. knee to ankle; Experiment 2). In addition, participants also performed simple animate/inanimate verification on a set of nouns. The nouns describing animate items were names of body parts. A spatial priming effect was found: Verification was faster for body part items preceded by body parts in close spatial proximity. This suggests automatic activation of spatial body information. Taken together, results from the distance comparison task and the property verification task showed that mental body representations contain both categorical and more metric spatial information. These findings are further discussed in terms of recent embodied cognition theories.     

Embodied representation of the body contains veridical spatial information

In two experiments, the extent to which mental body representations contain spatial information was examined. Participants were asked to compare distances between various body parts. Similar to what happens when people compare distances on a real visual stimulus, they were faster as the distance differences between body parts became larger (Experiment 1), and this effect could not (only) be explained by the crossing of major bodily categories (umbilicus to knee vs. knee to ankle; Experiment 2). In addition, participants also performed simple animate/inanimate verification on a set of nouns. The nouns describing animate items were names of body parts. A spatial priming effect was found: Verification was faster for body part items preceded by body parts in close spatial proximity. This suggests automatic activation of spatial body information. Taken together, results from the distance comparison task and the property verification task showed that mental body representations contain both categorical and more metric spatial information. These findings are further discussed in terms of recent embodied cognition theories.     

Genetic influences on the development of spatial skills during early adolescence

The course of development of skill at face encoding is disrupted in early adolescence. Evidence is provided that the timing of this disruption is under genetic control. Regardless of their age, girls in the midst of pubertal change encode faces less efficiently than prepubescent or postpubescent controls. This maturational influence on face encoding is contrasted with a different effect of pubertal development on another visuo-spatial ability, performance on the Embedded Figures Test (EFT). Regardless of their pubertal status at time of testing, girls who mature earlier are disadvantaged on EFT compared to those who mature later. The results for EFT replicate earlier findings on the relation between individual differences in the age at which adolescence begins and certain spatial skills. Several possible explanations for each of these effects—that of maturational status on face encoding and that of maturation rate on EFT—are discussed. Consideration of the relation between physical and mental growth is advocated as a source of constraints on explanations of cognitive development.     

The representation of spatial information in memory

Following memorisation of the spatial arrangement of an array of circles, subjects were asked to recall the circles in a type of free-recall task designed to determine the structure of the memorised information. Their performance showed that the circles tended to be recalled in an order that corresponded with a top-to-bottom ordering of circles on the array. In a second experiment the input order of the circles was varied by presenting them successively. The results indicated that input order influenced recall order. The implications for hypotheses about the structure and manipulation of stored spatial information were discussed.     

The spatial representation of power in children

Previous evidence demonstrates that power is mentally represented as vertical space by adults. However, little is known about how power is mentally represented in children. The current research examines such representations. The influence of vertical information (motor cues) was tested in both an explicit power evaluation task (judge whether labels refer to powerless or powerful groups) and an incidental task (judge whether labels refer to people or animals). The results showed that when power was explicitly evaluated, vertical motor responses interfered with responding in children and adults, i.e., they responded to words representing powerful groups faster with the up than the down cursor key (and vice versa for powerless groups). However, this interference effect disappeared in the incidental task in children. The findings suggest that children have developed a spatial representation of power before they have been taught power–space associations formally, but that they do not judge power spontaneously.     

Sensori-motor spatial training of number magnitude representation

An adequately developed spatial representation of number magnitude is associated with children's general arithmetic achievement. Therefore, a new spatial-numerical training program for kindergarten children was developed in which presentation and response were associated with a congruent spatial numerical representation. In particular, children responded by a full-body spatial movement on a digital dance mat in a magnitude comparison task. This spatial-numerical training was more effective than a non-spatial control training in enhancing children's performance on a number line estimation task and a subtest of a standardized mathematical achievement battery (TEDI-MATH). A mediation analysis suggested that these improvements were driven by an improvement of children's mental number line representation and not only by unspecific factors such as attention or motivation. These results suggest a benefit of spatial numerical associations. Rather than being a merely associated covariate, they work as an independently manipulated variable which is functional for numerical development.     

Past experience influences object representation in working memory

The nature of object representation in working memory is vital to establishing the capacity of working memory, which in turn shapes the limits of visual cognition and awareness. Although current theories discuss whether representations in working memory are feature-based or object-based, no theory has considered the role of past experience. However, work with humans and non-human primates suggests that once participants learn which features are important for category membership, these diagnostic features become more salient than non-diagnostic features in long-term memory and object recognition. Critically, the brain areas involved in this diagnosticity effect are also recruited during working memory tasks. We report two experiments testing whether a diagnosticity effect exists in working memory; and whether it is present when visual information is encoded into working memory, or if it is the result of maintenance within working memory. Results showed a diagnosticity effect which was present at encoding. Maintenance did not influence the nature of object representation in working memory. These findings show that the meaning we glean from our past experience has a profound influence on the nature of object representation in working memory.