Potentiation and overshadowing of shape by wall color in a kite-shaped maze using rats in a foraging task

The interaction between redundant geometric and featural cues in open field search tasks has been examined widely with results that are not always consistent. Cheng (1986) found evidence that when searching for food in rectangular environments, rats used the geometrical characteristics of the environment rather than local featural cues, suggesting that geometry had overshadowed featural cues. More recently, Graham et al. (2006) and Pearce et al. (2006) found that wall color facilitated (potentiated) learning about the shape of the environment by rats in a kite-shaped water maze. The first experiment in the present research replicated the paradigm used by Graham et al. and Pearce et al. using rats in a foraging situation, but with conditions similar, and found the same results, potentiation of shape by color. Experiments 2 and 3 revealed overshadowing instead of potentiation of shape by wall color under the same conditions except that the wall colors of the test environment were not the same as those used during training. The results are consistent with an analysis of the role of associations formed between wall color and geometry in such situations (Rhodes et al., 2009) and extend our understanding of how featural and spatial cues interact.     

Manipulations of start and food locations affect navigation on a foraging task

Rats were able to search multiple food cups in a foraging task and successfully return to a fixed, but not a variable, start location. Reducing the number of food cups to be searched resulted in an improvement in performance in the variable start condition. Performance was better when only one or two food cups had to be visited but was still impaired if the food was not found in the first cup searched. Variable start locations impaired performance when only one food cup had to be searched, if that cup was moved over the table. These findings suggest that there is an interaction between memory processes and the navigational processes that allows an animal to return to its start location after a foraging trip. It appears that a fixed location for the food or the start point of a foraging trip is a necessary precondition for accurate performance.     

Sex differences in the relation between math performance, spatial skills, and attitudes

Sex differences have been previously found in cognitive and affective predictors of math achievement, including spatial skills and math attitudes. It is important to determine whether there are sex differences not only in the predictors themselves, but also in the nature of their relation to math achievement. The present paper examined spatial skills and math attitudes as predictors of curriculum-based measures of math performance in middle-school students, specifically comparing the patterns of these predictive relations for boys and girls. The results of the current study showed that, despite similar levels of math performance for boys and girls, the significance of particular predictors varied as a function of sex. Specifically, spatial skills predicted math performance in boys, but not in girls. We suggest that sex differences in spatial reasoning in conjunction with the differential involvement of spatial reasoning in math problem solving may lead to later sex differences in math outcomes.     

Assessment of cognitive function across pregnancy using CANTAB: A longitudinal study

Significant changes in endogenous plasma hormone levels are required to sustain pregnancy which provides a unique opportunity to study their effect on cognitive function.     

Perspective-taking in dialogue as self-organization under social constraints

We present a dynamical systems account of how simple social information influences perspective-taking. Our account is motivated by the notion that perspective-taking may obey common dynamic principles with perceptuomotor coupling. We turn to the prominent HKB dynamical model of motor coordination, drawing from basic principles of self-organization to describe how conversational perspective-taking unfolds in a low-dimensional attractor landscape. We begin by simulating experimental data taken from a simple instruction-following task, in which participants have different expectations about their interaction partner. By treating belief states as different values of a control parameter, we show that data generated by a basic dynamical process fits overall egocentric and other-centric response distributions, the time required for participants to enact a response on a trial-by-trial basis, and the action dynamics exhibited in individual trials. We end by discussing the theoretical significance of dynamics in dialog, arguing that high-level coordination such as perspective-taking may obey similar dynamics as perceptuomotor coordination, pointing to common principles of adaptivity and flexibility during dialog.     

What Does Children's Spatial Language Reveal About Spatial Concepts? Evidence From the Use of Containment Expressions

Children's overextensions of spatial language are often taken to reveal spatial biases. However, it is unclear whether extension patterns should be attributed to children's overly general spatial concepts or to a narrower notion of conceptual similarity allowing metaphor‐like extensions. We describe a previously unnoticed extension of spatial expressions and use a novel method to determine its origins. English‐ and Greek‐speaking 4‐ and 5‐year‐olds used containment expressions (e.g., English into, Greek mesa) for events where an object moved into another object but extended such expressions to events where the object moved behind or under another object. The pattern emerged in adult speakers of both languages and also in speakers of 10 additional languages. We conclude that learners do not have an overly general concept of Containment. Nevertheless, children (and adults) perceive similarities across Containment and other types of spatial scenes, even when these similarities are obscured by the conventional forms of the language.     

Mr. Richie and the tourists

This paper tracks the affective intensity and emergent potential that is part of making contact with Richie, a local Creole villager from Walliceville, Belize. Tourists and expats are drawn to Richie and seduced by him, his colorful language and personality. My attention in this paper is directed to the spatialized force fields of contact between tourists, expats and local creole villagers, like Richie, by attending to the way these contact fields conjure forces of wild vitality that both agitate and fascinate social life in Belize. I focus on how Richie acts as a powerful representation of tropical “no worries” Creole life. But more than that, he carries a sensory charge, seducing tourists and expats into crazy moments of abandon, a “sensing beyond security” (Manning, 2007: 134–161), that exceeds the work of Caribbean tourist representations to become moments when forces are activated as impacts that provoke things, for better or for worse. I argue that such moments spawn worlds that build forms of attachment and become the vital fields of sensations that incite life as emergent forces coming into play in this postcolonial state of emergency taking shape as neo-liberal exception, on the edge of global empire, in Belize.     

Well‐Hidden Regularities: Abstract Uses of in and on Retain an Aspect of Their Spatial Meaning

Prepositions name spatial relationships (e.g., book on a table). But they are also used to convey abstract, non‐spatial relationships (e.g., Adrian is on a roll)—raising the question of how the abstract uses relate to the concrete spatial uses. Despite considerable success in delineating these relationships, no general account exists for the two most frequently extended prepositions: in and on. We test the proposal that what is preserved in abstract uses of these prepositions is the relative degree of control between the located object (the figure) and the reference object (the ground). Across four experiments, we find a continuum of greater figure control for on (e.g., Jordan is on a roll) and greater ground control for in (e.g., Casey is in a depression). These findings bear on accounts of semantic structure and language change, as well as on second language instruction.     

Evidence of a role for multiple memory systems in behavioral extinction

The acquisition of learned behavior involves multiple memory systems, and hippocampal system damage impairs cognitive learning while leaving stimulus-response habit learning intact. In view of evidence that extinction also involves new learning, the present experiments examined whether multiple memory systems theory may be applicable to the neural bases of extinction. Adult Long-Evans rats were trained to run in a straight-alley maze for food reward. Twenty-four hours later, rats matched for runway latencies during acquisition received extinction training. In a response extinction condition conducive to habit learning, rats performed a runway approach response to an empty food cup. In a latent extinction condition conducive to cognitive learning, rats were placed at an empty food cup without performing a runway approach response. Prior to daily extinction training, neural activity of the dorsal hippocampus was reversibly inactivated via infusion of bupivacaine (0.75%, 0.5 microl/side). Control rats receiving saline infusions displayed extinction behavior in both the response and latent training conditions. In contrast, rats receiving bupivacaine extinguished normally in the response condition, but did not display latent extinction. The findings (1) confirm that learning underlying extinction of the same overt behavior can occur with or without explicit performance of the previously acquired response, (2) indicate that extinction learning produced by response and latent training procedures can be neuroanatomically dissociated, and (3) suggest that similarly to initial task acquisition, the hippocampus may critically mediate extinction in situations requiring the use of cognitive learning, such as when performance of a previously acquired response habit is prevented.     

Spatial encoding by bumblebees (Bombus impatiens) of a reward within an artificial flower array

We presented bumblebees a spatial memory task similar to that used with other species (e.g., cats, dogs, and pigeons). In some conditions we allowed for presence of scent marks in addition to placing local and global spatial cues in conflict. Bumblebees (Bombus impatiens) were presented an array of artificial flowers within a flight cage, one flower offering reward (S+), while the others were empty (S−). Bees were tested with empty flowers. In Experiment 1, flowers were either moved at the time of testing or not. Bees returned to the flower in the same absolute position of the S+ (the flower-array-independent (FAI) position), even if it was in the wrong position relative to the S− and even when new flower covers prevented the use of possible scent marks. New flower covers (i.e., without possible scent marks) had the effect of lowering the frequency of probing behavior. In Experiment 2, the colony was moved between training and testing. Again, bees chose the flower in the FAI position of the S+, and not the flower that would be chosen using strictly memory for a flight vector. Together, these experiments show that to locate the S+ bees did not rely on scent marks nor the positions of the S−, though the S− were prominent objects close to the goal. Also, bees selected environmental features to remember the position of the S+ instead of relying upon a purely egocentric point of view. Similarities with honeybees and vertebrates are discussed, as well as possible encoding mechanisms.