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.     

MATHEMATICS,MODELS AND ZENO'S PARADOXES

A version of nonstandard analysis, Internal Set Theory, has been used to provide a resolution of Zeno's paradoxes of motion. This resolution is inadequate because the application of Internal Set Theory to the paradoxes requires a model of the world that is not in accordance with either experience or intuition. A model of standard mathematics in which the ordinary real numbers are defined in terms of rational intervals does provide a formalism for understanding the paradoxes. This model suggests that in discussing motion, only intervals, rather than instants, of time are meaningful. The approach presented here reconciles resolutions of the paradoxes based on considering a finite number of acts with those based on analysis of the full infinite set Zeno seems to require. The paper concludes with a brief discussion of the classical and quantum mechanics of performing an infinite number of acts in a finite time.     

Errorful and errorless learning: The impact of cue–target constraint in learning from errors

The benefits of testing on learning are well described, and attention has recently turned to what happens when errors are elicited during learning: Is testing nonetheless beneficial, or can errors hinder learning? Whilst recent findings have indicated that tests boost learning even if errors are made on every trial, other reports, emphasizing the benefits of errorless learning, have indicated that errors lead to poorer later memory performance. The possibility that this discrepancy is a function of the materials that must be learned—in particular, the relationship between the cues and targets—was addressed here. Cued recall after either a study-only errorless condition or an errorful learning condition was contrasted across cue–target associations, for which the extent to which the target was constrained by the cue was either high or low. Experiment 1 showed that whereas errorful learning led to greater recall for low-constraint stimuli, it led to a significant decrease in recall for high-constraint stimuli. This interaction is thought to reflect the extent to which retrieval is constrained by the cue–target association, as well as by the presence of preexisting semantic associations. The advantage of errorful retrieval for low-constraint stimuli was replicated in Experiment 2, and the interaction with stimulus type was replicated in Experiment 3, even when guesses were randomly designated as being either correct or incorrect. This pattern provides support for inferences derived from reports in which participants made errors on all learning trials, whilst highlighting the impact of material characteristics on the benefits and disadvantages that accrue from errorful learning in episodic memory.     

The Relationship Between a Mechanical Comprehension Test and Weapons-Training Tasks

The aim of the present study was to establish whether a relationship exists between recruit RT4 (mechanical comprehension) scores and a weapons-handling task from the Royal Marines (RM) recruit training course. This aim was achieved through the collection of subjective and objective performance data from RM recruits carrying out the tasks. Statistical analyses revealed that performance at weapons training was significantly related to RT4 score. On the basis of the findings, it was concluded that low mechanical comprehension scores appear to be related to difficulties with weapons-handling tasks. This is of interest given the known association between low mechanical comprehension scores and training wastage. It is recommended that the use of RT4 as a selection measure for RM training may reduce the number of recruits joining training who are at high risk of opting out at a later date.     

Floral guidance of learning a preference for symmetry by bumblebees

This study examines the mechanism underlying one way in which bumblebees are known to develop a preference for symmetric patterns: through prior non-differential reinforcement on simple patterns (black discs and white discs). In three experiments, bees were given a choice among symmetric and asymmetric black-and-white non-rewarding patterns presented at the ends of corridors in a radial maze. Experimental groups had prior rewarded non-discrimination training on white patterns and black patterns, while control groups had no pre-test experience outside the colony. No preference for symmetry was obtained for any of the control groups. Prior training with circular patterns highlighting a horizontal axis of symmetry led to a specific subsequent preference for horizontal over vertical symmetry, while training with a vertical axis abolished this effect. Circles highlighting both axes created a general avoidance of asymmetry in favour of symmetric patterns with vertical, horizontal or both axes of symmetry. Training with plain circles, but not with deformed circles, led to a preference for symmetry: there was no evidence that the preference emerged just by virtue of having attention drawn away from irrelevant pattern differences. Our results point to a preference for symmetry developing gradually through first learning to extract an axis of symmetry from simple patterns and subsequently recognizing that axis in new patterns. They highlight the importance of continued learning through non-differential reinforcement by skilled foragers. Floral guides can function not only to guide pollinators to the source of reward but also to highlight an axis of symmetry for use in subsequent floral encounters.     

Two Ways Of Looking At A Newtonian Supertask

A supertask is a process in which an infinite number of individuated actions are performed in a finite time. A Newtonian supertask is one that obeys Newton's laws of motion. Such supertasks can violate energy and momentum conservation and can exhibit indeterministic behavior. Perez Laraudogoitia, who proposed several Newtonian supertasks, uses a local, i.e., particle-by-particle, analysis to obtain these and other paradoxical properties of Newtonian supertasks. Alper and Bridger use a global analysis, embedding the system of particles in a Banach space, to determine the origin of the strange behavior. This paper provides a common framework for the discussion of both the local and global methods of analysis. Using this single framework, the areas of disagreement and agreement are made explicit. Further examples of supertasks are proposed to illuminate various aspects of the discussion.     

Walking as a ‘Radicalized’ Critical Psychological Method? A Review of Academic,Artistic and Activist Contributions to the Study of Social Environments

The study of social environments is a neglected site of research not only in psychology, but across academic disciplines ranging from human geography to cultural studies. This paper will review contributions to studying social environments through academic writings, situationism and psychogeographical groups. It will be argued that disorientating walking practices can be used as a means to reflect on experiences of places in order to begin to think how social environments could be radically changed. It is important to question the taken for granted ways that people make sense of urban environments. It is argued that psychogeographic practice can be used to extend qualitative epistemologies and methods to argue for a ‘turn to place’ in psychology and to open up new methods and approaches in critical psychology. Finally, the implications for radicalizing critical psychological research methods will be considered in relation to the current status of critical psychology, which suffers from an apathetic vision of radicalism and criticality.