Global and local spatial landmarks: their role during foraging by Columbian ground squirrels (Spermophilus columbianus)

Locating food and refuge is essential for an animal's survival. However, little is known how mammals navigate under natural conditions and cope with given environmental constraints. In a series of six experiments, I investigated landmark-based navigation in free-ranging Columbian ground squirrels (Spermophilus columbianus). Squirrels were trained individually to find a baited platform within an array of nine identical platforms and artificial landmarks set up on their territories. After animals learned the location of the food platform in the array, the position of the latter with respect to local artificial, local natural, and global landmarks was manipulated, and the animal's ability to find the food platform was tested. When only positions of local artificial landmarks were changed, squirrels located food with high accuracy. When the location of the array relative to global landmarks was altered, food-finding accuracy decreased but remained significant. In the absence of known global landmarks, the presence of a familiar route and natural local landmarks resulted in significant but not highly accurate performance. Squirrels likely relied on multiple types of cues when orienting towards a food platform. Local landmarks were used only as a secondary mechanism of navigation, and were not attended to when a familiar route and known global landmarks were present. This study provided insights into landmark use by a wild mammal in a natural situation, and it demonstrated that an array of platforms can be employed to investigate landmark-based navigation under such conditions.     

Tomberlin,Frege, and Guise theory: A note on the methodology of dia-philosophical comparisons

Conclusion Tomberlin's comparative claims about the superiority of the De Dicto-De Re Account over Guise Theory concerning referential opacity are abortively premature. Nevertheless, he may be right. Yet the order of the day is to develop the De Re-De Dicto Account to the hilt. Not until this is done can any useful dia-philosophical comparison of the two theories yield any fruit. My deep desire is, of course, for the sheer enjoyment of experiencing the world from the perspective of each of the two views, indeed, from the perspective of other views — e.g., Frege's Sense/Referent Theory — that can be developed to the same data-encompassing stage as Guise Theory.     

An integrated theory of prospective time interval estimation: the role of cognition, attention, and learning

A theory of prospective time perception is introduced and incorporated as a module in an integrated theory of cognition, thereby extending existing theories and allowing predictions about attention and learning. First, a time perception module is established by fitting existing datasets (interval estimation and bisection and impact of secondary tasks on attention). The authors subsequently used the module as a part of the adaptive control of thought--rational (ACT-R) architecture to model a new experiment that combines attention, learning, dual tasking, and time perception. Finally, the model predicts time estimation, learning, and attention in a new experiment. The model predictions and fits demonstrate that the proposed integrated theory of prospective time interval estimation explains detailed effects of attention and learning during time interval estimation.     

Social spatial cognition in rat tetrads: how they select their partners and their gathering places

Spatial organization is an extensively studied field, in which most of the research has been on how the physical environment is perceived and conceived. There is a consensus that physical attributes such as environment geometry and landmarks are key factors in shaping spatial cognition. Nevertheless, the numerous studies of spatial behavior have usually been carried out on individuals, thereby overlooking the possible impact of the social environment. In the present study, rats were exposed to an unfamiliar open-field, first alone and then in tetrads of unfamiliar individuals, in order to monitor and analyze when and how their individual spatial behavior converged to a group spatial behavior. We found that the unfamiliar rats spent most of their time in companionship, first with preferred partners and ultimately as a quartet. Specifically, group formation was dynamic and gradual, with the rats first forming duos, then trios, and ultimately a quartet. Trios and quartets mostly huddled in the same specific corner that became a shared home base, from which they took solo or duo roundtrips to the arena. The present study unveils how, by means of gradual interactions among self, place, and conspecifics, four unfamiliar rats organized together their social spatial behavior.     

Social cognition, artefacts, and stigmergy: A comparative analysis of theoretical frameworks for the understanding of artefact-mediated collaborative activity

Collective behaviour is often characterised by the so-called ‘coordination paradox’: looking at individual ants, for example, they do not seem to cooperate or communicate explicitly, but nevertheless at the social level cooperative behaviour, such as nest building, emerges, apparently without any central coordination. In the case of social insects such emergent coordination has been explained by the theory of stigmergy, which describes how individuals can effect the behaviour of others (and their own) through artefacts, i.e., the product of their own activity (e.g., building material in the ants’ case). Artefacts clearly also play a strong role in human collective behaviour, which has been emphasised, for example, by proponents of activity theory and distributed cognition. However, the relation between theories of situated/social cognition and theories of social insect behaviour has so far received relatively little attention in the cognitive science literature. This paper aims to take a step in this direction by comparing three theoretical frameworks for the study of cognition in the context of agent–environment interaction (activity theory, situated action, and distributed cognition) to each other and to the theory of stigmergy as a possible minimal common ground. The comparison focuses on what each of the four theories has to say about the role/nature of (a) the agents involved in collective behaviour, (b) their environment, (c) the collective activities addressed, and (d) the role that artefacts play in the interaction between agents and their environments, and in particular in the coordination of cooperation.     

Eyewitness decisions in simultaneous and sequential lineups: A dual-process signal detection theory analysis

Many eyewitness researchers have argued for the application of a sequential alternative to the traditional simultaneous lineup, given its role in decreasing false identifications of innocent suspects (sequential superiority effect). However, Ebbesen and Flowe (2002) have recently noted that sequential lineups may merely bring about a shift in response criterion, having no effect on discrimination accuracy. We explored this claim, using a method that allows signal detection theory measures to be collected from eyewitnesses. In three experiments, lineup type was factorially combined with conditions expected to influence response criterion and/or discrimination accuracy. Results were consistent with signal detection theory predictions, including that of a conservative criterion shift with the sequential presentation of lineups. In a fourth experiment, we explored the phenomenological basis for the criterion shift, using the remember-know-guess procedure. In accord with previous research, the criterion shift in sequential lineups was associated with a reduction in familiarity-based responding. It is proposed that the relative similarity between lineup members may create a context in which fluency-based processing is facilitated to a greater extent when lineup members are presented simultaneously.     

Goodness of regularity in dot patterns: global symmetry, local symmetry, and their interactions

Goodness is a classic Gestalt notion defined as salience or perceptual strength of a given pattern. All operational models of goodness have assigned a central role to mirror symmetry but not much attention has been paid to the distinction between global and local mirror symmetry, and their possible interactions. We designed eight different types of dot patterns (all consisting of 80 dots), combining different numbers (0, 1, and 2) and relative orientations (parallel or orthogonal to each other) of local and global axes of symmetry (affecting 50% or 100% of the dots, respectively) at different absolute orientations (vertical and horizontal). Each of 640 trials consisted of a short presentation of a new dot pattern, which subjects had to classify as regular or random. We hypothesised that the overall goodness of patterns is not the simple sum of the amount of regularity present in them but depends on the cooperation and competition between symmetries. The results confirmed our hypothesis, showing that performance in this regularity-detection task did not increase in a linear way when some symmetries were added to other symmetries.     

Interpersonal relatedness,self-definition,and their motivational orientation during adolescence: a theoretical and empirical integration

The authors examined a theoretical model linking interpersonal relatedness and self-definition (S.J. Blatt, 1974), autonomous and controlled regulation (E. L. Deci & R. M. Ryan, 1985), and negative and positive life events in adolescence (N = 860). They hypothesized that motivational orientation would mediate the effects of interpersonal relatedness and self-definition on life events. Self-criticism, a maladaptive form of self-definition, predicted less positive events, whereas efficacy, an adaptive form of self-definition, predicted more positive events. These effects were fully mediated by the absence and presence, respectively, of autonomous motivation. Controlled motivation, predicted by self-criticism and maladaptive neediness, did not predict negative events. Results illustrate the centrality of protective, pleasure-related processes in adaptive adolescent development.     

The integration of object levels and their content: a theory of global/local processing and related hemispheric differences

This article presents and tests the authors' integration hypothesis of global/local processing, which proposes that at early stages of processing, the identities of global and local units of a hierarchical stimulus are represented separately from information about their respective levels and that, therefore, identity and level information have to be integrated at later stages. It further states that the cerebral hemispheres differ in their capacities for these binding processes. Three experiments are reported in which the integration hypothesis was tested. Participants had to identify a letter at a prespecified level with the viewing duration restricted by a mask. False reporting of the letter at the nontarget level was predicted to occur more often when the integration of identity and level could fail. This was the case. Moreover, visual-field effects occurred, as expected. Finally, a multinomial model was constructed and fitted to the data.     

Channels and stages in human information processing: A limited analysis of theory and methodology

This article reviews the status of the theoretical construct of capacity. Four basic questions are discussed: (1) What is capacity? (2) How is capacity measured? (3) Is capacity limited? (4) If so, where is it limited? It is claimed that empirical answers to these questions have been unsatisfactory due to theoretical and methodological issues that need be resolved. Data are presented to illustrate such difficulties. The construct of capacity has become more and more vacuous and caution is required whenever capacity is invoked to explain behavior. These problems can be overcome by careful research and well-defined models. Capacity can be a soup stone, a millstone, or a touchstone, depending upon how it is used.     

Type 2 tasks in the theory of signal detectability: Discrimination between correct and incorrect decisions

It has been known for over 40 years that there are two fundamentally different kinds of detection tasks in the theory of signal detectability. The Type 1 task is to distinguish between events defined independently of the observer; the Type 2 task is to distinguish between one’s own correct and incorrect decisions about those Type 1 events. For the Type 1 task, the behavior of the detector can be summarized by the traditional receiver operating characteristic (ROC) curve. This curve can be compared with a theoretical ROC curve, which can be generated from overlapping probability functions conditional on the Type 1 events on an appropriate decision axis. We show how to derive the probability functions underlying Type 2 decisions from those for the Type 1 task. ROC curves and the usual measures of performance are readily obtained from those Type 2 functions, and some relationships among various Type 1 and Type 2 performance measures are presented. We discuss the relationshiPbetween Type 1 and Type 2 confidence ratings and caution against the practice of presenting transformed Type 2 ratings as empirical Type 1 ratings.     

Dynamic integration: affect, cognition, and the self in adulthood

Positive self- and emotional development is often measured by optimization of happiness, but a second aspect of positive development—the ability to tolerate tension and negativity in the interest of maintaining objective representations—needs to be integrated with this hedonic emphasis. The integration of these two aspects, optimization and differentiation, reflects a dynamic balance. Such integration is possible when emotional activation or arousal is moderate, but is impaired at very high levels of activation. From youth to middle adulthood, the capacity for integration increases, but later in life, limitations or poor regulation strategies foster compensatory processes that compromise integration.     

On the statistical and theoretical basis of signal detection theory and extensions: Unequal variance, random coefficient, and mixture models

Basic results for conditional means and variances, as well as distributional results, are used to clarify the similarities and differences between various extensions of signal detection theory (SDT). It is shown that a previously presented motivation for the unequal variance SDT model (varying strength) actually leads to a related, yet distinct, model. The distinction has implications for other extensions of SDT, such as models with criteria that vary over trials. It is shown that a mixture extension of SDT is also consistent with unequal variances, but provides a different interpretation of the results; mixture SDT also offers a way to unify results found across several types of studies.     

The influence of grammatical, local, and organizational redundancy on implicit learning: an analysis using information theory

People behave as if they know the structure of their environment. Because people rarely study that structure explicitly, several theorists have postulated an implicit learning system that abstracts that structure automatically. An alternative view is that people respond to local structure that derives from global structure. Measures are developed that quantify structure in a set of stimuli, in individual stimuli, and in encoded stimuli. The authors apply the measures to examine serial recall for sequences of colors generated using a stationary Markov grammar. They demonstrate that the 3 kinds of redundancy are confounded and show that the memorial advantage for grammatical stimuli reflects participants' use of local expressions of grammatical structure to aid learning.     

Testing assumptions of deliberate practice theory relevance, effort, and inherent enjoyment of practice with a novel task: study II

This study examined three assumptions of the theory of deliberate practice: that deliberate practice is perceived as relevant for improving performance and that it requires effort, but that it is not perceived as being inherently enjoyable. Of particular interest was how these perceptions change as practice difficulty changes. 30 college undergraduates practiced two different maze memorization and replication tasks and rated the practice relevance for improving performance on the task, the practice effort, and the inherent enjoyment of practice. The findings for each of the assumptions were consistent with those suggested by the theory and also showed that these perceptions are subject to the current performance on an activity and the difficulty of the practice.