Independent effects of geometry and landmark in a spontaneous reorientation task: a study of two species of fish

While disoriented humans and animals use both landmarks and environmental geometry to guide their navigation, it is not clear what kinds of cognitive mechanisms underlie these behaviors. Because traditional tests of trained navigation behavior in environments containing both landmarks and geometric information may cloud our insight into the nature of these processes, the present study tested the spontaneous use of landmarks and environmental shape by two species of fish-Redtail Splitfins (Xenotoca eiseni) and Zebrafish (Danio rerio). The results suggest that while geometry is spontaneously used by both species and both sexes to compute relative position or direction, the spontaneous use of landmarks is limited to direct beaconing and complicated by attraction to features and variability across species and sex. These findings support the view that while multiple cues may ultimately guide behavior, the computation of orientation and relative positions is specified by geometric input and is independent from other navigation processes such as beaconing.     

Introduction

This Introduction to the special issue on ??Skepticism and Justification?? provides a background to the nine articles collected here and a detailed summary of each, which highlights their interconnections and relevance to the debate at the heart of the issue.     

Assessing vividness of mental imagery: The Plymouth Sensory Imagery Questionnaire

Mental imagery may occur in any sensory modality, although visual imagery has been most studied. A sensitive measure of the vividness of imagery across a range of modalities is needed: the shorter version of Bett's Questionnaire upon Mental Imagery (Sheehan, 1967 , J. Clin. Psychology, 23, 386) uses outdated items and has an unreliable factor structure. We report the development and initial validation of the Plymouth Sensory Imagery Questionnaire (Psi‐Q) comprising items for each of the following modalities: Vision, Sound, Smell, Taste, Touch, Bodily Sensation, and Emotional Feeling. An exploratory factor analysis on a 35‐item form indicated that these modalities formed separate factors, rather than a single imagery factor, and this was replicated by confirmatory factor analysis. The Psi‐Q was validated against the Spontaneous Use of Imagery Scale (Reisberg et al., 2003 , Appl. Cogn. Psychology, 17, 147) and Marks' ( 1995 , J. Mental Imagery, 19, 153) Vividness of Visual Imagery Questionnaire‐2 (VVIQ‐2). A short 21‐item form comprising the best three items from the seven factors correlated with the total score and subscales of the full form, and with the VVIQ‐2. Inspection of the data shows that while visual and sound imagery is most often rated as vivid, individuals who rate one modality as strong and the other as weak are not uncommon. Findings are interpreted within a working memory framework and point to the need for further research to identify the specific cognitive processes underlying the vividness of imagery across sensory modalities.     

Psychometric Aspects of the Depressive Experiences Questionnaire: Implications for Clinical Assessment and Research

The Depressive Experiences Questionnaire (DEQ) is a self-report measure that assesses self-criticism and dependency, 2 personality traits that confer vulnerability to depression (Blatt, 2004 Blatt, S. J. (2004). Experiences of depression: Theoretical, clinical, and research perspectives. Washington, DC: American Psychological Association.[Crossref] , [Google Scholar]). Over several decades, different, shortened versions of the DEQ have been constructed to offer an alternative to the complex scoring procedure of the original DEQ. This study explores the factor structure as well as the construct and convergent validity of the DEQ by comparing a clinical and nonclinical sample. We also compared the original DEQ with 5 shortened versions. There were 621 participants (358 university students and 263 outpatients). Fit indexes for models of the original DEQ did not meet minimum fit criteria. Moreover, the only versions with satisfactory fit were the Theoretical Depressive Experiences Questionnaire–21 (TDEQ–21) and the Theoretical Depressive Experiences Questionnaire–12 (TDEQ–12), which also showed acceptable construct and convergent validity. Finally, the diagnostic and clinical applicability of the DEQ is discussed.     

Structural Equation Models in a Redundancy Analysis Framework With Covariates

A recent method to specify and fit structural equation modeling in the Redundancy Analysis framework based on so-called Extended Redundancy Analysis (ERA) has been proposed in the literature. In this approach, the relationships between the observed exogenous variables and the observed endogenous variables are moderated by the presence of unobservable composites, estimated as linear combinations of exogenous variables. However, in the presence of direct effects linking exogenous and endogenous variables, or concomitant indicators, the composite scores are estimated by ignoring the presence of the specified direct effects.

To fit structural equation models, we propose a new specification and estimation method, called Generalized Redundancy Analysis (GRA), allowing us to specify and fit a variety of relationships among composites, endogenous variables, and external covariates. The proposed methodology extends the ERA method, using a more suitable specification and estimation algorithm, by allowing for covariates that affect endogenous indicators indirectly through the composites and/or directly. To illustrate the advantages of GRA over ERA we propose a simulation study of small samples. Moreover, we propose an application aimed at estimating the impact of formal human capital on the initial earnings of graduates of an Italian university, utilizing a structural model consistent with well-established economic theory.     

One, two, three, four, or is there something more? Numerical discrimination in day-old domestic chicks

Human adults master sophisticated, abstract numerical calculations that are mostly based on symbolic language and thus inimitably human. Humans may nonetheless share a subset of non-verbal numerical skills, available soon after birth and considered the evolutionary foundation of more complex numerical reasoning, with other animals. These skills are thought to be based on the two systems: the object file system which processes small values (<3) and the analogue magnitude system which processes large magnitudes (>4). Infants’ ability to discriminate 1 vs. 2, 1 vs. 3, 2 vs. 3, but not 1 vs. 4, seems to indicate that the two systems are independent, implying that the conception of a continuous number processing system is based on precursors that appear to be interrupted at or about the number four. The findings from the study being presented here indicating that chicks are able to make a series of discriminations regarding that borderline number (1 vs. 4, 1 vs. 5, 2 vs. 4) support the hypothesis that there is continuity in the number system which processes both small and large numerousness.     

Advanced Brief Strategic Therapy: An overview of interventions with eating disorders to exemplify how theory and practice work

This paper aims at introducing some of the central aspects of the evolution that brief strategic therapy has undergone at the Centro di Terapia Strategica of Arezzo, Italy, towards advanced therapeutic strategies which differ from the original Palo Alto model. (Fisch, Weakland, &; Segal, 1982; Watzlawick, 1978 Watzlawick, P. 1978. The language of change: Elements of therapeutic communication, New York: Basic Books.  [Google Scholar]; Watzlawick, Beavin, &; Jackson, 1967; Watzlawick, Weakland, &; Fisch, 1974). We will focus on how the concept of self-deception is central to the formation and the persistence of psychological disorders; and how the usage of non-ordinary logics and the understanding of the individual's perceptive-reactive system are of key importance in unravelling such disorders, allowing the therapist to guide the patient towards an efficacious and efficient solution. Rather than attempting to describe and enlist the theoretical corpus that underlies brief strategic therapy, we have chosen to exemplify some focal concepts that connect theory to practice, and vice versa, by presenting the outline of some therapeutic protocols devised for solving eating disorders which can be specifically tailored for each individual patient.     

Minds of their own

by Lesley J. Rogers, Allen & Unwin, 1997. $16.95 (x+212 pages) ISBN 1 86448 504 3.