Frontal-Lobe Involvement in Spatial Memory: Evidence from PET,fMRI, and Lesion Studies

Many studies have identified the prefrontal cortex as the brain area that is critical for spatial memory, both in humans and in other primates. Other studies, however, have failed to establish this relation. Therefore, the aim of this paper was to review the literature regarding the role of the human prefrontal lobe in spatial memory. This was done by examining the evidence obtained from neuropsychological patients and from studies using brain-imaging techniques (PET and fMRI). Evidence supporting the notion that the prefrontal cortex is extensively involved in spatial working memory was found. The majority of these studies, however, suggests that frontal-lobe involvement is not related to the type of material that is being processed (e.g., spatial vs. nonspatial), but to process-specific functions, such as encoding and retrieval. Theoretically, these functions could be linked to the central executive within Baddeley's working-memory model, or to recent theories that emphasize the various processes that play a role in working memory. Also, methodological issues were discussed. Further research is needed to enhance our understanding of the precise interaction of domain-specific and general processes.     

The role of surface attraction in perceiving volumetric shape

Rock [1973, Orientation and Form (New York: Academic Press)] showed that form perception generally depends more on the orientation of a stimulus in world coordinates than on its orientation in retinal coordinates. He suggested that the assignment of an object's 'environmental orientation' depends on gravity, visual frame of reference, and the observer's ability to impose orientation along one axis or another. This paper shows that the assignment of environmental orientation and perceived 3-D form also depends on the relationship between an object and retinally adjacent surfaces in the scene to which it might be attached. Whereas previous examples have demonstrated effects of orientation on 2-D form, we show that orientation can affect the perceived intrinsic 3-D shape of a volume.     

The generic viewpoint assumption and Bayesian inference

The task of human vision is to reliably infer useful information about the external environment from images formed on the retinae. In general, the inference of scene properties from retinal images is not deductive; it requires knowledge about the external environment. Further, it has been suggested that the environment must be regular in some way in order for any scene properties to be reliably inferred. In particular, Knill and Kersten [1991, in Pattern Recognition by Man and Machine Ed. R J Watt (London: Macmillan)] and Jepson et al [1996, in Bayesian Approaches to Perception Eds D Knill, W Richards (Cambridge: Cambridge University Press)] claim that, given an 'unbiased' prior probability distribution for the scenes being observed, the generic viewpoint assumption is not probabilistically valid. However, this claim depends upon the use of representation spaces that may not be appropriate for the problems they consider. In fact, it is problematic to define a rigorous criterion for a probability distribution to be considered 'random' or 'regularity-free' in many natural domains of interest. This problem is closely related to Bertrand's paradox. I propose that, in the case of 'unbiased' priors, the reliability of inferences based on the generic viewpoint assumption depends partly on whether or not an observed coincidence in the image involves features known to be on the same object. This proposal is based on important differences between the distributions associated with: (i) a 'random' placement of features in 3-D, and (ii) the positions of features on a 'randomly shaped' and 'randomly posed' 3-D object. Similar considerations arise in the case of inferring 3-D motion from image motion.     

Progress and innovation: personality disorders and the vanguard of psychopathology research

Important progress in our understanding of the natural course of personality disorders (PDs) is documented in the articles for this special section. This progress could set the stage for ideas developed in the study of PDs to play a central role in research on psychopathology more broadly conceived. The Collaborative Longitudinal Personality Disorders Study (Skodol et al., this issue), the Children in the Community Study (Cohen, Crawford, Johnson, & Kasen, this issue), and the McLean Study of Adult Development (Zanarini, Frankenburg, Hennen, Reich, & Silk, this issue) reveal the importance of personality in understanding psychopathology, and point toward a dimensional approach to conceptualizing psychopathology that could also frame categorical clinical decision making processes.     

On broadening the cognitive, motivational, and sociostructural scope of theorizing about gender development and functioning: comment on Martin, Ruble, and Szkrybalo (2002)

In their article on gender development, C. L. Martin, D. N. Ruble, and J. Szkrybalo (see record 2002-18663-003) contrasted their conception of gender development with that of social cognitive theory. The authors of this commentary correct misrepresentations of social cognitive theory and analyze the conceptual and empirical status of Martin et al.'s (2002) theory that gender stereotype matching is the main motivating force of gender development. Martin et al. (2002) based their claim for the causal primacy of gender self-categorization on construal of gender discrimination as rudimentary self-identity, equivocal empirical evidence, and dismissal of discordant evidence because of methodological deficiencies. The repeated finding that gendered preferences and behavior precede emergence of a sense of self is discordant with their theory. Different lines of evidence confirm that gender development and functioning are socially situated, richly contextualized, and conditionally manifested rather than governed mainly by an intrinsic drive to match stereotypic gender self-conception.     

Swimming against the mainstream: the early years from chilly tributary to transformative mainstream

This article traces the transformative paradigm shift in the theory and practice of personal change. Within a decade, new conceptual models, analytic methodologies and modes of treatment were created. Treatments were altered in the content, locus, and agents of change. This enterprising period also witnessed a sweeping shift in the public acceptance of behaviorally oriented treatments. The present article also analyzes the evolving theorizing and applications of social cognitive theory rooted in modeling, self-regulatory, and self-efficacy mechanisms of psychosocial change. This model of change is implemented from an agentic perspective to promote personal, institutional, and society-wide changes that address some of the most urgent global problems.     

Sex differences for selective forms of spatial memory

In the present study, a systematic comparison of sex differences for several tests of spatial memory was conducted. Clear evidence for more accurate male performance was obtained for precise metric positional information in a wayfinding task and in an object location memory task. In contrast, no sex difference characterized topological information processing (object-to-position assignment). Together, these findings provide further insight in the specificity of sex differences in spatial memory and in the functional architecture of spatial memory. Implications for the relevant evolutionary basis are discussed.