Representation and constraints: the inverse problem and the structure of visual space

Visual space can be distinguished from physical space. The first is found in visual experience, while the second is defined independently of perception. Theorists have wondered about the relation between the two. Some investigators have concluded that visual space is non-Euclidean, and that it does not have a single metric structure. Here it is argued (1) that visual space exhibits contraction in all three dimensions with increasing distance from the observer, (2) that experienced features of this contraction (including the apparent convergence of lines in visual experience that are produced from physically parallel stimuli in ordinary viewing conditions) are not the same as would be the experience of a perspective projection onto a frontoparallel plane, and (3) that such contraction is consistent with size constancy. These properties of visual space are different from those that would be predicted if spatial perception resulted from the successful solution of the inverse problem. They are consistent with the notion that optical constraints have been internalized. More generally, they are also consistent with the notion that visual spatial structures bear a resemblance relation to physical spatial structures. This notion supports a type of representational relation that is distinct from mere causal correspondence. The reticence of some philosophers and psychologists to discuss the structure of phenomenal space is diagnosed in terms of the simple materialism and the functionalism of the 1970s and 1980s.     

Semantics and semantic errors: implicit access to semantic information from words and nonwords in deep dyslexia

In this paper we describe dissociations of implicit versus explicit access to semantic information in a patient with deep dyslexia. This acquired reading disorder is characterized by the production of morphological (e.g., SLEEP read as SLEEPING) and semantic errors (e.g., HEART read as BLOOD) and consequently provides a potential window into the operation of both aspects of the language system. The deep dyslexic patient in this study (JO) demonstrated implicit semantic access to items in a number of tasks despite the fact that she was unable to correctly read these items aloud. The findings from this study are consistent with a model of lexical deficits that distinguishes between explicit and implicit access to lexical representations on the basis of inhibitory processes.     

Validity and reliability of the general well-being schedule with northern plains American Indians diagnosed with type 2 diabetes mellitus

The General Well-being Schedule is a brief indicator of subjective feelings of psychological well-being and distress. It is easy to administer, reliable, and valid, although its validity with American Indians has not been established. This study then assessed reliability, validity, and factor structure for a sample of 88 diabetic American Indians, who sought care for diabetes at an Indian Health Service hospital. Cronbach alpha was .89. A factor analysis indicated four dimensions. Adequate concurrent and divergent validity were noted in association with scores on the Beck Depression Inventory-Second Edition, the depression scale on the Symptom Checklist-90-Revised, and Family-Adaptation, Partnership, Growth, Affection, & Resolve. These results suggest that the General Well-being Schedule is a reliable and valid measure of general well-being for this population of American Indians.     

A role for ERK MAP kinase in physiologic temporal integration in hippocampal area CA1

Recent studies demonstrate a requirement for the Extracellular signal Regulated Kinase (ERK) mitogen-activated protein kinase (MAPK) cascade in both the induction of long-lasting forms of hippocampal synaptic plasticity and in hippocampus-dependent associative and spatial learning. In the present studies, we investigated mechanisms by which ERK might contribute to synaptic plasticity at Schaffer collateral synapses in hippocampal slices. We found that long-term potentiation (LTP) induced with a pair of 100-Hz tetani does not require ERK activation in mice whereas it does in rats. However, in mice, inhibition of ERK activation blocked LTP induced by two LTP induction paradigms that mimicked the endogenous θ rhythm. In an additional series of studies, we found that mice specifically deficient in the ERK1 isoform of MAPK showed no impairments in tests of hippocampal physiology. To investigate ERK-dependent mechanisms operating during LTP-inducing stimulation paradigms, we monitored spike production in the cell body layer of the hippocampus during the period of θ-like LTP-inducing stimulation. θ-burst stimulation (TBS) produced a significant amount of postsynaptic spiking, and the likelihood of spike production increased progressively over the course of the three trains of TBS independent of any apparent increase in Excitatory Post-Synaptic Potential (EPSP) magnitude. Inhibition of ERK activation dampened this TBS-associated increase in spiking. These data indicate that, for specific patterns of stimulation, ERK may function in the regulation of neuronal excitability in hippocampal area CA1. Overall, our data indicate that the progressive increase in spiking observed during TBS represents a form of physiologic temporal integration that is dependent on ERK MAPK activity.     

Attitudes toward human service organizations: perspectives from an urban black community.

Previous research has suggested that black Americans tend to view mental health services and community mental health centers more negatively than do white Americans. This article discusses a recent study that sought to determine whether black persons possess positive or negative attitudes, what factors influence attitude formation, and the implications of these findings. Based on a sample of black residents in a city in the Northeast, the study found that fewer than 20% of black persons possess negative attitudes toward community mental health centers, that 34% possess positive attitudes, that women and married persons tend to possess more positive attitudes than do men and unmarried persons, that those with high levels of racial consciousness tend to possess more positive attitudes than those who do not, and that those with a high tolerance of substance use tend to possess more negative attitudes than do less tolerant persons. The author suggests that human service agencies should educate social and health workers to become more aware of the cultural diversity and attitudes of the black community so that they may more effectively serve black clients.     

A Scorekeeping Error

Philosophical Studies -     

On the Unity of Compound Things: Living and Non-Living

There appear to be at least two kinds of compound physical substances: compound pieces of matter, which have their parts essentially, and living organisms, which do not. Examples of the former are carbon atoms, salt molecules, and pieces of gold; and examples of the latter are protozoa, trees, and cats. Given that there are compound entities of these two kinds, and given that they can be created or destroyed by assembly or disassembly, questions naturally arise about the nature of the causal relations which unite their parts. In answer to these questions, we first argue that the parts of a compound piece of matter are connected via a relation of dynamic equilibrium of attractive and repulsive forces. We then argue that the parts of an organic living thing are united in a different way: they are functionally connected in a broadly Aristotelian sense which is compatible with an ultimately non-teleological, naturalistic biology.