Spatial learning and memory is preserved in rats after early development in a microgravity environment

This study evaluated the cognitive mapping abilities of rats that spent part of their early development in a microgravity environment. Litters of male and female Sprague-Dawley rat pups were launched into space aboard the National Aeronautics and Space Administration space shuttle Columbia on postnatal day 8 or 14 and remained in space for 16 days. These animals were designated as FLT groups. Two age-matched control groups remained on Earth: those in standard vivarium housing (VIV) and those in housing identical to that aboard the shuttle (AGC). On return to Earth, animals were tested in three different tasks that measure spatial learning ability, the Morris water maze (MWM), and a modified version of the radial arm maze (RAM). Animals were also tested in an open field apparatus to measure general activity and exploratory activity. Performance and search strategies were evaluated in each of these tasks using an automated tracking system. Despite the dramatic differences in early experience, there were remarkably few differences between the FLT groups and their Earth-bound controls in these tasks. FLT animals learned the MWM and RAM as quickly as did controls. Evaluation of search patterns suggested subtle differences in patterns of exploration and in the strategies used to solve the tasks during the first few days of testing, but these differences normalized rapidly. Together, these data suggest that development in an environment without gravity has minimal long-term impact on spatial learning and memory abilities. Any differences due to development in microgravity are quickly reversed after return to earth normal gravity.     

Postmodernism Versus Modernism: Rethinking Theoretical Tensions in Social Gerontology

The interconnection of social theory to social aspects of aging has grown in recent years. The theoretical movement entitled structured dependency, couched in social class analysis, has tended to ignore an understanding of aging identity, the body, cultural representations of aging, and positive images of aging, all of which are central features of an emerging postmodern paradigm in gerontological theory. This article argues that the concept of gender can form a useful bridge, a continuity, between structured dependency and postmodernism in theoretical gerontology. Unfortunately, the compartmentalization of these two conceptual approaches has made their links difficult to forge. This article attempts to take a first step in this direction by highlighting the way postmodern ideas can be used to understand a modernist issue—gender in a gerontological context. Also, focusing on the aging body as a primary form of analysis generates some novel insights into the importance of both the theoretical understanding and cultural representations of the body.     

Word Frequency Effects on the Processing of Subject–Verb Number Agreement

This paper examines the role of word frequency in the computation of subject–verb number agreement. Previous research in both production and comprehension has demonstrated that processing difficulties can arise in sentence structures containing a singular subject noun followed by a plural distractor noun, as in The key to the cabinets.¨ A whole sentence reading task was employed to determine whether the relative frequency with which the distractor noun appears in its singular or plural form would affect the degree of processing difficulty experienced by readers. Results suggest that the agreement process is, indeed, sensitive to this factor and this finding is compatible with activation-based accounts of the implementation of number agreement.     

Key Word Index Volume 4

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Key Word Index Volume 4     

Emotional states and physical health

Positive emotional states may promote healthy perceptions, beliefs, and physical well-being itself. To explore potential mechanisms linking pleasant feelings and good health, the authors consider several lines of research, including (a) direct effects of positive affect on physiology, especially the immune system, (b) the information value of emotional experiences, (c) the psychological resources engendered by positive feeling states, (d) the ways in which mood can motivate health-relevant behaviors, and (e) the elicitation of social support. As anticipated by the Greek physician Hippocrates, positive emotions and healthy outcomes may be linked through multiple pathways.     

A shift of attention may be necessary, but it is not sufficient, for the generation of the Simon effect

The Simon effect is the performance advantage for spatially corresponding, compared to non-corresponding, target-response ensembles when the location of the target is task irrelevant. In four experiments, we tested the predictions of the attention-shift account of the Simon effect. In all experiments, subjects made choice responses with respect to the identity of a central target that followed a spatially non-informative peripheral precue. The first experiment showed a Simon effect away from the precue when the precue was a go/no-go signal: responses to spatially non-corresponding precue-response pairs were faster than responses to spatially corresponding precue-response pairs. The results of the second experiment suggested that this “reverse” Simon effect was not due to inhibition. In the third experiment, a secondary working memory task required the encoding, and later recall, of “oddball” precues. Although the Simon effect was absent, larger Simon effects towards the precue (i.e., responses were faster to spatially corresponding, compared to non-corresponding, precue-response ensembles) were correlated with poorer performance on the memory task. In the last experiment, the identity of completely non-informative precues was congruent, incongruent, or unrelated to the identity of the target. With precues that were unrelated to the identity of the target, there was a Simon effect towards the precues. Conversely, the Simon effect occurred away from the precue when the identity of the precue was related to that of the target. The findings suggest that a shift of attention alone is not sufficient to produce the Simon effect. Rather, the shift of attention must originate from an intentionally defined object. The results are discussed within a framework that integrates the attention-shift and referential-coding hypotheses. Received: 2 December 1999 / Accepted: 23 March 2000     

The Factor Structure of the Beavers Interactional Scales

Confirmatory factor analysis and regression analyses of the Beavers Interactional Scales did not appear to support the model offered by its developers, namely, several specified family attributes contributing respectively to two global factors of Family Competence and Family Style. Moreover, regression analysis indicated that only three of 12 items predicted raters' assessments of Global Family Health, and one of seven items predicted Global Family Style. Individuals interested in the family dynamic centripetal/centrifugal might best think of that as a unitary entity and rate it accordingly.     

Asymmetric interference between sex and emotion in face perception

Previous research with speeded-response interference tasks modeled on the Garner paradigm has demonstrated that task-irrelevant variations in either emotional expression or facial speech do not interfere with identity judgments, but irrelevant variations in identity do interfere with expression and facial speech judgments. Sex, like identity, is a relatively invariant aspect of faces. Drawing on a recent model of face processing according to which invariant and changeable aspects of faces are represented in separate neurological systems, we predicted asymmetric interference between sex and emotion classification. The results of Experiment 1, in which the Garner paradigm was employed, confirmed this prediction: Emotion classifications were influenced by the sex of the faces, but sex classifications remained relatively unaffected by facial expression. A second experiment, in which the difficulty of the tasks was equated, corroborated these findings, indicating that differences in processing speed cannot account for the asymmetric relationship between facial emotion and sex processing. A third experiment revealed the same pattern of asymmetric interference through the use of a variant of the Simon paradigm. To the extent that Garner interference and Simon interference indicate interactions at perceptual and response-selection stages of processing, respectively, a challenge for face processing models is to show how the same asymmetric pattern of interference could occur at these different stages. The implications of these findings for the functional independence of the different components of face processing are discussed.     

Does selective attention influence the octave illusion?

The octave illusion occurs when each ear receives a sequence of tones alternating by one octave, but with different frequencies in each ear. Most listeners report a high pitch in one ear alternating with a low pitch in the opposite ear. Deutsch and Roll proposed an influential suppression model of the illusion in which the pitch is determined by ear dominance, while the location of this pitch is determined by high-frequency dominance. Deutsch later suggested that this unusual division between 'what' and 'where' mechanisms is facilitated by sequential interactions within the eliciting sequence. A recent study has raised doubts about the suppression model and the role of sequential interactions in the illusion (Chambers et al, 2002 Journal of Experimental Psychology: Human Perception and Performance 28 1288-1302). Here, we examined whether this previous null effect of sequential interactions may have arisen because of uncontrolled influences of selective attention. The results reveal no evidence of a link between selective attention and sequential interactions, thus consolidating doubts about the validity of the suppression model.