Constitutive activation of the G-protein subunit Galphas within forebrain neurons causes PKA-dependent alterations in fear conditioning and cortical Arc mRNA expression

Memory formation requires cAMP signaling; thus, this cascade has been of great interest in the search for cognitive enhancers. Given that medications are administered long-term, we determined the effects of chronically increasing cAMP synthesis in the brain by expressing a constitutively active isoform of the G-protein subunit Galphas (Galphas*) in postnatal forebrain neurons of mice. Previously, we showed that Galphas* mice exhibit increased adenylyl cyclase activity but decreased cAMP levels in cortex and hippocampus due to a PKA-dependent increase in total cAMP phosphodiesterase (PDE) activity. Here, we extend previous findings by determining if Galphas* mice show increased activity of specific PDE families that are regulated by PKA, if Galphas* mice show PKA-dependent deficits in fear memory, and if these memory deficits are associated with PKA-dependent alterations in neuronal activity as mapped by Arc mRNA expression. Consistent with previous findings, we show here that Galphas* mice exhibit a significant compensatory increase in cAMP PDE1 activity and a trend toward increased cAMP PDE4 activity. Further, inhibiting the presumably elevated PKA activity in Galphas* mice fully rescues short- and long-term memory deficits in a fear-conditioning task, while extending the training session from one to four CS-US pairings partially rescues these deficits. Mapping of Arc mRNA levels suggests these PKA-dependent memory deficits may be related to decreased neuronal activity specifically within the cortex. Galphas* mice show decreased Arc mRNA expression in CA1, orbital cortex, and cortical regions surrounding the hippocampus; however, only the deficits in cortical regions surrounding the hippocampus are PKA dependent. Our results imply that chronically stimulating targets upstream of cAMP may detrimentally affect cognition.     

A Taxonomy of Equity Factors

A perplexing problem with Adams' (1963 ) equity theory has been the difficulty associated with operationalizing requisite components, perceived employee inputs, and outcomes. This study, involving 352 respondents, produced empirically derived, two-dimensional taxonomies of inputs and outcomes, laying the foundation for identification of key variables. Specifically, the study summarizes a typology of 9 distinct employee inputs perceived as controllable by individuals, including effort, education, attendance, and cooperativeness. Conversely, the study summarizes a typology of 14 distinct outcomes along a continuum of 4 dimensions, including personalized vs. generalized and economic vs. noneconomic characteristics. These typologies and incumbent regression analysis provide insight into the complexities associated with inputs and outcomes in the context of equity theory.     

Rationality and Judgment

Abstract: Philosophical/epistemic theories of rationality differ over the role of judgment in rational argumentation. According to the “classical model” of rationality, rational justification is a matter of conformity with explicit rules or principles. Critics of the classical model, such as Harold Brown and Trudy Govier, argue that the model is subject to insuperable difficulties. They propose, instead, that rationality be understood, ultimately, in terms of judgment rather than rules. In this article I respond to Brown's and Govier's criticisms of the classical model, and to the “judgment model” they propose in its place. I argue that that model is unable both to distinguish between rational and irrational judgment and to avoid recourse to rules, and is therefore inadequate as an account of rationality, critical thinking, or argument appraisal. More positively, I argue that an adequate account of rationality must include a place for both rules and judgment.     

The Perceived Benefits of Religious and Spiritual Coping Among Older Adults Living with HIV/AIDS

Although religious and spiritual beliefs and practices have been frequently associated with greater psychological well-being among illness populations, little is known about the specific benefits individuals perceive they receive from these beliefs and practices. This issue was examined in interviews with 63 older HIV-infected adults. Participants reported a variety of benefits from their religious and spiritual beliefs and practices, including: (1) evokes comforting emotions and feelings; (2) offers strength, empowerment, and control; (3) eases the emotional burden of the illness; (4) offers social support and a sense of belonging; (5) offers spiritual support through a personal relationship with God; (6) facilitates meaning and acceptance of the illness; (7) helps preserve health; (8) relieves the fear and uncertainty of death; (9) facilitates self-acceptance and reduces self-blame. These perceived benefits suggest potential mechanisms by which religion/spirituality may affect psychological adjustment.     

Very brief exposure: The effects of unreportable stimuli on fearful behavior

A series of experiments tested the hypothesis that very brief exposure to feared stimuli can have positive effects on avoidance of the corresponding feared object. Participants identified themselves as fearful of spiders through a widely used questionnaire. A preliminary experiment showed that they were unable to identify the stimuli used in the main experiments. Experiment 2 (N = 65) compared the effects of exposure to masked feared stimuli at short and long stimulus onset asynchronies (SOA). Participants were individually administered one of three continuous series of backwards masked or non-masked stimuli: unreportable images of spiders (25-ms SOA), clearly visible images of spiders (500-ms SOA), or unreportable images of trees (25-ms SOA). Immediately thereafter, they engaged in a Behavioral Avoidance Test (BAT) with a live, caged tarantula. Exposure to unreportable images of spiders resulted in greater approach towards the tarantula than unreportable neutral images. A post-hoc comparison with clearly visible exposure to these same images approached significance. These effects were maintained at a 1-week follow-up (N = 57). In Experiment 3 (N = 26), participants engaged in the BAT 1 week prior to the exposure manipulation in order to provide a baseline measurement of their avoidant behavior, and again immediately after the exposure manipulation. Exposure to unreportable images of spiders reduced avoidance of the tarantula. Similar exposure to trees did not. Implications for the non-conscious basis of fear are discussed.     

LOTTERIES AND THE TIME HORIZON

Abstract— People chose between hypothetical alternatives of (a) a million-dollar lottery prize and (b) a much smaller but certain amount of money When probabilities of winning the lottery were above about 1/100,000, subjects avoided risk, for example, a 1/100,000 probability of the million-dollar prize was chosen about as often as $700 for sure But at probabilities below 1/100,000, subjects sought risk, for example, a 1/1,000,000 probability of the million-dollar prize was chosen about as often as $9 for sure This crossover from risk aversion to risk seeking is predicted by Mazur's (1987) hyperbolic delay discount function with probability expressed as average delay due to strings of losses followed by a win, together with a time horizon limiting subjective delay     

Contingent color aftereffects: Reassessing old conclusions

Although there is considerable evidence supporting an associative interpretation of contingent color aftereffects, there are data that appear inconsistent with this interpretation. New findings from seven experiments are presented indicating that, contrary to earlier claims, contingent color aftereffects are observed after induction with (1) single orthogonal black bars on colored backgrounds, (2) geometric forms, and (3) two orthogonal grids of the same color. The results of these experiments are relevant to an associative interpretation of contingent color aftereffects, as well as to assessing alternative interpretations of the phenomenon.     

Social-cognitive and cognitive correlates of depression in children

The present investigation examined depression and its social-cognitive and cognitive correlates in a sample of 108 elementary school children: 36 children in each of grades 1, 4, and 8. Children were classified as depressed and nondepressed according to their scores on the Children's Depression Inventory (CDI). Depression appeared stable over a 3-week time interval. Depressed children reported a higher number of masking symptoms, were rated as more depressed by their teachers, and perceived their family environment to be more distressed. As posited, when compared to nondepressed children, depressed children have lower self-esteem, a more depressive attributional style, and more self-control deficits. Further, they have impaired performance on some cognitive tasks (block design, coding digit span) but not all (vocabulary). The prediction that depression would be manifested differently in first-, fourth-, and eighth-graders was not supported.This research was supported by a grant from the Hogg Foundation for Mental Health. We would like to specifically acknowledge the help of Dr. Wayne Holtzman, director of the Hogg Foundation.     

Argument Quality and Cultural Difference

Central to argumentation theory is a concern with normativity. Argumentation theorists are concerned, among other things, with explaining why some arguments are good (or at least better than others) in the sense that a given argument provides reasons for embracing its conclusion which are such that a fair- minded appraisal of the argument yields the judgment that the conclusion ought to be accepted -- is worthy of acceptance -- by all who so appraise it.This conception of argument quality presupposes that the goodness of arguments is characterizable in terms of features of the argument itself. It makes no reference either to the attributes of the persons appraising the argument and judging its normative force, or to the context in which that appraisal is carried out. But recent work by a wide range of philosophers, argumentation theorists, and social theorists rejects such an abstract, impersonal notion of argument goodness. Instead, these theorists insist upon taking seriously, in the evaluation of arguments, the features of the evaluators themselves. In particular, such theorists emphasize the importance of cultural difference in argument appraisal. Often locating themselves under the banner of multiculturalism, they argue that the quality of an argument depends upon culturally-specific beliefs, values, and presuppositions; that an argument may be of high quality in one cultural context but of low quality in another. Consequently, they contend, no abstract, impersonal characterization of argument quality can succeed.In this paper I consider this multiculturalist approach to argument quality. I argue that while there is much merit in the general multiculturalist perspective, the multiculturalist argument against impersonal conceptions of argument quality fails. It fails for several reasons detailed below; most fundamentally, it fails because it itself presupposes just the kind of impersonal account of argument quality it seeks to reject. I call this presupposition that of transcultural normative reach. I identify this presupposition in the multiculturalist argument, and show how it undercuts the multiculturalist challenge to abstract, impersonal, transcultural conceptions of argument quality. I conclude with an evaluation of the strengths, and weaknesses, of the multiculturalist challenge to such conceptions of argument quality.