The use of schematic knowledge about sources in source monitoring

Source monitoring refers to mental processes leading to attributions regarding the origin of information. We tested Johnson, Hashtroudi, and Lindsay's (1993) assumption that prior source-relevant knowledge is used in some source-monitoring tasks. In two experiments using different domains of schematic knowledge, two sources presented information that was expected for one source and somewhat unexpected for the other. In a later source-monitoring test, participants decided whether items had been presented by Source A, by Source B, or were new. The results of both experiments show that source identification is better for expected items than for somewhat unexpected items. Multinomial modeling analyses revealed that when participants do not remember the source of information, they guess that it was presented by the expected source. These results provide evidence for the claim that source monitoring can be based on prior knowledge and support a guessing hypothesis.     

Chronically increased Gsalpha signaling disrupts associative and spatial learning

The cAMP/PKA pathway plays a critical role in learning and memory systems in animals ranging from mice to Drosophila to Aplysia. Studies of olfactory learning in Drosophila suggest that altered expression of either positive or negative regulators of the cAMP/PKA signaling pathway beyond a certain optimum range may be deleterious. Here we provide genetic evidence of the behavioral and physiological effects of increased signaling through the cAMP/PKA pathway in mice. We have generated transgenic mice in which the expression of a constitutively active form of Gsalpha (Gsalpha* Q227L), the G protein that stimulates adenylyl cyclase activity, is driven in neurons within the forebrain by the promoter from the CaMKIIalpha gene. Despite significantly increased adenylyl cyclase activity, Gsalpha* transgenic mice exhibit PKA-dependent decreases in levels of cAMP due to a compensatory up-regulation in phosphodiesterase activity. Interestingly, Gsalpha* transgenic mice also exhibit enhanced basal synaptic transmission. Consistent with a role for the cAMP/PKA pathway in learning and memory, Gsalpha* transgenic mice show impairments in spatial learning in the Morris water maze and in contextual and cued fear conditioning tasks. The learning deficits observed in these transgenic mice suggest that associative and spatial learning requires regulated Gsalpha protein signaling, much as does olfactory learning in Drosophila.     

Effects of counseling Ashkenazi Jewish women about breast cancer risk

The goal of this study was to determine whether genetic counseling or psychosocial group counseling provided to Ashkenazi women can reduce breast cancer worry, cancer risk perception, and interest in having genetic testing. Women (N=211) were randomized to receive individual genetic risk counseling, to receive a group psychosocial group counseling, or to serve as a control group. The authors found that both counseling methods reduced cancer worry, lowered perceptions of breast cancer risk, and decreased interest in having genetic testing. Counseling can help women gain a more accurate perception of their risk, expose them to the benefits and limitations of genetic testing, and reduce their worry about cancer.     

Spatial relational learning in rufous hummingbirds (Selasphorus rufus)

There is increasing evidence that animals can learn abstract spatial relationships, and successfully transfer this knowledge to novel situations. In this study, rufous hummingbirds (Selasphorus rufus) were trained to feed from either the lower or the higher of two flowers. When presented with a test pair of flowers, one of which was at a novel height, they chose the flower in the appropriate spatial position rather than the flower at the correct height. This response may also have been influenced by a preference for taller flowers as acquisition of the task during experimental training occurred more readily when the reward flower was the taller of the pair. Thus, it appears that although learning abstract relationships may be a general phenomenon across contexts, and perhaps across species, the ease with which they are learned and the context in which they are subsequently used may not be the same.     

Adolescent depression and externalizing problems: testing two models of comorbidity in an inpatient sample

Differentiating between additive (quantitative) and interactive (qualitative) effects of comorbidity has important treatment implications. This study illustrates the heuristic superiority of a multifactorial approach over simple group comparisons in testing quantitative versus qualitative models of comorbidity. Analysis of variance was used to compare 266 adolescent inpatients identified as depressed, externalizing, both, or neither on self-report measures of personality, school problems, and substance abuse. The results support quantitative rather than qualitative models of comorbidity. Depressed status related most strongly to group differences in interpersonal and self-critical concerns. Externalizing status related most strongly to group differences in school problems and drug use. Main effects for the two statuses together explained especially elevated levels of reactance and alcohol abuse among the comorbid adolescents.     

Untreated recovery from eating disorders

This retrospective study explored the experience of recovery from anorexia nervosa and bulimia nervosa without professional treatment. A nine-question open-ended electronic survey was posted for a period of four months at a mid-western university. Sixteen female and two male respondents reported recovery from adolescent-onset full syndrome anorexia nervosa or bulimia nervosa. All respondents reported onset factors supporting a sociocultural etiology. Recovery was initiated through the empathic, participatory efforts of parents and friends, or was self-initiated. Respondents with the shortest disorder duration and most complete recovery reported early parental intervention. Onset factors similar to those in research with a clinically treated population were found. Implications of the findings are discussed.     

Six does not just mean a lot: preschoolers see number words as specific

This paper examines what children believe about unmapped number words - those number words whose exact meanings children have not yet learned. In Study 1, 31 children (ages 2-10 to 4-2) judged that the application of five and six changes when numerosity changes, although they did not know that equal sets must have the same number word. In Study 2, 15 children (ages 2-5 to 3-6) judged that six plus more is no longer six, but that a lot plus more is still a lot. Findings support the hypothesis that children treat number words as referring to specific, unique numerosities even before they know exactly which numerosity each word refers to.