An Application of Information Theory to the Problem of the Scientific Experiment

There are two basic approaches to the problem of induction:the empirical one, which deems that the possibility of induction depends on how theworld was made (and how it works) and the logical one, which considers the formation(and function) of language. The first is closer to being useful for induction, whilethe second is more rigorous and clearer. The purpose of this paper is to create an empiricalapproach to induction that contains the same formal exactitude as the logical approach.This requires: (a) that the empirical conditions for the induction are enunciatedand (b) that the most important results already obtained from inductive logic are againdemonstrated to be valid. Here we will be dealing only with induction by elimination,namely the analysis of the experimental confutation of a theory. The result will bea rule of refutation that takes into consideration all of the empirical aspect of theexperiment and has each of the asymptotic properties which inductive logic has shown tobe characteristic of induction.     

Emotional Reaction to Fragile X Premutation Carrier Tests Among Infertile Women

Female fragile X premutation carriers are at ∼10-fold increased risk of premature ovarian failure (follicle stimulating hormone >40 mIU/mL, amenorrhea, age <40). A milder degree of premature ovarian aging (diminished ovarian reserve, where follicle stimulating hormone levels are typically 10–20 mIU/mL) results in infertility. Approximately 10% of fertility clinic patients have this diagnosis. A cohort of 20 women diagnosed with diminished ovarian reserve provided a blood specimen (confidential results), and completed structured questionnaires that assessed emotional reactions to potentially being a premutation carrier (pretest questionnaire, n = 20) and the posttest known carrier status (3 month follow-up questionnaire, n = 18 non-carriers). Responses were measured using 9-point scales, and analyzed with Fisher exact and Wilcoxon exact tests. While most participants did not view fragile X premutations as a serious medical condition, perceptions of seriousness were positively correlated with anger and regret about not knowing sooner of the potential association of these premutations with infertility. Overall, when women (pretest) imagined themselves as carriers, their self-esteem and Health Orientation Scale responses were unchanged with the exception of feeling more afraid (p = 0.004). Despite strongly wishing for negative test results, they were glad to know there might be a medical explanation for their infertility. Financial Support: This work was financially supported by a University of Virginia School of Medicine Research & Development Award.     

Recognition memory and prefrontal cortex: dissociating recollection and familiarity processes using rTMS

Recognition memory can be supported by both the assessment of the familiarity of an item and by the recollection of the context in which an item was encountered. The neural substrates of these memory processes are controversial. To address these issues we applied repetitive transcranial magnetic stimulation (rTMS) over the right and left dorsolateral prefrontal cortex (DLPFC) of healthy subjects performing a remember/know task. rTMS disrupted familiarity judgments when applied before encoding of stimuli over both right and left DLPFC. rTMS disrupted recollection when applied before encoding of stimuli over the right DLPFC. These findings suggest that the DLPFC plays a critical role in recognition memory based on familiarity as well as recollection.     

Social support, sense of community in school, and self-efficacy as resources during early adolescence: an integrative model

Influences of different sources of social support (from parents and friends), school sense of community, and self-efficacy on psychosocial well being (as measured by self-reported life satisfaction and psychological symptoms) in early adolescence were investigated in an integrative model. The model was tested using structural equation modeling. Multi-group comparisons were used to estimate differences between sex and age groups. The survey sample was composed of 7,097 students in Northern Italy (51.4% male) divided into three age cohorts (equivalent to 6th, 8th, and 10th grades with median ages of 11, 13, and 15). Findings obtained using SEM were consistent with self-efficacy and school sense of community mediating effects of social support on psychosocial adjustment. The multi-group comparison indicates a need for more complex developmental models and more research on how changing forms of support interact with each other as their effects also change during this important stage of the life. Implications for primary prevention and cross-cultural comparisons are discussed.     

Signal detection theory analyses of semantic priming in word recognition

Word recognition, semantic priming, and cognitive impenetrability research have used signal detection theory (SDT) measures to separate perceptual and postperceptual processes. In the D. Norris (1986) checking model and model simulation (D. Norris, 1995), priming alters only postperceptual word decision criteria: Stimulus-related priming reduces uncertainty, increasing sensitivity; stimulus-unrelated priming increases false alarms more than hits, reducing sensitivity. This work is cited as strong evidence that criterion changes can alter perceptual sensitivity and that SDT is inappropriate for investigating complex cognitive processes. The authors' current SDT ideal observer analysis of the model demonstrates that related priming does not directly alter sensitivity and that unrelated priming increases only false-alarm rate, reducing sensitivity. This analysis provides new perspectives on SDT concepts of complex decision processing.     

What Incompleteness Arguments are and What They are Not

Cappelen and Lepore (2005) maintain that Incompleteness Arguments for context sensitivity are fallacious. In their view, Incompleteness Arguments are non sequitur fallacies whose conclusions are not logically related to premises. They affirm that the conclusions of Incompleteness Arguments are metaphysical claims about the existence of entities that might be constituents of propositions, while their premises concern psychological data about speakers' dispositions to truth evaluate sentences in contexts of utterance. Cappelen and Lepore reject Incompleteness Arguments because psychological data have no bearing on metaphysical issues. I do not dispute Cappelen and Lepore's claim that psychological data have no relevance to metaphysics. Nonetheless, I argue that Cappelen and Lepore's criticism is vitiated by a misunderstanding of the nature of Incompleteness Arguments that makes them overlook the link between semantics and linguistic competence. I try to shed light on the real nature of Incompleteness Arguments by pointing at the failure of Cappelen and Lepore's criticism. My aim is not to defend Semantic Contextualism, but to bring to attention the link between semantics and linguistic competence that should never be overlooked in debates in the field of semantics.     

How School can Teach Civic Engagement Besides Civic Education: The Role of Democratic School Climate

Civic engagement, defined as involvement in community life, is influenced by reciprocal relationships between individuals and contexts and is a key factor that contributes to positive youth development. The present study evaluates a theoretical model linking perceived democratic school climate with adolescent civic engagement (operationalized as civic responsibility and intentions for future participation), taking into account the mediating role of civic discussions and perceived fairness at school. Participants were 403 adolescents (47.9 % male) ranging in age from 11 to 15 years old (mean age = 13.6). Path analysis results partially validated the proposed theoretical model. Higher levels of democratic school climate were associated with higher levels of adolescent civic responsibility; the association was fully mediated by civic discussions and perceived fairness at school. Adolescents’ civic responsibility, then, was positively associated with a stronger intention to participate in the civic domain in the future.     

How do object reference frames and motion vector decomposition emerge in laminar cortical circuits?

How do spatially disjoint and ambiguous local motion signals in multiple directions generate coherent and unambiguous representations of object motion? Various motion percepts, starting with those of Duncker (Induced motion, 1929/1938) and Johansson (Configurations in event perception, 1950), obey a rule of vector decomposition, in which global motion appears to be subtracted from the true motion path of localized stimulus components, so that objects and their parts are seen as moving relative to a common reference frame. A neural model predicts how vector decomposition results from multiple-scale and multiple-depth interactions within and between the form- and motion-processing streams in V1–V2 and V1–MST, which include form grouping, form-to-motion capture, figure–ground separation, and object motion capture mechanisms. Particular advantages of the model are that these mechanisms solve the aperture problem, group spatially disjoint moving objects via illusory contours, capture object motion direction signals on real and illusory contours, and use interdepth directional inhibition to cause a vector decomposition, whereby the motion directions of a moving frame at a nearer depth suppress those directions at a farther depth, and thereby cause a peak shift in the perceived directions of object parts moving with respect to the frame.     

Sensing Aliveness

This study examines whether the categories animate/inanimate might be formed on the basis of information available to the cognitive system. We suggest that the discrimination of percepts according to these categories relies on proprioceptive information, which allows the perceiving subject to know that he is ‘animate’. Since other ‘objects’ in the world exhibit movements, reactions, etc. similar to those that the subject experiences himself, he can ‘project’ his knowledge onto these objects and recognize them as ‘animate’ like himself. On this basis we try to corroborate the empricist position in the debate concerning the organization of knowledge as opposed to the nativist view. Furthermore, we argue that the categorical dichotomy animate/inanimate is more basic than other analogous ones such as living/non-living, biological/non-biological and we sketch a ‘categorical stratification’ following the line ‘humans–animals–plants’ based on the hypothesis that humans detect different degrees of ‘vitality’ according to the degree of similarity they recognise between the considered instance and themselves.