Hempel’s logic of confirmation

This paper presents a new analysis of C.G. Hempel’s conditions of adequacy for any relation of confirmation [Hempel C. G. (1945). Aspects of scientific explanation and other essays in the philosophy of science. New York: The Free Press, pp. 3–51.], differing from the one Carnap gave in §87 of his [1962. Logical foundations of probability (2nd ed.). Chicago: University of Chicago Press.]. Hempel, it is argued, felt the need for two concepts of confirmation: one aiming at true hypotheses and another aiming at informative hypotheses. However, he also realized that these two concepts are conflicting, and he gave up the concept of confirmation aiming at informative hypotheses. I then show that one can have Hempel’s cake and eat it too. There is a logic that takes into account both of these two conflicting aspects. According to this logic, a sentence H is an acceptable hypothesis for evidence E if and only if H is both sufficiently plausible given E and sufficiently informative about E. Finally, the logic sheds new light on Carnap’s analysis.     

Depressed Adolescents and Comorbid Psychiatric Disorders: Are There Differences in the Presentation of Depression?

Patterns and correlates of comorbidity, as well as differences in manifest depressive profiles were investigated in a sample of depressed adolescents. A sub-sample of the youth were characterized as belonging to either a Pure depression group, an Internalizing group (depression and co-occurring internalizing disorders), or an Externalizing group (depression and co-occurring externalizing disorders). Item response theory (IRT) and differential item functioning (DIF) were used to assess whether the depressed adolescents from the different comorbidity groups presented with different depressive symptoms. Results indicated that the comorbidity groups were meaningfully distinct in terms of psychosocial correlates as well as showed differences in depressive symptom profiles as informed by DIF analyses. In particular, the comorbidity groups differed in terms of presentation of psychomotor changes and cognitive impairments. Implications for assessment are discussed.

Immediate priming and cognitive aftereffects

Three forced-choice perceptual word identification experiments tested the claim that transitions from positive to negative priming as a function of increasing prime duration are due to cognitive aftereffects. These aftereffects are similar in nature to perceptual aftereffects that produce a negative image due to overexposure and habituation to a stimulus. Each experiment tested critical predictions that come from including habituation in a dynamic neural network with multiple levels of processing. The success of this account in explaining the dynamics of repetition priming, associative-semantic priming, and forward masking effects suggests that habituation is a useful mechanism for reducing source confusion between successively presented stimuli. Implications are considered for visible persistence, repetition blindness, attention-based negative priming, attentional blink, inhibition of return, the negative compatibility effect, affect priming, and flanker preview effects.     

Context retrieval and context change in free recall: recalling from long-term memory drives list isolation

Three experiments used the "list-before-the-last" free recall paradigm (Shiffrin, 1970) to investigate retrieval for context and the manner in which context changes. This paradigm manipulates target and intervening list lengths to measure the interference from each list, providing a measure of list isolation. Correct target list recall was only affected by the target list length when participants engaged in recall between the lists, whereas there were effects of both list lengths with other activities. This suggests that the act of recalling drives context change, thus isolating the target list from interference. Correspondingly, incorrect recall of intervening list items was affected only by the length of the intervening list when recall occurred between the lists, but was otherwise affected by both list lengths. Concurrent with these changes in context similarity, there were apparent changes in context retrieval, as indicated by the overall levels of target retrieval versus intervening recall. A multinomial model of sampling and recovery was implemented to assess the adequacy of this account and to quantify context similarity and context retrieval.     

The weckud wetch of the wast: lexical adaptation to a novel accent

Two experiments investigated the mechanism by which listeners adjust their interpretation of accented speech that is similar to a regional dialect of American English. Only a subset of the vowels of English (the front vowels) were shifted during adaptation, which consisted of listening to a 20-min segment of the "Wizard of Oz." Compared to a baseline (unadapted) condition, listeners showed significant adaptation to the accented speech, as indexed by increased word judgments on a lexical decision task. Adaptation also generalized to test words that had not been presented in the accented passage but that contained the shifted vowels. A control experiment showed that the adaptation effect was specific to the direction of the shift in the vowel space and not to a general relaxation of the criterion for what constitutes a good exemplar of the accented vowel category. Taken together, these results provide evidence for a context-specific vowel adaptation mechanism that enables a listener to adjust to the dialect of a particular talker.     

Environmental stimulation, parental nurturance and cognitive development in humans

The effects of environmental stimulation and parental nurturance on brain development have been studied extensively in animals. Much less is known about the relations between childhood experience and cognitive development in humans. Using a longitudinally collected data set with ecologically valid in-home measures of childhood experience and later in-laboratory behavioral measures of cognitive ability, we were able to test hypotheses concerning the effects of environmental stimulation and parental nurturance. A double dissociation was found: On the one hand, there was a selective relation between parental nurturance and memory development, consistent with the animal literature on maternal buffering of stress hormone effects on hippocampal development. On the other hand, there was a selective relation between environmental stimulation and language development. The relevance of these findings to socioeconomic gradients in cognitive ability is discussed.     

Feeling Transparent: On Metaperceptions and Miscommunications

Individuals’ metaperceptions regarding how another person views them tend to be egocentrically biased by their own private self‐knowledge: They overestimate the extent to which their traits, feelings, and intentions are ‘transparent’, perceiving more congruence between their inner self and the other person's impressions than actually exists. In the present article, we examine the factors, such as self‐awareness and feelings of closeness, that increase individuals’ propensity to exaggerate their transparency to others. We also examine the interpersonal consequences of transparency overestimation and the related signal amplification bias, considering how they can reduce the likelihood of relationship formation, derail the seeking and provision of social support in ongoing relationships, and more generally lead to relational conflict. Lastly, we discuss the interventions available to reduce these biases.     

Conceptions of aggression and withdrawal in early childhood

Two studies investigate young children's beliefs about aggression and withdrawal in others with reference to the possibility of stability and change. Study 1 (N=41) provides evidence that preschool children (1) view aggression in more essentialist ways (i.e. they believe it to be more stable and less changeable) than withdrawal and (2) believe that friends hold a greater potential to create change in aggression and withdrawal than do other potential sources of influence, such as parents and teachers. Study 2 (N=25) replicates the findings of Study 1 and also demonstrates that by preschool age, children hold systematic ideas about the effectiveness of strategies that friends can use to change the behaviour of their peers. These ideas include the belief that prosocial strategies, such as showing peers how to make friends, are more effective than requests to stop engaging in undesirable behaviour. Study 2 also demonstrates that preschool‐aged participants engaged in essentialist reasoning to a greater extent than did a comparison group of 20 7–8 year olds. Copyright © 2004 John Wiley & Sons, Ltd.