Tuned to the signal: the privileged status of speech for young infants

Do young infants treat speech as a special signal, compared with structurally similar non‐speech sounds? We presented 2‐ to 7‐month‐old infants with nonsense speech sounds and complex non‐speech analogues. The non‐speech analogues retain many of the spectral and temporal properties of the speech signal, including the pitch contour information which is known to be salient to young listeners, and thus provide a stringent test for a potential listening bias for speech. Our results show that infants as young as 2 months of age listened longer to speech sounds. This listening selectivity indicates that early‐functioning biases direct infants’ attention to speech, granting speech a special status in relation to other sounds.     

Identification of tone duration, line length, and letter position: an experimental approach to timing and working memory deficits in schizophrenia

Patients with schizophrenia display numerous cognitive deficits, including problems in working memory, time estimation, and absolute identification of stimuli. Research in these fields has traditionally been conducted independently. We examined these cognitive processes using tasks that are structurally similar and that yield rich error data. Relative to healthy control participants (n = 20), patients with schizophrenia (n = 20) were impaired on a duration identification task and a probed-recall memory task but not on a line-length identification task. These findings do not support the notion of a global impairment in absolute identification in schizophrenia. However, the authors suggest that some aspect of temporal information processing is indeed disturbed in schizophrenia.     

Alexithymia and psychopathy: comparison and application of California Q-set Prototypes

Although alexithymia and psychopathy have long been linked, the relationship between the two constructs remains unclear. In this study, we used the California Q-set Alexithymia Prototype (CAQ-AP; Haviland & Reise, 1996) and Psychopathy Prototype (CAQ-PP; Reise & Oliver, 1994) to clarify the relationship between the two constructs and evaluate both in a sample of contemporary and historical political leaders (N = 42). Our data show that both individuals with prototypic alexithymia and psychopathy lack empathy and insight and are not introspective. The prototypic person with alexithymia, however, is anxious, overcontrolled, submissive, boring, ethically consistent, and socially conforming, whereas the prototypic individual with psychopathy is anxiety-free, undercontrolled, dominant, charming, deceitful, and nonconforming. Characteristics of both were relatively common among the 13 controversial and notorious leaders and relatively uncommon among the 29 generally respected leaders in the sample. The CAQ-AP and the CAQ-PP appear to be useful for evaluating alexithymic and psychopathic features in public figures.     

When do the stigmatized make attributions to discrimination occurring to the self and others? The roles of self-presentation and need for control

Two experiments examined how the goals of self-presentation and maintenance of control over one's outcomes influence women's tendencies to make or to avoid making attributions to discrimination. Demonstrating the importance of self-presentational goals, Experiment 1 showed that targets of discrimination were just as likely as similar others to make attributions to discrimination under private reporting conditions, but they were significantly less likely to do so under public reporting conditions. This experiment also provided initial evidence that need for personal control increases discrimination attributions. Experiment 2 demonstrated that targets' minimization of discrimination, observed in public reporting conditions, was eliminated when the need to reassert personal control was induced. Both experiments also demonstrated that failing to view events as discrimination has negative psychological costs.     

Accuracy of blood glucose estimation by children with diabetes: an investigation of repeated practice with growth curve modeling

This study used growth curve modeling to explore whether practicing the task of estimating blood glucose levels would increase accuracy in children with type 1 diabetes. It was predicted that accuracy would improve with practice and that younger, anxious, poorly adjusted children would improve most. 43 attendees at a diabetes summer camp participated. Their mean age was 13.4 yr. (SD = 1.6). All were Euro-American, and 22 were girls. Change in accuracy was best represented by a quadratic function, and this model fit the data well. Overall, participants' accuracy improved initially and then deteriorated. Results indicate that older children were more likely to improve and then deteriorate. Younger children were more likely to improve and sustain those improvements. Results indicate that practicing the task of estimating is not an effective way to increase accuracy and may be contra-indicated. These results can help guide research and clinical use of glucose estimation in children.     

Priming problem solving with conceptual processing of relevant objects

In the present study, the author explored the effect of processing relevant information on producing solutions to brief insight problems. She hypothesized that the conceptual processing of objects relevant to the target solution would facilitate that solution relative to unrelated objects or the shallow processing of words. The author also explored the effect of knowledge of the relationship between the initial object-processing task and the problem-solving task. The results showed that participants who conceptually processed objects related to the target solution (Experiment 1), but not those who shallowly processed words related to the target solution (Experiment 2), were more likely to produce the solution relative to the control; and knowledge of the relationship between objects and solutions made no difference in the frequency of target solutions produced. The results of Experiment 3 showed that conceptual processing of an object could prime a nondominant solution for an ambiguously worded problem. Taken together, the results of the studies supported the effect of conceptual processing on facilitating insight in problem solving.     

Modeling the effects of prior knowledge on learning incongruent features of category members

The authors conducted 3 experiments addressing the issue of how observations and multiple sources of prior knowledge are put together in category learning. In Experiments 1 and 2, learning was faster for critical features, which were predictable on the basis of prior knowledge, than for filler features, and this advantage increased as more observations were made. In addition, learning was fastest for incongruent features that could only be predicted using knowledge from other domains. In Experiment 3, presenting contradictory features that violated prior knowledge led to rote learning rather than use of prior knowledge. The results were simulated with the Baywatch model, which addresses how observations of category members lead to recruitment and selection of sources of prior knowledge.     

Using logistic regression to estimate delay-discounting functions

The monetary choice questionnaire (MCQ) and similar computer tasks ask preference questions in order to ascertain indifference, the perceived equivalence of immediate versus larger delayed rewards. Indifference data are then fitted with a hyperbolic function, summarizing the decline in perceived value with delay time. We present a fitting method that estimates the hyperbolic parameterk directly from survey responses. Binary preferences are modeled as a function of time (X₂) and a transformed reward ratio (X ₁), yielding logistic regression coefficients β₂ and β₁. The hyperbolic parameter emerges ask = β₂/β₁, where the logistic predictedp = .5 (the definition of indifference). The MCQ was administered to 1,073 adolescents and was scored using both standard and logistic methods. The means for ln(k) were similar (standard, −4.53; logistic, −4.51), and the results were highly correlated (ρ = .973). Simulated MCQ data showed thatk was unbiased, except where β₁ ≥ −1, indicating a vague survey response. Jackknife standard errors provided excellent coverage.     

Inhibition and attention deficit hyperactivity disorder in adults

The inhibitory account of attention deficit hyperactivity disorder (ADHD) was tested by examining the performance of college-aged adults on a variety of inhibitory tasks. The poorer performance of adults with ADHD compared with controls on negative priming, stopping, and continuous performance tasks, combined with similar group performances on a test of working memory capacity, indicates a specific inhibitory deficit as opposed to a general limitation in attentional capacity. Overall results provide evidence for extending the inhibitory deficit hypothesis to adult ADHD, not only for mechanisms of response (or motor) inhibition but also for mechanisms of cognitive inhibition.