Accentuate the negative: the positive effects of negative acknowledgment

Three studies investigated the capacity of negative acknowledgment, the admission of an unfavorable quality, to elicit relatively positive responses. In Study 1, an acknowledgment that a written paragraph was confusing led individuals to rate the paragraph as clearer than they did when no acknowledgment was offered. In Study 2, a foreign speaker was rated as possessing a clearer voice when he acknowledged his strong accent than when he did not. In Study 3, a hypothetical college applicant's acknowledgment of receiving less than stellar high school grades resulted in a more positive evaluation of those grades. The interpersonal risks and benefits of negative acknowledgment as an impression-management strategy are discussed.     

Visual noise reveals category representations

How are categories represented in human memory? Exemplar models assume that a category is represented by individual instances from that category that have been experienced. More generally, a category might be represented by multiple templates stored in memory. A new item is classified according to its similarity to these templates.Prototype models represent a category with a single summary abstraction (i.e., a single template), often the central tendency of the experienced items. A new item is classified according to its similarity to these category prototypes. Here, we show how a technique for correlating observers’ responses with external noise can be used not only to distinguish single- from multiple-template representations, but also to induce the form of these templates. The technique is applied to two tasks requiring categorization of simple visual patterns; the results demonstrate that observers used multiple traces to represent their categories, and thus highlight the procedure’s potential for use in more complex settings.     

Imitation of hierarchical action structure by young children

To provide the first systematic test of whether young children will spontaneously perceive and imitate hierarchical structure in complex actions, a task was devised in which a set of 16 elements can be modelled through either of two different, hierarchically organized strategies. Three-year-old children showed a strong and significant tendency to copy whichever of the two hierarchical approaches they witnessed an adult perform. Responses to an element absent in demonstrations, but present at test, showed that children did not merely copy the chain of events they had witnessed, but acquired hierarchically structured rules to which the new element was assimilated. Consistent with this finding, children did not copy specific sequences of actions at lower hierarchical levels.     

A daytime nap containing solely non-REM sleep enhances declarative but not procedural memory

The specialized role that sleep-specific brain physiology plays in memory processing is being rapidly clarified with a greater understanding of the dynamic, complex, and exquisitely orchestrated brain state that emerges during sleep. Behaviorally, the facilitative role of non-REM (NREM) sleep (primarily slow wave sleep) for declarative but not procedural memory performance in humans has been demonstrated in a number of nocturnal sleep studies. However, subjects in these studies were tested after periods of sleep that contained REM sleep in addition to NREM sleep, and comparison wake groups were subjected to mild sleep deprivation. To add some clarity to the findings of these nocturnal studies, we assessed performance on declarative and procedural memory tasks following a daytime training-retest interval containing either a short nap that included NREM without REM sleep, or wakefulness. Consistent with previous findings we show that, after a comparatively brief sleep episode, subjects that take a nap improve more on a declarative memory task than subjects that stay awake, but that improvement on a procedural memory task is the same regardless of whether subjects take a nap or remain awake. Slow wave sleep was the only sleep parameter to correlate positively with declarative memory improvement. These findings are discussed with reference to the general benefits of napping and within the broader context of a growing literature suggesting a role for NREM-specific physiology for the processing of declarative memory.     

Genetics of emotional regulation: the role of the serotonin transporter in neural function

Identifying biological mechanisms through which genes lead to individual differences in emotional behavior is paramount to our understanding of how such differences confer risk for neuropsychiatric illness. The emergence of techniques such as in vivo imaging of brain function in humans and genetic engineering in rodents has provided important new insights into the impact of serotonin (5-HT), a key modulator of emotional behavior, on neural systems subserving anxiety and depression. A major finding has been the discovery of genetic variation in a crucial regulatory molecule within the 5-HT system, the 5HT transporter (5-HTT), and its influence on emotional traits. The study of the 5-HTT provides a new foundation for understanding the neurobiological and genetic basis of emotional regulation and affective illness.     

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.     

Intramuscular electrical stimulation of facial muscles in humans and chimpanzees: Duchenne revisited and extended

The pioneering work of Duchenne (1862/1990) was replicated in humans using intramuscular electrical stimulation and extended to another species (Pan troglodytes: chimpanzees) to facilitate comparative facial expression research. Intramuscular electrical stimulation, in contrast to the original surface stimulation, offers the opportunity to activate individual muscles as opposed to groups of muscles. In humans, stimulation resulted in appearance changes in line with Facial Action Coding System (FACS) action units (AUs), and chimpanzee facial musculature displayed functional similarity to human facial musculature. The present results provide objective identification of the muscle substrate of human and chimpanzee facial expressions- data that will be useful in providing a common language to compare the units of human and chimpanzee facial expression.     

Timing in cognition and EEG brain dynamics: discreteness versus continuity

This article provides an overview of recent developments in solving the timing problem (discreteness vs. continuity) in cognitive neuroscience. Both theoretical and empirical studies have been considered, with an emphasis on the framework of operational architectonics (OA) of brain functioning (Fingelkurts and Fingelkurts in Brain Mind 2:291-29, 2001; Neurosci Biobehav Rev 28:827-836, 2005). This framework explores the temporal structure of information flow and interarea interactions within the network of functional neuronal populations by examining topographic sharp transition processes in the scalp EEG, on the millisecond scale. We conclude, based on the OA framework, that brain functioning is best conceptualized in terms of continuity-discreteness unity which is also the characteristic property of cognition. At the end we emphasize where one might productively proceed for the future research.     

Categorical and dimensional reports of experienced affect to emotion-inducing pictures in depression

Self-reported affect to positive and negative emotional pictures was contrasted in people with major depressive disorder (MDD) and never-depressed control participants (n = 25 in each group). The results revealed significant differences in response to positive images (reduced arousal, less pleasant valence, decreased happiness, increased sadness) in MDD but no clear group differences in response to negative stimuli. Extending earlier findings of reduced responsiveness to positive, but not negative, stimuli in MDD (D. M. Sloan, M. E. Strauss, S. W. Quirk, & M. Satajovik, 1997; D. M. Sloan, M. E. Strauss, & K. L. Wisner, 2001), the data indicate that blunted response to positive stimuli is found when both categorical and dimensional ratings are elicited. Further, the data replicate earlier findings of elevated sadness reports to positive stimuli (J. Rottenberg, K. L. Kasch, J. J. Gross, & I. H. Gotlib, 2002), which may reflect broader difficulties in regulating emotions in MDD.     

Sleep quality, sleep propensity and academic performance

We examined associations between measures of sleep propensity on the Epworth Sleepiness Scale, sleep quality on the Pittsburgh Sleep Quality Index and academic performance by GPA and grades in introductory psychology for 414 students. In the total sample, neither sleep propensity nor sleep quality correlated with GPA or introductory psychology grades. However, among students carrying a full course load, those reporting poor sleep quality performed less well on academic measures than those reporting a better quality of sleep. Further research is needed to assess the moderating influence of overall demands of daytime functioning on the association between sleep quality and academic performance.