Hemispheric asymmetries of near-far spatial attention.

Although most of the visual cognitive activities performed by the left hemisphere take place close to the body (peripersonal space), most visual cognitive activities mediated by the right hemisphere take place in extrapersonal space. The left hemisphere, therefore, may have a propensity to direct attention toward the body and the right hemisphere away from the body. Because attentional bias influences judgments of spatial magnitude, the authors tested this hypothesis. Normal participants were asked to compare the size of horizontal lines presented in the sagittal plane in either right or left hemispace. When participants looked leftward, lines appeared shorter than when participants looked rightward. These results are consistent with the hypothesis that the right hemisphere directs attention toward visual extrapersonal space and the left hemisphere directs attention toward visual peripersonal space. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hemispheric laterality and memory bias for threat in anxiety disorder.

Examined auditory perceptual asymmetries and explicit memory biases for threat in patients with panic disorder and generalized anxiety disorder relative to healthy control Ss. They did not find a greater explicit memory bias for threat in the anxiety patients. However, explicit memory biases for threat were associated with perceptual asymmetry scores; patients with a greater right-ear (left hemisphere) advantage exhibited an explicit memory bias for threat material, whereas patients with a lower right-ear advantage displayed apparent cognitive avoidance of threat material. Memory for threat words was unrelated to perceptual asymmetry in healthy control Ss. These findings suggest that neuropsychological variables may partly determine the degree to which anxiety patients process threatening stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hemispheric asymmetries for global and local visual perception: Effects of stimulus and task factors.

Although neurological and physiological studies indicate a right hemisphere superiority in global processing and a left hemisphere superiority in local processing of Navon-type hierarchical letters (D. Navon, 1977), most investigations of lateralized perception in healthy participants report neither asymmetry. In 6 experiments the authors examined the influence of attentional demands, stimulus properties, and mode of response on perceptual asymmetries for global and local perception. Consistent with their theoretical predictions, asymmetries were more robust on divided- than focused-attention tasks and in response to stimuli in which local and global levels were equally salient compared with those with greater global than local saliency. Contrary to their prediction, perceptual asymmetries were not influenced by the complexity of the motor response. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Role of the input in visual hemispheric asymmetries.

Because the nature of the input is one of the most important variables in determining how the brain will process information, findings from tachistoscopic studies aimed at assessing hemispheric lateralization of functions are examined in terms of the characteristics of the incoming information either available or required for processing. The basic features of tachistoscopic experiments are analyzed with a special emphasis on methodology. Variables determining the quality of the input are investigated as a function of the properties of the human visual system. Exposure duration, luminance, retinal eccentricity, and stimulus size all contribute to the efficiency of the hemispheres and interact in complex ways in the emergence of visual-field superiorities. Task demands are also examined in terms of the information necessary for efficient processing. The present review suggests that in tachistoscopic experiments, the factors determining the quality of the input must be controlled if this technique is to prove a reliable source of information for assessing hemispheric asymmetries. (5 p ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hemispheric asymmetries in vigilance and cerebral arousal mechanisms in younger and older adults.

Younger and older adults responded to an asterisk presented to either the left or right visual field, with delay interval between onset of a fixation cross and onset of the asterisk varied. At delay intervals longer than 3 s, reaction time was faster when the same visual field was stimulated on 2 successive trials than when different visual fields were stimulated. This prefield effect was larger in the left visual field (right hemisphere), consistent with hypotheses of hemispheric asymmetry for arousal and vigilance. For older adults, these results were obtained only when participants responded with the left hand, suggesting that some aspects of hemispheric asymmetry for attention-related processing or the efficiency of interhemispheric transfer may change in an age-related fashion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Directional asymmetries in interhemispheric transmission time: evidence from visual evoked potentials

The hypothesis was tested that interhemispheric transfer time (IHTT), as measured in the latency of bilaterally recorded visual evoked potentials, is directionally asymmetric, i.e. that an IHTT is faster for transmission from right-to-left hemisphere, than from left-to-right. A meta-analysis of 18 experiments within the published literature reporting visual evoked potential IHTTs indicates a significant experiment-wise predominance of faster right-to-left IHTTs. A new experiment is also reported in which significantly faster right-to-left IHTT was found in visual evoked potentials recorded from parietal electrodes to lateral visual field presentations while subjects performed a task requiring complex stimulus recognition and analysis, and a choice response.     

Obesity: Responding to the global epidemic.

Obesity has reached epidemic proportions in the United States and other developed nations. In the United States, 27% of adults are obese and an additional 34% are overweight. Research in the past decade has shown that genetic influences clearly predispose some individuals to obesity. The marked increase in prevalence, however, appears to be attributable to a toxic environment that implicitly discourages physical activity while explicitly encouraging the consumption of supersized portions of high-fat, high-sugar foods. Management of the obesity epidemic will require a two-pronged approach. First, better treatments, including behavioral, pharmacologic, and surgical interventions, are needed for individuals who are already obese. The second and potentially more promising approach is to prevent the development of obesity by tackling the toxic environment. This will require bold public policy initiatives such as regulating food advertising directed at children. The authors call not for the adoption of a specific policy initiative, but instead propose that policy research, based on viewing obesity as a public health problem, become a central focus of research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

New age-linked asymmetries: Aging and the processing of familiar versus novel language on the input versus output side.

This research demonstrates 3 new age-linked asymmetries between identifying versus retrieving phonological information. Young and older adults read aloud familiar isolated words (e.g., mind) and novel pseudowords (e.g., mond) in a production task and identified lexical status for identical stimuli in a comprehension task. Young adults made fewer errors than older adults in production but not comprehension (an age-related input-output asymmetry), and they produced pseudowords but not words with fewer errors than older adults (a lexical-status asymmetry). The lexical-status asymmetry also occurred for response onset times but not for output durations (an onset-output asymmetry). All 3 asymmetries were predicted under the transmission deficit hypothesis (D. G. MacKay & D. M. Burke, 1990) but contradict theories such as general slowing that cannot explain why aging affects some types of information processing more than others. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A comparative MRI study of the relationship between neuroanatomical asymmetry and interhemispheric connectivity in primates: Implication for the evolution of functional asymmetries.

The authors tested the theory that hemispheric specialization evolved as a consequence of reduced interhemispheric connectivity by examining whether neuroanatomical asymmetries were associated with variation in the ratio of corpus callosum size to brain volume (CC:VOL) and to neocortical surface area (CC:NEO) in human and nonhuman primates. Magnetic resonance images were collected in a sample of 45 primates including 8 New World monkeys, 10 Old World monkeys, 4 lesser apes, 17 great apes, and 6 humans. CC:VOL and CC:NEO were determined and correlated with measures of brain asymmetry. The results indicate that brain asymmetry significantly predicted CC:VOL and CC:NEO. Subsequent analyses revealed that species variation in functional asymmetries in the form of handedness are also inversely related to CC: NEO. Taken together, these results support the hypothesis that leftward brain asymmetries may have evolved as a consequence of reduced interhemispheric connectivity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hemispheric asymmetries in the perception of rapid (timbral) and slow (nontimbral) amplitude fluctuations of complex tones.

Hemispheric asymmetries for processing rapid (timbral) and slow (nontimbral) amplitude fluctuations of complex tones were investigated in 32 right-handed nonmusicians. Two monaural matching-to-sample tests with contralateral white noise and attention directed to 1 ear were used, 1 with tones presenting slow fluctuations of amplitude and 1 with tones presenting rapid fluctuations of amplitude perceived as different timbres. Stimuli were generated by altering the amplitude envelope of a steady state complex tone. Dependent variables were reaction time and accuracy. The results suggest an important role for the right hemisphere in the perception of temporal variations of intensity of sounds both when these variations are rapid and perceived as timbral qualities and when they are slow and perceived as changes of loudness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging on the input versus output side: Theoretical implications of age-linked asymmetries between detecting versus retrieving orthographic information.

This experiment tested for age-linked asymmetries predicted under Node Structure theory (NST; D.G. MacKay & D. M. Burke, 1990) between detecting versus retrieving orthographic information. Older adults detected that briefly presented words were correctly spelled (e.g., endeavor) or misspelled (e.g., endeavuor) as readily as did young adults. However, they were less able than young adults to retrieve the correctly and incorrectly spelled words that they had seen. These age-linked asymmetries were not due to educational factors, stimulus characteristics, sensory-level factors, task complexity, floor or ceiling effects, general slowing, or cohort-related activities, but they were consistent with NST predictions and with similar asymmetries in a wide range of other studies. By contrast, repetition deficits in detecting and retrieving repeated- versus unrepeated-letter misspellings (e.g., elderdly vs. elderkly) were symmetrical or equivalent in magnitude for young and older adults. Implications for a wide range of theories of cognitive aging and of repetition deficits are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Investigations of interhemispheric processing: Methodological considerations.

This article is a review and critique of a number of methodological issues pertaining to investigations of information exchange and coordination between the cerebral hemispheres. The methods required to address issues of interhemispheric interaction are demonstrated to be distinct from those typically used in studies of lateralization of function. Methodology in this area is examined in reference to three main topics: (a) the requirements for illustrating that an effect is specific to the interaction of the hemispheres, (b) the requirements for demonstrating that interhemispheric processing relies on a particular neural substrates, and (c) the requirements for making inferences about the role of interhemispheric processing in certain neurobehavioral syndromes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Responding to the HIV epidemic: A national strategy.

Admiral James Watkins (Retired), the chairman of the Presidential Commission on the Human Immunodeficiency Virus Epidemic, discusses the work of the commission, including obstacles to progress the nation faces in attempting to respond to the epidemic and recommendations for improving the nation's response. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effectiveness of play therapy: Responding to the critics.

Notes that play therapy has long been criticized for a lack of adequate research base to prove its efficacy. For 6 decades, while play therapists conducted small research studies, critics challenged the utility and efficacy of play therapy as a viable psychotherapy intervention. The purpose of this study was to conduct a meta-analysis of 94 research studies focusing on the efficacy of play therapy, filial therapy, and combined play therapy and filial therapy. The following electronic databases were used in the authors 3-yr search for studies on play therapy: PsycLit, PsycINFO, ERIC, FirstSearch, and Dissertation Abstracts. Meta-analysis revealed a large positive effect on treatment outcomes with children. Play therapy appeared effective across modality, age, gender, clinical vs nonclinical populations, setting, and theoretical schools of thought. Additionally, positive play therapy effects were found to be greatest when there was parent involvement in treatment and an optimal number of sessions provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hemispheric contributions to nonverbal abstract reasoning and problem solving.

Hemispheric involvement in reasoning abilities has been debated for some time, and it remains unclear whether the right hemisphere's involvement in problem solving is modality specific or dependent on the type of spatial reasoning required. In the current study, 2 types of nonverbal reasoning abilities were examined, spatial reasoning and proportional reasoning, in 109 patients with cerebrovascular disease that was confined to either the right or the left hemisphere or was diffuse in nature. Results indicated that no lateralizing effects were present based on type of spatial reasoning. Findings are consistent with the suggestion that higher order cognitive processes involved in nonverbal abstraction and problem solving are not strongly lateralized to the right hemisphere but rather are more generally distributed throughout the cortex. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Responding to trauma—extraordinarily meaningful.

The behavioral and psychological component of trauma is critical. It is noted that the National Highway Traffic Safety Administration seeks to ensure that every citizen in the US is served by an organized and coordinated system of timely and effective emergency medical care. However, the field of emergency medical services is changing and these changes require new players and partners. States are focusing on inclusive systems of emergency medical care that encompass trauma care and injury prevention. Thus, behavioral scientists will play a greater role than ever before. An example is given of training for trauma intervention, in which a school of professional psychology operates the local hospital emergency room crisis service. Staffed by faculty and students, they triage, treat, or refer all mental health emergencies. A case is also made for more research on causation and prevention of accidental deaths and injury. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional bias to threat: A perceptual accuracy approach.

To investigate attentional bias to threatening information, the authors propose a new version of the spatial cueing paradigm in which the focus is on perceptual accuracy instead of response speed. In two experiments, healthy volunteers made unspeeded discriminations between three visual targets presented left or right. Each target was preceded by a visual cue (colored rectangle) at either the same (valid) or opposite (invalid) location. By means of differential classical conditioning with aversive white noise, a threat cue and a control cue were created. Analyses of error rates showed that cueing effects (lower proportion of errors in valid trials relative to invalid trials) were more pronounced in threat trials than in neutral trials. This threat-related bias was particularly because of threat cues reducing accuracy in invalid trials, indicating difficulty disengaging attention from threatening information. Engagement of attention was not affected by threat, as threat cues did not facilitate the processing of targets in valid trials. The findings are discussed in light of the strengths and limitations of spatial cueing tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The hardy personality: Cognitive and physiological responses to evaluative threat.

Hardy persons are hypothesized to be resistant to stress-induced illness, because of their adaptive cognitive style and a subsequently reduced level of physiological arousal. We assessed the cognitive and physiological responses of high and low hardy male undergraduates to a challenging task under high and low evaluative threat. As predicted, hardy subjects endorsed more positive self-statements than did low hardy subjects in the high treatment condition. High hardy subjects also reported fewer negative self-statements overall, but this was attributable to the overlap of measures of hardiness and neuroticism. Hardy subjects displayed marginally lower arousal while waiting for the task to begin, but this finding did not approach significance when neuroticism was controlled. Hardy subjects also had higher levels of systolic blood pressure, perhaps because of their active coping efforts. Results support the hypothesized hardy cognitive style but raise questions about the type and timing of organismic strain linking hardiness and health. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A major threat to children's mental health: Psychological maltreatment.

Psychological maltreatment appears to be more prevalent and potentially more destructive than other forms of child abuse and neglect. However, it receives little attention from the public or professional sector and is seldom the target of research or intervention. This article reviews the literature and concludes that psychological maltreatment is the core issue in child maltreatment and poses a serious mental health threat that should be brought to the forefront of psychology's efforts in policy development, research, intervention, and prevention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Responding to membership in a disadvantaged group: From acceptance to collective protest.

The question addressed is, when do disadvantaged-group members accept their situation, take individual action, or attempt to instigate collective action? Ss attempted to move from a low-status group into an advantaged, high-status group and were asked to respond to their subsequent rejection. Ss who believed that the high-status group was open to members of their group endorsed acceptance and individual actions. When access to the high-status group was restricted, even to the point of being almost closed (tokenism), Ss still preferred individual action. Disruptive forms of collective action were only favored by Ss who were told that the high-status group was completely closed to members of their group. Ss who believed they were near to gaining entry into the high-status group favored individual protest, while Ss distant from entry were more likely to accept their position. The theoretical and societal implications of these findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)