Determinants of cognitive outcomes of perinatal and childhood stroke: A review

Our understanding of cognitive and behavioral outcomes of perinatal and childhood stroke is rapidly evolving. A current understanding of cognitive outcomes following pediatric stroke can inform prognosis and direct interventions and our understanding of plasticity in the developing brain. However, our understanding of these outcomes has been hampered by the notable heterogeneity that exists amongst the pediatric stroke population, as the influences of various demographic, cognitive, neurological, etiological, and psychosocial variables preclude broad generalizations about outcomes in any one cognitive domain. We therefore aimed to conduct a detailed overview of the published literature regarding the effects of age at stroke, time since stroke, sex, etiology, lesion characteristics (i.e., location, laterality, volume), neurologic impairment, and seizures on cognitive outcomes following pediatric stroke. A key theme arising from this review is the importance of interactive effects among variables on cognitive outcomes following pediatric stroke. Interactions particularly of note include the following: (a) age at Stroke x Lesion Location; (b) Lesion Characteristics (i.e., volume, location) x Neurologic Impairment; (c) Lesion Volume x Time Since Stroke; (d) Sex x Lesion Laterality; and (e) Seizures x Time Since Stroke. Further, it appears that these relationships do not always apply uniformly across cognitive domains but, rather, are contingent upon the cognitive ability in question. Implications for future research directions are discussed.     

Recipients' affective responses to affirmative action interventions: A cross-cultural perspective

This study investigated whether individualism-collectivism (cultural) differences would account for the observed relationship between ethnic group status and affective responses to and fairness perceptions of affirmative action interventions. Forty-nine international (Latin America and East Asia), 116 minority, and 106 majority participants from a major southwestern university and its community provided fairness and affective response ratings to an affirmative action scenario. Implementation policy and qualification of the recipient were also manipulated. Though ethnicity was related to individualism-collectivism, the latter did not explain any variance in affective response ratings. Minority and international participants reported more positive affect and higher agreement and fairness levels than did majority participants. Participants in the preferential treatment and equally qualified conditions had more favorable responses than those in the reverse-discrimination and less qualified conditions.     

A longitudinal study of temperament in infancy: stability and convergence of measures

This study analyzed the stability of individual differences in temperament and the convergence between two kinds of measures used to assess temperament: maternal report (IBQ and TBAQ), and laboratory measures. Sixty children were assessed at 3, 6, 9 and 12 months of age and their mothers' reports were collected at the same time. Mothers' perceptions of their children's temperament showed high stability across the range of children's ages. In laboratory, however, moderate stability was found only for the period between 9 and 12 months. Convergence between laboratory and maternal report measures was found at 6 and 12 months. Copyright © 2000 John Wiley & Sons, Ltd.     

The global precedence effect is not affected in inhibition of return

This study assessed whether inhibitory processes occurring in IOR affect perceptual processing of hierarchically organised stimuli. Experiment 1 used a global/local task that presented stimuli to the left or the right side. Results showed a global task advantage and a larger interference in the local than in the global task—the global precedence effect (GPE). These effects were larger than in previous studies using centrally presented stimuli, which suggests a greater involvement of low spatial frequency analysis with peripheral than with central stimuli. Experiment 2 combined the global/local task with IOR. Results replicated those of Experiment 1 but there was no interaction with stimulus location. That is, the GPE was not affected in IOR. Thus, we conclude that the GPE and inhibitory processing occurring in IOR are subserved by different mechanisms.     

Processing of “unattended” threat-related information: Role of emotional content and context

Unpleasant, pleasant, or neutral visual scenes served as a context for the presentation of threat-related, positive, and neutral words. On each trial, 2 simultaneous prime words (one foveal, i.e., at fixation, and one parafoveal, i.e., 2.2° apart) appeared for 150 ms, followed by a foveally presented probe word in a lexical decision task. Results showed facilitation in response times for probe threat words when primed by an identical parafoveal word, in comparison with priming by an unrelated parafoveal word, and this effect was enhanced in an emotionally congruent unpleasant context. In contrast, no parafoveal effect appeared for positive words, even in a pleasant context. This reveals parallel processing of threat-related words outside the focus of attention.     

BRIEF REPORT: LATENCY FUNCTIONAL ANALYSIS OF ELOPEMENT

Elopement is a potentially dangerous problem behavior prevalent among individuals with developmental disabilities. However, functional analysis of elopement presents unique challenges including potential confounds because of the need for participant retrieval during functional analysis sessions. In the current study, we implemented a latency functional analysis with an eight‐year‐old child with an intellectual disability, in which the dependent measure was latency to elopement. Following the latency functional analysis, a functional communication intervention was developed and its effectiveness in decreasing elopement was evaluated using an ABAB design. Findings suggest that a functional analysis of latency may be a suitable methodology to identify the operant function of elopement. Copyright © 2013 John Wiley & Sons, Ltd.     

Enhancing recognition memory in adults through differential outcomes

It has been widely demonstrated that the differential outcomes procedure (DOP) facilitates both the learning of conditional relationships and the memory for the conditional stimuli in animal subjects. For conditional discriminations in humans, the DOP also produces an increase in the speed of acquisition and/or final accuracy. However, the potential facilitative effects of differential outcomes in human memory have not been fully assessed. In the present study, we aimed to test whether this procedure improves performance on a recognition memory task in healthy adults. Participants showed significantly better delayed face recognition when differential outcomes were used. This novel finding is discussed in the light of other studies on the differential outcomes effect (DOE) in both animals and humans, and implications for future research are presented.     

The effects of sleep deprivation on the attentional functions and vigilance

The study of sleep deprivation is a fruitful area of research to increase our knowledge of cognitive functions and their neural basis. In the current work, 26 healthy young adults participated in a sleep deprivation study, in which the Attentional Networks Test for Interactions and Vigilance (ANTI-V) was performed at 10a.m. after a night of normal sleep and again at 10 a.m. after 25.5-27.5 h of total sleep deprivation. The ANTI-V is an experimental task that provides measures of alerting, orienting and executive control attentional functions. Compared with previous versions, the ANTI-V includes a vigilance task, more reliable auditory alerting signals, non-predictive peripheral orienting cues, and also a neutral no-cue condition allowing the analysis of reorienting costs and orienting benefits. Thus, new evidence to evaluate the influence of sleep deprivation on attentional functioning is provided. Results revealed differences in both tonic and phasic alertness after sleep deprivation. Vigilance performance was deteriorated, while a warning tone was more helpful to increase participants' alertness, resulting in slightly faster RT and, in particular, fewer errors. The reorienting costs of having an invalid spatial cue were reduced after sleep loss. No sleep deprivation effect on the executive control measure was found in this study. Finally, since no control group was used, particular precautions were taken to reduce the influence of potential practice effects.     

Changes in Behaviour and Body Weight Following a Single or Double Social Defeat in Rats

In a series of experiments, the consequences of a single and double social conflict on various behaviours and body weight in rats were studied. Animals were subjected to social defeat by placing them into the territory of an aggressive male conspecific for one hour, either once, or twice at the same time on two consecutive days. To assess the consequences of social defeat, three experiments were performed with independent groups of rats. In the first experiment, an open field test was performed two days after the last conflict. Locomotor activity was strongly reduced after social defeat. There were no differences between the single and double defeat group. To assess the effects of social defeat on subsequent social behaviour, a second experiment was performed in which experimental animals were confronted with an unfamiliar non-aggressive rat two days after a single or double conflict. Social defeat resulted in a reduction of social contact with the unfamiliar conspecific. There was no difference between the single and double conflict group. In the third experiment, the effects of social conflict on food intake, body weight and saccharine preference were measured. Food intake was not affected after a single conflict, but in the double conflict group food intake was decreased for several days. Body weight gain was decreased after both single and double social defeat. The decrease was stronger in the double conflict group. Water intake and saccharine preference were not significantly affected. This study revealed that social defeat in rats causes pronounced changes in various behaviours and body weight. Different aspects of behaviour are differentially affected by defeat with respect to the magnitude and time course of the changes induced. Moreover, different behavioural parameters are differentially sensitive to repetition of the stressor.     

Recognition of Facial Expression in Diverging Socioeconomic Levels

Cerebral organization has been seen to vary in different social or ethnic groups; also, sociocultural retardation is a serious obstacle to development in poorer countries. The ability of the right hemisphere to recognize facial emotions in a tachistoscopic task was tested in university and low-socioeconomic-level subjects. All were male and right-handed. The university students recognized facial emotions projected to their left field-right hemisphere significantly better than with their right field-left hemisphere; the low-socioeconomic-level subjects showed no differences in hemispheric performance. The explanation of laterality as a function of social class may be of importance in dealing with sociocultural retardation.