There is no central stimulus encoding during saccadic eye shifts: A case against general parallel processing notions

Three experiments are reported about the question whether perceptual processing of a signal viewed during a fixation, can continue during a subsequent saccadic eye shift to another signal. In the first experiment it was found that the size of the effect of degraded signal quality, measured in a traditional choice reaction task, was fully reflected in the duration of the fixation. The results of the second experiment showed that presentation time of the signal had no effect on fixation duration. In a final study the signal was preceded by a tone. Subjects were instructed to start the saccade upon hearing the tone, which had the effect that the signal was only briefly viewed. The results showed, first, that this instruction was hard to obey and, second, that, when obeyed, processing only continued when fixating the next signal and not during the saccade. Together, the results are most consistent with a serial sequence and difficult to reconcile with a parallel notion of perceptual encoding and saccadic shift.     

A comparison of the effects of child management and planned activities training in five parenting environments

This study compared the effects of two procedures designd to enhance the extratraining effects of behavioral parents training. Twenty parents of oppositianal children were randomly assign to either a child manangment training condition or a combined child management plus planned activity condition. A further 10 nonproblem children and their parents serve as a social validation group. Observation of both parents and children behavior were conducted in each of five home observation setting (breakfirst time, kindy (kindergarten) or school exit, a structured playtime, bathtime, and bedtime). Both training procedures result in change in both child oppositional and parents oversive behaviosr in all observation settings. In addition, desire positive parents behaviour also improve in all setting. Treatment effect were maintained in all setting at 3-month follow up. Composition between oppositional children following treatment and children in the social validation group showed that they each displayed similarly low lavels of oppositional behaviour in all settings. The inplecation of the results for faciliating generalised changes in behavioral parent training are discusssd.This study was supported by a grant from the National Health and Medical Research Council (NHMRC324 82 579049). We wish to thank all families, therapists, and observers who participated in the project.     

Awareness of subtle emotional feelings: a comparison of long-term meditators and nonmeditators

The authors explored whether meditation training to enhance emotional awareness improves discrimination of subtle emotional feelings hypothesized to guide decision-making. Long-term meditators and nonmeditators were compared on measures of self-reported valence and arousal, skin conductance response (SCR), and facial electromyography (EMG) to masked and nonmasked emotional pictures, and on measures of heartbeat detection and self-reported emotional awareness. Groups responded similarly to nonmasked pictures. In the masked condition, only controls showed discrimination in valence self-reports. However, meditators reported greater emotional clarity than controls, and meditators with higher clarity had reduced arousal and improved valence discrimination in the masked condition. These findings provide qualified support for the somatic marker hypothesis and suggest that meditation may influence how emotionally ambiguous information is processed, regulated, and represented in conscious awareness.     

Learning during the newborn's first meal: special resistance to retroactive interference

At their first postnatal meal, 3-hour-old rats learned an association between an odor and a sweet or bitter taste. Retention after a long interval or after associative interference was compared to that of 1-day-old rats. Despite equivalent and negligible effect of the long retention interval, contrary to infantile amnesia, newborns differed strikingly from 1-day-olds in susceptibility to associative interference. When lemon odor predicted saccharin in the first episode but quinine in the second, 1-day-olds had strong retroactive interference, but the newborn's first memory was unaffected by the second. The results were identical when the first memory was a lemon-quinine association and the second a lemon-saccharin association. It is uncertain whether this special robustness of memories associated with the first postnatal meal is best understood in terms of cognitive primacy or neurochemical and physiological consequences of the birth process.     

IQ stability: the relation between child and young adult intelligence test scores in low-birthweight samples

The stability of IQ from childhood to adulthood in low-birthweight subjects was measured in two independent samples with follow-up intervals of approximately 14 and 9.5 years. In both samples, intelligence was assessed with the WISC at a mean age of 9.5. Twenty-six subjects were retested with the WAIS at a mean age of 23.5, and 78 subjects with the BPP (the Danish Military Draft Board Intelligence Test) at the age of 19.1. Both samples obtained childhood and adult test scores below the expected means. For the Wechsler Verbal, Performance and Full-Scale IQs, the stability quotients were 0.86, 0.86, and 0.89 in the WAIS sample, and the retest correlations for the three IQs with the BPP score were 0.66, 0.65, and 0.74. Thus, the majority of children showed stable patterns of intellectual development from middle childhood to young adulthood.     

Pre-training prevents context fear conditioning deficits produced by hippocampal NMDA receptor blockade

These experiments explore parallels between the neurobiological substrates of spatial and context learning. Male Long-Evans rats were employed in a context fear conditioning protocol that involved sequential acquisition and testing in two distinct contexts. Rats received three unsignaled footshocks in one context and were tested for context fear, measured as freezing, the next day. Four days later, the procedure was repeated in a different, distinct context. Rats received a hippocampal infusion of either the NMDA receptor antagonist 5-amino-phosphonovaleric acid (APV, 10 microg) or vehicle prior to training in each context. NMDA receptor blockade was effective in impairing context learning only in the first context. Context fear acquisition was not impaired by APV in the second context, indicating that pre-training (in the first context) mitigated the effects of APV. These data agree with those seen previously in the water maze, where pre-training prevented learning deficits produced by NMDA receptor blockade. The data thus suggest that the neurobiological substrates of context learning and place learning overlap.