Effect of deviations from temporal expectations on tempo discrimination of isochronous tone sequences

The effect of deviations from temporal expectations on tempo discrimination was studied in 3 experiments using isochronous auditory sequences. Temporal deviations consisted of advancing or delaying the onset of a comparison pattern relative to an "expected" onset, defined by an extension of the periodicity of a preceding standard pattern. An effect of onset condition was most apparent when responses to faster and slower comparison patterns were analyzed separately and onset conditions were mixed. Under these conditions, early onsets produced more "faster" judgments and lower thresholds for tempo increases, and late onsets produced more "slower" judgments and lower thresholds for tempo decreases. In another experiment, pattern tempo had a similar effect: Fast tempos led to lower thresholds for tempo increases and slow tempos led to lower thresholds for tempo decreases. Findings support oscillator-based approaches to time discrimination.     

The development of verbal memory in childhood and adolescence: Findings from the Munich Longitudinal Study.

The authors assessed developmental changes in verbal memory from the beginning of elementary school to late adolescence on the basis of data from the Munich Longitudinal Study. Major issues concern the stability of individual differences in strategy use as well as interrelationships among different components of verbal memory and the impact of educational context on verbal memory development. Long-term stability of strategic memory was low to moderate in late childhood and adolescence. Interrelations among the verbal memory components were also moderate and did not change much over time. Unexpectedly, no impact of educational context was found. Overall, individual differences in verbal memory performance develop very early in life and are relatively unaffected by differences in educational experiences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Parental meta-emotion philosophy and the emotional life of families: Theoretical models and preliminary data.

This article introduces the concepts of parental meta-emotion, which refers to parents' emotions about their own and their children's emotions, and meta-emotion philosophy, which refers to an organized set of thoughts and metaphors, a philosophy, and an approach to one's own emotions and to one's children's emotions. In the context of a longitudinal study beginning when the children were 5 years old and ending when they were 8 years old, a theoretical model and path analytic models are presented that relate parental meta-emotion philosophy to parenting, to child regulatory physiology, to emotion regulation abilities in the child, and to child outcomes in middle childhood. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analysis of single trials in pigeons' timing performance.

Response distributions of pigeons on the peak procedure, averaged over many trials, were well fitted by a Gaussian function plus either a straight line or a ramp. But, each of 11 distributions analyzed showed a systematic positive skew. Response distributions on individual trials showed break–run–break patterns with abrupt transitions in the rate of responding. Within the run phase was an inner run phase at yet a higher rate. Intercorrelations among the starting time, ending time, middle, duration, and rate of the run showed a similar pattern in the outer and inner runs. A positive correlation between starting and ending times suggests variance across trials in clock speed, delay to start the clock, or expected time of reward. A negative correlation between starting time and duration suggests variance across trials in the threshold or thresholds to start and end the run. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-specific problems in rhythmic timing.

The authors investigated performance in 2 rhythm tasks in young (M?=?23.8 years) and older (M?=?71.4 years) amateur pianists to test whether slowing of a central clock can explain age-related changes in timing variability. Successive keystrokes in the rhythm tasks were separated by either identical (isochronous) time intervals or varying (anisochronous) intervals. Variability was comparable for young and older adults in the isochronous task; pronounced age effects were found for the anisochronous rhythm. Analyses of covariances between intervals rule out slowing of a central clock as an explanation of the findings, which instead support the distinction between target specification, timekeeper execution, and motor implementation proposed by the rhythm program hypothesis (D. Vorberg & A. M. Wing, 1996). Age stability was found at the level of motor implementation, but there were age-related deficits for processes related to target-duration specification. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evidence for a 40-Hz oscillatory short-term visual memory revealed by human reaction-time measurements.

Four experiments show that presentation of a synchronous premask frame within a 40-Hz, flickering premask matrix primes subsequent detection of a Kanizsa-type square by generation of a 40-Hz prime. Reaction time (RT) priming effects indicated a 150–200-ms prime duration following premask display. RTs were also found to be sensitive to the phase relationship between offset of the premask display relative to the onset time of the target: Priming effects were maximal when the target was presented out of phase with premask presentation (i.e., at interstimulus intervals displaced by 180° relative to the 40-Hz rhythm of premask-frame presentation). Taken together, these results demonstrate the existence of a very short-term visual memory that oscillates at 40 Hz. The findings are discussed in the context of complementary psychological and neurophysiological findings related to visual-object coding and the role of gamma-band activity in the brain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The interplay between metric and figural rhythmic organization.

Three experiments investigated the relative importance of figural and metric rhythmic organizations. Figural organization is determined by the numbers of tones in successive groups. For figural organization alone, the timings between the onsets of each group are relatively unavailable, so listeners cannot discriminate between 2 rhythms that have the same sequence of groups but different timings between the groups. Thus, traditional views argue that a metric organization is necessary: The timing between adjacent groups is perceived by means of the strong-weak sequence of beats. These experiments, however, suggest a limited role for meter. The metric strength of the individual rhythms affected discrimination of pairs of different rhythms with the same figural organization only when an external meter pulse accompanied the rhythm and only when the rhythm with the stronger meter was the first of the pair. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

High-resolution HLA typing for the DRB3/4/5 genes by sequence-based typing

The mechanisms underlying the circadian rhythm of methotrexate (MTX)-induced toxicity (body weight loss and leukopenia) were investigated from the viewpoints of the sensitivity of living organisms to the drug and the pharmacokinetics of the drug. ICR male mice were housed in a standardized light-dark cycle (lights on at 0700, off at 1900) with food and water ad libitum. The body weight loss after an intraperitoneal injection of MTX (400 mg/kg) was more serious in the late dark period and the early light period and milder in the late light period and the early dark period. The MTX-induced leukopenia was more serious in the late dark period and the light period and milder in the early dark period. Lower toxicity was observed when DNA synthesis, dihydrofolate reductase (DHFR) activity in bone marrow cells and folate level in plasma decreased, and higher toxicity was observed when they increased. There was a significant circadian rhythm in plasma MTX concentration, with a higher level in the light period and a lower level in the dark period. The circadian rhythm of plasma MTX concentration was associated with that of MTX-induced toxicity. The present study suggests that the circadian rhythm of MTX-induced toxicity is caused by that of the sensitivity of living organisms to the drug and the pharmacokinetics of the drug.     

Comprehensive computerized assessment of cognitive sequelae of a complete 12-16 hour fast.

Food deprivation has been shown to deleteriously affect human cognition, but findings are equivocal, and few studies have examined several cognitive domains. In this study, the authors used computerized testing to describe the profile of shifts in cognition attributable to short-term religious fasting. Multiple cognitive domains were evaluated at midday and late afternoon following complete abstention from eating and drinking beginning at midnight. Cross-domain, fasting-related deficits were found for tasks requiring perception of spatial relations. Fasting-related information processing deficits were found for response time but not accuracy for test levels of intermediate difficulty. Time-of-day effects often reflected poorer afternoon performance. These findings provide a detailed profile of cognitive consequences of food deprivation, affected by time of day, task demands, and type of outcome. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of stimulus–response probability on choice reaction time: Evidence from the lateralized readiness potential.

The lateralized readiness potential (LRP) was measured in 2-choice reaction time (RT) tasks with unequally probable stimuli and responses. Responses were faster and more accurate in high- than in low-probability trials. LRPs indicated that participants prepared the high-probability response and suggested that this preparation speeded high-probability responses relative to low-probability responses. When stimulus onset was temporally predictable, the high-probability response was clearly prepared prior to stimulus onset. When stimulus onset was unpredictable, preparation of the high-probability response occurred just after stimulus onset, even on low-probability trials where this preparation was inappropriate. With unpredictable stimulus onsets, RT distributions were adequately represented by a mixture model with prepared versus unprepared states; with predictable onsets, they were not. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Flat-panel digital radiology with amorphous selenium and active-matrix readout

The influence of respiratory activity of the abdominal muscles on their reaction time in a postural task was evaluated. The electromyographic (EMG) onsets of the abdominal muscles and deltoid were evaluated in response to shoulder flexion initiated by a visual stimulus occurring at random throughout the respiratory cycle. Increased activity of the abdominal muscles was produced by inspiratory loading, forced expiration below functional residual capacity, and a static glottis-closed expulsive maneuver. During quiet breathing, the latency between activation of the abdominal muscles and deltoid was not influenced by the respiratory cycle. When respiratory activity of the abdominal muscles increased, the EMG onset of transversus abdominis and internal oblique, relative to deltoid, was significantly earlier for movements beginning in expiration, compared with inspiration [by 97-107 ms (P < 0.01) and 64-90 ms (P < 0.01), respectively]. However, the onset of transversus abdominis EMG was delayed by 31-54 ms (P < 0.01) when movement was performed during a static expulsive effort, compared with quiet respiration. Thus changes occur in early anticipatory contraction of transversus abdominis during respiratory tasks but they cannot be explained simply by existing activation of the motoneuron pool.     

Word learning in predictable text.

Predictable text has become widely used for beginning readers but has not been the subject of much research. This study used predictable books to compare 3 reading treatments reflecting different components of a whole-to-part instructional model. In 3 first-grade classrooms, beginning readers working with isolated words in a modified word bank activity learned more words than when they worked with sentence strips. They also learned more words using sentence strips than when they simply read and reread the books. There was a significant treatment effect, justifying the theoretical position that beginning readers learn more words when those words are removed from the supportive context offered by predictable text. Students with higher levels of literacy skill learned 5 times as many words as those with lower levels. The overall number of words learned in these predictable books appears limited. These findings have important implications for the use of texts in beginning reading programs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dynamics of EEG spindle frequency activity during extended sleep in humans: relationship to slow-wave activity and time of day

The dynamics of EEG spindle frequency activity (SFA; spectral power density in the 12.25-15.0 Hz range) and its relationship to slow-wave activity (SWA; 0.75-4.5 Hz) were investigated in long sleep episodes (> 12 h). Young healthy men went to bed at either 19:00 h (early sleep; prior waking 36 h, n = 9) or 24:00 h (late sleep; prior waking 17 h, n = 8). In both nights, SWA in non-rapid-eye-movement sleep (NREMS) decreased over the first three to four 1.5-h intervals and remained at a low level in the subsequent five to six 1.5-h intervals. In contrast, the changes of SFA were more variable and differed between the lower (12.25-13.0 Hz), middle (13.25-14.0 Hz) and higher frequency bin (14.25-15.0 Hz). A pronounced influence of time of day was present in the lower and higher SFA bin, when the dynamics were analyzed with respect to clock time. In both the early and late sleep condition, power density in the lower bin was highest between 2:00 and 5:00 h in the morning and decreased thereafter. In the higher bin, power density was low in the early morning hours and increased as sleep was extended into the daytime hours. The results provide further evidence for a frequency-specific circadian modulation of SFA which becomes more evident at a time when SWA is low.     

Day/night differences in the stimulation of adenylate cyclase activity by calcium/calmodulin in chick pineal cell cultures: evidence for circadian regulation of cyclic AMP

In chick pineal cell culture, stimulation of adenylate cyclase with the diterpene forskolin was greater during the subjective night than during the subjective day. This rhythm of cyclic AMP (cAMP) stimulation mimicked the rhythm of unstimulated cAMP measured previously during LD cycles from flow-through culture. Direct measurement of adenylate cyclase activity in permeabilized cells revealed an adenylate cyclase activity activated by Ca2+/calmodulin during the night but not during the day. However, this difference in adenylate cyclase activity at two times of the circadian cycle is apparent only when permeabilized cells were prewashed with buffer containing GTE When cAMP was measured from flow-through cultures maintained in continuous darkness to determine whether a circadian clock may regulate cAMP, a low-amplitude rhythm was measured. The circadian rhythm of cAMP was similar to the cAMP rhythm previously measured on LD cycles except that the rhythm in darkness had a lower amplitude. Similar to the suppression of melatonin, cAMP was suppressed by light presented during the middle of the night. LD differences in nocturnal cAMP levels were abolished with dipyridamole, an inhibitor of cyclic GMP (cGMP) phosphodiesterase. These results suggest that the rhythm of cAMP in chick pineal cells involves the stimulation of adenylate cyclase by Ca2+/calmodulin during the night and a GTP-dependent suppression of adenylate cyclase activity during the day. The photic suppression of cAMP at night involves the activation of a dipyridamole-sensitive, cGMP phosphodiesterase.     

Aging, rhythms of physical performance, and adjustment to changes in the sleep-activity cycle

OBJECTIVES: Shiftwork causes disturbances of the normal sleep-wake cycle and circadian rhythm. There is concern that aging workers have more problems than younger counterparts when the human body clock is disrupted. This review considers issues relating to aging, the circadian body clock, and adjustment to altered sleep-wake schedules. METHODS: Reports on effects of aging on the human body clock were reviewed. Research concerned with adjustment to circadian phase shifts (as occurs in night work) was considered. RESULTS: With aging there is an increased tendency towards morningness which is linked with difficulties in sleeping. The peak time and amplitude of normal circadian rhythms are altered. Tolerance of shiftwork can be linked with social factors as well as adaptation of the body clock. CONCLUSIONS: People habituated to night work seem to have developed mechanisms which allow them to cope with disruptions to lifestyle and the endogenous body clock. Elderly people are more suited to phase advances, as occur in morning workshifts, than to phase delays such as nocturnal work.     

Regulation mechanism of melatonin rhythm in the pineal gland by light: experimental studies by in vivo microdialysis

Light has dual effects on the pineal melatonin; one is the entrainment of the circadian rhythm and the other is suppression of the melatonin synthesis. It is not known whether the entraining and suppressing effects of light are mediated by the same pathway or not. To elucidate the mechanism of the dual effects of light, (1) the sensitivity of the retina, (2) effects of acetylcholine agonist and, (3) the arrhythmicity induced by longterm continuous light, were studied by measuring melatonin continuously from a single rat by means of in vivo microdialysis. Pineal melatonin was suppressed by light more strongly at the late dark phase than at midnight, and by green light (520nm) than by red light (660nm). Pineal melatonin measured by microdialysis was decreased rapidly by a short light exposure and the melatonin rhythm was shifted on the following days. Microinjection of cholinergic agonist, carbachol, into the suprachiasmatic nucleus neither suppressed nor entrained the pineal melatonin rhythm. Immediately after the blinding, rats showed the circadian rhythm in pineal melatonin which had been abolished under long-term continuous light. While, it took several days for the locomotor rhythm to reappear. It is concluded that, (1) suppression of the pineal melatonin by light depends on the circadian phase and on the wavelength of light, (2) the threshold for light suppression is lower than that for phase-shift, (3) the melatonin rhythm starts to phase-shift on the following day of light pulse. (4) Acetylcholine is unlikely to be involved in the photic transmission both to the circadian clock and to the pineal, (5) arrhythmicity induced by long-term continuous light seems to be due to masking for the melatonin rhythm, and to uncoupling from the clock for the locomotor rhythm.     

Differential performance of TRISS-like in early and late blunt trauma deaths

OBJECTIVES: (1) To independently validate the Trauma and Injury Severity Score-Like (TRISS-Like) model derived by Offner et al. (Revision of TRISS for intubated patients. J Trauma. 1992;32:32-35) in a population of Canadian blunt trauma victims, and (2) to compare the ability of this model to predict mortality in early and late trauma deaths. STUDY POPULATION: Prospective cohort of blunt trauma cases with Injury Severity Score > 12 identified from the Ontario Trauma Registry over a 5-year period. STUDY DESIGN: The TRISS-Like model consisting of age, Injury Severity Score, systolic blood pressure, and best motor response of the Glasgow Coma Scale was evaluated as to its ability to predict mortality by determining the sensitivity, specificity, and the area under the receiver operating characteristic curve. The sample was then divided into early (< or = 7 days) and late mortality subgroups in which model performance was evaluated with respect to time of death. RESULTS: A total of 7,703 patients were included in this analysis. The overall mortality was 12.3%. The TRISS-Like model allowed for assessment of an additional 23% of patients than would standard TRISS and performed with a sensitivity of 97.1%, specificity of 39.8% and an area under the receiver operating characteristic curve of 0.873. Analysis of mortality with respect to time demonstrated that 75% of deaths occurred by day 7. The specificity and receiver operating characteristic area increased in the early (< or = 7 days) subgroup, 46.5% and 0.935, respectively, compared with 20.8% and 0.778 in the late mortality group. CONCLUSIONS: TRISS-Like demonstrated similar performance to that reported with the standard TRISS model but with the additional advantage that it is more generalizable because it can be applied to intubated patients. TRISS-Like demonstrated substantially superior performance in early trauma deaths compared with those that occurred late. This differential performance may be because the model does not include risk factors for late mortality.     

Personality and patterns of adherence and nonadherence to the social clock.

Illustrated how the concepts of "social clock project" and "pattern" may be applied by examining the results of a questionnaire administered at college graduation; scores from the California Psychological Inventory administered in college, 5 yrs after graduation, and 21–23 yrs after graduation; and questionnaires administered during the 2 follow-up periods to 104 42–45 yr old women. Results show that personality characteristics were related to life outcomes across the 1st 20 yrs of adulthood. 70 Ss who had their 1st child by age 28 were on the feminine social clockwork; 20 Ss were late adherents, having their 1st child after age 28; remaining Ss followed neither social clock pattern, or they followed a masculine occupational clock. It is suggested that, having described social clock projects and their normative time parameters, the relative goodness of fit between individuals' needs and the ecology of nested contexts in which they feel they must try to gratify them can be examined. (76 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Predicting risk for pregnancy by late adolescence: A social contextual perspective.

To evaluate a model of social contextual influences on risk for adolescent pregnancy, 368 target adolescents (52% female, 48% male) and their mothers, fathers, and closest age siblings were assessed 6 times over a 7-year period beginning when the target adolescents were in 7th grade. Two pathways were found to increase risk for involvement in a pregnancy by late adolescence. Middle adolescent risk-taking behavior mediated the influence of early adolescent parental warmth–involvement and deviant-peer affiliations on involvement in a pregnancy by 12th grade. Also, early adolescent academic competence mediated the relationship between parental warmth–involvement and involvement in a pregnancy by 12th grade. Theoretical and practical implications of the results are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)