Correct Temporal Order Research Articles

Measurement of temporal-order judgment in children

Abnormal auditory temporal processing might be an underlying deficit in language disabilities. The auditory temporal-order threshold, one measure for temporal processing abilities, is defined as the shortest time interval between two acoustic events necessary for a person to be able to identify the correct temporal order. In our study, we examined the reliability of the auditory temporal-order threshold during a one-week period and over a time interval of four months in normally developing children aged 5 to 11 years. The results of our method show that children younger than 7 years have difficulties performing the task successfully. The reliability of the assessment of the temporal-order threshold during a period of one week is only moderate, and its stability over a time interval of four months is low. The results show that auditory-order thresholds in children have to be treated with caution. A high temporal-order threshold does not necessarily predict disabilities in temporal processing.

Comparison of various RAVLT scores in the detection of noncredible memory performance

Sixty-one noncredible patients (as documented by psychometric and behavioral criteria) scored significantly below 25 controls and 88 credible clinic patients with no motive to feign on most RAVLT scores, including added indices of implicit and “automatic” memory. A combination of true recognition (i.e., recognition minus false positives) + implicit memory score (i.e., the number of word stems completed with RAVLT items) + “automatic” memory score (i.e., the number of correct temporal order judgments) ≤22 was associated with 75.7% sensitivity with specificity at 91.5%. However, sensitivity was nearly as high when scores available from the standard RAVLT administration alone (i.e., no word stem or temporal order trials) were combined. Specifically, a cut-off of ≤12 for true recognition (recognition minus false positives) + primacy recognition (i.e., number of words recognized from the first third of the test) was associated with 73.8% sensitivity at 90% specificity. These results indicate that combined indices of recognition memory from the RAVLT are effective in identifying noncredible memory performance in “real world” samples and are modestly superior to the 67.2% sensitivity obtained with the standard recognition score.

Simulations of evolutionary radiations and their application to understanding the probability of a Cambrian explosion

A molecular survey of animal phylogeny (Wray et al., 1996) recovered the presumed correct temporal order of the phylogenetic splits Protostomata-Deuterostomata, Echinodermata-Chordata, and Agnatha-Gnathostomata in studies of six of seven gene sequences. This result raised the question of how this order could be recovered if all of the phyla had appeared in a Cambrian “explosion” of less than 10 m.y., given the expected erratic nature of the molecular “clock.” We simulated trees, and molecular sequence evolution along the trees, under different evolutionary radiation scenarios, with different periods of radiation, relative to times of subsequent evolution. Simulations and phylogenetic analyses of sequences derived from a simulated “Cambrian explosion” of 10–35 million years did not allow the successful recovery of the correct tree, using neighbor-joining, maximum likelihood, or parsimony methods. Success in recovering phylogenies under a Cambrian divergence scenario (520 million years ago) did not exceed 80 percent without an extended divergence time interval of at least 100 m.y. An increased substitution rate during the initial radiation improved the ability to recover correct phylogenies, especially when the rate was 8–10 times the rate following the radiation. Our results militate against the likelihood of an Early Cambrian or slightly longer explosion of the animal phyla, as apparently supported by the fossil record. Some limitations to these conclusions are discussed.

Illusory reversal of temporal order: the bias to report a dimmer stimulus as the first

When two objects are presented in rapid succession, observers find it difficult to discriminate their temporal order. Below certain limit (e.g., 20–70 ms), the rate of correct temporal order judgement is reported to be about 50% (i.e., close to chance level). However we have found stimulus conditions where order discrimination drops significantly below chance level: the stimulus that is presented as the second is reported as the first. It is necessary that the stimuli are very brief, spatially overlapping, clear-cut backward and forward masking is absent, stimulus onset asynchronies are very short, and luminance contrast of the following stimulus is considerably lower than luminance contrast of the first stimulus. The higher the contrast ratio, the stronger the order reversal effect. However, because also in the conditions where the two stimuli are presented synchronously, the dimmer target is perceived as the first, the effect should be attributed to some implicit bias which enforces subjects to regard a more contrasted stimulus as the one that appears subsequent to the less contrasted stimulus.

Resonant neural dynamics of speech perception

What is the neural representation of a speech code as it evolves in time? How do listeners integrate temporally distributed phonemic information across hundreds of milliseconds, even backwards in time, into coherent representations of syllables and words? What sorts of brain mechanisms encode the correct temporal order, despite such backwards effects, during speech perception? How does the brain extract rate-invariant properties of variable-rate speech? This article describes an emerging neural model that suggests answers to these questions, while quantitatively simulating challenging data about audition, speech and word recognition. This model includes bottom-up filtering, horizontal competitive, and top-down attentional interactions between a working memory for short-term storage of phonetic items and a list categorization network for grouping sequences of items. The conscious speech and word recognition code is suggested to be a resonant wave of activation across such a network, and a percept of silence is proposed to be a temporal discontinuity in the rate with which such a resonant wave evolves. Properties of these resonant waves can be traced to the brain mechanisms whereby auditory, speech, and language representations are learned in a stable way through time. Because resonances are proposed to control stable learning, the model is called an Adaptive Resonance Theory, or ART, model.

Coupling gene expression and multicellular morphogenesis during fruiting body formation in Myxococcus xanthus.

A recurring theme in morphogenesis is the coupling of the expression of genes that drive morphogenesis and the morphogenetic process per se. This coupling ensures that gene expression and morphogenesis are carried out in synchrony. Morphogenesis of the spore-filled fruiting bodies in Myxococcus xanthus illustrates this coupling in the construction of a multicellular structure. Fruiting body formation involves two stages: aggregation of cells into mounds and the position-specific sporulation of cells that have accumulated inside mounds. Developmental gene expression propels these two processes. In addition, gene expression in individual cells is adjusted according to their spatial position. Progress in the understanding of the cell surface-associated C-signal is beginning to reveal the framework of an intercellular signalling system that allows the coupling of gene expression and multicellular morphogenesis. Accumulation of the C-signal is tightly regulated and involves transcriptional activation of the csgA gene and proteolysis of the full-length CsgA protein to produce the shorter cell surface-associated 17 kDa C-signal protein. The C-signal induces aggregation, sporulation and developmental gene expression at specific thresholds. The ordered increase in C-signalling levels, in combination with the specific thresholds, allows the C-signal to induce these three processes in the correct temporal order. The contact-dependent C-signal transmission mechanism, in turn, guarantees that C-signalling levels reflect the spatial position of individual cells relative to other cells and, thus, allows the cells to decode their spatial position during morphogenesis. By this mechanism, individual cells can tailor their gene expression profile to one that matches their spatial position. In this scheme, the molecular device that keeps gene expression in individual cells in register with morphogenesis is the C-signalling system, and the morphological structure, which is assessed, is the spatial position of individual cells relative to that of other cells.

Serial memory strategies in macaque monkeys: behavioral and theoretical aspects.

Serial memory is the ability to encode and retrieve a list of items in their correct temporal order. To study nonverbal strategies involved in serial memory, we trained four macaque monkeys on a novel delayed sequence-recall task and analysed the mechanisms underlying their performance in terms of a neural network model. Thirty fractal images, divided into 10 triplets, were presented repeatedly in fixed temporal order. On each trial the monkeys viewed three sequentially presented sample images, followed by a test stimulus consisting of the same triplet of images and a distractor image (chosen randomly from the remaining 27). The task was to touch the three images in their original order, avoiding the distractor. The monkeys' most common error was touching the distractor when it had the same ordinal position (in its own triplet) as the correct image. This finding suggests that monkeys naturally categorize images by their ordinal number. Additional, secondary strategies were eventually used to avoid distractor images. These include memory of the sample images (working memory) and associations between triplet members. Further direct evidence for ordinal number categorization was provided by a transfer of learning to untrained images of the same ordinal category, following reassignment of image categories within each triplet. We propose a generic three-tier neuronal framework that can explain the components and complex set of characteristics of the observed behavior. This framework, with its intermediate level representing ordinal categories, can also explain the transfer of learning following category reassignment.

Sequential organization of multiple movements: involvement of cortical motor areas.

Much of our normal behavior depends on the sequential execution of multiphased movements, or the execution of multiple movements arranged in a correct temporal order. This article deals with the issue of motor selection to arrange multiple movements in an appropriate temporal order, rather than the issue of constructing spatio-temporal structures in a single action. Planning, generating, and controlling the sequential motor behavior involves multiple cortical and subcortical neural structures. Studies on human subjects and nonhuman primates, however, have revealed that the medial motor areas in the frontal cortex and the basal ganglia play particularly important roles in the temporal sequencing of multiple movements. Cellular activity observed in the supplementary and presupplementary motor areas while performing specifically designed motor tasks suggests the way in which these areas take part in constructing the time structure for the sequential execution of multiple movements.

Memory for temporal order in patients with schizophrenia

There is some evidence that memory for temporal order is a process that may be impaired independently of other forms of memory. For example, patients with Korsakoff's syndrome have been shown to have poorer temporal-order memory than other amnesic patients, despite item memory being equivalent. Patients with schizophrenia have been reported to have a variety of memory problems, although memory for the order of events has not been examined very frequently. In this study, we tested memory for temporal order in patients with schizophrenia and in control subjects. Subjects were presented with two lists of 15 words (at two different times) and were later asked to reproduce the order of each list from a random array of the words. In both versions of the test, patients with schizophrenia were impaired in placing the items in the correct temporal order. Recall and recognition of the actual words used to comprise the lists were also impaired in the schizophrenic patients. However, when recall measures were covaried, and when patients were matched with controls for recall, post-hoc group differences in temporal memory were eliminated. In contrast, covarying recognition (indexed by d′ or matching for recognition) did not eliminate group differences. Therefore, although memory for temporal order is compromised in patients with schizophrenia, this deficit is highly correlated with generally poorer item-specific memory retrieval (i.e., recall). It is possible that both impairments are due to some third process that underlies and aids in the reconstruction of episodes.

The effect of flashback on children's understanding of television crime content

First, third, and fifth graders viewed an edited version of a televised police drama presented in canonical order, jumbled order, or flashback. Children who viewed the canonical version were able to sequence central scenes better than those who viewed other versions. Contrary to expectations, sequencing of the flashback version was not superior to sequencing of the jumbled version. Temporal order did not affect children's comprehension of central, peripheral, or implicit content. Memory for central content was better than for peripheral and implicit content. Results indicate children remember a police drama equally well across different temporal orders, but can sequence events better when viewed in correct temporal order.

Retrieving the sequence of autobiographical event components

This study examined ability to sequence components from within autobiographical events. Subjects took photographs of their experiences, and the films were developed and coded for sequences (e.g. six photographs of a picnic). Experiment 1 found ability to place photographs into the correct temporal order was generally poor, but improved when testing occurred within a week of the event's occurrence. Experiment 2 replicated the generally poor level of sequencing performance found in Experiment 1 and found that an ability to recall event detail facilitated sequencing performance. An Event Component Ordering Model (ECOM) was developed which suggests event components are initially linked to their general event representation by detail access associations. It is suggested that detail access associations are routinely accessed in temporal order. Thus the order in which event components are recalled is typically the order in which they were encoded and there is no actual encoding of temporal information for event components. Finally, activation of partially decayed detail access associations is suggested to indicate that recall order no longer equates to encoding order. © 1998 John Wiley & Sons, Ltd.

Combined clozapine-lithium treatment in schizophrenia and schizoaffective disorder

Previous research suggests that time perception is supported by the same attentional resources involved in sequence processing. The present experiment was designed to clarify this connection by examining the relation between timing and reasoning tasks that involved either sequencing or non-sequencing judgments. For the timing task, subjects produced a series of 5-s intervals. For the reasoning tasks, subjects judged whether pairs of statements describing common actions either (a) were presented in the correct temporal order (sequencing), or (b) described similar actions or objects (similarity). Subjects performed the timing and reasoning tasks both separately and concurrently in a series of 3-minute trials. Comparisons of single-task and dual-task performance assessed interference patterns between concurrent tasks. Both reasoning tasks interfered with timing by making temporal productions longer and more variable. Timing had differential effects on the two reasoning tasks. Concurrent timing caused sequencing judgments to become slower, less accurate, and less sensitive relative to sequencing-only conditions. In contrast, similarity judgments were either unaffected or affected to a lesser degree by the concurrent timing task. These results support the notion that timing and sequencing are closely related processes that rely on the same set of cognitive resources or mechanisms.

RCC1, a regulator of mitosis, is essential for DNA replication.

Temperature-sensitive mutants in the RCC1 gene of BHK cells fail to maintain a correct temporal order of the cell cycle and will prematurely condense their chromosomes and enter mitosis at the restrictive temperature without having completed S phase. We have used Xenopus egg extracts to investigate the role that RCC1 plays in interphase nuclear functions and how this role might contribute to the known phenotype of temperature-sensitive RCC1 mutants. By immunodepleting RCC1 protein from egg extracts, we find that it is required for neither chromatin decondensation nor nuclear formation but that it is absolutely required for the replication of added sperm chromatin DNA. Our results further suggest that RCC1 does not participate enzymatically in replication but may be part of a structural complex which is required for the formation or maintenance of the replication machinery. By disrupting the replication complex, the loss of RCC1 might lead directly to disruption of the regulatory system which prevents the initiation of mitosis before the completion of DNA replication.

RCC1, a regulator of mitosis, is essential for DNA replication.

Temperature-sensitive mutants in the RCC1 gene of BHK cells fail to maintain a correct temporal order of the cell cycle and will prematurely condense their chromosomes and enter mitosis at the restrictive temperature without having completed S phase. We have used Xenopus egg extracts to investigate the role that RCC1 plays in interphase nuclear functions and how this role might contribute to the known phenotype of temperature-sensitive RCC1 mutants. By immunodepleting RCC1 protein from egg extracts, we find that it is required for neither chromatin decondensation nor nuclear formation but that it is absolutely required for the replication of added sperm chromatin DNA. Our results further suggest that RCC1 does not participate enzymatically in replication but may be part of a structural complex which is required for the formation or maintenance of the replication machinery. By disrupting the replication complex, the loss of RCC1 might lead directly to disruption of the regulatory system which prevents the initiation of mitosis before the completion of DNA replication.

Putting the horse before the cart: The use of temporal order in recall of events by one-year-old children.

Previous research has shown that 16- and 20-month-old children recall action sequences depicting familiar, script-based events, and also novel event sequences, in the correct temporal order. In 2 experiments, elicited imitation was used to assess 11.5- and 13.5-month-olds' immediate recall of familiar and novel event sequences. In Experiment 1,13.5-month-olds were tesfed on 2-act and 3-act sequences depicting both familiar and novel events. They reliably recalled the event sequences in the correct temporal order. In Experiment 2, the results were extended to 11.5-month-olds: They accurately recalled 2-act sequences depicting familiar and novel events. The results demonstrate that by late in the 1st year of life, children are able to accurately remember (a) specific sequences depicting familiar events and (b) novel event sequences. In contrast to traditional conceptualizations of preschoolers as unable to represent information in other than a piecemeal fashion (e.g., Fraisse, 1963; Piaget, 1926,1969), more recent research has shown that even young children recall both stories and personally experienced events in an organized manner similar to that of older children and adults (Mandler, 1978; Nelson, 1986). Like adults, in response to questions about what happens in the course of everyday events and routines, children as young as 3 recount events in their usual or canonical order (Nelson & Gruendel, 1981,1986). Although familiarity with events facilitates ordered recall (e.g, Fivush & Mandler, 1985), repeated experience is not necessary for recall to be temporally ordered. Three- to 7-year-olds provide well-ordered accounts of events after only a single experience of them (Hudson, 1986; B. S. Smith, Ratner, & Hobart, 1987). Furthermore, like older children and adults, preschoolers are sensitive to the structure of to-be-remembered material: They recall aspects of events with

Implication of the guaranteed, reliable, secure broadcast technology to office information systems

Guaranteed, Reliable, Secure Broadcast (GRSB) - is a protocol that provides reliable and secure broadcast/multicast communications. Four logical nodes are enforced in the network - a Central Retransmitter, a Security Controller, a Designated Acknowledger, a (many when need) Playback Recorder(s). Through the coordinated service of the four nodes, every user node can be guaranteed to receive all broadcast messages in a secure manner and in the correct temporal order. This paper focuses on the implication of GRSB to office information systems. How GRSB coherently supports several progressive functional requirements, from small number of user nodes to complex, but integrated functions, is elaborated.

An in vitro globin gene switching model based on differentiated embryonic stem cells.

We used mouse embryonic stem (ES) cells to study globin gene expression and switching in vitro. We show that ES-derived embryoid bodies express the full complement of mouse embryonic globin genes in the correct temporal order and that on further differentiation, a switch occurs to the fetal/adult genes. In addition, the erythroid-specific transcription factor NF-E1 was shown to be expressed coordinately with that of globin in embryoid bodies. We conclude from these experiments that the ES cell system provides a good model to study hematopoietic development. When the human epsilon- or beta-globin genes driven by the dominant control region (DCR) are introduced into this system, the human epsilon-globin gene, in contrast to the beta-globin gene, is not deregulated by the presence of the DCR and is expressed strictly as an embryonic gene. We conclude from this that the epsilon-globin gene is not regulated by competition with other genes in the human beta-globin locus.

Memory for the temporal order of events in patients with frontal lobe lesions and amnesic patients

Patients with frontal lobe lesions, amnesic patients with Korsakoff's syndrome, other (non-Korsakoff) amnesic patients, and control subjects were given tests of memory for temporal order. In the first experiment, subjects were presented with a list of 15 words and then asked to reproduce the list order from a random array of the words. In the second experiment, they were asked to arrange in chronological order a random display of 15 factual events that occurred between 1941 and 1985. In both experiments, patients with frontal lobe lesions were impaired in placing the items in the correct temporal order, despite normal item memory (i.e. normal recall and recognition memory for the words and facts). The two groups of amnesic patients exhibited impaired memory for temporal order as well as impaired item memory. Patients with Korsakoff's syndrome exhibited poorer temporal order memory than the other amnesic patients, despite similar levels of item memory. These findings demonstrate that patients with frontal lobe lesions have difficulty organizing information temporally. Patients with Korsakoff's syndrome, who have both diencephalic and frontal damage, have memory impairment together with a disproportionate deficit in memory for temporal order.

Developmental versus sensory deficit effects on perceptual processing in the reading disabled.

Thirty children and 5 adults participated in two experiments designed to compare visual processing in normal and reading disabled children. The children were aged 8, 10, and 12 years. In Experiment 1, subjects were asked to detect the temporal order of two briefly presented stimuli. In Experiment 2, subjects sorted cards containing bracket stimuli that did or did not produce perceptual grouping effects. Poor readers required more time to make accurate temporal order judgments and showed stronger perceptual grouping effects. For both good and poor readers, the amount of time necessary to make a correct temporal order judgment decreased, and perceptual grouping effects became weaker with age. However, the magnitude of the difference between the groups did not lessen with age. These results suggest that there are visual processing differences between good and poor readers that do not appear to correct by age 12.

Eye movements and spatial coding in reading

Two experiments are reported which test the hypothesis that during reading subjects maintain in working memory a record of the spatial location of items and that this code is used to guide reinspections. In the first experiment the premisses of short syllogisms were read, one word at a time, under three presentation conditions: (a) in correct temporal order and in appropriate sequential spatial locations; (b) in correct temporal order but in random spatial locations; (c) in correct temporal order and in a single central location. A measure was taken of the time to respond to possible conclusions of the syllogisms. Solution times were longer in conditions (b) and (c) relative to (a). In the second experiment eye movements were recorded as subjects judged the soundness of auditorily presented conclusions following visual presentation of the premisses of syllogisms. Non-random eye movements took place during the solution phase directed to locations previously occupied by text in the display.