Backward Order Research Articles

Preterm infants show an atypical processing of the mother's voice

To understand the consequences of prematurity on language perception, it is fundamental to determine how atypical early sensory experience affects brain development. At term equivalent age, ten preterm and ten full-term newborns underwent high-density EEG during mother or stranger speech presentation, in the forward or backward order. A general group effect terms > preterms is evident in the theta frequency band, in the left temporal area, with preterms showing significant activation for strangers’ and terms for the mother’s voice. A significant group contrast in the low and high theta in the right temporal regions indicates higher activations for the stranger's voice in preterms. Finally, only full terms presented a late gamma band increase for the maternal voice, indicating a more mature brain response.EEG time–frequency analysis demonstrate that preterm infants are selectively responsive to stranger voices in both temporal hemispheres, and that they lack selective brain responses to their mother’s forward voice.

Forward and backward recall dynamics.

Although possible to recall in both forward and backward order, recall proceeds most naturally in the order of encoding. Prior studies ask whether and how forward and backward recall differ. We reexamine this classic question by studying recall dynamics while varying the predictability and timing of forward and backward cues. Although overall accuracy did not differ by recall direction, recall dynamics highlight key distinctions. Forward recall exhibits a modest advantage for correct transitions following errors, independent of cueing predictability and list length. Without consistent directional cueing, participants initiate backward recall more accurately, but this effect reverses with predictable directional cues. Following omissions, participants commit more fill-in errors in backward recall. Our findings implicate an asymmetric, cue-dependent retrieval process underlying forward and backward recall, with relative contributions of primacy and recency depending on directional predictability. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Fear-Conditioning to Unpredictable Threats Reveals Sex and Strain Differences in Rat Fear-Potentiated Startle (FPS).

Fear-potentiated startle (FPS) has been widely used to study fear processing in humans and rodents. Human studies showed higher startle amplitudes and exaggerated fear reactivity to unpredictable vs. predictable threats in individuals suffering from post-traumatic stress disorder (PTSD). Although human FPS studies use both sexes, a surprisingly limited number of rodent FPS studies use females. Here we investigate the effects of signal-threat contingency, signal-threat order and threat predictability on FPS in both sexes. We use a classic fear-conditioning protocol (100% contingency of cue and shock pairings, with forward conditioning such that the cue co-terminates with the shock) and compare it to modified fear-conditioning protocols (70% contingency; backward conditioning; or cue and shock un-paired). Although there are no sex differences in the startle amplitudes when corrected for body weight, females consistently demonstrate higher shock reactivity during fear-conditioning. Both sexes and strains demonstrate comparable levels of cued, non-cued, and contextual fear in the classic FPS and FPS following fear-conditioning with 70% contingency or backward order (cue co-starts with shock). However, in the classic FPS, Sprague-Dawley females show reduced proportion between cued fear and cue-elicited vigilant state than males. Lastly, a prominent sex difference is uncovered following unpredictable fear-conditioning (cue and shock un-paired), with Wistar, but not Sprague-Dawley, females showing significantly higher startle overall during the FPS recall, regardless of trial type, and higher contextual fear than males. This striking sex difference in processing unpredictable threats in rodent FPS might help to understand the mechanisms underlying higher incidence of PTSD in women.

Story order in attribution of moral responsibility

AbstractDiscourse comprehension relies on the construction of a mental model that represents the unfolding in time of the events described. In causal scenarios, where the action of one agent (the enabler) temporally precedes and enables the action of another agent (the causer), discourse may reflect the underlying event structure by describing the enabler’s action first and then the causer’s action (story order) or may describe the causer’s action first (backward order). Studies in the literature have shown that adults consider causers to be more responsible than enablers in moral scenarios. Based on the assumption that story order favors the construction of a mental model of events, we conducted an experiment to test the prediction that preference for the causer over the enabler should be greater when events are presented in story order than in backward order. The participants in the experiment were 42 fifth-grade children, 42 adolescents, and 42 adults. The results of the experiment confirmed the prediction for all three groups of participants. We discuss the practical implications of these results for learning contexts, legal contexts, and the psychology of moral judgments.

Neural basis of working memory in ADHD: Load versus complexity

Working memory (WM) deficits are key in attention deficit hyperactivity disorder (ADHD). Nevertheless, WM is not universally impaired in ADHD. Additionally, the neural basis for WM deficits in ADHD has not been conclusively established, with regions including the prefrontal cortex, cerebellum, and caudate being implicated. These contradictions may be related to conceptualizations of WM capacity, such as load (amount of information) versus operational-complexity (maintenance-recall or manipulation). For instance, relative to neurotypical (NT) individuals, complex WM operations could be impaired in ADHD, while simpler operations are spared. Alternatively, all operations may be impaired at higher loads. Here, we compared the impact of these two components of WM capacity: load and operational-complexity, between ADHD and NT, behaviorally and neurally. We hypothesized that the impact of WM load would be greater in ADHD, and the neural activation would be altered. Participants (age-range 12–23 years; 50 ADHD (18 females); 82 NT (41 females)) recalled three or four objects (load) in forward or backward order (operational-complexity) during functional magnetic resonance imaging scanning. The effects of diagnosis and task were compared on performance and neural engagement. Behaviorally, we found significant interactions between diagnosis and load, and between diagnosis, load, and complexity. Neurally, we found an interaction between diagnosis and load in the right striatum, and between diagnosis and complexity in the right cerebellum and left occipital gyrus. The ADHD group displayed hypo-activation compared to NT group during higher load and greater complexity. This informs mechanisms of functional problems related to WM in adolescents and young adults with ADHD (e.g., academic performance) and remedial interventions (e.g., WM-training).

Grammar modulates discourse expectations: evidence from causal relations in English and Korean

abstractThis paper investigates whether differences in grammar affect the production of discourse relations. We report the results of two story continuation experiments on speakers of two typologically unrelated languages, English and Korean, and in two different discourse genres, monologues (Experiment 1) and conversations (Experiment 2), focusing on the contrast between the explanation discourse relation and the result discourse relation. Since the grammar of clause linkage in Korean, but not English, disfavors a backward causal order (explanation relation), we predicted that Korean speakers are less likely to produce EXPLANATION continuations in MONOLOGUES than English speakers. We also predicted that this difference disappears in conversation, as questions that can be uttered in conversations are not subject to the same constraints on clause linkage in Korean. The results confirmed our predictions. The effect of language on the production of discourse relations in monologue suggests that LINGUISTIC STRUCTURES can affect speakers’ discourse expectation and production, while the absence of language effect in conversation suggests that this language effect is not due to differences in the way speakers causally relate events or to conceptual or cultural differences in preferences for iconic discourse between English and Korean speakers.

Associative models fail to characterize transitive inference performance in rhesus monkeys (Macaca mulatta).

It has been suggested that non-verbal transitive inference (if A > B and B > C, then A > C) can be accounted for by associative models. However, little is known about the applicability of such models to primate data. In Experiment 1, we tested the fit of two associative models to primate data from both sequential training, in which the training pairs were presented in a backward order, and simultaneous training, in which all training pairs are presented intermixed from the beginning. We found that the models provided an equally poor fit for both sequential and simultaneous training presentations, contrary to the case with data from pigeons. The models were also unable to predict the robust symbolic distance effects characteristic of primate transitive choices. In Experiment 2, we used the models to fit a list-linking design in which two seven-item transitive lists were first trained independently (A > B…. > F > G and H > I …. > M > N) then combined via a linking pair (G+ H-) into a single, 14-item list. The model produced accurate predictions for between-list pairs, but did not predict transitive responses for within-list pairs from list 2. Overall, our results support research indicating that associative strength does not adequately account for the behavior of primates in transitive inference tasks. The results also suggest that transitive choices may result from different processes, or different weighting of multiple processes, across species.

Neuropsychological and Educational Profile of Children with Dyscalculia and Dyslexia: A Comparative Study

Abstract This paper aims to compare the neuropsychological and educational profiles of Brazilian children with dyscalculia (n = 8), dyslexia (n = 13) and without learning disabilities (n = 12). The neuropsychological profile was composed of: (a) intelligence - assessed by the Wechsler Intelligence Scale for Children (WISC-III); (b) attention - WISC-III Coding and Symbol Search subtests; (c) executive functions - Digit Span (backward order) and WISC-III Arithmetic subtests, Pseudoword Repetition Test for Brazilian Children, Stroop Test and Wisconsin Card Sorting Test; (d) memory - WISC-III Digit Span subtest (forward order) and Rey Complex Figures. The educational profile was composed of reading, writing and mathematics, assessed by the Academic Performance Test and the Arithmetic Test. It was found that the groups with dyscalculia and dyslexia did not differentiate in any of the neuropsychological abilities, only in the reading and writing abilities. Neuropsychological variables that could explain these results were discussed.

Emerging evidence for speeded alphabet printing as a measure of processing speed and working memory

Alphabet Printing (in the forward and backward order) is a brief and highly portable test with promise as a screening measure of processing speed and simple working memory, constructs which are only minimally assessed in many of the most commonly-used cognitive screening instruments. The aim of this project was to examine the construct validity of timed Alphabet Printing in a sample of 254 Veterans with cognitive complaints and a history of possible head injury. Criterion measures included more established tests of processing speed and simple working memory, including the Trail Making Test and the Digit Span subtest from the fourth edition of the Wechsler Adult Intelligence Scales. Alphabet Printing scores moderately correlated with the criterion measures of attention, working memory, and processing speed, and demonstrated acceptable classification accuracy in discriminating between individuals with and without evidence of cognitive impairment on Trails B. These findings provide additional support for the possible utility of including Alphabet Printing during cognitive screenings or as part of a larger neuropsychological test battery.

Overt language production plays a key role in the Hebb repetition effect.

When asked to recall verbatim a short list of items, performance is very limited. However, if the list of items is repeated across trials, recall performance improves. This phenomenon, known as the Hebb repetition effect (Hebb, 1961; Brain Mechanisms and Learning: A Symposium, pp. 37-51), is considered a laboratory analogue of language learning. In effect, learning a new word implies the maintenance of a series of smaller units, such as phonemes or syllables, in the correct order for a short amount of time before producing them. The sequence of smaller units is typically presented more than once. In the present study, we investigated the role of overt language production in language learning by manipulating recall direction. If the learning of a repeated list of items relies on overt language production processes, changing list production order by manipulating recall direction should impact the learning of the list. In Experiment 1, one list was repeated every third trial, and recall direction of the repeated list changed on the ninth repetition. In Experiment 1a, the repeated list changed from a forward to a backward order recall, where participants had to recall the items in reverse presentation order. In Experiment 1b, the repeated list changed from a backward to a forward order recall. Results showed a cost in recall performance for the repeated list when recall direction switched from forward to backward recall, whereas it was unaffected by the change from backward to forward recall. In Experiment 2, we increased the number of trials before introducing the change from a backward to a forward order recall. Results showed a decrement in recall performance for the repeated list following the change in recall direction, suggesting that language production processes play a role in the Hebb repetition effect.

Dental caries in schoolchildren: influence of inattention, hyperactivity and executive functions.

Attention-deficit/hyperactivity disorder (ADHD) is characterized by inappropriate levels of hyperactivity, impulsivity, and/or inattention. Individuals with ADHD may present limitations with regard to executive functions and performing activities that involve planning and/or attention/concentration. The aim of the study was to investigate the association between dental caries and signs of ADHD in a representative sample of schoolchildren. A representative sample of 851 schoolchildren aged seven to 12 years was randomly selected from public and private schools. Data acquisition involved a clinical dental examination for cavitated permanent and deciduous teeth using the DMFT/dmft indices. Neuropsychological evaluations, including the assessment of intelligence (Raven's Colored Progressive Matrix Test) and executive functions (Corsi Tapping Blocks tests and Digit Span test) were also performed. Parents/caregivers and teachers answered the SNAP-IV Questionnaire for the investigation of signs of inattention and hyperactivity in the family and school environment. Parents/caregivers also answered questionnaires addressing socioeconomic and socio-demographic characteristics. Descriptive analysis of the variables and Poisson regression with robust variance were performed. Parental reports of signs of inattention (PR: 1.28; p < 0.05) and hyperactivity (PR: 1.15; p < 0.05) were associated with a greater occurrence of caries. A better performance on the backward order of the Corsi Tapping Blocks tests (PR: 0.94; p < 0.05) and higher level of mother's schooling were associated with a lower frequency of caries. A better performance on executive function tasks was a protective factor against dental caries, whereas children considered inattentive and/or hyperactive by their parents had a higher prevalence rate of dental caries.

Neural correlates of implicit knowledge about statistical regularities.

In this study, we examined the neural correlates of implicit knowledge about statistical regularities of temporal order and item chunks using functional magnetic resonance imaging (fMRI). In a familiarization scan, participants viewed a stream of scenes consisting of structured (i.e., three scenes were always presented in the same order) and random triplets. In the subsequent test scan, participants were required to detect a target scene. Test sequences included both forward order of scenes presented during the familiarization scan and backward order of scenes (i.e., reverse order of forward scenes). Behavioral results showed a learning effect of temporal order in the forward condition and scene chunks in the backward condition. fMRI data from the familiarization scan showed the difference of activations between the structured and random blocks in the left posterior cingulate cortex including the retrosplenial cortex. More important, in the test scan, we observed brain activities in the left parietal lobe when participants detected target scenes on temporal order information. In contrast, the left precuneus activated when participants detected target scenes based on scene chunks. Our findings help clarify the brain mechanisms of implicit knowledge about acquired regularities.

Differences in Verbal and Visuospatial Forward and Backward Order Recall: A Review of the Literature.

How sequential, verbal and visuospatial stimuli are encoded and stored in memory is not clear in cognitive psychology. Studies with order recall tasks, such as the digit, and Corsi span, indicate that order of presentation is a crucial element for verbal memory, but not for visuospatial memory. This seems to be due to the different effects of forward and backward recall in verbal and visuospatial tasks. In verbal span tasks, performance is worse when recalling things in backward sequence rather than the original forward sequence. In contrast, when it comes to visuospatial tasks, performance is not always worse for a modified backward sequence. However, worse performance in backward visuospatial recall is evident in individuals with weak visuospatial abilities; such individuals perform worse in the backward version of visuospatial tasks than in the forward version. The main aim of the present review is to summarize findings on order recall in verbal and visuospatial materials by considering both cognitive and neural correlates. The results of this review will be considered in the light of the current models of WM, and will be used to make recommendations for future studies.

Rule-based scheduling of multi-stage multi-product batch plants with parallel units

Abstract A novel rule-based model for multi-stage multi-product scheduling problem (MMSP) in batch plants with parallel units is proposed. The scheduling problem is decomposed into two sub-problems of order assignment and order sequencing. Firstly, hierarchical scheduling strategy is presented for solving the former sub-problem, where the multi-stage multi-product batch process is divided into multiple sequentially connected single process stages, and then the production of orders are arranged in each single stage by using forward order assignment strategy and backward order assignment strategy respectively according to the feature of scheduling objective. Line-up competition algorithm (LCA) is presented to find out optimal order sequence and order assignment rule, which can minimize total flow time or maximize total weighted process time. Computational results show that the proposed approach can obtain better solutions than those of the literature for all scheduling problems with more than 10 orders. Moreover, with the problem size increasing, the solutions obtained by the proposed approach are improved remarkably. The proposed approach has the potential to solve large size MMSP.

Learning a Behavioral Sequence: An Accessible Challenge for Myrmica sabuleti Workers?

We aimed to investigate on the ability of the ant Myrmica sabuleti in learning a behavioral sequence. We created two sequences consisting in navigating through five successive elements on the way to the nest, and tried to learn them to foragers. They could progressively learn a sequence for which the different steps were presented in a backward order. Doing so, each exhibited step leaded to an already known step and thus to the reward consisting in finally entering the nest. The ants were unable to learn a behavioral sequence for which the different steps were presented in a forward order. With the latter kind of presentation, each exhibited step leaded to an unknown step and thus not to the reward. Myrmica sabuleti ants learned thus a behavioral sequence when going through operant conditioning and not by using the response to a step as a motivation for responding to the next step. On the contrary, highly evolved mammals (monkey, humans) and birds (parrots) can learn a behavioral sequence according to a backward or a forward chaining, or by being presented with the entire sequence and memorizing, then imitating the different steps.

Visual statistical learning produces implicit and explicit knowledge about temporal order information and scene chunks: Evidence from direct and indirect measures

ABSTRACTWe examined whether visual statistical learning (VSL) produced implicit and/or explicit knowledge about temporal order information and scene chunks, using a rapid serial visual presentation target detection task and a two-alternative forced-choice (2AFC) familiarity test as indirect and direct measures of VSL, respectively. In the familiarization phase, participants viewed a visual stream of natural scenes consisting of four triplets (i.e., three images that always appeared in the same order). In the subsequent target detection task, participants were required to detect target items embedded in a stream of 12 images or 12 words representing each natural scene. In the final 2AFC familiarity test, participants observed two test sequences (statistically related triplets vs. unrelated foils) and decided whether the first or second sequence was more familiar based on the familiarization phase. In both test phases, we included the same (forward) and reverse (backward) order of scenes as presented during the familiarization phase to examine whether the expression of VSL was based on temporal order of scenes or scene chunks. The results of the target detection task showed a learning effect for both temporal order in the forward condition and chunks in the backward condition, irrespective of whether stimuli were images or words; in contrast, we did not observe a learning effect in the backward condition for scene images in the familiarity test. Our findings are compatible with a learning mechanism that has both implicit and explicit components based on temporal order information and scene chunks.

Time-headway distribution for periodic totally asymmetric exclusion process with various updates

The totally asymmetric exclusion process (TASEP) with periodic boundaries is considered as traffic flow model. The large-L approximation of the stationary state is used for the derivation of the time-headway distribution (an important microscopic characteristic of traffic flow) for the model with generalized update (genTASEP) in both, forward- and backward-sequential representations. The usually used updates, fully-parallel and regular forward- and backward-sequential, are analyzed as special cases of the genTASEP. It is shown that only for those cases, the time-headway distribution is determined by the flow regardless to the density. The qualitative comparison of the results with traffic data demonstrates that the genTASEP with backward order and attractive interaction evinces similar properties of time-headway distribution as the real traffic sample.

The immediate retrieval of verbal sequences in late-life span: a developmental approach

ABSTRACTThe present study aims to explore the mechanisms underpinning forward and backward immediate serial recall in young (i.e., 20–30 years), old (i.e., 65–74 years), and very old (i.e., 75–84 years) adults. Participants had to retrieve verbal lists from forward and backward perspectives where position-item and item-item pairings were reiterated from the start or the end of the sequence across four consecutive lists. The results showed that the age and type of the repeated cues across the lists influenced memory performance. That is, old participants outperformed the very old group in both recall modalities; furthermore, the repetition of positional and inter-item cues from the list start facilitates memory performance in forward and backward conditions. Overall, these findings suggest that the list start is the most significant marker for encoding serial information and support the idea of a common mechanism underpinning the immediate recall of serial information in forward and backward order.

Backward multiple imputation estimation of the conditional lifetime expectancy function with application to censored human longevity data

The conditional lifetime expectancy function (LEF) is the expected lifetime of a subject given survival past a certain time point and the values of a set of explanatory variables. This function is attractive to researchers because it summarizes the entire residual life distribution and has an easy interpretation compared with the popularly used hazard function. In this paper, we propose a general framework of backward multiple imputation for estimating the conditional LEF and the variance of the estimator in the right-censoring setting. Simulation studies are conducted to investigate the empirical properties of the proposed estimator and the corresponding variance estimator. We demonstrate the method on the Beaver Dam Eye Study data, where the expected human lifetime is modeled with smoothing-spline ANOVA given the covariates information including sex, lifestyle factors, and disease variables.

CONSEQUENCE OF BACKWARD EULER AND CRANK-NICOLSOM TECHNIQUES IN THE FINITE ELEMENT MODEL FOR THE NUMERICAL SOLUTION OF VARIABLY SATURATED FLOW PROBLEMS

Modeling water flow in variably saturated, porous media is important in many branches of science and engineering. Highly nonlinear relationships between water content and hydraulic conductivity and soil-water pressure result in very steep wetting fronts causing numerical problems. These include poor efficiency when modeling water infiltration into very dry porous media, and numerical oscillation near a steep wetting front. A one-dimensional finite element formulation is developed for the numerical simulation of variably saturated flow systems. First order backward Euler implicit and second order Crank?Nicolson time discretization schemes are adopted as a solution strategy in this formulation based on Picard and Newton iterative techniques. Five examples are used to investigate the numerical performance of two approaches and the different factors are highlighted that can affect their convergence and efficiency. The first test case deals with sharp moisture front that infiltrates into the soil column. It shows the capability of providing a mass-conservative behavior. Saturated conditions are not developed in the second test case. Involving of dry initial condition and steep wetting front are the main numerical complexity of the third test example. Fourth test case is a rapid infiltration of water from the surface, followed by a period of redistribution of the water due to the dynamic boundary condition. The last one-dimensional test case involves flow into a layered soil with variable initial conditions. The numerical results indicate that the Crank?Nicolson scheme is inefficient compared to fully implicit backward Euler scheme for the layered soil problem but offers same accuracy for the other homogeneous soil cases.