Syntactic Chain Research Articles

Neural substrates for regulating self-grooming behavior in rodents.

Grooming, as an evolutionarily conserved repetitive behavior, is common in various animals, including humans, and serves essential functions including, but not limited to, hygiene maintenance, thermoregulation, de-arousal, stress reduction, and social behaviors. In rodents, grooming involves a patterned and sequenced structure, known as the syntactic chain with four phases that comprise repeated stereotyped movements happening in a cephalocaudal progression style, beginning from the nose to the face, to the head, and finally ending with body licking. The context-dependent occurrence of grooming behavior indicates its adaptive significance. This review briefly summarizes the neural substrates responsible for rodent grooming behavior and explores its relevance in rodent models of neuropsychiatric disorders and neurodegenerative diseases with aberrant grooming phenotypes. We further emphasize the utility of rodent grooming as a reliable measure of repetitive behavior in neuropsychiatric models, holding promise for translational psychiatry. Herein, we mainly focus on rodent self-grooming. Allogrooming (grooming being applied on one animal by its conspecifics via licking or carefully nibbling) and heterogrooming (a form of grooming behavior directing towards another animal, which occurs in other contexts, such as maternal, sexual, aggressive, or social behaviors) are not covered due to space constraints.

Rats Lacking the Dopamine Transporter Display Inflexibility in Innate and Learned Behavior.

Playing a key role in the organization of striatal motor output, the dopamine (DA)-ergic system regulates both innate and complex learned behaviors. Growing evidence clearly indicates the involvement of the DA-ergic system in different forms of repetitive (perseverative) behavior. Some of these behaviors accompany such disorders as obsessive-compulsive disorder (OCD), Tourette's syndrome, schizophrenia, and addiction. In this study, we have traced how the inflexibility of repetitive reactions in the recently developed animal model of hyper-DA-ergia, dopamine transporter knockout rats (DAT-KO rats), affects the realization of innate behavior (grooming) and the learning of spatial (learning and reversal learning in T-maze) and non-spatial (extinction of operant reaction) tasks. We found that the microstructure of grooming in DAT-KO rats significantly differed in comparison to control rats. DAT-KO rats more often demonstrated a fixed syntactic chain, making fewer errors and very rarely missing the chain steps in comparison to control rats. DAT-KO rats' behavior during inter-grooming intervals was completely different to the control animals. During learning and reversal learning in the T-maze, DAT-KO rats displayed pronounced patterns of hyperactivity and perseverative (stereotypical) activity, which led to worse learning and a worse performance of the task. Most of the DAT-KO rats could not properly learn the behavioral task in question. During re-learning, DAT-KO rats demonstrated rigid perseverative activity even in the absence of any reinforcement. In operant tasks, the mutant rats demonstrated poor extinction of operant lever pressing: they continued to perform lever presses despite no there being reinforcement. Our results suggest that abnormally elevated DA levels may be responsible for behavioral rigidity. It is conceivable that this phenomenon in DAT-KO rats reflects some of the behavioral traits observed in clinical conditions associated with endogenous or exogenous hyper-DA-ergia, such as schizophrenia, substance abuse, OCD, patients with Parkinson disease treated with DA mimetics, etc. Thus, DAT-KO rats may be a valuable behavioral model in the search for new pharmacological approaches to treat such illnesses.

Neurobiology of Supporting Syntactic Chains of Self-Grooming in Rodents and Its Biochecmical Characteristics

Neurobiology of Supporting Syntactic Chains of Self-Grooming in Rodents and Its Biochecmical Characteristics

A dystonia mouse model with motor and sequencing deficits paralleling human disease

The dystonias are a group of movement disorders characterized by involuntary twisting movements and postures. A lack of well characterized behavioral models of dystonia has impeded identification of circuit abnormalities giving rise to the disease. Most mouse behavioral assays are implemented independently of cortex, but cortical dysfunction is implicated in human dystonia. It is therefore important to identify dystonia models in which motor cortex-dependent behaviors are altered in ways relevant to human disease. The goal of this study was to characterize a cortically-dependent behavior in the recently-developed Dlx-CKO mouse model of DYT1 dystonia. Mice performed two tasks: skilled reaching and water-elicited grooming. These tests assess motor learning, dexterous skill, and innate motor sequencing. Furthermore, skilled reaching depends strongly on motor cortex, while dorsal striatum is critical for normal grooming. Dlx-CKO mice exhibited significantly lower success rates and pellet contacts compared to control mice during skilled reaching. Despite the skilled reaching impairments, Dlx-CKO mice adapt their reaching strategies. With training, they more consistently contacted the target. Grooming patterns of Dlx-CKO mice are more disorganized than in control mice, as evidenced by a higher proportion of non-chain grooming. However, when Dlx-CKO mice engage in syntactic chains, they execute them similarly to control mice. These abnormalities may provide targets for preclinical intervention trials, as well as facilitate determination of the physiologic path from torsinA dysfunction to motor phenotype.

Experimental approach of the prosodic component in the linguistic input of gardenpath sentences in Brazilian Portuguese

This study investigates what part the prosodic component plays in linguistic processing. Can prosodic cues be computed early in the linguistic process and influence the syntactic processing? Some studies in American English (Kjelgaard&Speer, 1999; DeDe 2010) and German (Steinhaueret al 1999) have shown that yes, furthermore, prosodic elements like intonational phrases can modify the syntactic chain during processing. Our work is based on the premises that, during the perceptive processing, an early activation of the prosodic component in the linguistic input can lead the sentence’s syntactic structure.There have been studies in Brazilian Portuguese that show how prosody influences parsing (Lourenço-Gomes 2008; Magalhães& Maia 2006), however, none that tested the effects of prosodic constituents’ organization in online tasks.

Obtaining Description for Simple Images using Surface Realization Techniques and Natural Language Processing

This paper aims at developing a simple mechanism to deduce corpora pertaining to an image through various computer vision and natural language processing techniques. The output of the vision detection is combined with the sentence formation approach to get the visual content in textual form. Vision detections are smoothed using a number of approaches to prune undesired combination of words that are semantically incorrect. Descriptions are generated based on syntactic trees and Markov Chains and compared for human likeness based on survey. The results of the survey indicate that the descriptions generated with the help of Markov Chains sound more human like. These generated descriptions can be indexed in lucene and image search can be made more efficient bridging the semantic gap.

CONCEPT AS MENTAL REPRESENTATION OF SUPERTEXT

The article defines the concept as the result of categorization from the standpoint of cognitive linguistics; it overviews the variety of scientific approaches to this mental entity. The article assumes that the concept is not a rigorous ontological taxonomy, but rather a diffusive set, formed with the involvement of diverse paradigms. The basic concepts of a culture or its cultural constants are regarded as the mental representations of its supertexts i.e. text models resulting from the convergence of texts from the semantic field studied. The difference between these two abstract constructs lies in the fact that the concept contains non-verbalized features and the supertext has strict algorithms of their predication and verbalization in syntactic chains deployed from the common paradigm. The article delimitates the meaning of a lexical unit, the conceptual content and the supertextual structure. It is accepted that meaning is a unit of the semantic level, or an element of the system of linguistic meanings related to how a particular lexeme functions; the concept is a unit of the cognitive-conceptual level, which incorporates the mental features of a particular phenomenon; it is not a combination of seems, which are singled out differentially. The article also emphasizes the potential of verbalizing the concept in both key words and supertexts of a culture. The article comes up with a semantic scheme of reconstructing the concept via analyzing the recurrent syntactic structures from the textual tradition; it stresses the necessity of turning to the literary text when studying concepts and their verbalizations, as the concept does not only contain features that are “objectively true”. The concept is a multidimensional verbal and non-verbal construct embedded in the system of human experience; it exists in the cultural space – the global assumptive universe of a people, which contains the set of axiological values and is extant over a certain historic period.

Unilateral Lesion of Dopamine Neurons Induces Grooming Asymmetry in the Mouse.

Grooming behaviour is the most common innate behaviour in animals. In rodents, it consists of sequences of movements organized in four phases, executed symmetrically on both sides of the animal and creating a syntactic chain of behavioural events. The grooming syntax can be altered by stress and novelty, as well as by several mutations and brain lesions. Grooming behaviour is known to be affected by alterations of the dopamine system, including dopamine receptor modulation, dopamine alteration in genetically modified animals, and after brain lesion. While a lot is known about the initiation and syntactic modifications of this refined sequence of movements, effects of unilateral lesion of dopamine neurons are unclear particularly regarding the symmetry of syntactic chains. In the present work we studied grooming in mice unilaterally lesioned in the medial forebrain bundle by 6-hydroxydopamine. We found a reduction in completion of grooming bouts, associated with reduction in number of transitions between grooming phases. The data also revealed the development of asymmetry in grooming behaviour, with reduced tendency to groom the contralateral side to the lesion. Symmetry was recovered following treatment with L-DOPA. Thus, the present work shows that unilateral lesion of dopamine neurons reduces self-grooming behaviour by affecting duration and numbers of events. It produces premature discontinuation of grooming chains but the sequence syntax remains correct. This deficient grooming could be considered as an intrinsic symptom of Parkinson’s disease in animal models and could present some similarities with abnormalities of motor movement sequencing seen in patients. Our study also suggests grooming analysis as an additional method to screen parkinsonism in animal models.

Dopamine receptor modulation of repetitive grooming actions in the rat: Potential relevance for Tourette syndrome

Studies of rodent grooming can provide valuable insight for dopamine contributions to the initiation, organization, and repetition of motor patterns. This information is useful for understanding how brain dysfunctions contribute to movement disorders such as Tourette syndrome and obsessive compulsive disorder, in which patients are driven to reiterate particular movement patterns. In rodents, dopamine D1 receptor stimulation causes a complex behavioral super-stereotypy in the form of excessive production and rigid execution of whole sequences of movements known as syntactic grooming chains. Sequential super-stereotypy of grooming chains may be particularly advantageous for modeling movement sequences and treatments in Tourette syndrome and related disorders. Here, we report that co-administration of haloperidol, one available treatment for Tourette syndrome and primarily a D2 receptor antagonist, prevented D1 stimulation with SKF38393 from inducing sequential super-stereotypy, which manifests as an exaggeration of the tendency to complete all four phases of a syntactic chain in rigid serial order once the first phase has begun. In a separate experiment, we showed that in contrast to acute D1 agonist administration, 39 h withdrawal from chronic (3 weeks) administration of the D1 antagonist SCH23390 (which has been suggested to increase D1 receptor expression in the basal ganglia) did not elicit sequential super-stereotypy after drug cessation. Instead, rats suddenly removed from repeated SCH23390 spent more time performing simple stereotypies that included intense scratching and biting behaviors. Together, these results have implications for understanding how dopamine receptors facilitate particular stereotypies manifest in animal models of Tourette syndrome and obsessive compulsive disorder.

Movement Chains at the Interfaces

AbstractWe argue that Agree is an asymmetric relation. According to Asymmetric Agree, ifxAgrees withy, then the features ofymust be properly included in the features ofx. If the links of a chain created by movement are related by Agree, this correctly predicts the properties of syntactic movement chains. And if the links of a chain created by movement are subject to the Proper Inclusion Condition, that accounts for the (un)availability of extraction out of a moved XP. The following distinctions interact with Asymmetric Agree: whether movement is A or A-bar, whether or not the constituent extracted out of the moved phrase is selected by the head of that phrase, and whether movement is overt or covert. Syntactic movement is feature-structure preserving, in that the Proper Inclusion Condition applies to sets of features in a particular configuration.

Dopamine D1 activation shortens the duration of phases in stereotyped grooming sequences

Rats frequently emit grooming actions in a highly stereotyped, syntactic chain in which three distinct phases of facially directed forearm movements are sequentially emitted in a rule-governed pattern and followed by body-directed licking. The present study evaluated the effects of the full dopamine D1 agonist, SKF 81297, and the partial dopamine D1 agonist, SKF 38393, on the duration of individual phases of stereotyped grooming chains. We found that systemic administration of SKF 81297 significantly shortened grooming chain duration. An examination of the fine temporal structure of syntactic grooming chain actions showed that duration changes were correlated with decreased numbers of actions in phases I and IV of the chain. Phases II and III were not changed in duration, although there were some structural distortions introduced. The partial D1 agonist, SKF 38393, had no effect on duration or number of component actions in the grooming chain. Based on these results, we hypothesize that the timing of syntactic grooming phase transitions may involve a D1-mediated internal clock process that is altered by full D1 agonist activation. By this model, SKF 81297 increases the speed of the clock used for the temporal control of grooming actions, and thus shortens phase durations.

Semantic composition in reflexivization

It has been commonly assumed since Chomsky (1981) that the distribution of reflexive pronouns is subject to Binding Condition A. Reinhart and Reuland (1993) formulate Condition A in terms of the notion of syntactic predicate. The proposal I will develop in this paper is to factor out semantic and syntactic conditions on the occurrence of reflexive pronouns and to reduce them to independently motivated semantic and syntactic mechanisms. The semantic part is attributed to a theory of semantic composition recently developed by Chung and Ladusaw (2004), while the syntactic residue falls into the proper characterization of syntactic chains, as proposed by Reinhart and Reuland (1993) and Reuland (2001). To the extent that this approach is successful, Binding Condition A is rendered superfluous.

Distinct patterns of language impairment in Down's syndrome and Williams syndrome: The case of syntactic chains

This study presents experimental results on syntactic binding of reflexive and non-reflexive pronouns and on the comprehension of active and passive sentences in eight adolescents with Down's Syndrome (DS), and 10 with Williams Syndrome (WS). We propose a syntactic account of the difficulties of people with DS in these domains. We also compare our results on DS and WS with previous findings from studies using the same experimental tasks on adolescents with Specific Language Impairment (SLI). Distinct patterns of linguistic impairment were found for these developmental disorders indicating that at least in these syntactic domains different genetic etiologies are associated with different specifically linguistic patterns of impairment.

Basal ganglia neural mechanisms of natural movement sequences

Natural rodent grooming and other instinctive behavior serves as a natural model of complex movement sequences. Rodent grooming has syntactic (rule-driven) sequences and more random movement patterns. Both incorporate the same movements--only the serial structure differs. Recordings of neural activity in the dorsolateral striatum and the substantia nigra pars reticulata indicate preferential activation during syntactic sequences over more random sequences. Neurons that are responsive during syntactic grooming sequences are often unresponsive or have reverse activation profiles during kinematically similar movements that occur in flexible or random grooming sequences. Few neurons could be categorized as strictly movement related--instead they were activated only in the context of particular sequential patterns of movements. Particular sequential patterns included "syntactic chain" grooming sequences of paw, head, and body movements and also "warm-up" sequences, which consist of head and body/limb movements that precede locomotion after a period of quiet resting (Golani 1992). Activation during warm-up was less intense and less frequent than during grooming sequences, but both sequences activated neurons above baseline levels, and the same neurons sometimes responded to both sequences. The fact that striatal neurons code 2 natural sequences which are made up of different constituent movements suggests that the basal ganglia may have a generalized role in sequence control. The basal ganglia are modulated by the context of the sequence and may play an executive function in the complex natural patterns of sequenced behaviour.

Grammaticality judgments on sentences with and without movement of phrasal constituents—an event-related fMRI study

One of the leading neurolinguistic theories of syntactic comprehension disorders in agrammatic aphasic subjects—the Trace Deletion Hypothesis—postulates a specific impairment in processing syntactic chains, and that this function is mediated by Broca's area. The aim of this study was to investigate whether the specific involvement of Broca's area in processing syntactic traces can be verified using functional brain imaging. We used event-related functional magnetic resonance imaging (fMRI) while healthy subjects were asked to judge the grammaticality of visually presented sentences with and without movement of phrasal constituents. During both kinds of sentences, fMRI showed activation in language-related brain regions. Comparing both kinds of sentences did not result in differential brain activation of left frontal or temporal regions. In particular, Broca's area was similarly activated in processing both moved and nonmoved sentences. Thus, Broca's area seems to be involved in general syntactic processing as required by grammaticality judgments rather than having a specific function in transmitting syntactic relations.

Action sequencing is impaired in D1A-deficient mutant mice.

The role of dopamine in the production of behaviour is multifarious in that it can influence different aspects of movement (e.g. movement initiation, sensorimotor integration, and movement sequencing). A characteristic of the dopamine system which seems to be critical for the expression of this diverse influence is its varied receptor population. Previous studies have shown that specific receptor subtype activation leads to specific behavioural responses or alterations of selective aspects of movement. It is known that one of the important influences of dopamine includes sequential co-ordination of 'syntactic' patterns of grooming movements because moderate loss of the dopaminergic nigrostriatal projections specifically disrupts these patterns without affecting grooming actions in a general fashion (Berridge, K.C. Psychobiology, 15, 336, 1989). The specific receptors of the dopamine family which play a key part in this co-ordination of movement sequences is not known. In the present study, we examined the serial order of particular syntactic sequences or chains of grooming actions in mice lacking D1A receptors to explore the relationship between this receptor subtype and movement sequencing. Mutant mice had shorter grooming bouts and a disruption of the organization of sequential patterns compared with wild-type littermate controls. Sequential disruption was reflected in the failure of D1A mutants to follow the syntactic pattern of grooming to completion. This sequential disruption deficit appeared to be specific, as mutant mice initiated more syntactic chains than wild-type controls even though they were less likely to complete them. These results support the hypothesis that D1A receptor activation plays a part in the sequencing of natural action. This conclusion has important implications for the understanding of the functional heterogeneity of dopamine receptor subtypes and of the aetiology of symptoms observed in patients with basal ganglia disease.

Coding of Serial Order by Neostriatal Neurons: A “Natural Action” Approach to Movement Sequence

The neostriatum controls behavioral sequencing, or action syntax, as well as simpler aspects of movement. Yet the precise nature of the neostriatums role in sequencing remains unclear. Here we used a "natural action" approach that combined electrophysiological and neuroethological techniques. We identified neostriatal neurons that code the serial order of natural movement sequences of rats. During grooming behavior, rats emit complex but highly predictable species-specific sequences of movements, termed "syntactic chains." Neuronal activity of 41% of cells in the dorsolateral and ventromedial neostriatum coded the sequential pattern of syntactic chains. Only 14% coded simple motor properties of grooming movements. Neurons fired preferentially during syntactic chains compared with similar grooming movements made in different sequential order or to behavioral resting. Sequential coding differed between the dorsolateral and ventromedial neostriatum. Neurons in the dorsolateral site increased firing by 116% during syntactic chains, compared with only a 30% increase by neurons in the ventromedial site, and dorsolateral neurons showed strongest coding of grooming syntax by several additional criteria. These data demonstrate that neostriatal neurons code abstract properties of serial order for natural movement and support the hypothesis that the dorsolateral neostriatum plays a special role in implementing action syntax.

Implementation of Action Sequences by a Neostriatal Site: A Lesion Mapping Study of Grooming Syntax

The neostriatum and its connections control the sequential organization of action ("action syntax") as well as simpler aspects of movement. This study focused on sequential organization of rodent grooming. Grooming syntax provides an opportunity to study how neural systems coordinate natural patterns of serial order. The most stereotyped of these grooming patterns, a "syntactic chain," has a particularly stereotyped order that recurs thousands of times more often than could occur by chance. The purpose of the present study was to identify the crucial site within the striatopallidal system where lesions disrupt the syntax or serial order of syntactic grooming chains without disrupting constituent movements. Small excitotoxin lesions were made using quinolinic acid at bilateral sites within the dorsolateral, dorsomedial, ventrolateral, or ventromedial neostriatum, or in the ventral pallidum or globus pallidus of rats. An objective technique for mapping functional lesions was used to quantify cell death and to map precisely those lesions that disrupted grooming syntax. Our results identified a single site within the anterior dorsolateral neostriatum, slightly more than a cubic millimeter in size (1.3 x 1.0 x 1.0 mm), as crucial to grooming syntax. Damage to this site did not disrupt the ability to emit grooming actions. By contrast, damage to sites in the ventral pallidum and globus pallidus impaired grooming actions but left the sequential organization of grooming syntax intact. Neural circuits within this crucial "action syntax site" seem to implement sequential patterns of behavior as a specific function.

Comprehension of Wh-Questions in Two Broca's Aphasics

This study investigated comprehension of wh-questions in two Broca's aphasics. Patients were presented for comprehension with two types of wh-questions: questions headed bywhichand questions headed bywho. These two types were chosen because according to recent syntactic analyses they give rise to different types of syntactic "chains." These questions were presented in both subject gap versions (e.g.,which cat chased the dog?) and object gap versions (e.g.,which cat did the dog chase?). Comprehension ofwhichquestions was asymmetric, with subject gap versions comprehended significantly better than object gap versions, the latter yielding chance-level performance. This finding is consistent with previous reports of subject–object asymmetries in comprehension of relative clauses and clefts, as well as active–passive comprehension asymmetries. In contrast, comprehension ofwhoquestions was symmetrical over subject gap and object gap versions: Both patients performed equally well (significantly better than chance) on subject gap and object gapwhoquestions. These findings are inconsistent with current formulations of "chain" or "trace"-based theories of agrammatic comprehension which assume a deficit that affects both types of syntactic chains. We suggest that linguistic descriptions of agrammatic comprehension should be limited to deficits involving only one type of chain. We also suggest that there are processing differences underlying the syntactic distinctions betweenwhich-type andwho-type questions and that this may account for different patterns of comprehension on these and other constructions.

Ontogeny of Action Syntax in Altricial and Precocial Rodents: Grooming Sequences of Rat and Guinea Pig Pups

Abstract Behavior occurs as coordinated patterns of serial order, with rules of 'action syntax'. Grooming behavior of adult rodents provides several striking examples of action syntax rules. The most stereotyped of these is a 'syntactic chain' pattern, which organizes up to 25 facial strokes and licking movements into a predictable sequence. This pattern previously has been found to be emitted by diverse rodent species from all major suborders: myomorph, sciuromorph, and caviomorph. In this study, we compared the postnatal ontogeny of grooming syntax in two rodent species: rat versus guinea pig. Rats are relatively altricial at birth, whereas guinea pigs are precocial. A day-by-day study of the fine-grain structure of sequential patterns was carried out during the first three weeks after birth, using slow-motion videoanalyses and a choreographic notation system for scoring behavioral grooming sequences. The results showed that substantial action syntax rules exist in guinea pig grooming even on the day of birth. For guinea pigs, postnatal grooming syntax development was limited to minor increments in the strength of the syntactic pattern and in postural control. By contrast, for rat pups, action syntax did not begin to appear until the second postnatal week, and developed gradually into the third week. The development of rodent syntactic patterns in both species appeared to be independent of the maturation of the movements that composed the pattern. Our results indicate that action syntax rules develop as hierarchical entities independent from constituent movements.