Summary

Grooming is increasingly recognized as a reliable marker of stress-related disturbances in animal models of neuropsychiatric disorders. We previously reported that subchronic exposure to 10 mg/kg of phencyclidine (PCP) for 15 days in rats increased grooming expression under both stressful and appetitive conditions, but impaired grooming syntax only when the behavior was elicited with stressful water sprays directed at the face. For the purpose of this chapter, new indexes from the same rats subjected to the water spray condition were analyzed. Results showed that the PCP group aborted less chains after face washing and spent a lower proportion of time in anterior grooming than control animals. Phencyclidine treatment also increased incorrect chain initiations and enhanced the duration of Phase IV within completed syntactic chains. Finally, PCP-injected rats were less engaged in nongrooming activities, and were more inactive. In a context where grooming was needed rostrally after facial contacts with water sprays, these results indicate that subchronic PCP treatment compromised hygiene efficiency and engendered an unfocused and perseverative grooming, most likely combined with an abnormal stress response. These observations suggest that the two leading approaches in the study of grooming patterning may provide pivotal sets of qualitative observations that help identify hygienic and stress-related irregularities in animal models.

The functional triangle of language, mind and brain

In a classical perspective a language consists of the set of its words and sentences determined by its lexicon and grammar. Words and sentences are realized as sound patterns and are mentally registered when we hear them as sound patterns or when we identify them as letter figures on paper. Today they can also be realized and identified as letter configurations on the computer screen.

But there is more. When recalling something said to us, the memorized words and sentences appear as sound images in our minds together with our mental understanding of the words’ and sentences’ meanings. We may also learn that, while our mind thinks, understands, or speaks, some of the grey cells in our brain are active. In a naïve understanding it may appear to us that pieces of uttered words and meanings are realized and kept in the brain like being printed on a physiological tabula rasa or in a storage space.

Many linguists disagree with the assumption that our mind images everything that is relevant for speaking or understanding. They emphasize that when we speak correct language we have no conscious image of all aspects of meaning and the rules that determine grammatical correctness. Indeed for speaking and understanding normal words and sentences the system of grammatical regularities is somehow operative, but we almost never have conscious mental images of them. Thus we must assume that the rules of grammar and the rules of lexical word relations can at best be represented structurally in the manner of an abstract system description. The mental system seems to be similar to other systems of rules such as the well learned intuitive competence of the rules of chess. When we are fluent players of chess we play without consciously concentrating at any moment on the rules.

Some philosophers’ pan-organic outlook: instead of an introduction

The introduction of the first chapter was a plea for the future development of our functional triangle: linguistics–phenomenological psychology–neurocognition. The following illustrations and introductory explanations of brain elements emphasize the enormous challenge of understanding the functional integration of the three disciplines. Serious difficulties confront the interdisciplinary studies due to the differences of empirical methods and different frameworks for principles of thoughts, theorizing and trying to construct fruitful working models. Since this book is not so much concerned with presenting details of measurements and observations the focus is rather on theorizing and clarifying the disciplines’ principles that underlie the conceptual frames for plausible and justified working models.

The differences of interdisciplinary thought are clear. Linguists work with formal constructions considered as plausible and justified working models structuring grammar and systems of meaning rules that describe semantic and pragmatic structure dependencies of lexical words. Their constructions are arrangements of conceptual terms in static relational patterns. The set of terms can only contribute to principles of organization, that is to the topic of the present chapter, when systems of construction rules are added to the collection of terms, rules whose operations identify, combine or separate letter symbols and formal symbol patterns or arrange them in systematically justified patterns representing relations. In modern linguistics these principles of organization have been adapted from organizations introduced in formal logic and formal meta-mathematics during the first half of the past century.

The phenomenon of creativity and advanced forms of experience

The previous chapters concentrated on neural perspectives of concrete semantics such as seeing, acting, memorizing, and meaningful understanding. But in general the frameworks discussed were automatic processes in perception–action hierarchies. Their initiation might be caused by a conscious intention but their detailed execution does not involve or even require conscious control and intentional direction. Even grammatically correct speech acts organized in Broca’s and Wernicke’s areas have been characterized as automatic neural processes. The previous chapter has explained the surprising fact that, though automatic, the organization of vision requires a much more complicated system of cooperating brain components. They are most appropriately explained by the procedures of saccadic eye-movements when they organize identifications of objects and situations.

But not all organizations of vision and speech are automatic. The organization is essentially different in creative acts of human vision and thinking, and also in concrete feeling of self, other self and social cooperation. The present chapter will study these phenomenological aspects and neurocognitive organizations that are involved. Given the phenomenal complexity I will not begin with neurocognitive models but rather with phenomenological considerations of vision and visual imaging. The reason is that the status of different stages of complexity is best understood by explaining the steps leading from the simplest acts of concrete vision over standard visual identification of the objects of the environment to experienced studies of works of art. The subsequent sections will show that creativity in understanding of visual art may be given a key role since it has some similarity with other ranges of creativity, as for instance science.

The gap between formalist structure definition and neural dynamic

Acknowledged mental knowledge theories and neuronal brain analysis should not remain separated. The challenge is particularly addressed to linguistics as a mental study both in the abstract form of formal linguistics and in formats of “Grammar as life”. In the present research situations we cannot do more than propose and study models that seem to be plausible for bringing structures and organizations of the linguistic mind and the neurocognitive brain into correspondences. Even this is a difficult task, in particular when we want to correlate techniques of passive formal symbolic structure representations and central processing combination with systematic descriptions of connection-based and radically dynamic organization in cognitive neuroscience! This was already explained in earlier chapters: In principled biological perspective there are only self-organizing units in cognitive neuroscience in Aristotle’s, Spinoza’s and Leibniz’ philosophy, today scientifically systematized by Fuster and Damasio.

We must expect that perspective correspondence is more difficult to model than the similar task of relating software and hardware processes in computer science. The “software” and “data structures” that appropriately constitute the functional mind must be far more tightly bound up with the biological nature of the neuronal networks. This certainly holds for the relation between mental linguistic structure and neuronal brain structure-based organization.

Summary

“Barbering” is an abnormal behavior in mice. Barbering mice pluck fur and/or whiskers from cage-mates and/or themselves, leaving idiosyncratic patches of hair loss. The behavior is a paradox: barbering is common in laboratory mice, but it is not seen in wild mice, it does not benefit the plucker, and it is costly to the recipient. This chapter will attempt to resolve the barbering paradox by asking how and why barbering behavior occurs. Using Tinbergen's (1963) framework for an ethological analysis, we assess barbering in terms of adaptive function, phylogeny, development, and mechanism.

The first section discusses hypotheses of adaptive function. The dominance hypothesis is refuted by several studies; the coping hypothesis remains untested; and the pathology hypothesis is supported by multiple lines of evidence. The pathology hypothesis therefore provides the best resolution to the barbering paradox. Accordingly, throughout, we compare and contrast barbering to trichotillomania (TTM) and other human disorders characterized by repetitive behavior. The second section assesses the phylogenetic underpinnings of barbering by comparing and contrasting hair-plucking behavior across species and between mouse strains. The third section reviews the developmental processes that underlie barbering behavior, particularly developmental risk factors, learning, the laboratory environment, and transgenic effects. The final section reviews the behavioral mechanisms, eliciting stimuli, and physiological mechanisms that might mediate barbering. Here, we outline the role of cortico–striatal circuitry in abnormal repetitive behavior in general, how it can be used to delineate disorders, and insights it provides into barbering.

Our dynamic perspective

The intention of the first part of this book was to familiarize linguists with an overview of neurocognitive science in the wide sense. This second part looks in the other direction: Linguistics should be introduced to neuroscientists.

For the linguists the first part of this book presented neurocognitive perspectives of brain architecture and brain dynamics. The analyses and descriptions of distributed brain areas of the cortex and sub-cortical areas and nuclei were related to psychological functions supported by the interactive cooperation of brain components. The reality of language form organization in cortical core areas was justified about 150 years ago. Thus language was marked as a central psychological function in the brain. But I also emphasized that, though very important, the organization of linguistic forms in phonology, morphology and syntax must be supplemented by organizations of concrete meanings of perception and action. Form and meaning cooperation require the interaction of form organization with perception–action and feeling-based brain processing. In fact almost any Broca-Wernicke external area can contribute with its specific organization of concrete semantics by processes of perception and action, attention and intention, memorizing, memory recall of autobiographic and systematic knowledge involving data and processing of knowledge data based on reflective competence systems of conceptual planning organization, emotion and feeling, internal body experiences and self-experiences. Normally these meaning organizers, which are usually distant from Broca’s and Wernicke’s areas, constitute universes of concrete meaning and background understanding. Both are actively integrated by “neural network binding,” thus constituting the understanding of situation, discourse and thought.

Summary

Both the estrogen-synthesizing enzyme and estrogen receptors are present in the brain. The distribution of estrogen-sensitive cells in the brain corresponds to regions that control sexual differentiation, masculine and feminine sexual behaviors, and aggressive behaviors as well as grooming. All these are indicative that estrogens play diverse roles in several neural circuits. From observing animal models and psychiatric patients, it is evident that estrogens have modulatory effects on grooming and related behaviors.

Introduction

Traditionally viewed as female reproductive hormones, estrogens have in the past decade been shown to have widespread biological actions in both males and females. Estrogens are C-18 steroids derived from cholesterol and occur naturally in the human body in three different forms: 17β-estradiol (E2), estrone (E1), and estriol (E3) (Young et al. 1964). The last step in estrogen biosynthesis is the aromatization of androgens, including testosterone and androstenedione, to estradiol and estrone respectively. In addition to the reproductive organs, estrogens are expressed in many tissues including: breast, fat, muscle, bone, and brain (Carreau et al. 1999; Jenkins et al. 1993; Sasano and Ozaki 1997; Sasano et al. 1997, 1998; Simpson et al. 1997a). Investigations on the mechanism of action of estrogens have escalated greatly over the past decade due to the discovery of three types of estrogen receptors: estrogen receptor α (ERα; Green et al. 1986) estrogen receptor β (ERβ; Kuiper et al. 1996), and membrane ER (ERX; Watson et al. 1999). However, the last is probably ERα in most cases.

Stages of complexity development in the perception–action system

The first chapter concentrated on principles concerning the global schemata of brain architecture and dynamic neural units. The second exposed the basic characteristics of the perception–action system in the mammalian cortex. I introduced a radical extension of Fuster’s classical schema, complementing it by adding the organization components of language form perception together with structure-determined articulation action. This component also contains processing mechanisms that serve complex forms of higher order organization of formal meaning relations, intelligence, and creativity of art and so on. One usually assumes that these processes are located in Broca’s and Wernicke’s areas of the left hemisphere cortex. On the other hand concrete semantics and pragmatics may be distributed in almost any cortical area, locally or distributed, depending on the concrete meaning that the area or the area connection organizes.

In contrast to the previous chapters’ schematic accounts of basically automatic perception–action organization, the present chapter will discuss a number of experimental brain studies concerned with special mental functions that marked breakthroughs in our understanding of processes in the cognitive cortex.

I think that an explanation of the functional systems and neurobiological architectures is more transparent when we do not directly consider the complete complexity of the adult’s brain. Instead, we should study how the organization of competence develops in stages. Phenomenological observations of early phenomena and developmental stages of the brain’s maturation during childhood and adolescence will help our understanding of functions and cortical processes. Let me indicate a few characteristics.

Summary

Grooming disorders, such as trichotillomania (TTM), nail biting, and skin picking, are receiving increasing attention from researchers and clinicians. This is in part due to their possible link to obsessive–compulsive disorder (OCD). It is imperative that these disorders are categorized correctly in order to facilitate research and aid diagnosis and treatment. However, within current psychiatric classification systems TTM is currently conceptualized as an impulse control disorder and nail biting, lip biting, and skin picking are not yet included in the official nomenclature. It is therefore unclear whether these grooming disorders should form a category on their own (i.e., “grooming disorders” or “pathological grooming behaviors”), or whether they should be classified as obsessive–compulsive spectrum disorders (OCSD), impulse control disorders, or as body-focused repetitive behaviors. This chapter will discuss these diagnostic and taxonomic issues particularly as they pertain to clinical practice, fostering further discussion on the psychopathology of aberrant grooming behaviors.

Introduction

The positioning of TTM and other conditions characterized by self-directed repetitive behaviors (e.g., nail biting and pathological skin picking [PSP]) within existing psychiatric classification systems has recently been debated (e.g., Stein et al. 2007). Trichotillomania is classified in the most recent edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR; APA, 2000) as an impulse control disorder. However, some researchers suggest that TTM is an OCSD (Swedo and Leonard 1992).

Summary

This chapter has taken two distinctive but complementary approaches to mouse grooming. The first is based upon Frances Stilwell's intuitive perceptions in the 1970s of previously unappreciated order in grooming sequences. An important principle here is that early stages in research depend upon sensitivity to what our animals can show us. Premature narrowing of observational perspective can limit the richness of analytical questions that are initially hidden from view. In the second part of the chapter, John Fentress outlines some of the richness of subsequent research that sensitive descriptions have led up to. Mouse grooming has led to a host of studies in behavioral genetics, development, brain mechanisms, and motivational models including stress.

Introduction

This chapter is intentionally divided into two parts. The first part, by Frances Stilwell, outlines the discovery of rules underlying order in the rich patterning of mouse grooming. As Stilwell discovered in the early 1970s, there is indeed syntax, perhaps even a grammar, in these rodent movements. One of the lessons here is to look closely at rules of order in seemingly inconsequential action patterns of the animals around us. They are rich in their structure. Mouse grooming has led to a number of important insights about brain and behavior. Furthermore, Stilwell's comments are not only refreshingly personal, but also important as a picture of how research sometimes actually progresses. This reminds us of the insights early ethologists, such as N. Tinbergen, came up with by just watching.

Summary

Trichotillomania (TTM) is a common debilitating impulse control disorder, which is under-recognized in clinical practice. New research shows interesting similarities between TTM, other impulse control disorders, and obsessive–compulsive disorder (OCD), while also revealing important differences in some endophenotypic measures. In this chapter we review new advances in genetic, family, neurocognitive, neuroimaging, and neuropharmacological studies. Neural abnormalities in the amygdalo–hippocampal formation and frontal–subcortical circuits are discussed. Animal models of hair pulling are also outlined and may prove a fruitful avenue for future research.

Introduction

Trichotillomania is a neuropsychiatric disorder characterized by noticeable hair loss due to a recurrent failure to resist impulses to pull out hairs. The hair pulling is usually preceded by mounting tension and followed by a sense of relief or gratification (WHO 2002). It predominantly affects females (Swedo and Leonard 1992), and its onset is usually in late childhood and adolescence (Walsh and McDougle 2001). A subgroup with very early onset of hair pulling in children under the age of six may be more benign and self-limiting (Keren et al. 2006). Often accompanied by shame and distress, TTM is under-recognized in clinical practice and its prevalence is likely to be greater than currently understood (Bohne et al. 2005b). There have been no population-based epidemiological studies of TTM. In a sample of 2579 college students in the United States, a lifetime prevalence of TTM was seen in 0.6%, though subthreshold symptoms not reaching diagnostic criteria were identified in 1.5% of males and 3.4% of females (Christenson et al. 1991b).