Psychogenic movement disorders refer to functional abnormalities in the modulation of voluntary movement. In this chapter, I will describe evidence that the fundamental abnormalities involve specific deficits in self-aware consciousness, which can be reliably quantified by specific measures of personality in my Temperament and Character Inventory (TCI) (1,2). Much is now known about the modulation of self-aware consciousness (3,4), and further work on movement disorders should extend and clarify this growing body of knowledge in ways that will be clinically and theoretically valuable.

Psychogenic movement disorders are classified as conversion disorders in the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) (5). A conversion disorder refers to a symptom or deficit “affecting voluntary motor or sensory function that suggests a neurologic or other general medical condition.” The official criteria further stipulate that the symptoms or deficits cannot be explained by a neurologic or general medication condition and are not intentionally produced or feigned. On the other hand, psychological factors may be judged to be associated with the symptom or deficit “because the initiation or exacerbation of the
symptom or deficit is preceded by conflicts or other stressors.” However, all these criteria require judgments that are difficult and sometimes unreliable because patients with involuntary neurologic deficits also experience conflict and distress, which may lead to a functional overlay to an involuntary neurologic disorder.

The unreliability of diagnosis of individual conversion disorders led Eli Robins, Samuel Guze, and me to develop criteria for what is now called somatization disorder in DSM-IV (6). Somatization disorder requires the presence of four pain symptoms, two gastrointestinal symptoms, and one sexual symptom in addition to a pseudoneurologic symptom. These criteria identify a group of patients with chronic unexplained somatic and neurologic complaints. The disorder has a chronic fluctuating course with many complaints, and unnecessary medical treatment and surgeries, often highly disabling and expensive. The disorder is heritable, as shown by adoption studies I carried out in Sweden through access to national registers of all medical treatment and sick-leave disability (7,8). The vulnerability factors for somatization disorder can also be measured reliably as personality traits, and much is now known about the brain imaging, neurobiology, and molecular genetics of personality traits underlying somatization and conversion disorders (4,9, 10, 11). The heritability of vulnerability to psychogenic movement disorders suggests that there are real psychobiologic processes underlying these complex phenomena, as described later.

Most patients with unexplained somatic and neurologic complaints do not satisfy the stringent criteria for somatization disorder. As a result, physicians are usually still in great need of a valid and reliable way to evaluate the psychobiologic processes that modulate voluntary choice and movement in patients who do not satisfy criteria for somatization disorder. Much can be learned from careful observation and interpretation of the mental status examination of patients with unexplained somatic complaints or conversion disorders.

At the time when conversion symptoms occur, a person is lacking in awareness of their voluntary control of what they are doing. This lack of self-aware consciousness is characterized by little or no ability to recollect the spatiotemporal and psychosocial context in which the symptoms are occurring. As a result, clinicians describe such patients as “vague and inconsistent historians” when trying to elicit the history and doing mental status examination. They may be unable to provide an account of relevant stressors that collateral informants can readily describe or that can be observed directly. They may be able to report the occurrence of events as separate facts, but still are unaware of interdependent relationships that define the context in which their sensations and movements occur. The patient may be excessively dramatic or excessively emotionally detached because they do not have much awareness or understanding of their psychosocial context. Often doctors are frustrated by the inconsistent, vague, and overdramatic history, failing to realize that this style of presentation actually characterizes the fundamental deficit in self-awareness and episodic memory underlying the disorder. If a person has a chronic deficit in self-awareness (i.e., their usual thoughts are childlike, immature, or lacking in self-awareness), then they are described as having a chronic personality disorder. Most often the patients have impulsive (“Cluster B”) personality disorders, such as antisocial, histrionic, or borderline personality disorder. However, individuals without a chronic personality disorder may regress to an immature state of consciousness that is brief or sustained while they are under unusual stress. The mental status at the time that the patient’s conversion symptoms are active is what is most important to observe.

I developed a comprehensive model of human personality over the past 15 years to understand the psychobiologic factors underlying vulnerability to psychopathology, such as somatization and conversion disorders (9,12, 13, 14, 15). Most previous models of personality describe traits that differ among individuals, but do not explain the psychobiological processes within an individual that lead to these differences. For example, DSM-IV is a purely descriptive system that distinguishes several categories of personality disorder, such as antisocial, avoidant, and schizoid personality disorders. DSM-IV provides behavioral criteria for identifying these disorders, but provides no explanation whatsoever of the brain processes that cause these disorders. Fortunately, I have been able to develop a model of personality that explains the observable differences among individuals (as described in DSM-IV) and provides a testable model of the psychobiologic processes that cause these variations in personality and susceptibility to mental disorders, including psychogenic movement disorders (4).

Human personality can be described in terms of three systems of learning and memory: (i) procedural learning of habits and skills, which involves four dimensions of temperament; (ii) declarative or semantic learning of facts, which involves three dimensions of character; and (iii) self-aware consciousness or episodic memory, which involves autobiographic recollection of personal continuity, subjective time, and the spatiotemporal context in which facts about events occur in experience (4,11). The four temperament dimensions are measured as individual differences in
associative conditioning of responses to simple emotional stimuli, eliciting fear (Harm Avoidance, anxiety-prone vs. risk-taking); anger (Novelty Seeking, impulsive vs. rigid); disgust (Reward Dependence, sociable vs. aloof); and ambition (Persistence, overachieving vs. underachieving). The three character dimensions are measured as individual differences in supervisory cognitive processes, including executive functions (Self-directedness, or the sense of personal agency); legislative functions (Cooperativeness, or the sense of flexible voluntary choice based on making rules to govern social interactions); and judicial functions (Self-transcendence, or the intuitive understanding of when rules apply and should be executed). The self-report of usual patterns of emotional response and mental self-government are reliably reported facts or semantic knowledge that is abstracted from self-aware consciousness in episodic memory. In addition, the dynamic movement of thought in time can be quantified in terms of a nonlinear matrix of subplanes of thought through which human beings move from moment to moment in self-aware consciousness. This movement in autobiographic memory has multiple steps and stages that can be reliably rated and quantified with interrater reliability around 0.88 using methods I have recently developed and described (4), as described in the next section.

Each of the four dimensions of temperament and three dimensions of character have heritabilities of about 50% estimated from large-scale twin studies in the United States and Australia. Each of the seven dimensions has unique genetic determinants (16). Each dimension has specific brain circuitry and carries out specific information-processing tasks, as has been demonstrated by functional brain imaging and evoked potential studies (11,17, 18, 19, 20, 21). A detailed description is provided elsewhere (4).

Each dimension measures variability in a complex adaptive system involving the nonlinear interaction of multiple genetic and environmental variables. In fact, there is a hierarchy of such complex coupled networks at increasing levels of information or self-aware consciousness. The hierarchy extends from the level of the matter to the cell, then the physiology of individual organisms, the psychology of individuals in social groups, and so on. Human beings are unique in their capacity for self-aware consciousness, so that a self-aware human being can be described as development and evolution conscious of itself. Great apes have intellectual reasoning and mirror recognition, but not self-aware consciousness in which there is autobiographical recollection of events in a spatiotemporal context (22). Other primates can learn facts, but only human beings can recollect when or where they learned those facts.

The succession of human thoughts in consciousness involves abrupt transitions between thoughts that are synchronous with transitions in spatiotemporal connections between changing sets of brain networks. Discrete thoughts are linked with distinct brain microstates that can be measured by segmentation of abrupt transitions in EEGs (23, 24, 25). Different thoughts are associated with distinct brain microstates. These discrete mind-brain states recur in a nonlinear fashion. In other words, different thoughts occur in complex sequences that are not fully predictable in terms of initial conditions or antecedent events.

The content of human thought can be defined in terms of the variability encompassed by individual differences in the seven dimensions of personality measured by the TCI. It is also possible to rank order the range of thought in terms of level of coherence or integration, which I have done by studies of disorganization of thought by induction of fears and increasing coherence of thought by induction of relaxation and meditative states. Then the movement of thought through the hierarchy of varying levels of coherence can be quantified. The modulation of movement of thought is measured by the TCI character dimensions, which correspond to individual differences in higher cognitive processes instantiated as supervisory brain networks regulating attention, affect, and motor activity (4,26). For example, individual differences in TCI Self-directedness are strongly correlated (r = 0.75) with individual differences in efficiency of activation of the medial prefrontal cortex (Brodmann areas 9/10) during tasks of executive function (19).

Individual differences in the content and movement of thought are about equally influenced by genetic factors and by variables unique to each individual. Judicial functions, as measured by TCI Self-transcendence, are correlated −0.7 with individual differences in 5HT1a receptor density in the neocortex, hippocampus, and raphe nuclei (27). Presynaptic 5HT1a receptors inhibit neuronal firing in the raphe and all projection areas, providing a means of modulating the activity of a widespread distributed network. The expression of the dopamine D4 (DRD4) receptor is also correlated with this same character trait (28). DRD4 is one of the most variable human genes known, and most of its diversity is the result of variation in a 48-base pair tandem repeat in exon 3 that encodes the third intracellular loop of the DRD4 dopamine receptor (29). Different allelic forms of DRD4 influence the sensitivity of the receptor to dopamine, so that individuals with the seven-repeat allele have much greater neuronal excitability than those with the ancestral four-repeat allele. As a result, the levels of TCI Novelty Seeking and Self-transcendence vary substantially as a result of gene-gene interactions among the DRD4 polymorphism and other genes that regulate the catabolism and transport of dopamine, such as catechol-O-methyltransferase and the dopamine transporter (4,30,31). Also gene-environment interactions influence the development of personality, so that childhood experience of a hostile environment and adult experience of stressful life events modify gene expression and personality development (32,33). In this way, each individual can adapt to his unique experiences in a flexible
manner in ways that are partly heritable and partly creative (i.e., free of initial conditions and antecedent influences).

Much discussion of consciousness has been confused because of a failure to recognize that the movement of thought in self-aware consciousness is a quasi-continuous process with multiple stages. All human thinking has five steps that are modulated by three processes, as summarized in Table 1. The five steps in thought are: (i) the initial perspective in which there is intuitive recognition of what is given in experience; (ii) labeling the intuition and reasoning about intentions; (iii) emotional responses to those labels and intentions; (iv) intellectual judgments to execute the intention; and (v) the action itself, which with repetition leads to habits. The degree of coherence of a person’s thought (that is, their level of character development) passes through stages that differ qualitatively as a person becomes consciously self-aware of these processes underlying their thinking. Individuals with conversion and personality disorders usually operate in the intuitive step without self-aware consciousness of the later steps in thought. Ordinary adults operate with self-awareness of the first two or three steps in thought, which is called reflection or ordinary adult cognition (“first stage of self-aware consciousness”) (4). Self-awareness of the fourth step in thought involves metacognition, which is “thinking about thinking” or meditation in which we become aware of thoughts that were previously subconscious. Self-awareness of all the stages of thought involve spontaneous flow states in which there is simultaneous coherence of intuition, intention, and action without effort or conflict, which is called contemplation (“third stage of self-aware consciousness”) (4).

The first four steps are each regulated by one of the temperaments: intuition by Harm Avoidance, reasoning by Novelty Seeking, emotion by Reward Dependence, and intellectual judgments and intentions by Persistence. The emotional aspects of these steps are also supervised by the three processes indicated in Table 1: Agency or the executive initiation of responses, as measured by TCI self-directedness; Flexibility or the legislative selection of voluntary responses, as measured by TCI Cooperativeness; and Understanding or the judicial monitoring of responses, as measured by TCI Self-transcendence. The fifth step is the result of the character processes.

Each of the three character processes has five subscales corresponding to the five steps in thought, as summarized in Table 1. For example, the intuitive step is regulated by the first subscales of the three character dimensions: SD1, responsible versus controlled and victimized; CO1, tolerant
versus prejudiced and hateful; ST1, sensible versus hysterical and repressive. The first step corresponds to the onset of preparatory activity in the brain as measured by the cortical “readiness potential” in experiments of Libet and others. The degree of preparatory activity is also measured by the P300 evoked potential in oddball experimental paradigms, which is moderately correlated with TCI Self-directedness (18). The time course of cortical event-related potentials allows the dissociation of the early intuitive recognition of stimuli from later decision making (34). Intuitions are only immediately conscious in the third stage of self-aware consciousness.