Quantification of the ossification of the lateral cuneiform in the feet of young children with unilateral congenital talipes equinovarus.

AIMS: After the initial correction of congenital talipes equinovarus (CTEV) using the Ponseti method, a subsequent dynamic deformity is often managed by transfer of the tendon of tibialis anterior (TATT) to the lateral cuneiform. Many surgeons believe the lateral cuneiform should be ossified before surgery is undertaken. This study quantifies the ossification process of the lateral cuneiform in children with CTEV between one and three years of age. PATIENTS AND METHODS: The length, width and height of the lateral cuneiform were measured in 43 consecutive patients with unilateral CTEV who had been treated using the Ponseti method. Measurements were taken by two independent observers on standardised anteroposterior and lateral radiographs of both feet taken at one, two and three years of age. RESULTS: All dimensions of the lateral cuneiform on the affected side increased annually but remained smaller than the corresponding dimensions of the unaffected foot (p < 0.01). The lateral cuneiform resembled a 9 mm cube at two years and an 11 mm cube at three years. CONCLUSION: At one and two years, the ossification centre of the lateral cuneiform may not be large enough to accommodate a drill hole for tendon transfer. However, by three years, it has undergone sufficient ossification to do so. Cite this article: Bone Joint J 2017;99-B:1109-14.

Emotion, motivation, and anxiety: brain mechanisms and psychophysiology.

The organization of response systems in emotion is founded on two basic motive systems, appetitive and defensive. The subcortical and deep cortical structures that determine primary motivated behavior are similar across mammalian species. Animal research has illuminated these neural systems and defined their reflex outputs. Although motivated behavior is more complex and varied in humans, the simpler underlying response patterns persist in affective expression. These basic phenomena are elucidated here in the context of affective perception. Thus, the research examines human beings watching uniquely human stimuli--primarily picture media (but also words and sounds) that prompt emotional arousal--showing how the underlying motivational structure is apparent in the organization of visceral and behavioral responses, in the priming of simple reflexes, and in the reentrant processing of these symbolic representations in the sensory cortex. Implications of the work for understanding pathological emotional states are discussed, emphasizing research on psychopathy and the anxiety disorders.

Neuroanatomical correlates of pleasant and unpleasant emotion.

Substantial evidence suggests that a key distinction in the classification of human emotion is that between an appetitive motivational system association with positive or pleasant emotion and an aversive motivational system associated with negative or unpleasant emotion. To explore the neural substrates of these two systems, 12 healthy women viewed sets of pictures previously demonstrated to elicit pleasant, unpleasant and neutral emotion, while positron emission tomographic (PET) measurements of regional cerebral blood flow were obtained. Pleasant and unpleasant emotions were each distinguished from neutral emotion conditions by significantly increased cerebral blood flow in the vicinity of the medial prefrontal cortex (Brodmann's area 9), thalamus, hypothalamus and midbrain (P < 0.005). Unpleasant was distinguished from neutral or pleasant emotion by activation of the bilateral occipito-temporal cortex and cerebellum, and left parahippocampal gyrus, hippocampus and amygdala (P < 0.005). Pleasant was also distinguished from neutral but not unpleasant emotion by activation of the head of the left caudate nucleus (P < 0.005). These findings are consistent with those from other recent PET studies of human emotion and demonstrate that there are both common and unique components of the neural networks mediating pleasant and unpleasant emotion in healthy women.

The varieties of emotional experience: a meditation on James-Lange theory.

James-Lange theory influenced a century of emotion research. This article traces the theory's origins in philosophical psychology, considers differences in the thinking of James and Lange, and assesses Cannon's early critique and the resulting debate. Research is reviewed evaluating physiological patterns in emotion, the discordance of reported feelings and visceral reactivity, and the role of generalized arousal. NeoJamesian theories of attribution and appraisal--and alternative views based on dynamic psychology--are critically examined. A conception of emotion is presented, on the basis of developments unknown to James in conditioning theory, information processing, and neuroscience. Computational models of mentation are discussed, and implications are drawn for the classical debate on cognition and emotion. In concluding, new paths for emotion research are outlined and homage paid to the inspiration of William James.

Emotion, attention, and the startle reflex.

This theoretical model of emotion is based on research using the startle-probe methodology. It explains inconsistencies in probe studies of attention and fear conditioning and provides a new approach to emotional perception, imagery, and memory. Emotions are organized biphasically, as appetitive or aversive (defensive). Reflexes with the same valence as an ongoing emotional state are augmented; mismatched reflexes are inhibited. Thus, the startle response (an aversive reflex) is enhanced during a fear state and is diminished in a pleasant emotional context. This affect-startle effect is not determined by general arousal, simple attention, or probe modality. The effect is found when affects are prompted by pictures or memory images, changes appropriately with aversive conditioning, and may be dependent on right-hemisphere processing. Implications for clinical, neurophysiological, and basic research in emotion are outlined.

Strategies of arousal control: biofeedback, meditation, and motivation.

A series of four experiments assessed the effects of instructions to lower heart rate on heart rate change and general arousal reduction. Various conditions of biofeedback, cognitive load, incentive, knowledge of results, and the experimenter-subject relationship were tested. Experiment 1 compared physiological responses to the delivery of direct organ feedback (i.e., heart rate) with responses to electromyographic biofeedback from the frontalis muscle area and with responses to a nonfeedback tracking task. The results suggest that neither heart rate nor muscle tension feedback is an especially powerful method for achieving sustained reductions in heart rate. Furthermore, although some specificity of physiologic pattern is apparent, biofeedback is no more effective in lowering general activation level than simple instructions to relax accompanied by a general knowledge of results. The second experiment was designed to assess the role of cognitive load in arousal reduction. Heart rate biofeedback was compared with a procedure involving minimal external information processing--the secular meditation exercise of Wallace and Benson. The results indicated a clear superiority for the meditation strategy in effecting reductions in cardiac rate and lowering activation. However, in a third experiment, meditation subjects lowered heart rate much less than observed in the previous study, and this time the reduction did not exceed that achieved by feedback subjects. Subsequent analysis suggested that the quality of the subject-experimenter relationship (active-supportive vs. formal-distant) was a significant variable in accounting for outcome differences. The above hypothesis was supported by a fourth experiment. Under conditions of high subject-experimenter involvement, the superior meditation performance of Experiment 2 was reproduced; under low-involvement conditions the Experiment 3 result of no difference between training groups was obtained. The findings suggest that the effectiveness of any method for achieving relaxation (or physiological control) rests on a complex interaction between informational and motivational imperatives of the stimulus context and definable aspects of the interpersonal exchange between subject and experimenter. This research raises serious questions about the effectiveness of the usual biofeedback paradigm as an aid to arousal reduction and the cost efficiency of its applications in the clinical situation. Furthermore, these results demonstrate the great power in relaxation experiments of psychosocial and other moderator variables, and signal the practical difficulty of their control when these variables appear to be as potent in changing physiology as the primary training methods.

Emotion, novelty, and the startle reflex: habituation in humans.

Previous research with both animal and human subjects has shown that startle reflex magnitude is potentiated in an aversive stimulus context, relative to responses elicited in a neutral or appetitive context. In the present experiment, the same pleasant, unpleasant, and neutral picture stimuli were repeatedly presented to human subjects. Startle reflex habituation was assessed in each stimulus context and was compared with the habituation patterns of heart rate, electrodermal, and facial corrugator muscle responses. All systems showed initial differentiation among affective picture contents and general habituation over trials. The startle reflex alone, however, continued to differentiate among pleasant, neutral, and unpleasant pictures throughout the presentation series. These results suggest that (a) the startle probe reflex is relatively uninfluenced by stimulus novelty, (b) the startle modulatory circuit (identified with amygdala-reticular connections in animals) varies systematically with affective valence, and (c) the modulatory influence is less subject to habituation than is the obligatory startle pathway or responses in other somatic and autonomic systems.

Startle potentiation: shock sensitization, aversive learning, and affective picture modulation.

This study investigated the size of, and relationship between, different modulatory effects of aversive stimulation on the acoustic startle reflex. This reflex is potentiated by shock exposure and associative shock conditioning (in animals and human volunteers) and unpleasant pictures (in human volunteers). In this study, dramatic sensitization of the probe-startle response was observed after shock exposure but not after a control task. Magnitude of sensitization was significantly larger than associative shock conditioning and picture modulation effects (also significant). Sensitization and conditioning scores showed modest, significant correlations with one another but not with picture modulation scores, consistent with animal data showing that partially overlapping brain mechanisms (i.e., amygdaloid-reticular projections) mediate these effects. The present results also indicate that sensitization of startle in human volunteers is a relatively more robust defensive response to aversive stimulation.

Fear imagery and the startle-probe reflex.

Blink reflexes to acoustic probes, heart rate, and subjective reports were studied during affective memory imagery. Thirty-six undergraduates memorized 6 pairs of neutral and fearful sentences. After learning each pair, they relaxed and listened to a series of uniform tones, one every 6 s. A change in tone pitch (higher or lower) cued recall of one of the two sentences. At the first cue tone, groups (n = 12) were under different instructions: (a) ignore the sentence and relax, (b) silently articulate the sentence, and (c) imagine the sentence content as a personal experience. At the second cue tone, all subjects performed the imagery task. Startle probes (50-ms, 95-dB white noise) were presented unpredictably during relaxation and recall trials. Probe blink reflexes were larger and cardiac rate faster at fear sentence recall than at neutral sentence recall or relaxation. For probe reflexes, this effect was greater for imagery than for nonsemantic recall tasks.

Fear conditioning, meaning, and belongingness: a selective association analysis.

Twenty-three subjects rated the belongingness of pairs of conditionable (photographic slides) and unconditioned (e.g., shock, tone, human scream) stimuli. Forty new subjects were then classically conditioned, using rating-defined high (angry face/scream) and low (landscape/scream) belongingness pairs. Finger-pulse responses to the high-belongingness pairs showed superior acquisition and resistance to extinction. Another 40 subjects were conditioned to compound stimuli: a slide (either landscape or angry face) that was the same over trials, and a yellow or blue background that was the discriminant cue for the unconditioned stimulus (scream). When the angry face (the high-belongingness slide) was the invariant part of the compound, relatively poorer differential pulse-volume and skin-conductance conditioning was observed. Thus, depending on the task, a priori belongingness rendered stimuli selectively conditionable, either enhancing or inhibiting visceral response associations.

Emotion in the criminal psychopath: startle reflex modulation.

Startle-elicited blinks were measured during presentation of affective slides to test hypotheses concerning emotional responding in psychopaths. Subjects were 54 incarcerated sexual offenders divided into nonpsychopathic, psychopathic, and mixed groups based on file and interview data. Consistent with findings for normal college students, nonpsychopaths and mixed subjects showed a significant linear relationship between slide valence and startle magnitude, with startle responses largest during unpleasant slides and smallest during pleasant slides. This effect was absent in psychopaths. Group differences in startle modulation were related to affective features of psychopathy, but not to antisocial behavior per se. Psychopathy had no effect on autonomic or self-report responses to slides. These results suggest an abnormality in the processing of emotional stimuli by psychopaths that manifests itself independently of affective report.

Emotion in the criminal psychopath: fear image processing.

We tested the hypothesis that the response mobilization that normally accompanies imagery of emotional situations is deficient in psychopaths. Cardiac, electrodermal, and facial muscle responses of 54 prisoners, assigned to low- and high-psychopathy groups using R. D. Hare's (1991) Psychopathy Checklist--Revised, were recorded while subjects imagined fearful and neutral scenes in a cued sentence-processing task. Groups did not differ on self-ratings of fearfulness, imagery ability, or imagery experience. Low-psychopathy subjects showed larger physiological reactions during fearful imagery than high-psychopathy subjects. Extreme scores on the antisocial behavior factor of psychopathy predicted imagery response deficits. Results are consistent with the idea that semantic and emotional processes are dissociated in psychopaths.

Emotional imagery in simple and social phobia: fear versus anxiety.

In a first study, phobic volunteer subjects (N = 60) reacted psychophysiologically with greater vigor to imagery of their own phobic content than to other fearful or nonaffective images. Imagery heart rate responses were largest in subjects with multiple phobias. For simple (dental) phobics, cardiac reactivity was positively correlated with reports of imagery vividness and concordant with reports of affective distress; these relationships were not observed for social (speech) phobics. In a second study, these phobic volunteers were shown to be similar on most measures to an outpatient clinically phobic sample. In an analysis of the combined samples, fearful and socially anxious subtypes were defined by questionnaires. Only the fearful subtype showed a significant covariation among physiological responses, imagery vividness, and severity of phobic disorder. This fearful-anxious distinction seems to cut across diagnostic categories, providing a heuristic perspective from which to view anxiety disorders.

Emotional learning, hedonic change, and the startle probe.

A multiple-response analysis of aversive learning was conducted in human subjects. For each subject, two pictorial stimuli were presented--one paired with electric shock. After training, the magnitude of the acoustic startle eyeblink reflex elicited in the context of the shocked picture increased dramatically and was significantly larger than for reflexes elicited during the nonshocked stimulus. Five different picture contents were tested in separate groups: Reflex potentiation was larger for pictures rated as pleasant than pictures rated as unpleasant. Conditioned responses were also evident for skin conductance, heart rate, and affective judgments. Different systems reflected different aspects of the acquired fear response: Conductance change covaried with arousal, and startle probe magnitude varied with affective valence (pleasure). The neurophysiological implications of the data are elucidated, and parallels drawn between animal and human subjects findings.

The psychopath as observer: emotion and attention in picture processing.

This study extended prior work showing abnormal affect-startle modulation in psychopaths. Male prisoners viewed specific categories of pleasant (erotic or thrilling) and unpleasant (victim or direct threat) slide pictures, along with neutral pictures. Acoustic startle probes were presented early (300 and 800 ms) and late (1,800, 3,000, and 4,500 ms) in the viewing interval. At later times, nonpsychopaths showed moderate and strong reflex potentiation for victim and threat scenes, respectively. For psychopaths, startle was inhibited during victim scenes and only weakly potentiated during threat. Psychopaths also showed more reliable blink inhibition across pleasant contents than nonpsychopaths and greater heart rate orienting to affective pictures overall. These results indicate a heightened aversion threshold in psychopaths. In addition, deficient reflex modulation at early times suggested a weakness in initial stimulus evaluation among psychopaths.

Fear and anxiety: animal models and human cognitive psychophysiology.

The aim of this paper is to explicate what is special about emotional information processing, emphasizing the neural foundations that underlie the experience and expression of fear. A functional, anatomical model of defense behavior in animals is presented and applications are described in cognitive and physiological studies of human affect. It is proposed that unpleasant emotions depend on the activation of an evolutionarily primitive subcortical circuit, including the amygdala and the neural structures to which it projects. This motivational system mediates specific autonomic (e.g., heart rate change) and somatic reflexes (e.g., startle change) that originally promoted survival in dangerous conditions. These same response patterns are illustrated in humans, as they process objective, memorial, and media stimuli. Furthermore, it is shown how variations in the neural circuit and its outputs may separately characterize cue-specific fear (as in specific phobia) and more generalized anxiety. Finally, again emphasizing links between the animal and human data, we focus on special, attentional features of emotional processing: The automaticity of fear reactions, hyper-reactivity to minimal threat-cues, and evidence that the physiological responses in fear may be independent of slower, language-based appraisal processes.

Relationship between facial expressiveness and sympathetic activation in emotion: a critical review, with emphasis on modeling underlying mechanisms and individual differences.

Two important questions bearing on personality processes and individual differences are how do facial expressiveness and sympathetic activation vary as a function of the intensity of an emotional stimulus, and what is the functional mechanism underlying facial expressiveness and sympathetic activation in emotion? A formulation is proposed that is based on 2 propositions: (a) All strong emotions result in some degree of activation of the organism (i.e., principle of stimulus dynamism) and (b) there are individual differences in the gain (amplification) operating on the facial expressive and sympathetic response channels (i.e., principle of individual response uniqueness). This formulation organizes much of the existing data on internalizers and externalizers and yields novel predictions regarding the subpopulation labeled as generalizers.

The emotion probe. Studies of motivation and attention.

Emotions are action dispositions--states of vigilant readiness that vary widely in reported affect, physiology, and behavior. They are driven, however, by only 2 opponent motivational systems, appetitive and aversive--subcortical circuits that mediate reactions to primary reinforcers. Using a large emotional picture library, reliable affective psychophysiologies are shown, defined by the judged valence (appetitive/pleasant or aversive/unpleasant) and arousal of picture percepts. Picture-evoked affects also modulate responses to independently presented startle probe stimuli. In other words, they potentiate startle reflexes during unpleasant pictures and inhibit them during pleasant pictures, and both effects are augmented by high picture arousal. Implications are elucidated for research in basic emotions, psychopathology, and theories of orienting and defense. Conclusions highlight both the approach's constraints and promising paths for future study.

Psychophysical judgment: electro-cortical and heart rate correlates of accuracy and uncertainty.

The relationship between perceptual accuracy and physiological response amplitude was investigated in an auditory pitch discrimination experiment. Confidence ratings were obtained from all subjects following each trial. The stimulus set consisted of three tones of different frequencies spaced in a manner to provide both easy and difficult discriminations. Heart rate, EEG and vertical eye movement were recorded throughout the experiment. The results of the experiment indicated that the largest evoked cardiac rate response was elicited by the stimulus which produced the fewest errors in judgment; larger auditory evoked potentials, particularly the late positive component (P300), were associated with the 'easy' stimulus; greater cortical negativity was associated with the difficult stimuli. Eye activity was found to covary with judgmental accuracy; cortical slow wave activity was particularly sensitive to the confidence, or 'uncertainty' parameter. A 'decision tree' model was hypothesized to describe the processing mechanism involved in solving the discrimination problem.

Brain potentials in affective picture processing: covariation with autonomic arousal and affective report.

Emotionally arousing picture stimuli evoked scalp-recorded event-related potentials. A late, slow positive voltage change was observed, which was significantly larger for affective than neutral stimuli. This positive shift began 200-300 ms after picture onset, reached its maximum amplitude approximately 1 s after picture onset, and was sustained for most of a 6-s picture presentation period. The positive increase was not related to local probability of content type, but was accentuated for pictures that prompted increased autonomic responses and reports of greater affective arousal (e.g. erotic or violent content). These results suggest that the late positive wave indicates a selective processing of emotional stimuli, reflecting the activation of motivational systems in the brain.