Ambulatory accelerometry to quantify involuntary movements and tics in the syndrome of Gilles de la Tourette

Gilles de la Tourette syndrome is a chronic neuropsychiatric disorder characterizedby recurrent and involuntary tics, in addition to complex behavioral symptoms. Objective quantification of the nonspecific movements in Tourette patients can contribute much to understanding the pathophysiology of this disease. We used three accelerometersto characterizehead movement patterns and to objectively quantify head motility in the lateral, sagittal, and transversal planes in 9 Tourette patients and 14 controls during periods of rest, conversation, and watching a videotape with an entertaining program. Characteristic head movement patterns can be documented by means of accelerometry. Head motility levels in the lateral, sagittal, and transversal planes were significantly higher in the patients than in the controls during all the procedures. The patients and the controls showed a similar significant increase in head motility during conversation, but not during video watching. This first study shows that for both standardized and ambulatory research, accelerometry may provide an objective tool by which to quantify the severity and temporal dynamics of tics or nonspecific movements.     

Sociometric Status and Social Drinking: Observations of Modelling and Persuasion in Young Adult Peer Groups

Because young adult drinking occurs primarily in peer groups, this should be taken into account when studying influences on drinking behaviour. This paper aimed to assess influences on drinking by observing existing peer groups in a naturalistic setting. We first analysed the basic levels at which two types of influence take place. The first, modelling (imitating others' drinking), was found to significantly influence individual drinking, whereas for the second one, persuasion (drinking resulting from others offering drinks), no predictions were found. Subsequently, we examined whether peer group members' sociometric status in the group affected the amount of influence and persuasion exerted and received. No indications were found that sociometric status had an impact on influence in alcohol consumption within a drinking situation. Features and weaknesses of the study are discussed.     

Killing begets killing: evidence from a bug-killing paradigm that initial killing fuels subsequent killing

Killing appears to perpetuate itself even in the absence of retaliation. This phenomenon may occur in part as a means to justify prior killing and so ease the threat of prior killing. In addition, this effect should arise particularly when a killer perceives similarity to the victims because similarity should exacerbate threat from killing. To examine these ideas, the authors developed a bug-killing paradigm in which they manipulated the degree of initial bug killing in a "practice task" to observe the effects on subsequent self-paced killing during a timed "extermination task." In Studies 1 and 2, for participants reporting some similarity to bugs, inducing greater initial killing led to more subsequent self-paced killing. In Study 3, after greater initial killing, more subsequent self-paced killing led to more favorable affective change. Implications for understanding lethal human violence are discussed.     

The Instructional Hierarchy as a Model of Stimulus Control over Student <Emphasis Type="Italic">and</Emphasis> Teacher Behavior: We're Close but are We Close Enough?

As a stage-based model of learning, the Instructional Hierarchy offers a useful heuristic for organizing research on effective instructional strategies at different levels of skill proficiency. In this paper, we summarize and highlight the unique contributions of each empirical study presented in the special issue. We describe common methodological features across the studies that likely contributed to intervention effectiveness, and present several implications for research and practice.     

Free Will and Psychosis: Theoretical and Therapeutic Implications

In this article the determinants of psychotic disorder and correlated free will is examined. Althought there is empirical evidence for significant cognitive, emotional and neurobiological correlates of psychosis the precise impact of these abnornalities on free will is largely unclear. More research is needed into a) the role of free will into psychotic etiology and maintenance and b) the impact of different categories of psychotic disorder on free will of the patient. Director of “W. Kahn Institute of Theoretical Psychiatry and Neuroscience” and advisor Psychiatry appointed by the European Commision (Leonardo da Vinci).     

Controlling your mind without ironic consequences: Self-affirmation eliminates rebound effects after thought suppression

Thought suppression can ironically lead to a rebound of unwanted thoughts [Wegner, D. M. (1994). Ironic processes of mental control. Psychological Review, 101, 34-52.]. The present research explored whether self-affirmation may eliminate rebound effects after thought suppression. Participants either suppressed or used stereotypes in an impression formation task. Subsequently, self-affirmation was manipulated by providing participants with positive or neutral personality feedback, and stereotype accessibility was assessed. The results showed that suppression led to a rebound of stereotypic associations among neutral-feedback participants, but not among positive-feedback participants. The authors conclude that self-affirmation enhances the efficiency of mental control.     

One-trial conditioning of aerial respiratory behaviour in Lymnaea stagnalis

Repeated spaced training sessions of contingent tactile stimulation to the pneumostome as it opens are required to cause long-term memory (LTM) formation of aerial respiratory behaviour making if difficult to determine exactly when memory forms. We have devised a single-trial aversive operant conditioning training procedure in Lymnaea to be better able to elucidate the causal mechanisms of LTM formation. Observations of baseline breathing behaviour in hypoxia were first made. Twenty-four hours later the snails were trained using the single trial procedure, by placing them in a small Petri dish containing 4 ml of 25 mM KCl for 30-35s as soon as the first pneumostome opening in hypoxia was attempted. LTM was present if (1) breathing behaviour following training was significantly less than before; and (2) breathing behaviour post-training was significantly less in experimental groups than in yoked control groups. LTM persisted for 24 h but not 48 h. Yoked controls that received an aversive stimulus not contingent with pneumostome opening had no evidence of memory. Cooling directly after, but not at any other time, blocks LTM formation. LTM formation was also prevented by removal of the cell body of the neuron RPeD1 before training.     

Do familiarity and expectations change perception? Drivers’ glances and response to changes

The present study shows that repeated exposure to a road environment changes eye movement behaviour. In addition, repeated exposure may result in inadequate responses to unexpected changes in the road environment. Participants drove a low-cost simulator while their eye movements were recorded. With repeated exposure participants’ glances at traffic signs along the route were shorter while having a better recollection of the traffic signs along the route. At the last drive, the priority situation at an intersection was changed (a priority road was changed into a yield situation). Even though drivers glanced at the sign that indicated the new priority situation, they did not sufficiently process the information to show an adequate response. Only two out of 12 drivers showed any response, being a response only after crossing the priority road markings. The current finding that unexpected but relevant information may be missed by drivers is relevant for other monitoring tasks.     

Medial frontal cortex function: An introduction and overview

The growing attention being given to medial frontal cortex (MFC) in cognitive neuroscience studies has fostered a number of theoretical and paradigmatic perspectives that diverge in important ways. This has led to a great deal of research fractionation, with investigators studying domains and issues in MFC function that sometimes bear (at least at the surface) little relation to the questions addressed by others studying the same brain region. The present issue of Cognitive, Affective, & Behavioral Neuroscience presents articles inspired by a conference bringing together views from across this diversity of research, highlighting both the richness and vibrancy of the field and the challenges to be faced in terms of integration, synthesis, and precision among the theoretical accounts. The present article presents a brief introduction, overview, and road map to the field and to the special issue devoted to MFC function.     

Drink alcohol and dim the lights: The impact of cognitive deficits on medial frontal cortex function

Scalp electroencephalogram (EEG) recordings indicate that regions in the medial frontal cortex (MFC) are active following errors. Alcohol consumption reduces this error-related activity, perhaps suggesting that alcohol disrupts the operation of an error-monitoring system in the MFC. However, it could also be that alcohol consumption affects the MFC only indirectly, by impairing stimulus processing and thus making errors harder to detect. This interpretation leads to the prediction that stimulus degradation should likewise reduce error-related activity in the MFC. To test this hypothesis, behavioral and EEG data were collected as participants performed a speeded response task with either bright or very dim stimuli. The results using dim stimuli replicated the observed effects of alcohol consumption—with slowed responses accompanied by reduced error-related MFC activity. The sensitivity of the MFC to disrupted processing elsewhere in the brain suggests complications in interpreting evidence of disturbed MFC function. This research was supported by the National Institutes of Health Conte Center for Neuroscience Research (Grant P50-MH62196 to N.Y.) and by the Netherlands Organization for Scientific Research (to S.N.).