Neurological soft signs as trait markers of a subset of patients with obsessive-compulsive disorder with low insight and altered cognitive abilities.

Neurological soft signs (NSS) are subtle motor control impairments that include involuntary movements and abnormalities of motor coordination, sensory integration and lateralization. They engage different brain networks, including the prefrontal networks that support the higher cognitive functions that are dysfunctional in obsessive-compulsive disorder (OCD). This study investigated the relationships between the presence of NSS and patients' severity of OCD symptoms, insight, and treatment resistance in a sample of 63 patients.

High treatment resistance is associated with lower performance in the Stroop test in patients with obsessive-compulsive disorder.

Around 50% of the patients with obsessive-compulsive disorder (OCD) are resistant to treatment, and patients with OCD show alterations in a broad range of cognitive abilities. The present study investigated the links between treatment-resistance, executive and working memory abilities, and the severity of OCD symptoms among 66 patients with OCD. The patients performed seven tests gauging their executive functions and working memory and filled in questionnaires for OCD severity and insight into their pathology.

Looking for a word or for its meaning? The impact of induction tasks on adolescents' visual search for verbal material.

An eye-tracking experiment was conducted to examine whether the pre-activation of different word-processing pathways by means of semantic versus perceptual induction tasks could modify the way adults and 11- to 15-year-old adolescents searched for single target words within displays of nine words. The presence within the search displays of words either looking like the target word or semantically related to the target word was manipulated. The quality of participants' lexical representations was evaluated through three word-identification and vocabulary tests.

From simple agents to information sources: Readers' differential processing of story characters as a function of story consistency.

The study examined how readers integrate information from and about multiple information sources into a memory representation. In two experiments, college students read brief news reports containing two critical statements, each attributed to a source character. In half of the texts, the statements were consistent with each other, in the other half they were discrepant.

What eye movements reveal about strategy encoding of words in younger and older adults.

The main goal of this study was to explore the organizational strategies used by younger and older adults when encoding words, using eye-tracking. Participants had to learn a set of organizable words and then a set of non-organizable words, each presented on a single display. Participants were then asked to recall the words of each set in the order in which they came to their mind.

Adolescents' Developing Sensitivity to Orthographic and Semantic Cues During Visual Search for Words.

Two eye-tracking experiments were conducted to assess the influence of words either looking like the target word (orthographic distractors) or semantically related to the target word (semantic distractors) on visual search for words within lists by adolescents of 11, 13, and 15 years of age. In Experiment 1 (literal search task), participants saw the target word before the search (e.g.

Relevance versus big numbers: Students' criteria for selecting scholarly references online.

This study examined the effect of the number of citations attributed to documents on third year psychology students' selection of bibliographical references. Our main assumption was that students would take high numbers of citations as accessible relevance cues and use them heuristically to facilitate decision making, potentially bypassing deeper relevance assessment based on semantic processing. Experiment 1 presented the students with a reference selection task while manipulating the number of citations attributed to references, and found that the number of citations had a strong impact on reference selection.

Modulation of parafoveal word processing by cognitive load during modified visual search tasks.

During visual search for simple items, the amount of information that can be processed in parafoveal vision depends on the cognitive resources that are available. However, whether this applies to the semantic processing of words remains controversial. This work was designed to manipulate simultaneously two sources of cognitive load to study their impact on the depth of parafoveal word processing during a modified visual search task.

Visual search for verbal material in patients with obsessive-compulsive disorder.

This study aimed at investigating attentional mechanisms in obsessive-compulsive disorder (OCD) by analysing how visual search processes are modulated by normal and obsession-related distracting information in OCD patients and whether these modulations differ from those observed in healthy people. OCD patients were asked to search for a target word within distractor words that could be orthographically similar to the target, semantically related to the target, semantically related to the most typical obsessions/compulsions observed in OCD patients, or unrelated to the target. Patients' performance and eye movements were compared with those of individually matched healthy controls.

Conflicting but close: Readers' integration of information sources as a function of their disagreement.

According to the documents model framework (Britt, Perfetti, Sandak, & Rouet, 1999), readers' detection of contradictions within texts increases their integration of source-content links (i.e., who says what).

Task-dependent modulation of word processing mechanisms during modified visual search tasks.

During visual search for words, the impact of the visual and semantic features of words varies as a function of the search task. This event-related potential (ERP) study focused on the way these features of words are used to detect similarities between the distractor words that are glanced at and the target word, as well as to then reject the distractor words. The participants had to search for a target word that was either given literally or defined by a semantic clue among words presented sequentially.

Impairment of shooting performance by background complexity and motion.

In many visual displays such as virtual environments, human tasks involve objects superimposed on both complex and moving backgrounds. However, most studies investigated the influence of background complexity or background motion in isolation. Two experiments were designed to investigate the joint influences of background complexity and lateral motion on a simple shooting task typical of video games.

Impact of the motion and visual complexity of the background on players' performance in video game-like displays.

The visual interfaces of virtual environments such as video games often show scenes where objects are superimposed on a moving background. Three experiments were designed to better understand the impact of the complexity and/or overall motion of two types of visual backgrounds often used in video games on the detection and use of superimposed, stationary items. The impact of background complexity and motion was assessed during two typical video game tasks: a relatively complex visual search task and a classic, less demanding shooting task.

Orthographic versus semantic matching in visual search for words within lists.

An eye-tracking experiment was performed to assess the influence of orthographic and semantic distractor words on visual search for words within lists. The target word (e.g.

Readers' use of source information in text comprehension.

In two experiments, we examined the role of discrepancy on readers' text processing of and memory for the sources of brief news reports. Each story included two assertions that were attributed to different sources. We manipulated whether the second assertion was either discrepant or consistent with the first assertion.

Maximizing players' anticipation by applying the proximity-compatibility principle to the design of video games.

Objective: Two experiments were conducted to investigate elements of the spatial design of video game interfaces.

Background: In most video games, both the objects and the background scene are moving. Players must pay attention to what appears in the background to anticipate events while looking at head-up displays.

Safety and efficacy of repetitive transcranial magnetic stimulation in the treatment of obsessive-compulsive disorder: a review.

Objectives: Obsessive-compulsive disorder (OCD) is a chronic, often severe, neuropsychiatric disorder leading to a dramatic impairment in interpersonal and occupational functions. rTMS has been tried out in several studies in patients with OCD with different characteristics. In this paper, we review the safety and efficacy of rTMS in the treatment of mostly severe resistant OCD.

Vestibular critical period, maturation of central vestibular neurons, and locomotor control.

Mutant mice are a good model to study to what extent the postnatal activity of sensory afferents is necessary for the maturation of central neurons. In particular, the question arises whether the signals carried by the first-order vestibular neurons, which encode information on the head movement of pups, are necessary for the maturation of second-order vestibular neurons. To address that question, juvenile and adult transgenic, vestibular-deficient mutants where a null mutation of the KCNE1 potassium-channel gene leads to degeneration of all hair cells of the inner ear just after birth were studied.

Behavioral effects of a deletion in Kcnn2, the gene encoding the SK2 subunit of small-conductance Ca2+-activated K+ channels.

Small-conductance Ca(2+)-activated potassium (SK) channels are heteromeric complexes of SK alpha-subunits and calmodulin that modulate membrane excitability, are responsible for part of the after-hyperpolarization (AHP) following action potentials, and thus control the firing patterns and excitability of most central neurons. An engineered knockout allele for the SK2 subunit has previously been reported. The hippocampal neurons of these mice lacked the medium latency component of the AHP, but the animals were not described as presenting any overt behavioral phenotype.

Differential intrinsic response dynamics determine synaptic signal processing in frog vestibular neurons.

Central vestibular neurons process head movement-related sensory signals over a wide dynamic range. In the isolated frog whole brain, second-order vestibular neurons were identified by monosynaptic responses after electrical stimulation of individual semicircular canal nerve branches. Neurons were classified as tonic or phasic vestibular neurons based on their different discharge patterns in response to positive current steps.

Oscillatory and intrinsic membrane properties of guinea pig nucleus prepositus hypoglossi neurons in vitro.

Numerous models of the oculomotor neuronal integrator located in the prepositus hypoglossi nucleus (PHN) involve both highly tuned recurrent networks and intrinsic neuronal properties; however, there is little experimental evidence for the relative role of these two mechanisms. The experiments reported here show that all PHN neurons (PHNn) show marked phasic behavior, which is highly oscillatory in approximately 25% of the population. The behavior of this subset of PHNn, referred to as type D PHNn, is clearly different from that of the medial vestibular nucleus neurons, which transmit the bulk of head velocity-related sensory vestibular inputs without integrating them.

Unilateral labyrinthectomy modifies the membrane properties of contralesional vestibular neurons.

Vestibular compensation after a unilateral labyrinthectomy leads to nearly complete disappearance of the static symptoms triggered by the lesion. However, the dynamic vestibular reflexes associated with head movements remain impaired. Because the contralesional labyrinth plays a prominent role in the generation of these dynamic responses, intracellular recordings of contralesional medial vestibular nucleus neurons (MVNn) were done after 1 mo of compensation.

Vestibular evoked myogenic potentials in patients suffering from an unilateral acoustic neuroma: a study of 170 patients.

Objective: To determine the value of investigating the vestibular evoked myogenic potentials (VEMP's) induced by clicks and 500 Hz short tone burst (STB) for the diagnosis of acoustic neuromas.

Methods: We studied the average responses to 100dB clicks and 500 Hz STB in the ipsilateral sternomastoid muscle. Ninety-five healthy subjects and 170 patients suffering from a unilateral acoustic neuroma were included in that study.

Static and dynamic membrane properties of lateral vestibular nucleus neurons in guinea pig brain stem slices.

In vitro intracellular recordings of central vestibular neurons have been restricted so far to the medial vestibular nucleus (MVN). We performed intracellular recordings of large Deiters' neurons in the lateral vestibular nucleus (LVN) to determine their static and dynamic membrane properties, and compare them with those of type A and type B neurons identified in the MVN. Unlike MVN neurons (MVNn), the giant-size LVN neurons (LVNn) form a homogeneous population of cells characterized by sharp spikes, a low-amplitude, biphasic after-hyperpolarization like type B MVNn, but also an A-like rectification like type A MVNn.

Long-term plasticity of ipsilesional medial vestibular nucleus neurons after unilateral labyrinthectomy.

Unilateral labyrinthectomy results in oculomotor and postural disturbances that regress in a few days during vestibular compensation. The long-term (after 1 mo) consequences of unilateral labyrinthectomy were investigated by characterizing the static and dynamic membrane properties of the ipsilesional vestibular neurons recorded intracellularly in guinea pig brain stem slices. We compared the responses of type A and type B medial vestibular nucleus neurons identified in vitro to current steps and ramps and to sinusoidal currents of various frequencies.