Obsessive-compulsive disorder (OCD) is a psychiatric condition that varies considerably in severity and resistance to treatment. The aim of this study was to identify error detection abnormalities in OCD patients using evoked potential recordings and to determine whether links could be established between individual patients' error detection processes and their severity and resistance to treatment. To answer this question, the potentials evoked by participants' responses to a flanker task, i.e., the error-related negativity (ERN/CRN component) and subsequent positivity (Pe/Pc component), were recorded. Twenty-six OCD patients with a wide range of pathology severity and treatment resistance and 26 control participants matched for gender, age, and education level with the patients were included in the study. The amplitude of the error-related negativity (ERN) evoked by false responses was positively correlated with the severity of patients' pathology, while the lower the amplitude of the negativity evoked by correct responses (CRN), the more resistant patients were to treatment. The ERN/CRN components could therefore be used as markers of the severity and treatment resistance of OCD patients' pathology. Furthermore, under the present experimental conditions, the positive Pe/Pc component, supposed to reflect patients' awareness of the correctness of their responses, was virtually absent compared to control participants. This suggests a major deficit in the patients' monitoring of the consequences of their actions. The discovery of this disappearance of action feedback signals in patients leads to proposing an original neurodevelopmental model for the onset of pathology in childhood or adolescence.
Although the time available to read a text is crucial for comprehension, there is not yet any comprehensive within-participant study describing how text comprehension decreases and readers’ eye movements are adjusted with increasing time constraints. Consequently, this study examined how imposing reading times influenced both text comprehension and eye movements. Thirty participants had to read three-sentence texts within a time limit (6.3, 9.5, 19.0 or 38.0 s) or without a time constraint, and then to answer a question about each text to assess comprehension. At the longest reading time, text comprehension was good, with 87
Patients suffering from obsessive-compulsive disorder (OCD) show an attentional bias towards pathology-related words. Electroencephalographic cognitive potentials were used to investigate how patients responded to words related to their obsessions and compulsions. Forty OCD patients with various levels of severity and treatment-resistance were included to assess links between word-evoked potentials and patients' clinical variables, and compared with 40 control participants. The P200 component evoked by both neutral and pathology-related words was greater in patients than in controls, suggesting that patients were more attentive overall. In the N400 time window, pathology-related words evoked less negative potentials than neutral words in OCD patients, suggesting that pathology-related words were particularly familiar to them and permanently pre-activated in their mental lexicon. Finally, correlations were detected between pathology severity and the profile of word-evoked potentials in the N400 time window, and between the patients' treatment resistance and the amplitude of late word-evoked positive potentials (P600).
Visually searching for verbal information is a complex activity for young readers. An eye-tracking experiment was conducted to investigate whether preactivation of different word-processing pathways by means of semantic or perceptual induction tasks could help children aged 9 to 11 to search for answers to questions in short texts (about 150 words). The type of questions asked (surface vs. inferential) and the nature of the induction tasks (semantic vs. perceptual) were manipulated. In addition, the quality of students' lexical representations was assessed using word identification and discrimination tests. Children made more errors when answering global inferential questions than local inferential questions, and more errors when answering local inferential questions than surface questions. Children's error rates were mostly unrelated to the amount of time they spent looking for answers in texts, which suggests that children did not spontaneously adapt their search time to question complexity or perceive that some questions were more complex than others. After performing a semantic rather than perceptual induction task, the accuracy rate of children's answers to inferential questions increased (81.5% vs. 72.5%), in relation to an increase of the time spent searching the texts. As expected, information-seeking times were significantly shorter for children with higher quality lexical representations. The impact of the semantic induction task was greater for children in the lower half of lexical quality scores than for those with high scores, who tended to spontaneously use effective strategies and did not appear to have any difficulty identifying the answer in the text.
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. Treatment-resistance was assessed considering all the treatments the patients received during the course of their disease. The four dimensions of OCD defined in the dimensional obsessive-compulsive scale were considered. Links between the patients’ cognitive abilities and NSS were assessed using tests targeting specifically the core components of executive functions.As expected, OCD patients displayed more NSS than individually matched control participants. In OCD patients, high NSS scores were associated with poor insight and lower cognitive abilities. Multiple regression analysis identified worse visuospatial working memory, attentional control, and verbal fluency as predictive factors of high NSS scores among cognitive functions. Unexpectedly, the patients displaying symptoms in the contamination/washing dimension displayed less NSS than the other patients. In contrast, neither the severity of OCD symptoms nor long-range treatment resistance was significantly related to patients’ NSS scores. Altogether, our findings suggest that high NSS scores may be a trait marker of a subset of OCD patients with low insight and particularly altered cognitive abilities who would not express the contamination/washing dimension of the pathology.
Several studies have shown that the acquisition of number meaning is related to finger motor representations. However, no study has tried to distinguish the respective roles of fingers representation and finger kinematics in this effect. Forty-three children (23 boys and 20 girls) enrolled in the middle class of kindergarten took part in the study. They were divided into two equivalent groups and compared on the acquisition of number meaning after a 2-week program designed to teach them a song about the numbers 1–9, scaffolded by visual supports. Each visual support included the symbolic representation of the number, the picture of an object mentioned in the song that rhymed with the number in French, and either a static image (static group) or an animated point-light display (animated group) of the finger representation. Results showed no difference between the two groups on the acquisition of numbers regarded as low (i.e., less than 5) but the animated group performed significantly better for numbers regarded as high (i.e., more than 5). Therefore, the present study shows the interest of using the observation of animated counting movement to teach number meaning in young children and suggests that finger kinematics may be more instrumental than static finger representation in the learning of number meaning. Future research is needed to confirm and specify this effect.
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. Performing a semantic induction task rather than a perceptual one on the target word before searching for it increased search times by 15% in all age groups, reflecting an increase in both the number and duration of gazes directed to non-target words. Moreover, performing the semantic induction task increased the impact of distractor words that were semantically related to the target word on search efficiency. Participants’ search efficiency increased with age because of a progressive increase in the quality of adolescents’ lexical representations, which allowed participants to more quickly reject the distractors on which they fixated. Indeed, lexical quality scores explained 43% of the variance in search times independently of participants’ age. In the simple visual search task used in this study, fostering semantic word processing through the semantic induction task slowed down visual search. However, the literature suggests that semantic induction tasks could, in contrast, help people find information more easily in more complex verbal environments where the meaning of words must be accessed to find task-relevant information.
This chapter evaluates the functional implications of the sensitivity of central vestibular neurons to monoamines. A better knowledge of the modulatory effects of monoamines on vestibular neurones should supply a better understanding of vestibular-related pathologies, and could lead to the elaboration of more efficient pharmaceutical treatments. The chapter includes the results of in vitro studies on slices, designed in order to precisely define the actions of monoaminergic agonists on the different cell types present in the medial vestibular nucleus. Only five main monoaminergic molecules are functioning as neurotransmitters in vertebrates. The three catecholamines (dopamine, noradrenaline, and adrenaline) are all synthesized from the amino acid tyrosine. In contrast, serotonin derives from tryptophane, whereas histamine is produced by a decarboxylation of histidine. Since noradrenaline and adrenaline act through tire same set of specific receptors, data concerning them will be grouped together. The presence of specific dopaminergic binding sites on central vestibular neurones has been confirmed by several electrophysiological works.
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. In addition, the executive and working memory abilities of a subset of these patients were compared with those of individually matched control participants. In contrast with previous studies, patients' treatment resistance was evaluated by considering the clinical outcomes of all the treatments that they received during the course of their disease. Higher treatment resistance was associated with lower performance in one particular executive test, the Stroop test, which assessed patients' ability to inhibit prepotent/automatic responses. Older age and more severe OCD symptoms were also associated with higher treatment resistance. Regardless of OCD severity, the patients displayed small to moderate deficits across most components of executive functions compared to control participants. Interestingly, patients with OCD took more time than control participants to perform speeded neuropsychological tests but never made more errors. Altogether, this study shows that the treatment-resistance of patients with OCD may be reliably quantified over the course of years and treatments using Pallanti and Quercioli's (2006) treatment resistance-related scales. The data suggest that the Stroop test could be used clinically to anticipate treatment outcomes in to-be-treated patients.
Introduction The physiopathology of patients with treatment-resistant obsessive-compulsive disorder (OCD) may differ from that of treatment-responsive patients. Cognitive evoked potentials may be one of the ways to detect these differences. The error-related negativity (ERN) is an electrophysiological correlate of error detection during the execution of a motor task, which is larger in patients with OCD than in typical people. According to the literature, the ERN could vary according the patients’ treatment-resistance. Objectives The main goal of this study was to assess whether the ERN, which begins 20 ms before the motor response and reaches its maximum 80 ms later, was different between non-resistant and highly resistant OCD patients. Methods Forty-seven OCD patients and their age- and gender-matched controls were asked to perform a flanker task while the potentials evoked by their motor responses were recorded. For each participant, the difficulty of the task was adjusted to get an error rate of about 20%. Treatment-resistance was evaluated using Pallanti and Quercioli’s (Prog Neuropsychopharmacol Biol Psychiatry 2006; 30 400-412) resistance scales. Results In all participants, response errors evoked an ERN at fronto-central electrodes [Fz, FCz, red and green lines on the figure], whereas the negativity was absent or smaller for correct responses (black and blue lines on the figure, both p s < .01). As expected, the ERN of OCD patients was consistently larger and of longer duration than that of control participants (compare the green and blue lines with the red and black ones, respectively). Interestingly, the amplitude of the potentials evoked by correct responses at central and centro-parietal electrodes on the left side of the brain [C5, C3, CP5] was significantly less negative in treatment-resistant patients (all p s < .05). In control participants, the ERN recorded at fronto-central electrodes were followed by a positive wave which reached its maximum between 170 and 270 ms after the response, and was larger after errors than after correct response. In OCD patients in contrast, this positive wave was absent whether the response was correct or not. Image: Conclusions The significant correlation observed between OCD patients’ treatment resistance and the potential evoked by correct responses on the left side of the brain suggest that this potential could be used as a marker of treatment-resistance. The absence in OCD patients of the positive wave that follows the ERN in control participants suggests that OCD patients were not fully aware of whether or not their response was correct. Disclosure of Interest None Declared
Text comprehension theories propose that readers try to achieve a coherent representation of the situation depicted in a text. When reading multiple texts on the same topic, however, achieving a coherent representation of a situation poses additional challenges. Different sources may offer inconsistent descriptions or interpretations of the situation, or even contradict one another. Thus, additional assumptions are needed to explain how readers build a coherent representation of a situation when reading multiple individual texts on the same subject. This paper reviews research contributions from the psychology of text comprehension on how readers integrate inconsistent information from multiple sources. We concentrate on two key processes: The construction of an interconnected representation of sources and text contents, and the evaluation of the acquired information. We begin by briefly discussing the standard approach of single-text comprehension theories to representational coherence. Then, we examine the Documents Model Framework and other, associated proposals that claim that readers can achieve coherence of divergent text contents by constructing a representation of the texts which integrates information about the sources of the contents. We also consider the role of source evaluation as a reader strategy for constructing a single, coherent solution. Finally, we discuss theoretical and practical implications and we make suggestions for further readings.
In order to consider the relevant relationships between emotion, information processing and judicial judgment, this study evaluated the impact of positive (amusement), negative (sadness) or neutral mood induction on 128 mock jurors' visual attentional focus, as measured by their eye fixations on the face of a witness filmed while giving testimony in a criminal court. Participants then rated their perceptions of the witness's and their own emotions on the Differential Emotional Scale, before indicating their final judicial judgment. As expected, results showed that sadness can favour information processing in a in more effortful mode, with more steady visual attention, while a positive emotional state such as amusement can favour information processing based more on the witness's emotions, a source of useful clues for establishing the judicial judgment. These results are discussed in relation to how the cognitive approach can shed light on the processes underlying judicial judgment.
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. Each story also featured a non-source character (who made no statement). The hypothesis was that discrepant statements, as compared to consistent statements, would promote distinct attention and memory only for the source characters. Experiment 1 used short interviews to assess participants' ability to recognize the source of one of the statements after reading. Experiment 2 used eye-tracking to collect data during reading and during a source-content recognition task after reading. As predicted, discrepancies only enhanced memory of, and attention to source-related segments of the texts. Discrepancies also enhanced the link between the two source characters in memory as opposed to the non-source character, as indicated by the participants' justifications (Experiment 1) and their visual inspection of the recognition items (Experiment 2). The results are interpreted within current theories of text comprehension and document literacy.
Text comprehension involves the ability to understand how texts relate to the situation they describe and to each other (i.e., a Document model). Research into Document models has emphasized the role of information sources in structuring readers' mental models of situations. The present article reviews research on source comprehension and examines new hypotheses regarding source encoding during text comprehension. Two experiments examined college students' evaluation and recognition of two embedded sources as a function of the consistency of their statements (Experiments 1 and 2) and the demands of the reading task (Experiment 2). Sources were introduced either with a knowledge feature (e.g., how the source knew what they knew) or a control feature. Readers were more likely to select the knowledgeable source as more competent and to justify their selection by referring to the knowledge feature (Experiment 1). Experiment 2 found that readers' preference for knowledgeable sources was stronger when the content statements were discrepant. Preference for knowledgeable sources was also stronger when the task focused on source knowledge, as compared to a control evaluation task or a baseline reading task. The source knowledge evaluation task distinctively enhanced participants' integration of the source designations with their respective statements, as compared to the control and baseline conditions. Results are discussed in light of current theories of single and multiple document comprehension.
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. Hence, the participants' encoding strategies revealed by eye-tracking could be directly related to their subsequent memory performance. The results confirmed the detrimental impact of aging on memory and the weaker use of organizational strategies by older adults during the recall phase. The eye-tracking data showed that when they encode the words, older adults do not look at them for as long as younger adults, probably because of slower eye movements. They also revealed that compared to younger adults, older adults were much less able to adapt their word scanning strategy according to whether the words to encode were organizable or not. Finally, the relationships that were found between the recall scores and the eye-tracking data suggest that the eye movement pattern at learning can predict how people will recall the 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., “raven”), whereas in Experiment 2 (categorical task) the target word was only defined by its semantic category (e.g., “bird”). In both experiments, participants’ search times decreased from fifth to ninth grade, both because older adolescents gazed less often at non-target words during the search and because they could reject non-target words more quickly once they were fixated. Progress in visual search efficiency was associated with a large increase in word identification skills, which were a strong determinant of average gaze durations and search times for the categorical task, but much less for the literal task. In the literal task, the presence of orthographic or semantic distractors in the list increased search times for all age groups. In the categorical task, the impact of semantic distractor words was stronger than in the literal task because participants needed to gaze at the semantic distractors longer than at the other words before rejecting them. Altogether, the data support the assumption that the progressive automation of word decoding up until the age of 12 and the better quality of older adolescents’ lexical representations facilitate a flexible use of both the perceptual and semantic features of words for top-down guidance within the displays. In particular, older adolescents were better prepared to aim at or reject words without gazing at them directly. Finally, the overall similar progression of the maturation of single word visual search processes and that of more real-life information search within complex verbal documents suggests that the young adolescents’ difficulties in searching the Web effectively could be due to their insufficiently developed lexical representations and word decoding abilities.
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. Methods. A review of the English literature from 1966 to 2010 pertaining to rTMS in the treatment of OCD was conducted using MEDLINE by selectively entering the search terms "transcranial magnetic stimulation", "repetitive transcranial magnetic stimulation", "obsessive-compulsive disorder" and "OCD". Twelve studies including open and randomized, sham-controlled trials were included in this review. Results. Although available data about the use of rTMS in OCD treatment are quite heterogeneous in terms of sample size, study design, stimulus parameters used and stimulation areas targeted, promising findings regarding rTMS efficacy appeared for two structures based on recent controlled studies: the supplementary motor area and the orbitofrontal cortex. On the other hand, rTMS of the dorsolateral prefrontal cortex is not significantly effective when compared to sham rTMS. Conclusions. Three target areas have already been selected of which the supplementary motor area in particular and the orbitofrontal cortex seem to be the most promising in terms of potential efficacy and could more accurately be targeted with the help of neuronavigational techniques. Larger randomized controlled trials should be conducted in order to better clarify the therapeutic role of rTMS in OCD.