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Objective The present study seeks to provide an overview of executive (inhibition and flexibility) deficits in Parkinson's disease (PD) by combining a cognitive and behavioral approach. Methods Fifteen PD patients and 15 healthy controls underwent a neuropsychological and behavioral assessment including the Hayling and Trails Tests, the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease (QUIP-RS), the Behavior Rating Inventory of Executive Function (BRIEF-A), and the Short Form-36 Health Survey (SF-36). The level of awareness of executive functioning was also analyzed. We finally explored how these neuropsychological and clinical outcomes could relate to each other. Results PD patients performed significantly worse in both neuropsychological tasks designed to evaluate inhibition abilities. They also reported more inhibition difficulties in everyday life and poorer quality of life. Associations between neuropsychological measures and self-reports were found. Moreover, as indicated by the discrepancy score, PD patients were as accurate as their relatives in self-reporting their executive daily difficulties. Conclusion Inhibition and cognitive flexibility impairments assessed by the neuropsychological tests (Hayling and Trails tests) seem to capture daily life executive problems in PD. Furthermore, our study provides a deeper understanding of PD patients' and their relatives' experience of these executive dysfunctions., This study was part of AS's doctoral thesis. AS received support from the Spanish Ministry of Economy and Competitivity in the form of a FPU predoctoral studentship (REF FPU18/00761). PA was supported by the Ministry of Science, Innovation and Universities (REF PSI2016-75484-R), the Spanish State Agency for Research (AEI), and the European Regional Development Fund (FEDER).

The issue of whether sex offenders have cognitive deficits remains controversial. The objective of this study was to compare the neuropsychological function of older adult first time sex-offenders (FTSO), who had not previously been charged with a sexual offence prior to the age of 50, to historical long-term sex offenders (HSO) and non-sex offenders (NSO). The hypotheses were (a) that FTSO would demonstrate greater deficits in executive function, decision-making, and memory compared to non-sex offenders; and (b) the HSOs would present similar neuropsychological deficits to non-sex offenders.A battery of neuropsychological measures was administered to 100 participants comprising 32 FTSOs, 36 HSOs, and 32 NSOs.Both FTSOs and HSOs showed significant impairment on tests of executive function (including verbal fluency, trail-making, and the Hayling test of response inhibition) as well as on tests of verbal and verbal memory compared to NSOs; however, there was no difference between the two sex offender groups.Older adult sex offenders, overall, demonstrated poorer neuropsychological performance than older adult non-sex offenders did, although there was no difference between older first-time and historical offenders. Cognitive deficits may increase the risk of sexual offending due to impaired capacity in self-regulation, planning, judgment, and inhibition. A proportion of older adult sex offenders may be harboring acquired frontal lobe pathology.

Background Neurological illness can produce a disorganization of behavior, including verbal disinhibition, despite apparent preserved intelligence. Neuropsychological tests of such behavioral control mechanisms may predict real-world performance of healthy people, such as success or misbehavior in educational contexts. Method In two separate studies, we examined how the Hayling Test of verbal response suppression predicts grades and classroom misbehavior. Results Verbal suppression errors and spontaneous strategy use were significant predictors of undergraduate grades. Using a modified version of the Hayling Test designed to reduce strategic responding with high school students (mean age 16), higher grades were predicted by shorter response suppression latencies and better working memory scores, and classroom misbehavior was predicted by lower working memory scores. Conclusion Verbal response suppression and spontaneous strategy use, both closely linked to disorganized behavior in neuropsychological patients, predict academic achievement but seem unrelated to classroom misbehavior, which is associated with weakness in working memory.

Objectives To describe normative data for the Hayling Test and the Trail Making Test (TMT) in a sample of Brazilian adults, and to investigate the effects of age and education on test performance. Method A total of 313 (TMT) and 364 (Hayling) individuals with age ranges of 19-39, 40-59, and 60-75 years, and with at least 5 years of formal education, participated in this study. The tests were administered as part of a large battery of a normative project. Individuals were evaluated individually in silent, ventilated rooms at a university clinic. Instrument protocols were scored by trained research assistants and double-checked to ensure data reliability. Results There were major effects of age on the TMT (Time B, Errors B, B-A) and on the Hayling Test (Errors B/15, B/45), and major effects of education on the TMT (Time B, Errors B, B-A) and on the Hayling Test (Time A, Errors B/15, B/45). Interaction effects were found in Time B and B-A for the Hayling Test and in Time A for the TMT. Conclusions Age and education were critical for performance on both verbal and non-verbal executive functions. Resumo Objetivos Descrever dados normativos do Teste Hayling e do Teste de Trilhas em uma amostra de adultos brasileiros e investigar os efeitos de idade e escolaridade no desempenho das tarefas. Método Participaram deste estudo um total de 313 (TMT) e 364 (Hayling) indivíduos com idades nos intervalos de 19-39, 40-59 e 60-75 anos e com pelo menos 5 anos de escolaridade formal. Os testes foram administrados como parte de uma bateria maior de um projeto de normatização. Os indivíduos foram avaliados individualmente em salas silenciosas e ventiladas em uma clínica universitária. As pontuações dos protocolos foram realizadas por assistentes de pesquisa treinados e foram checadas duplamente para garantir a fidedignidade dos dados. Resultados Foram encontrados efeitos principais de idade no TMT (Tempo B, Erros B e Tempo B-A) e no Teste Hayling (Erros B/15 e B/45), e efeitos principais de educação no TMT (Tempo B, Erros B e Tempo B-A) e no Teste Hayling (Tempo A, Erros B/15 e B/45). Foram encontrados efeitos de interação entre variáveis nos Tempos B e B-A do Teste Hayling e no Tempo A do TMT. Conclusões Idade e escolaridade foram fatores críticos para o desempenho em ambos os testes verbal e não-verbal de avaliação das funções executivas.

Objective The Hayling and Brixton tests constitute a short test battery that quickly assesses verbal and spatial inhibition and flexibility. This battery has shown high construct validity and strong reliability in clinical and experimental settings. The aim of this study was to develop an Italian version of the Hayling and Brixton tests and obtain normative values. Method We collected normative data from 301 healthy Italian participants aged between 16 and 94 years, taking into account all demographics. To maximize the sample size, we used the overlapping interval strategy. Adjusted scores for demographics were obtained by linear regression analysis. Results The performance on the Hayling and Brixton tests was influenced by age and education. In particular, age affected verbal accuracy and response time on the Hayling Sentence Completion Test, whereas education only affected the former. Differently, the spatial component, as measured by the Brixton Spatial Anticipation Test, was shaped only by age, which decreased the number of correct responses. Conclusions Our study provides normative data that have been adjusted for relevant demographics and percentile grids in an Italian population. Our data support the use of the Hayling and Brixton tests as a valid instrument for performing neuropsychological evaluations and longitudinal analyses of executive functions in clinical practice and for research purposes.

Objective Cognitive aging is commonly associated with a decrease in executive functioning (EF). A specific component of EF, semantic inhibition, is addressed in the present study, which presents a meta-analytic review of the literature that has evaluated the performance on the Hayling Sentence Completion test in young and older groups of individuals in order to assess the magnitude of the age effect. Method A systematic search involving Web of Science, PsyINFO, PsychARTICLE, and MedLine databases and Google Scholar was performed. A total of 11 studies were included in this meta-analysis, encompassing a total of 887 participants; 440 young and 447 older adults. The effect sizes for group differences on four measures of the Hayling test, latency responses and error scores on the Automatic and Inhibition sections of the test were calculated using the Comprehensive Meta-Analysis software package Results The results revealed large age effects for response latencies in both the Automatic (Hedges’ g = 0.81) and Inhibitory conditions (Hedges’ g = 0.98), though the latter two effect sizes did not differ from each other. In contrast, analysis of errors revealed a significant difference between the small effect seen in the Automatic condition (Hedges’ g = 0.13) relative to the moderate effect seen in the Inhibition condition (Hedges’ g = 0.55). Conclusions These results may be important for a better understanding of the inhibitory functioning in elderly individuals, although they should be interpreted with caution because of the limited number of studies in the literature to date. This research was supported in part by research grant FF12014-54088-P (Ministry of Science and Innovation of Spain).

Some children with high-functioning autistic spectrum conditions (ASC) have been noted clinically to produce accounts and responses akin to confabulations in neurological patients. Neurological confabulation is typically associated with abnormalities of the frontal lobes and related structures, and some forms have been linked to poor performance on source monitoring and executive function tasks. ASC has also been linked to atypical development of the frontal lobes, and impaired performance on source monitoring and executive tasks. But confabulation in autism has not to our knowledge previously been examined experimentally. So we investigated whether patterns of confabulation in autism might share similarities with neurologically-based confabulation. Tests of confabulation elicitation, source monitoring (reality monitoring, plus temporal and task context memory) and executive function were administered to four adolescents with ASC who had previously been noted to confabulate spontaneously in everyday life. Scores were compared to a typically developing (TD) and an ASC control group. One confabulating participant was significantly impaired at reality monitoring, and one was significantly worse at a task context test, relative to both the ASC and TD controls. Three of the confabulators showed impairment on measures of executive function (Brixton test; Cognitive Estimates test; Hayling Test B errors) relative to both control groups. Three were significantly poorer than the TD controls on two others (Hayling A and B times), but the ASC control group was also significantly slower at this test than the TD controls. Compared to TD controls, two of the four confabulating participants produced an abnormal number of confabulations during a confabulation elicitation questionnaire, where the ASC controls and TD controls did not differ from each other. These results raise the possibility that in at least some cases, confabulation in autism may be less related to social factors than it is to impaired source memory or poor executive function.

Childhood neuropsychology is a growing scientific area in Brazil. Regarding cognitive function in infancy, executive function (EF) has been the main focus of several studies because of its importance for and complexity in human cognition and behavior. Executive functions can be considered a set of cognitive processes related to control and integration devoted to the execution of goal-directed behaviors. Research has shown that these abilities begin in infancy and progressively develop until adulthood. Although some studies on EF development in children have already been conducted, our knowledge on this topic is still incipient. Because of the relevant role of age in cognition and EF development, the present study investigated whether differences exist between children aged 6 to 12 years concerning their performance on the Hayling test-adult version, an instrument that assesses the EF components of initiation and inhibition. Pilot data are presented that verify the applicability of this test to children. Significant differences were found between comparable age groups only in three of the seven main Hayling test scores, suggesting that the adult version may not be appropriate for children, and an adaptation of the test for child assessment is necessary. The study may lead to an initial reflection on the development of these components and thus contribute to improvements in the field of child neuropsychology.

Research regarding executive functioning (EF) in children rarely focuses on populations in African or Middle-Eastern Arabic-speaking countries. The current study used a cross-sectional design to examine the developmental trajectories of school-age Tunisian children in three domains of executive control (inhibition of prepotent responses, cognitive flexibility, and working memory) as well as their mutual interactions and the effects of gender and parents? education level. Inhibitory processes, cognitive flexibility, and working memory were assessed using the Stroop test, a version of the Hayling test adapted for children, simple and alternating tasks of verbal fluency, and verbal and visuospatial span tasks (forward and backward spans). The study population included 120 7- to 12-year-old Tunisian children (60 girls, 60 boys) who were grouped and matched for age, gender, and parents? education level. The results revealed an overall effect of age on executive performance, whereas gender and parents? education level showed non-significant effects. In addition, executive indices were significantly associated with fluid intelligence level. Partial correlation analyses (controlled for age) found significant links between indices that assessed the same executive process, except for inhibitory processes; the temporal indices for inhibitory processes showed relative independence. The correlations between indices that assessed distinct executive processes were weaker (but significant). Overall, the results suggest that executive components in school-age Tunisian children operate according to relatively homogeneous developmental trajectories, marked by peaks of maturity that differ according to the assessed index. A transcultural approach to EF is discussed in terms of the unity and diversity of its components. Scopus

Initiation and suppression deficits are documented in patients with frontal lesions although this has typically been with different tasks that are hard to compare. The Hayling Sentence Completion Test (Burgess & Shallice, 1997) was designed to tap initiation, suppression and strategy use within the same sentence completion task. There are few studies specifically investigating the neural correlates of initiation and suppression using the same task in frontal patients. We investigated initiation, suppression and strategy use on the Hayling Test in 40 frontal patients, 30 posterior patients and 40 matched healthy controls. Lesions were analysed with a finer-grained frontal localisation method (Right/Left Lateral, Medial) and traditional methods (i.e., anterior/posterior). We analysed the standard clinical measures (Initiation RT, Suppression RT, Suppression Errors and Overall Score), composite error scores and strategic responses. The results showed that all four Hayling Test clinical measures were sensitive to frontal lesions; however, only Suppression Errors and the Overall measure were specific to frontal lobe damage. All frontal patients produced blatant suppression failures but there was a specific Right Lateral frontal effect for producing subtly incorrect responses. In addition, Right Lateral patients produced fewer correct strategic responses and incurred longer response times in doing so. These findings suggest that the right lateral frontal cortex plays a role in suppression and strategic processes.

Verbal initiation, suppression and strategy generation/use are cognitive processes widely held to be supported by the frontal cortex. The Hayling Test was designed to tap these cognitive processes within the same sentence completion task. There are few studies specifically investigating the neural correlates of the Hayling Test but it has been primarily used to detect frontal lobe damage. This study investigates the components of the Hayling Test in a large sample of patients with unselected focal frontal (n = 60) and posterior (n = 30) lesions. Patients and controls (n = 40) matched for education, age and sex were administered the Hayling Test as well as background cognitive tests. The standard Hayling Test clinical measures (initiation response time, suppression response time, suppression errors and overall score), composite errors scores and strategy-based responses were calculated. Lesions were analysed by classical frontal/posterior subdivisions as well as a finer-grained frontal localization method and a specific contrast method that is somewhat analogous to voxel-based lesion mapping methods. Thus, patients with right lateral, left lateral and superior medial lesions were compared to controls and patients with right lateral lesions were compared to all other patients. The results show that all four standard Hayling Test clinical measures are sensitive to frontal lobe damage although only the suppression error and overall scores were specific to the frontal region. Although all frontal patients produced blatant suppression errors, a specific right lateral frontal effect was revealed for producing errors that were subtly wrong. In addition, frontal patients overall produced fewer correct responses indicative of developing an appropriate strategy but only the right lateral group showed a significant deficit. This problem in strategy attainment and implementation could explain, at least in part, the suppression error impairment. Contrary to previous studies there was no specific frontal effect for verbal initiation. Overall, our results support a role for the right lateral frontal region in verbal suppression and, for the first time, in strategy generation/use.

The present study compared decision-making processing between patients with traumatic brain injury (TBI) and healthy controls. The study also sought to identify dissociations in the frequency of deficits in executive functions (EF) tasks that mainly assess decision making (DM; hot component) and inhibition (cold component) following TBI. The sample was composed of 16 post-TBI adults aged between 18 and 68 years and 16 healthy controls matched by age and education. Decision-making was assessed with the Iowa Gambling Task (IGT), and inhibitory control was assessed with the Trail Making Task (TMT) and Hayling Test. No differences were found between groups in total scores and block scores on the IGT. However, TBI patients preferred the disadvantageous decks, with no evidence of learning during the task. Seven patients presented dissociations between deficient DM on the IGT and accurate inhibition on the Hayling Test and TMT. Conversely, five patients presented partial dissociations between deficits in the IGT and TMT and opposite performance in the Hayling Test. Only three patients exhibited deficits on all of the instruments. These results indicate that patients can maintain comparable performance on the IGT after TBI. Therefore we found dissociations in hot and cold executive components.

217 σ., Αντικείμενο της παρούσας διδακτορικής διατριβής είναι η μελέτη της επίδρασης ηλεκτρομαγνητικής ακτινοβολίας από ασύρματο τερματικό εξοπλισμό στα ηλεκτρικά σήματα του εγκεφάλου. Χρησιμοποιήθηκαν ήδη υπάρχοντα δεδομένα και διεξήχθησαν καινούργια πειράματα για τη συλλογή νέων μετρήσεων με σκοπό τη μελέτη εγκεφαλικών σημάτων παρουσία ακτινοβολίας. Έγινε επεξεργασία και στατιστική ανάλυση των μετρήσεων με διάφορες μεθόδους για την εξαγωγή αποτελεσμάτων και συμπερασμάτων. Αρχικά παρουσιάζεται η δομή των νευρικών κυττάρων και τα δυναμικά που αναπτύσσονται σε αυτά με αποτέλεσμα τη δημιουργία και μετάδοση των ηλεκτρικών σημάτων. Περιγράφεται ο τρόπος καταγραφής του εγκεφαλικού σήματος και αναλύονται τα κύρια χαρακτηριστικά του, όπως οι φασματικές συνιστώσες και οι βασικές κορυφώσεις σε σχέση με το χρόνο των προκλητών δυναμικών. Στη συνέχεια παρουσιάζεται μία βιβλιογραφική επισκόπηση για την εξέλιξη της έρευνας στο θέμα της επίδρασης ακτινοβολίας στην ανθρώπινη εγκεφαλική λειτουργία και περιγράφονται οι πειραματικές διατάξεις που χρησιμοποιήθηκαν για τη συλλογή των δεδομένων. Αναλύεται η πειραματική διαδικασία στην οποία υπεβλήθησαν συνολικά 39 άτομα, κατά τη διάρκεια δύο πειραμάτων, υπό και χωρίς την επίδραση ηλεκτρομαγνητικής ακτινοβολίας στις συχνότητες που λειτουργούν τα κινητά τηλέφωνα (900 και 1800 MHz) καθώςκαι η οργάνωση των καταγεγραμμένων δεδομένων. Όσον αφορά στo ηλεκτροεγκεφαλογράφημα που καταγράφεται εν ηρεμία γίνεται εφαρμογή του μετασχηματισμού Fourier και παρουσιάζονται τα αποτελέσματα που προέκυψαν για την ενέργεια των φασματικών συνιστωσών του σήματος ύστερα από στατιστική επεξεργασία. Στα μετασχηματισμένα δεδομένα εφαρμόζεται η μέθοδος της συσχέτισης φασματικής ισχύος για την εξαγωγή περαιτέρω συμπερασμάτων. Ακολούθως περιγράφονται οι μέθοδοι επεξεργασίας των δεδομένων του ηλεκτροεγκεφαλογραφήματος στο τμήμα που αφορά στα προκλητά δυναμικά, δηλαδή της δραστηριότητας του εγκεφάλου ύστερα από την έλευση ενός εξωτερικού ερεθίσματος. Παρουσιάζονται τα αποτελέσματα της επεξεργασίας όπου μελετώνται οι διαφοροποιήσεις των κορυφώσεων του σήματος σε σχέση με την επίδραση της ακτινοβολίας καθώς και άλλων παραγόντων (φύση ερεθισμού, φύλο εξετασθέντων, σειρά ερωτήσεων). Στη συνέχεια περιγράφεται η πειραματική διαδικασία που διενεργήθηκε για τη συλλογή δεδομένων υπό την επίδραση Wi-Fi σήματος και στην οποία υπεβλήθησαν 30 άτομα. Παρουσιάζεται η επεξεργασία αυτών και αναλύονται αποτελέσματα για το τμήμα του σήματος που αφορά στα προκλητά δυναμικά ως προς την επίδραση ακτινοβολίας, φύλου και ψυχολογικής δοκιμασίας που ακολουθήθηκε., The purpose of the present thesis is to study the effect of electromagnetic radiation from wireless terminal equipment on the electrical brain signals. Existing data were used and new experiments were conducted to collect new measurements in order to study brain signals in the presence of radiation. The measurements were processed and statistical analyzed using various methods for the extraction of results and conclusions. In the beginning of the thesis, the structure of nerve cells and the potentials developed in them resulting in the creation and transmission of electrical signals are described. The technique that brain signals are captured is presented and the main features, such as spectral components and main peaks in relation to time of evoked potentials are analyzed. Then, literatures review on the evolution of research into the effects of radiation on human brain function is presented and the experimental setups used to collect data are described. The experimental procedure and the organization and processing of the data are then described. A total of 39 subjects participated in two experiments with and without the influence of electromagnetic radiation of 900 and 1800 MHz. Regarding the resting electroencephalogram, Fourier transformation was applied and the results obtained for the energy of the spectral components of the signal are presented. The transformed data were analyzed using the method of spectral power coherence in order to extract further conclusions. The procedure of processing the evoked related potentials, ie the activity of the brain after the onset of an external stimulus, is then explained. The results of this processing are analyzed illustrating the variation of the signal peaks in relation to the effects of radiation and other factors (type of stimulation, gender, sequence of questions). In addition the experimental procedure that was conducted to collect data under the influence of Wi-Fi signal, in which 30 people participated, is presented. The EEG data processing is described and results for the evoked related potentials are analyzed concerning the effect of the radiation, the gender and the psychological test that was undertaken., Χρυσανθη Δ. Χουνταλα

Individual differences in working memory (WM) have been shown to reflect the ability to control attention in order to prevent interference. This study examines the role of WM capacity in resisting interference in the Hayling task, in samples of younger and older adults. In each age group, high and low WM span individuals had to complete high-cloze sentences with either expected words (initiation) or words providing no meaning to the sentences (interference). Results showed increased response times and decreased correct responses in interference, as compared to initiation. As interference increased, older adults demonstrated lower accuracy than younger ones. Further, low spans demonstrated higher interference costs than high spans on accuracy, while the reverse pattern was found for response times. Our findings suggest that both age and individual differences in WM capacity need to be considered to account for differences in the ability to resist to interference.

Childhood neuropsychology is a growing scientific area in Brazil. Regarding cognitive function in infancy, executive function (EF) has been the main focus of several studies because of its importance for and complexity in human cognition and behavior. Executive functions can be considered a set of cognitive processes related to control and integration devoted to the execution of goal-directed behaviors. Research has shown that these abilities begin in infancy and progressively develop until adulthood. Although some studies on EF development in children have already been conducted, our knowledge on this topic is still incipient. Because of the relevant role of age in cognition and EF development, the present study investigated whether differences exist between children aged 6 to 12 years concerning their performance on the Hayling test-adult version, an instrument that assesses the EF components of initiation and inhibition. Pilot data are presented that verify the applicability of this test to children. Significant differences were found between comparable age groups only in three of the seven main Hayling test scores, suggesting that the adult version may not be appropriate for children, and an adaptation of the test for child assessment is necessary. The study may lead to an initial reflection on the development of these components and thus contribute to improvements in the field of child neuropsychology.

International audience; Dans la schizophrénie, l’altération de l’intégrité du cortex préfrontal pourrait être à l’origine de la déficience des fonctions exécutives, dont la capacité à inhiber une réponse automatisée. Afin d’évaluer cette fonction précise de l’inhibition qui a été décrite par Hasher et al. comme « fonction de restriction », nous avons utilisé une tâche spécifique : le Hayling completion sentence task, et ce dans une version comportementale et par imagerie par résonance magnétique fonctionnelle (IRMf). Ce test nécessite la mise en œuvre d’une inhibition consciente et volontaire impliquant une notion de contrôle coûteuse en ressources attentionnelles qui intervient lorsqu’une réponse dominante doit être supprimée intentionnellement. En IRMf, ce test s’accompagne d’une activation du cortex préfrontal souvent altérée dans la schizophrénie. Nos résultats mettent en évidence à la fois un ralentissement et un nombre élevé d’erreurs chez les patients. Ces données vont dans le sens d’une moindre efficience de la fonction de freinage avec parfois un échec des processus inhibiteurs induisant des erreurs. En IRMf, nos données ne montrent pas d’altération frontale mais une hyperactivation pariétale, qui corrobore la nécessité de ressources de traitement supplémentaires dans la schizophrénie pour ce type d’inhibition.

The cortical areas involved in inhibition processes were examined with positron emission tomography (PET). The tasks administered to subjects were an adaptation of the Hayling test. In the first condition (response initiation), subjects had to complete sentences with a word clearly suggested by the context, whereas in the second condition (response inhibition), subjects had to produce a word that made no sense in the context of the sentence. Results indicated that the response initiation processes were associated to increases of activity in the left inferior frontal gyrus (BA 45/47), whereas response inhibition processes led to increases in a network of left prefrontal areas, including the middle (BA 9 and BA 10) and inferior (BA 45) frontal areas.

SynopsisThis study is an attempt to demonstrate confabulation in schizophrenia. Twelve patients who met DSM-III-R criteria for schizophrenia were matched for age, sex and pre-morbid IQ with 12 volunteers, 9 of whom were normal healthy subjects, with the remainder being depressed patients. To elicit confabulation, subjects were asked to recall narratives. In addition, subjects were examined on a number of neuropsychological tests. Confabulation was denned as recall of information not present in the narrative. Variable amounts of confabulation were observed in all schizophrenics, while only one control subject confabulated. The content and structure of their productions differed from previously reported forms of confabulation in that schizophrenic patients spontaneously rearranged the original narratives to produce new ideas. The amount of confabulation was found to be related to difficulties in suppressing inappropriate responses (Hayling test) and formal thought disorder, but unrelated to understanding of the gist or moral of the narratives. Tentative mechanisms for the process of confabulation are proposed, based on specific difficulties with comprehension, response monitoring and response suppression.