Neurocognitive insight and executive functioning in schizophrenia

Introduction. This study explored whether integrity of executive functioning is required for good neurocognitive insight (NI) in subjects with schizophrenia.

Methods. NI was measured by subtracting executive difficulties (errors in the Modified Card Sorting Task) from executive cognitive complaints (Subjective Scale to Investigate Cognition in Schizophrenia) in 40 outpatients with schizophrenia and 42 normal controls. The schizophrenia sample was a priori divided into two subgroups on the basis of executive level. Multivariate analyses were conducted to compare groups and to control for potential confounding factors.

Results. Only the schizophrenia dysexecutive subgroup had a poorer NI compared to normal controls. Group differences remained significant after adjustment for potential confounding factors (education, depression, anxiety and self-esteem).

Conclusion. These results provide support for the hypothesis that executive dysfunctioning is a limiting factor for NI, independently from depressive and anxiety symptoms.     

Discriminating between first- and second-order cognition in first-episode paranoid schizophrenia*

Introduction: An impairment of visually perceiving backward masked stimuli is commonly observed in patients with schizophrenia, yet it is unclear whether this impairment is the result of a deficiency in first or higher order processing and for which subtypes of schizophrenia it is present.

Methods: Here, we compare identification (first order) and metacognitive (higher order) performance in a visual masking paradigm between a highly homogenous group of young first-episode patients diagnosed with paranoid schizophrenia (N?=?11) to that of carefully matched healthy controls (N?=?13).

Results: We find no difference across groups in first-order performance, but find a difference in metacognitive performance, particularly for stimuli with relatively high visibility.

Conclusions: These results indicate that the masking deficit is present in first-episode patients with paranoid schizophrenia, but that it is primarily an impairment of metacognition.     

Humans are not cooperative breeders but practice biocultural reproduction

Context: Alloparental care and feeding of young is often called “cooperative breeding” and humans are increasingly described as being a cooperative breeding species.

Objective: To critically evaluate whether the human offspring care system is best grouped with that of other cooperative breeders.

Methods: (1) Review of the human system of offspring care in the light of definitions of cooperative, communal and social breeding; (2) re-analysis of human lifetime reproductive effort.

Results: Human reproduction and offspring care are distinct from other species because alloparental behaviour is defined culturally rather than by genetic kinship alone. This system allows local flexibility in provisioning strategies and ensures that care and resources often flow between unrelated individuals. This review proposes the term “biocultural reproduction” to describe this unique human reproductive system. In a re-analysis of human life history data, it is estimated that the intense alloparenting typical of human societies lowers the lifetime reproductive effort of individual women by 14–29% compared to expectations based upon other mammals.

Conclusion: Humans are not cooperative breeders as classically defined; one effect of the unique strategy of human biocultural reproduction is a lowering of human lifetime reproductive effort, which could help explain lifespan extension.     

Correlation of Proteinuria with Podocyte Foot Process Effacement in IgA Nephropathy: An Ultrastructural Study

Background: Proteinuria is an uncommon clinical manifestation of IgA nephropathy and is usually seen in cases with severe lesions like endocapillary proliferation. However, it is occasionally seen even with cases with mild glomerular manifestations and may even be of nephrotic range.

Predictor: Podocyte foot process effacement.

Outcome: Severity of proteinuria.

Measurements: Podocyte foot process effacement was measured. Morphometric analysis was performed on transmission electron microscope images using a computerized digital photomicrograph system (BioWizard 4.2 Image analysis software, New Delhi, India). Proteinuria was measured quantitatively assigned into five grades.

Results: It was found that as the extent of proteinuria increased, the effacement ratio also increased, and this was most significant between “no” proteinuria and the rest of the categories.

Conclusion: Nephrotic presentation in IgA nephropathy is a known phenomenon and in certain cases may show near normal glomerular morphology with severe foot process effacement on EM being the only significant finding to explain the proteinuria. Proteinuria in these cases shows a significant correlation with degree of foot process effacement. Renal biopsy is important in these cases because they are known to have a better prognosis and are usually steroid responsive.     

Confabulations in schizophrenia

Introduction. Current theories of confabulation are based primarily on the observation of neurological patients. The present paper evaluates these theories based on evidence from schizophrenia. Schizophrenia is unique in that it presents with a pathophysiology which differs from that of other neuropsychiatric conditions, and yet the candidate's deficits that various theories of confabulation implicate are often simultaneously present in schizophrenia.

Methods. A selective review of literature on schizophrenic and neurological confabulations was undertaken.

Results. Schizophrenic confabulation differs from neurological confabulation in terms of its characteristic features and association with symptoms, cognition and linguistic functions. Current evidence also suggests that confabulation may be conceptualized as a special class of delusions pertaining to memory phenomena.

Conclusions. Schizophrenia presents with confabulations that cannot be fully accounted for by the existing theories. It also presents with confabulations with unique features, which have different cognitive correlates and relation to other symptoms of the condition.     

Secular trends in cranial morphological traits: a socioeconomic perspective of change and sexual dimorphism in North Americans 1849–1960

Background: The human body has undergone significant changes in stature and other areas, which reflect secular trends associated with socioeconomics.

Aim: To analyse cranial morphological traits for deciphering if they are subject to secular trends.

Subjects and methods: Two documented skeletal collections were sampled for a total of 525 individuals from 1849–1960. Cranial morphological traits were scored and input into time series statistics (logistic regression).

Results: In females, nuchal crests have enlarged, while glabella has decreased. In males, supraorbital margins have dulled, while glabella decreased. Sexual dimorphism increased in supraorbital margins.

Conclusion: The patterns in the data here reflect those found in other areas of the skeleton, namely height, as regards to secular trends. These findings can be extended to stature and cranial changes that parallel socioeconomic trends during the Industrial Revolution, antebellum period and after.     

Isometric torso muscle endurance profiles in adolescents aged 15–18: normative values for age and gender differences

Objective: The aim of this study was to establish normative values for torso muscle endurance in adolescents aged 15–18 years. It was hypothesized that torso endurance profiles of adolescents differs between males and females and between adolescents and adults.

Background: Decreased torso muscle endurance has been identified as a potential personal risk factor for low back pain development in both adolescents and later years together with being detrimental for athletic performance.

Design: Measurement of torso muscle endurance, established through four tests performed in random order in a healthy adolescent population.

Setting: High school in Novi Sad, Province of Vojvodina, Republic of Serbia.

Methods: Two hundred and ninety-four adolescents from one high school (178 males and 116 females) were grouped into four age strata. Selected isometric torso muscle endurance tests were: Biering-Sørensen test for extensor endurance; Flexor endurance test; right and left Side Bridge tests. The mean, ratio, standard deviation and 25th, 50th and 75th percentile scores were determined for each gender/age strata.

Results and conclusion: Males had higher lateral torso endurance than females. Adolescents in general demonstrate their peak lifetime endurance as they appear more endurable than children and comparable adult groups. These data of endurance times, their ratios and percentiles in healthy normal subjects form a database bridging existing data for children and adults that may be useful for guiding training and rehabilitation.     

Cued fluency protocol reveals dynamic symptomatic-dependent processes of goal-directed behaviours in schizophrenia

Introduction. Differential impairments of willed actions and routine behaviours are the subject of many studies into schizophrenia. These impairments in generating and controlling goal-directed behaviours are reported in studies showing the effect of cueing in cognitive or motor tasks in people with schizophrenia. The aim of this study was to assess the performance of people with schizophrenia in a cued fluency protocol reworked to fit the concept of goal-directed behaviour. The extent to which results could be better explained by goal-directed generation issues, according to a symptomatic framework, than by semantic retrieval or semantic processing impairments, was also investigated.

Methods. We compared the performance of 43 individuals with schizophrenia to a control group of 26 participants. Participants were assessed with neuropsychological tests. The dominance of positive and negative symptoms, and apathetic profile, were also evaluated. All participants completed a cued fluency protocol.

Results. Despite a significant improvement, not all people with schizophrenia exhibited equal cueing benefits. The participants with negative symptom dominance appeared to benefit more from cueing, even though their baseline performance was lower.

Conclusions. These results suggest that, in addition to semantic memory impairments, some cognitive tasks may be more broadly influenced by difficulties in generating goal-directed behaviours.     

Cognition and social cognition in non-psychotic siblings of patients with schizophrenia

Introduction. Deficits in Social Cognition are common in people with schizophrenia. However, it is not clear if these deficits are a vulnerability marker and whether they are independent to cognitive difficulties. This study investigates these two issues in individuals with a genetic liability to psychosis.

Methods. Twenty-one healthy siblings of patients with schizophrenia were compared with 21 healthy individuals on a range of cognitive and social cognitive measures. Significant differences in cognitive domains were controlled for when comparing the two groups on measures of social cognition.

Results. Siblings of people with schizophrenia performed significantly worst on tests of theory of mind and social perception but not on affect recognition. Scores on tests of executive function, processing speed and general IQ were also lower in the sibling group. When controlled for differences in cognitive tests, the two groups still retained significant differences in theory of mind and social perception. However, executive function significantly contributed to theory of mind and processing speed to social perception differences.

Conclusions. These results further suggest that difficulties in some domains of social cognition are associated with a genetic vulnerability for schizophrenia. In these areas, cognitive difficulties account only partially for social cognition problems suggesting that these two domains may represent relatively independent liability factors.     

Body image,body dissatisfaction and weight status in children from Emilia-Romagna (Italy): comparison between immigrant and native-born

Background: Cross-sectional study among immigrant and native children from Emilia-Romagna (Italy).

Aim: The purpose of the present study was to examine the relative contribution of weight status, ethnicity and sex on body dissatisfaction in a sample of children from Emilia-Romagna (Italy).

Subjects and methods: Primary school children (226 immigrants and 1206 Italians) aged 6–11 years were measured: immigrant children were divided into Asians, Africans, Latin Americans and East Europeans. Height and weight were measured and Body Mass Index (BMI) was calculated. Body image perception was assessed using Body Silhouette Charts. A body dissatisfaction score (BDS) was derived by subtracting the "ideal self" from the "self" score.

Results: Weight status disorders were higher in immigrants than in native-born males; Italian females had higher prevalence of underweight and overweight and lower prevalence of obesity than immigrants peers. BDS rose with the increase of weight status categories.

Conclusions: Awareness of body image size and increasing body dissatisfaction with higher weight status is established in childhood, regardless of ethnicity and gender.     

Is this my voice or yours? The role of emotion and acoustic quality in self-other voice discrimination in schizophrenia

Introduction: Impairments in self-other voice discrimination have been consistently reported in schizophrenia, and associated with the severity of auditory verbal hallucinations (AVHs). This study probed the interactions between voice identity, voice acoustic quality, and semantic valence in a self-other voice discrimination task in schizophrenia patients compared with healthy subjects. The relationship between voice identity discrimination and AVH severity was also explored.

Methods: Seventeen chronic schizophrenia patients and 19 healthy controls were asked to read aloud a list of adjectives characterised by emotional or neutral content. Participants’ voice was recorded in the first session. In the behavioural task, 840 spoken words differing in identity (self/non-self), acoustic quality (undistorted/distorted), and semantic valence (negative/positive/neutral) were presented. Participants indicated if the words were spoken in their own voice, another person’s voice, or were unsure.

Results: Patients were less accurate than controls in the recognition of self-generated speech with negative content only. Impaired recognition of negative self-generated speech was associated with AVH severity (“voices conversing”).

Conclusions: These results suggest that abnormalities in higher order processes (evaluation of the salience of a speech stimulus) modulate impaired self-other voice discrimination in schizophrenia. Abnormal processing of negative self-generated speech may play a role in the experience of AVH.     

Preserved priming effect in individuals with schizophrenia: cues towards rehabilitation

Introduction. Individuals with schizophrenia and affective disorders show relatively intact implicit memory as compared to declarative memory. Implicit memory is usually assessed with skill learning and priming tasks. Whereas priming is thought to involve storage changes in the posterior neocortex, skill learning is thought to rely more on the corticostriatal pathway. Since frontostriatal and frontotemporal dysfunctions are, respectively, found in schizophrenia and affective disorders, we hypothesised that individuals with schizophrenia and first-episode psychosis would exhibit disturbances in skill learning, but not priming.

Methods. Thirty-five patients (11 first-episode psychosis; 11 schizophrenia; 13 affective disorders) and 10 controls completed a procedural learning and priming task. Participants had to identify fragmented images throughout five training sessions. The improvement of the threshold at which the images could be identified between the first and last session was used as an index of procedural learning. In a final session, the identification thresholds for old and new images were compared to assess the priming effect.

Results. Whereas individuals with schizophrenia and first-episode psychosis showed impaired skill learning, the priming effect was similar in all groups.

Conclusion. Even though some aspects of learning and memory are affected in schizophrenia, our results suggest that the posterior cortical pathway remains efficient at modulating the priming effect. This intact ability could be used to guide the elaboration of new rehabilitation programmes.     

Milk immunity and reproductive status among Ariaal women of northern Kenya

Background: The immune factors in human milk protect infants from infection and promote immune development. Evidence suggests that the production of milk-specific immunoproteins is energetically costly, making them a form of maternal investment in offspring health that is subject to life history trade-offs.

Aim: This research tests the relationship between measures of reproductive effort and the production of milk immunoglobulin A (IgA) among Ariaal women, a settled northern Kenyan pastoralist population that experiences nutritional and disease stress.

Subjects and methods: Two hundred and forty-three lactating Ariaal women participated in a questionnaire, anthropometric measurement and milk collection. Milk IgA was analysed using ELISA.

Results: There was a significant U-shaped relationship between post-partum months and milk IgA, reflecting decreasing investment in the current offspring over the early post-partum period and subsequent recovery of maternal energy status near the end. There was also a significant inverse U-shaped relationship between milk IgA and parity, with high parity women showing a drop in milk IgA. In contrast, anthropometric measures of energy status were not associated with the production of milk IgA.

Conclusion: This research shows that patterns of reproductive investment can be demonstrated in milk IgA in the absence of measured energy changes.     

Effects of cognitive remediation therapy on neurocognition and negative symptoms in schizophrenia: an Italian naturalistic study

Introduction: Cognitive remediation therapy (CRT) has been reported to positively affect neurocognitive processes among patients with schizophrenia; however, the degree to which changes in cognition is linked to improved clinical symptoms, remains poorly understood. The current study aimed to investigate whether cognitive gains were associated to improvements in negative symptoms’ severity in patients with schizophrenia living in two Italian psychiatric facilities.

Methods: Patients with a diagnosis of schizophrenia were consecutively assigned to CRT (n?=?33) and compared with an historical control group (n?=?28). Assessments were performed at baseline and post-treatment using a neuropsychological battery (Trail Making Test A and B, Self-Ordered Pointing Task, California Verbal Learning Test), along with clinical and functioning measures.

Results: Visual attention (TMT-A score change) was found as the only significant predictor of improvement in negative symptoms subscale of the Positive and Negative Syndrome Scale. Furthermore, a mediation path analysis confirmed that better performance in visual attention acts as mediator of the positive association between CRT intervention and lower post-treatment negative symptoms score.

Conclusions: CRT can have a positive impact on a measure of visual attention in patients with schizophrenia and on negative symptoms reduction that is mediated by this significant intervention effect.     

Impact of childhood trauma and cognitive emotion regulation strategies on risk-aversive and loss-aversive patterns of decision-making in patients with depression

Introduction: Although poor decision-making ultimately impairs quality of life in depression, few studies describe the clinical characteristics of patients suffering from dysfunctional decision-making. This study aims to delineate the effect of childhood trauma and other personality factors on risk-aversive and loss-aversive patterns of decision-making in patients with depression.

Methods: A total of 50 depressive patients completed surveys for the measurement of sociodemographic factors, trauma loads and other clinical characteristics, including depression, anxiety, and strategies for emotion regulation. Risk aversion and loss aversion were quantified using probability discounting task and a 50:50 gamble on monetary decision-making task under specified risks. Stepwise multiple regression analysis was performed to determine the factors, predicting risk aversion or loss aversion in depression.

Results: Childhood trauma was the most prominent factor predicting loss aversion in patients with depressive disorders. Overall maladaptive emotion regulation strategies were associated with risk aversion.

Conclusion: Childhood trauma and specific strategies of emotion regulation contribute to risk or loss aversion in patients with depression. These findings may provide useful insight into elaborative evaluation and interventions to improve decision-making and quality of life in patients with depression.     

Temporal context and the organisational impairment of memory search in schizophrenia

Introduction. An influential theory of schizophrenic deficits in executive function suggests that patients have difficulty maintaining and utilising an internal contextual representation, whose function is to ensure that stimuli are processed in a task-appropriate manner. In basic research on episodic memory, retrieved-context theories propose that an internal contextual representation is critically involved in memory search, facilitating the retrieval of task-appropriate memories. This contextual machinery is thought to give rise to temporal organisation during free recall: the tendency for successive recall responses to correspond to items from nearby positions on the study list. If patients with schizophrenia have a generalised contextual deficit, then this leads to the prediction that these patients will exhibit reduced temporal organisation in free recall.

Methods. Using a combination of classic and recently developed organisational measures, we characterised recall organisation in 75 patients with schizophrenia and 72 nondisordered control participants performing a multi-trial free-recall task.

Results. Patients with schizophrenia showed diminished temporal organisation, as well as diminished subjective organisation of their recall sequences relative to control participants. The two groups showed similar amounts of semantic organisation during recall.

Conclusions. The observation of reduced temporal organisation in the patient group is consistent with the proposal that the memory deficit in schizophrenia can be characterised as a deficit in contextual processing.     

Self-imagination can enhance memory in individuals with schizophrenia

Objective: Previous research has demonstrated that self-referential strategies can be applied to improve memory in various memory- impaired populations. However, little is known regarding the relative effectiveness of self-referential strategies in schizophrenia patients. The main aim of this study was to assess the effectiveness of a new self-referential strategy known as self- imagination (SI) on a free recall task.

Methods: Twenty schizophrenia patients and 20 healthy controls intentionally encoded words under five instructions: superficial processing, semantic processing, semantic self-referential processing, episodic self-referential processing and semantic self- imagining. Other measures included depression, psychotic symptoms and cognitive measures.

Results: We found a SI effect in memory as self- imagining resulted in better performance in memory retrieval than semantic and superficial encoding in schizophrenia patients. The memory boost for self-referenced information in comparison to semantic processing was not found for other self-referential strategies. In addition no relationship between clinical variables and free recall performances was found. In controls, the SI condition did not result in better performance. The three self-referential strategies yielded better free recall than both superficial and semantic encoding.

Conclusions: This study provides evidence of the clinical utility of self-imagining as a mnemonic strategy in schizophrenia patients.     

Influence of observing another person’s action on self-generated performance in schizophrenia

Introduction. Observing another person’s action influences the execution of one’s own action via the mirror neuron system. However, the ability to control the effect of such action observation on one’s voluntary action has not been investigated. The aim of this study was to elucidate the influence of observing another’s action on own voluntary movement in patients with schizophrenia.

Methods. Fifteen patients with schizophrenia and 15 healthy age-matched controls participated in this study. Subjects were asked to perform a gripping task at 50% of their maximal voluntary force (MVF), whereas simultaneously watching others performed the same task with a different grip force (0%, 50% and 100% MVF).

Results. The healthy controls applied a constant grip force under each condition. In patients with schizophrenia, the grip force was significantly reduced during viewing the gripping of others at 50% MVF compared to during viewing other’s gripping at 0% and 100% MVF. The score of the Brief Psychiatric Rating Scale (BPRS) and the Scale for the Assessment of Positive Symptoms were correlated with the fluctuation in grip force among the action observation conditions.

Conclusion. Patients with schizophrenia might have difficulty controlling the influence of action observation on self-generated performance.     

Characterising receptive language processing in schizophrenia using word and sentence tasks

Introduction. Language dysfunction is proposed to relate to the speech disturbances in schizophrenia, which are more commonly referred to as formal thought disorder (FTD). Presently, language production deficits in schizophrenia are better characterised than language comprehension difficulties. This study thus aimed to examine three aspects of language comprehension in schizophrenia: (1) the role of lexical processing, (2) meaning attribution for words and sentences, and (3) the relationship between comprehension and production.

Methods. Fifty-seven schizophrenia/schizoaffective disorder patients and 48 healthy controls completed a clinical assessment and three language tasks assessing word recognition, synonym identification, and sentence comprehension. Poorer patient performance was expected on the latter two tasks.

Results. Recognition of word form was not impaired in schizophrenia, indicating intact lexical processing. Whereas single-word synonym identification was not significantly impaired, there was a tendency to attribute word meanings based on phonological similarity with increasing FTD severity. Importantly, there was a significant sentence comprehension deficit for processing deep structure, which correlated with FTD severity.

Conclusions. These findings established a receptive language deficit in schizophrenia at the syntactic level. There was also evidence for a relationship between some aspects of language comprehension and speech production/FTD. Apart from indicating language as another mechanism in FTD aetiology, the data also suggest that remediating language comprehension problems may be an avenue to pursue in alleviating FTD symptomatology.