Associative learning and perceptual style: Are associated events perceived analytically or as a whole? \ud \ud

The present study examined whether the formation of associations is affected by individual differences in perceptual style (analytic vs. holistic). Ninety undergraduate students were tested on their ability to associate concurrent events (i.e. word—colour) and were assessed on measures of field dependence and intelligence. The analysis revealed that analytic perceptual style (field independence) was associated with better performance on associative learning, and that this relationship was retained after controlling for differences in intelligence, age, and gender. The obtained results lent support to elemental theories of associative learning suggesting that concurrent stimuli tend to be perceived as separate units.\u

Referral trends in mental health services for adults with intellectual disability and autism spectrum disorders \ud \ud

ABSTRACT Researchers have paid increasing attention to mental \ud health issues in adults with autism spectrum disorders (ASDs) over the \ud last decades. However, little is known about how rates of clinical \ud referrals,types of mental health diagnoses and treatment in adults with \ud ASDs and intellectual disability have changed. We examined patterns \ud of change in referral trends to specialist mental health services in south \ud London from 1983 to 2000 (N= 137). The majority of the cases \ud (58.4%) did not have a diagnosable psychiatric disorder. Schizo- \ud phrenia was the most frequent psychiatric diagnosis followed by \ud depression, adjustment reaction and anxiety. There was a significant \ud change in the rate of referrals,an increase in the diagnosable psychi- \ud atric disorders over time and a significant reduction of medication at \ud time of referral. There were no significant changes in the use of other \ud therapeutic interventions. The proportion of participants living inde- \ud pendently increased. Implications for services and future research are \ud discussed. \ud \u

Logical reasoning in schizotypal personality

It was examined whether psychotic-like personality traits in a sample of 205 college students could predict logical reasoning deficits, akin to those seen in schizophrenia. The participants were tested on their ability to assess the logical validity of premises (Logical Reasoning Task), and completed a multi-dimensional schizotypy inventory (O-LIFE). Low accuracy was associated with increased levels of disorganized schizotypy (‘Cognitive Disorganization’), while elevated errors were associated with increased levels of positive (‘Unusual Experiences’), negative (‘Introvertive Anhedonia’) and impulsive (‘Impulsivity Non-conformity’) schizotypy. Nevertheless, multiple regression analyses revealed that negative schizotypy was retained as the only significant predictor after performance was corrected for random guessing, and the contribution of the average amount of time spent on each premise was controlled. The results suggest that, although most schizotypy dimensions have a detrimental effect on reasoning performance, possibly due to disadvantageous test-taking strategies, negative schizotypy is the most reliable predictor of logical reasoning deficits. It is proposed that social/interpersonal schizotypal traits, like negative symptoms of schizophrenia, are accompanied by deficient executive functions of working memory, which appear to undermine, inter alia, logical reasoning processing

LATENT INHIBITION AND PSYCHOMETRICALLY DEFINED SCHIZOTYPY: AN EXPERIMENTAL INVESTIGATION

The review of the literature suggests that the interpretation of the disruption of latent inhibition within the schizophrenia continuum remains elusive due to a number of methodological and theoretical problems. This thesis adopted a personality-based approach to experimental psychopathology testing alternative interpretations of latent inhibition deficits as a function of psychotic-like features in non-clinical participants. Results from 12 Experiments are discussed in terms of a two-component (attentional + associative) model of latent inhibition deficits

Perceptual biases and positive schizotypy: The role of perceptual load

The study investigated the effects of perceptual load on the bias to report seeing non-existing events—a bias associated with positive symptoms of schizophrenia and positive schizotypal symptoms. Undergraduate students completed psychometric measures of schizotypy and were asked to detect fast moving words among non-words under different levels of perceptual load. Perceptual load was manipulated through stimulus motion. Overall, the results showed that the higher the perceptual load, the stronger the bias to report seeing words in non-word trials. However, the observed bias was associated with positive schizotypy (Unusual Experiences) only when visual detection was performed under conditions of medium perceptual load. \ud No schizotypy measure was associated with accuracy. The results suggest that, although some amount of perceptual ambiguity seems to be necessary for schizotypal bias generation, an increase in the perceptual load can inhibit this process possibly by preventing perception of task-irrelevant internal events, such as loose word associations. \ud \u

Visuo-spatial processing and dimensions of schizotypy: figure-ground segregation as a function of psychotic-like features

The aim of the reported study was to determine whether the ability to segregate a simple figure embedded in a complex visual ground, was associated with psychotic-like features in a sample of undergraduate students. The participants (N =100) were tested on the Hidden Figures Test, as well as the Raven’s Progressive Matrices, and completed a multi-dimensional schizotypy inventory (O–LIFE). The IQ scores were positively related to the number of correct responses on the Hidden Figures Test, but were unrelated to any of the schizotypy measures. Impaired Performance on the Hidden Figures Test was associated with negative schizotypy (‘Introvertive Anhedonia’), and enhanced performance was associated with the ‘Impulsive Non-Conformity’ scale. Performance on the Hidden Figures Test was independent of the positive (‘Unusual Experiences’), and the disorganized (‘Cognitive Disorganization’), schizotypy. The results are discussed in terms of a putative involvement of the frontal lobes in the negative symptomatology of schizophrenia, and in top-down (goal-driven) perceptual processing, as well as the possible compensatory functional aspect of impulsivity in terms of allocating attention

Seeing words that are not there: Detection biases in schizotypy

Objective. The present studies introduced a novel word-detection paradigm to examine detection biases as a function of different schizotypy dimensions in a sample of undergraduate students. Method. The participants (N = 80) were asked to detect fast moving (8 frames/sec) words among simultaneously moving non-words. Results. Positive schizotypy was associated with a tendency to report words that never appeared in the trials. This effect was independent of task order, impulsivity and social desirability. None of the schizotypy measures was associated with correct words (detection accuracy). Conclusions. It is inferred that a bias to report events in the absence of corresponding events may constitute a cross-modal mechanism responsible for translating internally generated experiences into perceptual experiences

Traumatic experiences and life events in people with \ud intellectual disability

Purpose of review \ud The aim of this article is to present and critically evaluate recent research on life events and traumatic experiences as predictors of psychopathology in people with intellectual \ud disability. \ud \ud Recent findings \ud The area has not developed significantly in the last years. Although life events have been associated with a range of mental health problems, only few studies have tried to clarify their role in psychopathology. It is often the case that differences between life events and traumatic experiences have been overlooked, mainly because establishing a clear cut-off point between the two types of events is not always possible. In addition, traumatic experiences per se, and as potential predictors of psychopathology, have been scarcely investigated in people with intellectual disability. \ud \ud Summary \ud The role of recent life events and traumatic experiences across the life-span of people with intellectual disability deserves more research. An outstanding question is whether these events are risk factors or triggering factors, as well as how to differentiate between traumatic and life events. Identifying possible protective factors for mental health seems to be a very promising line for future research with important clinical implications. \u

Do Positive Schizotypal Symptoms Predict False Perceptual Experiences in Nonclinical Populations?

We examined whether positive schizotypy (i.e., reports of hallucinatory and delusional-like experiences) in nonclinical participants could predict false perceptual experiences during detection of fast-moving words beyond a possible response bias. The participants (N = 160) were assigned to one of two conditions: they were asked either to make presence/absence judgments (loose criterion) or to read aloud every detected word (strict criterion). Regression analysis showed that high levels of positive schizotypy predicted false alarms in the loose condition and false perceptions of words in the strict condition. The obtained effects were independent of detection accuracy, task order, impulsivity, and social desirability. We discuss the results in the context of information processing biases linked to the positive symptomatology of schizophrenia. Clinical and theoretical implications are also considered