Embedded figures detection in autism and typical development: preliminary evidence of a double dissociation in relationships with visual search

Individuals with autism show relatively strong performance on tasks that require them to identify the constituent parts of a visual stimulus. This is assumed to be the result of a bias towards processing the local elements in a display that follows from a weakened ability to integrate information at the global level. The results of the current study showed that, among children with autism, ability to locate a figure embedded in a larger stimulus was only related to performance on visual search trials where the target was identified by a unique perceptual feature. In contrast, control children's embedded figures performance was specifically related to their performance on visual search trials where the target was defined by a conjunction of features. This double dissociation suggests that enhanced performance on perceptual tasks by children with autism is not simply a consequence of a quantitative difference in ability to engage in global processing.     

Cortical regions associated with different aspects of object recognition performance

In the present object recognition study, we examined the relationship between brain activation and four behavioral measures: error rate, reaction time, observer sensitivity, and response bias. Subjects perceptually matched object pairs in which structural similarity (SS), an index of structural differentiation, and exposure duration (DUR), an index of task difficulty, were manipulated. The SS manipulation affected the fMRI signal in the left anterior fusiform and parietal cortices, which in turn reflected a bias to respond same. Conversely, an SS-modulated fMRI signal in the right middle frontal gyrus reflected a bias to respond different. The DUR manipulation affected the fMRI signal in occipital and posterior fusiform regions, which in turn reflected greater sensitivity, longer reaction times, and greater accuracy. These findings demonstrate that the regions most strongly implicated in processing object shape (SS-modulated regions) are associated with response bias, whereas regions that are not directly involved in shape processing are associated with successful recognition performance.     

Repetition blindness: out of sight or out of mind?

Does repetition blindness represent a failure of perception or of memory? In Experiment 1, participants viewed rapid serial visual presentation (RSVP) sentences. When critical words (C1 and C2) were orthographically similar, C2 was frequently omitted from serial report; however, repetition priming for C2 on a postsentence lexical decision task was equivalent whether or not C1 was similar to C2. In Experiment 2, participants monitored RSVP sentences for a predetermined target. Participants frequently failed to detect the target when it was preceded by an orthographically similar word. In Experiment 3, the authors investigated the role of the attentional blink in this effect. These experiments suggest that repetition blindness is a failure of conscious perception, consistent with predictions of the token-individuation hypothesis.     

Listening comprehension and working memory are impaired in attention-deficit hyperactivity disorder irrespective of language impairment

This study investigated listening comprehension and working memory abilities in children with attention-deficit hyperactivity disorder (ADHD), presenting with and without language impairments (LI). A 4-group design classified a community sample (n = 77) of boys aged 9–12 into ADHD, ADHD + LI, LI, and Normal groups. Children completed tests of basic language and cognitive skills, verbal and spatial working memory, and passage-level listening comprehension. Multivariate analyses and post hoc comparisons indicated that ADHD children who did not have co-occurring LI comprehended factual information from spoken passages as well as normal children, but were poorer at comprehending inferences and monitoring comprehension of instructions. ADHD children did not differ from normal children in verbal span, but showed significantly poorer verbal working memory, spatial span, and spatial working memory. The ADHD + LI and LI groups were most impaired in listening comprehension and working memory performance, but did not differ from each other. Listening comprehension skills were significantly correlated with both verbal and spatial working memory, and parent–teacher ratings of inattention and hyperactivity/impulsivity. Findings that children with ADHD but no LI showed subtle higher-level listening comprehension deficits have implications for both current diagnostic practices and conceptualizations of ADHD.     

Alienation and irrational beliefs in a nonclinical university population

A total of 126 college students, 53 men and 73 women, completed the Manifest Alienation Scale and the Irrational Beliefs Scale to assess alienation and irrationality. A linear relationship indicated students with elevated Alienation scores showed substantially higher irrationality than did students scoring lower. Analysis suggests that a positive linear effect for measured irrationality and reported Alienation characterizes students in a nonclinical population. The relationship between normal and pathological Alienation and irrational belief are addressed, and potential interventions in clinical situations are considered.     

The Effect of Inhibition of Return on Lexical Access

Abstract—Inhibition of return refers to a bias against returning attention to a location or object that has been recently attended. Recent research has shown that inhibition of return can be found not only in simple detection tasks, but also in tasks requiring relatively simple discrimination judgments. The present experiments examined whether inhibition of return occurs in tasks that require complex discriminations such as lexical decision and categorization tasks. Not only was inhibition of return found in both experiments, but a greater amount of inhibition was found for low-frequency words than for high-frequency words. These findings suggest that inhibition of return not only inhibits returning attention to previously attended locations, but can also affect the processing that is required for lexical access.     

The assessment of obsessionality using the Padua inventory: its validity in a British non-clinical sample

The Padua Inventory (PI) is a measure of obsessive–compulsive phenomena, which permits measurement of both number and severity of symptoms. Data is available from Italy, the US, the Netherlands and Australia on non-clinical samples. The present study provides a psychometric evaluation of the PI on a British non-clinical sample (N=1855). Comparisons are made with other data and further suggestions for the use of the PI are made. Results from the present study indicate that the PI has similar, though not identical, factor structure to previous studies, adequate internal reliability and construct validity. Four factors emerged, containing clusters of items broadly relating to ‘impaired control over mental activities/doubting', ‘contamination', ‘checking' and ‘worries about losing control over motor behaviour' and these included most of the items loading on the same factors in earlier studies together with additional items.The relationships of age and gender with the PI scores are investigated. Differences were found from the Sanavio (1988) [Sanavio, E. (1988). Obsessions and compulsions: the Padua Inventory. Behaviour Research and Therapy, 26, 169–177.] Italian sample. These differences are in keeping with other available data from British samples and other data on the epidemiology of Obsessive Compulsive Disorder. The five factor structure found in the one study using clinical and non-clinical subjects is discussed in relation to the present analyses.     

Who got vaccinated against H1N1 pandemic influenza? A longitudinal study in four U.S. cities

The recent H1N1 pandemic influenza stimulated numerous studies into the attitudes and intentions about the H1N1 vaccine. However, no study has investigated prospective predictors of vaccination behaviour. We conducted a two-wave longitudinal study among residents in four U.S. cities during the course of the H1N1 outbreak, using Internet surveys to assess demographic, cognitive and emotional predictors of H1N1 vaccination behaviour. Surveys were conducted at two time points, before (Time 1) and after (Time 2) the H1N1 vaccine was widely available to the public. Results show that Time 2 vaccination rates, but not Time 1 vaccination intentions, tracked H1N1 prevalence across the four cities. Receipt of seasonal influenza vaccine in the previous year, worry, compliance with recommended interventions, household size and education assessed at Time 1 were significant prospective predictors of vaccination behaviour. Perception of the H1N1 vaccine, social influence and prioritised vaccine recipient status assessed at Time 2 also predicted vaccination behaviour. Critically, worry about H1N1 mediated the effects of both objective risk (prevalence at the city level) and perceived risk on vaccination behaviour. These results suggest that H1N1 vaccination behaviour appropriately reflected objective risk across regions, and worry acted as the mechanism by which vaccination behaviour followed objective risk.     

Attention and social functioning in children with malformations of cortical development and stroke

Attention and social functioning and their interrelationships have not been routinely examined in children with early brain insult (EBI). This study aimed to describe attention and social functioning in children with two types of EBI: malformations of cortical development (MCD) and stroke. Children diagnosed with MCD (n = 14, 6 males) or stroke (n = 14, 8 males) aged 8 to 14 years (M = 12 years 11 months) completed neuropsychological assessments to examine attention processes. Primary caregivers completed a questionnaire to assess executive components of children's attention and teachers completed a questionnaire to measure children's social functioning. Brain scans (MRI or CT) were coded by a pediatric neuroradiologist. Higher rates of impairments in attention and social function were found in children with EBI compared with normative expectations. Children with MCD experienced more global and clinically significant levels of impairment than children with stroke; though impairments were present in both groups. A strong association between executive components of attention and social function was observed. In addition, complex attention processes were associated with social function. The findings emphasize the reciprocity between attention, behavior and social outcomes, and the vulnerability of social function following EBI.