The effects of processing requirements on neurophysiological responses to spoken sentences

Ten English speaking subjects listened to sentences that varied in sentential constraint (i.e., the degree to which the context of a sentence predicts the final word of that sentence) and event-related potentials (ERPs) were recorded during the presentation of the final word of each sentence. In the Control condition subjects merely listened to the sentences. In the Orthographic processing condition subjects merely listened to the sentences. In the Orthographic processing condition subjects decided, following each sentence, whether a given letter had been present in the final word of the preceding sentence. In the Phonological processing condition the subjects judged whether a given speech sound was contained in the terminal word. In the Semantic processing condition subjects determined whether the final word was a member of a given semantic category. A previous finding in the visual modality that the N400 component was larger in amplitude for low constraint sentence terminations than for high was extended to the auditory modality. It was also found that the amplitude of a N200-like response was similarly responsive to contextual constraint. The hypothesis that N400 amplitude would vary significantly with the depth of processing of the terminal word was not supported by the data. The "N200" recorded in this language processing context showed the classic frontocentral distribution of the N200. The N400 to spoken sentences had a central/centroparietal distribution similar to the N400 in visual modality experiments. It is suggested that the N400 obtained in these sentence contexts reflects an automatic semantic processing of words that occurs even when semantic analysis is not required to complete a given task. The cooccurrence and topographical dissimilarity of the "N200" and N400 suggest that the N400 may not be a delayed or a generic N200.     

Developmental Trajectories of Girls’ and Boys’ Delinquency and Associated Problems

Developmental trajectories in delinquency through adolescence were studied along with family and peer relationship problems. Drawing from eight waves of data over seven years, we conducted trajectory analyses with a sample of 746 students (402 girls; 344 boys). Analyzing girls and boys together, a five-class model emerged: 60% of the adolescents rarely reported delinquency; 27.7% reported low initial levels with moderate levels of delinquency over time; 6% in the late onset group reported initially low and rising levels of delinquency; 5% in the early onset group reported moderate initial levels which increased and then decreased in later adolescence. A small group of only boys (1.3%) labeled chronic reported high initial levels of delinquency that increased over time. Group comparisons revealed problems in internalizing, parent and peer relationship problems. The findings provide direction for early identification and interventions to curtail the development of delinquency.     

Intimacy, identity and status: Measuring dating goals in late adolescence and emerging adulthood

Individuals?? goals can direct their own social behavior and development. We extended and validated a social dating goals measure (SDGS-R) to assess identity, intimacy and status goals, and compared goals by age, gender, sexual orientation and romantic status. Participants were 121 adolescents and 249 emerging adults (age M?=?20.6). The expected 3-factor structure of the SDGS-R was found and confirmed (18 items). Identity, intimacy and status goals had small correlations with each other and analyses validated the meaning and uniqueness of each goal. Participants reported more identity and intimacy goals than status goals. Intimacy goals were more prominent among older compared to teenage participants and those with a partner rather than without one. Females reported more identity dating goals than males. There was no difference in the goals of same-sex and other-sex attracted youth. The availability of the SDGS-R will allow further study of romantic development and relationship functioning.     

How does thought suppression impact upon beliefs about uncontrollability of worry?

According to Wells’ metacognitive model of generalised anxiety disorder (GAD; [Wells, A. (1995). Meta-cognition and worry: A cognitive model of generalised anxiety disorder. Behavioural and Cognitive Psychotherapy, 23, 301–320]), GAD patients attempt to suppress intrusions that trigger worry. Wells postulates that these attempts are rarely effective and may increase the frequency of worry triggers. These apparent failures are interpreted as evidence for loss of mental control, thereby exacerbating beliefs about worry uncontrollability. The current study tested these predictions. Sixty-two high worriers completed a naturalistic experiment comprising two sessions separated by 1 week. In Session 1, participants recorded their beliefs about worry in general, including its uncontrollability. They then selected a current worry and recorded how often it came to mind over the following week. The Suppression group (N=32) suppressed their chosen worry during the week. The Mention group (N=30) simply monitored its occurrence. In Session 2, Session 1 measures were repeated. Contrary to prediction, the Suppression group reported a significant increase in worry controllability in general. No shift was demonstrated by the Mention group. In addition, relative to the Mention group, the Suppression group reported more success at suppressing their chosen worries, spent less time thinking about them, and found them more controllable and less distressing. Findings are discussed within the context of Wells’ model.     

Why is visual search superior in autism spectrum disorder?

This study investigated the possibility that enhanced memory for rejected distractor locations underlies the superior visual search skills exhibited by individuals with autism spectrum disorder (ASD). We compared the performance of 21 children with ASD and 21 age‐ and IQ‐matched typically developing (TD) children in a standard static search task and a dynamic search task, in which targets and distractors randomly changed locations every 500 ms, precluding the use of memory in search. Children with ASD exhibited overall faster reaction time (RT) relative to TD children, and showed no disruption in search efficiency in the dynamic condition, discounting the possibility that memory for rejected distractors augments their visual search abilities. Analyses of RT x set size functions showed no group differences in slopes but lower intercepts for the ASD group in both static and dynamic search, suggesting that the ASD advantage derived from non‐search processes, such as an enhanced ability to discriminate between targets and distractors at the locus of attention. Eye‐movement analyses revealed that the ASD and TD groups were similar in the number and spatial distribution of fixations across the search array, but that fixation duration was significantly shorter among children with ASD. Lower intercepts in static search were related to increased symptom severity in children with ASD. In summary, ASD search superiority did not derive from differences in the manner in which individuals with ASD deployed their attention while searching, but from anomalously enhanced perception of stimulus features, which was in turn positively associated with autism symptom severity.     

Axiomatic quantum mechanics and radioactive decay

This paper explores the consequences of the orthodox resolution of the measurement problem for the axiomatic base of non-relativistic elementary quantum mechanics. It is argued that the standard resolution of the measurement problem generates a paradox whose dissolution may be achieved through an enrichment of the axiomatic foundations of quantum mechanics. These results are also linked to some recent creative proposals by Nancy Cartwright concerning the nature of the so-called reduction of the wave packet.     

Projective invariance and visual shape constancy

As one moves about a table, the projection of its shape on the retina varies enormously, yet the table's shape appears constant. The various retinal images of a single object are nearly congruent in projective geometry. To explain apparent constancy, standard theories of vision assume that the visual system has access to this projective congruence. We present four experiments that undermine this assumption (i.e., the projective thesis). The basic result is that observers' estimates of shape in a simple production task represent gross departures from correct projection, even when observers are given aids to fixation. We manipulate both observer sample and experimental procedure in an attempt to find a source of these persistent errors. Our present hypothesis is that observers lack the sensitivity or implicit knowledge of projective geometry that has been attributed to them.