Retrieving information from a hierarchical plan

Plans give structure to behavior by specifying whether and when different tasks must be performed. However, the structure of behavior need not mirror the structure of the plan. To investigate this idea, the authors studied how plan information is retrieved in the context of a novel sequence-position cuing procedure, wherein subjects memorize two task sequences, then perform trials on which they are randomly cued to perform a task at one of the serial positions in a sequence. Several empirical effects were consistent with retrieval from a hierarchically structured representation (but not a non-hierarchical representation), including large sequence-repetition benefits, position-repetition benefits only for sequence repetitions, and a lack of robust task-repetition benefits. The data were successfully modeled by assuming that retrieval was time-consuming, susceptible to priming, cue-dependent, structurally constrained, and token-specific. In tandem, the empirical data and modeling work provide deeper insight into the representation of and access to information in memory that comprises a plan for guiding behavior.     

Convergent and discriminative validity of interview and questionnaire measures of personality disorder in mentally disordered offenders: a multitrait-multimethod analysis using confirmatory factor analysis

Measures of personality disorder from the International Personality Disorder Examination, Personality Diagnostic Questionnaire, and Millon Clinical Multiaxial Inventory (MCMI-II) were obtained from detained male mentally disordered offenders (N = 156), and convergent and discriminant validity were examined by confirmatory factor analysis of the multitrait-multimethod matrix. Hierarchical comparisons of models varying in their specification of trait and method variance established the appropriateness of a model supporting both convergence and discrimination across methods, but these were variable across constructs and measures. Convergence was good for avoidant, schizoid, and antisocial disorders, but poor for histrionic, narcissistic, and obsessive-compulsive disorders. Avoidant, schizoid, and schizotypal disorders were not clearly distinguishable from each other. Measurement error attributable to method variance was substantial for all instruments and for most disorders. The commonly alleged superiority of interview over questionnaire methods was not supported, and the MCMI-II demonstrated proportionately more "true" variance. However, assessment methods may be differentially sensitive to different kinds of personality disorder problems.     

Object localisation and frames of reference

In this paper, we explore which spatial frames of reference, egocentric or allocentric, are used to locate objects either in relation to ourselves (i.e. subject-to-object localisation) or to other objects (i.e. object-to-object localisation). In particular, we wanted to know whether the same or different frames of reference are used in these two different kinds of localisation after learning the environment in an egocentric way. Egocentric frames of reference are determined by the position of the person in relation to the spatial layout, whereas allocentric frames of reference are centred on the environment or on objects, independent of a persons position. We hypothesised that subject-to-object localisation is based on egocentric spatial representations, whereas object-to-object localisation is based on allocentric spatial representations. Participants were asked to study eight common objects, placed in a circle. Next, half of the participants had to point to an object in relation to their imagined position (egocentric condition) and the other half to an object in relation to another object (allocentric condition). The overall results show no difference between subject-to-object and object-to-object localisation. In both cases, access to positions corresponding to the front/back body axis was facilitated, in terms of both latency and error. Moreover, participants were able to retrieve objects positions better from the perspective from which they had learned the spatial array than from new perspectives. These results support the conclusion that egocentric coordinates, which are selected on the basis of our body-centred experience of the environment, define spatial representations underlying both subject-to-object and object-to-object localisation.     

Predicting cognitive styles from spatial abilities

Previous studies on spatial memory reveal that people represent spatial information in 3 different forms: landmark, route, and survey. The aim of this work was to assess spatial abilities in order to predict a person's cognitive style. In order to do this we used 9 different spatial tasks, which were linked with these 3 forms of spatial representations. We found that the 9 spatial tasks are able to distinguish different levels of spatial ability.     

Comparing language lateralization determined by dichotic listening and fMRI activation in frontal and temporal lobes in children with epilepsy

We investigated the relationship between ear advantage scores on the Fused Dichotic Words Test (FDWT), and laterality of activation in fMRI using a verb generation paradigm in fourteen children with epilepsy. The magnitude of the laterality index (LI), based on spatial extent and magnitude of activation in classical language areas (BA 44/45, 21/22, 39) differed significantly for patients classified with unilateral left, compared to bilateral, language representation based on FDWT scores. Concordance with fMRI was higher for those classified with unilateral left, than bilateral language representation on the FDWT. Of note, asymmetry in temporal lobe, rather than frontal lobe, activation was more strongly related to the LI from the dichotic listening test. This study shows that the FDWT can provide a quick and valid estimate of lateralization in pre-surgical candidates, which can be readily adopted for other clinical or research purposes when an estimate of language dominance is desired.     

Clever homunculus: is there an endogenous act of control in the explicit task-cuing procedure?

Does the explicit task-cuing procedure require an endogenous a act of control? In 5 experiments, cues indicating which task to perform preceded targets by several stimulus onset asynchronies (SOAs). Two models were developed to account for changes in reaction time (RT) with SOA. Model 1 assumed an endogenous act of task switching for cue alterations but not for cue repetitions. Model 2 assumed no such act. In Experiments 1 and 2, the cue was masked or not masked. Masking interacted underadditively with repetition and alternation, consistent with Model 2 but not Model 1. In Experiments 3 and 4, 2 cues were used for each task. RT was slower for task repetition than for cue repetition and about the same as RT for task alternation, consistent with Model 2 but not Model 1. The results suggest that the explicit task-cuing procedure does not require an endogenous act of control.     

Conscious and unconscious lexical retrieval blocking in younger and older adults

The effects of orthographically overlapping prime words in a word fragment completion task (modified from S. M. Smith & D. R. Tindell, 1997) were studied in younger and older adults. Participants studied words and then completed word fragments corresponding to those words. Fragments were preceded by a blocking, unrelated, or neutral prime. In Experiment 1, all participants were slower and less likely to complete the word fragments correctly in the blocking prime condition. Older adults also were more likely to use the blocking prime to incorrectly complete the word fragment compared with younger adults, even when warned against doing so (Experiment 2). Experiment 3 used a masked priming paradigm in younger adults to examine whether conscious processing of the prime word was necessary to produce blocking effects. Reliable blocking effects were obtained, including an intrusion rate similar to that observed in older adults in the first two experiments. These results suggest that certain aspects of word-finding failures in normal aging may be related to the reduced ability to control the activation of a lexical competitor when attempting to retrieve a target word.     

Interpreting instructional cues in task switching procedures: the role of mediator retrieval

In 3 experiments the role of mediators in task switching with transparent and nontransparent cues was examined. Subjects switched between magnitude (greater or less than 5) and parity (odd or even) judgments of single digits. A cue-target congruency effect indicated mediator use: subjects responded faster to congruent cue-target combinations (e.g., ODD-3) than to incongruent cue-target combinations (e.g., ODD-4). Experiment 1 revealed significant congruency effects with transparent word cues (ODD, EVEN, HIGH, and LOW) and with relatively transparent letter cues (O, E, H, and L) but not with nontransparent letter cues (D, V, G, and W). Experiment 2 revealed significant congruency effects after subjects who were trained with nontransparent letter cues were informed of the relations between cues and word mediators halfway through the experiment. Experiment 3 showed that congruency effects with relatively transparent letter cues diminished over 10 sessions of practice, suggesting that subjects used mediators less as practice progressed. The results are discussed in terms of the role of mediators in interpreting instructional cues.     

Awareness of faces is modulated by their emotional meaning

A central question in perception is how stimuli are selected for access to awareness. This study investigated the impact of emotional meaning on detection of faces using the attention blink paradigm. Experiment 1 showed that fearful faces were detected more frequently than neutral faces, and Experiment 2 revealed preferential detection of fearful faces compared with happy faces. To rule out image artifacts as a cause for these results, Experiment 3 manipulated the emotional meaning of neutral faces through fear conditioning and showed a selective increase in detection of conditioned faces. These results extend previous reports of preferential detection of emotional words or schematic objects and suggest that fear conditioning can modulate detection of formerly neutral stimuli.     

Higher-order dimensions of personality disorder: hierarchical structure and relationships with the five-factor model, the interpersonal circle, and psychopathy

Two studies examined the higher-order factor structure of DSM-IV personality disorders using the International Personality Disorder Examination in male forensic psychiatric patients. In Study 1 (N = 168), exploratory factor analysis at the level of individual personality disorder criteria indicated nine primary factors. Exploratory and confirmatory factor analyses of these first-order factors supported a hierarchical structure in which two of three second-order factors covaried to yield a third-order factor. The two resulting superordinate factors were labelled Anxious-Inhibited and Acting Out. In Study 2 (N = 160), we used exploratory and confirmatory factor analyses to test hypotheses of common dimensions underlying these superordinate factors of personality disorder and superordinate factors of the five-factor model of personality, dimensions of the interpersonal circle, and psychopathy. Of three common factors, one combined Anxious-Inhibited disorders, "neurotic introversion," and hostile-submission. The other two factors of Acting Out/ psychopathy and antagonism/hostile-dominance covaried to yield a superordinate factor. Possible substrates underlying two superordinate dimensions common to normal and abnormal personality were identified in the theoretical literature.