Scene-based and object-centered inhibition of return: evidence for dual orienting mechanisms

We investigated whether inhibition of return (IOR) could be observed in location-based, scene-based, and object-centered frames of reference. IOR was found to move both with a separate cued object (scene-based) and with a location within a single rotating object (object-centered). Importantly, however, IOR was also associated with the environmental location cued when cuing was of a separate object (scene-based), whereas facilitation of the cued location was found when cuing was of a component within an object. These results suggest that location is of central importance to scene-based representations of separate objects, which appear to be encoded in viewer-centered coordinates, whereas environmental locus is of little relevance when attention orients within a single object. The results also provide further evidence for the coexistence of both excitation and inhibition associated with uninformative exogenous cues.     

Monitoring and assessing symptoms of chronic fatigue syndrome: use of time series regression

Chronic Fatigue Syndrome's principal symptoms are severe and include prolonged fatigue and a number of other minor symptoms. Behavioral data collection methods were used in a case study to show some of the benefits that can be derived from monitoring symptoms hourly and daily. Using time series regression, several statistically significant correlates of fatigue were found both within days and between days. Perceived energy, physical exertion, and mental exertion were significantly related to fatigue in both analyses. Collection of such data may help resolve a number of theoretical and methodological problems in research on the Chronic Fatigue Syndrome.     

A connectionist model of visual-word recognition that accounts for interactions between mask size and word length

Summary A connectionist model is described, which accounts for data showing a mask appropriateness effect in word and letter recognition. In a backward-masking paradigm, if the letter fragment masks that are used are of a similar size to the word or word fragment they are masking, performance is better than if the masks are longer or discontinuous (Jordan, 1990). The model simulates these effects by adding to the familiar architecture of the interactive activation model length units, which are stimulated whenever word units of a particular letter length are active, and mask units, which are stimulated by masks of particular sizes and in turn stimulate length units. Detailed predictions of the model are examined for both forward and backward masking, and are found to be in good accord with the data.     

Caregiver-implemented toilet training procedures for children with autism spectrum disorder

Children with Autism Spectrum Disorder often exhibit deficits in daily living skills, including toileting skills. Previous studies have evaluated components of common toilet training practices, including differential reinforcement, sit schedules, fluid loading, underwear, and wet alarms. The purpose of this study was to replicate and extend previous work by delivering all coaching remotely. Three caregiver-child dyads participated in this study. A researcher coached caregivers on the implementation of the protocol using a modified behavioral skills training approach via telehealth. Caregivers submitted daily toileting data and weekly audio recordings for treatment integrity checks. The sit schedule fading was individualized to meet the needs and preferences of each family. All caregivers implemented the protocol with high integrity. Two participants met the mastery criteria at the 90-min sit schedule and maintained performance at the 1- and 6-week maintenance follow up probes. The third participant, despite an interruption of treatment, also reached mastery.     

Establishing arbitrary comparative relations and referential transformations of stimulus function in individuals with autism

Relational Frame Theory posits that complex language develops through arbitrarily applicable relational networks, with potential implications for individuals with autism. Responding relationally based on comparison occurs when participants respond to any number of comparative properties, such as “bigger” or “faster.” Experiment 1 established two 3-member comparative networks, in which a stimulus A was conditioned as “bigger” or “faster” than a stimulus B, and the stimulus B was conditioned as “bigger” or “faster” than a stimulus C in 2 children with autism. Both participants met the mastery criterion for the trained relations and demonstrated the emergence of the untrained combinatorially entailed A–C and C–A relations. The participants could also match the arbitrary A stimuli with larger or faster objects and the C stimuli with smaller or slower objects. The results were replicated in Experiment 2 with the same participants, where a 5-member relational network was established for the bigger/smaller relation.     

Becoming team players: team members' mastery of teamwork knowledge as a predictor of team task proficiency and observed teamwork effectiveness

The authors explored the idea that teams consisting of members who, on average, demonstrate greater mastery of relevant teamwork knowledge will demonstrate greater task proficiency and observed teamwork effectiveness. In particular, the authors posited that team members' mastery of designated teamwork knowledge predicts better team task proficiency and higher observer ratings of effective teamwork, even while controlling for team task proficiency. The authors investigated these hypotheses by developing a structural model and testing it with field data from 92 teams (1,158 team members) in a United States Air Force officer development program focusing on a transportable set of teamwork competencies. The authors obtained proficiency scores on 3 different types of team tasks as well as ratings of effective teamwork from observers. The empirical model supported the authors' hypotheses.     

A computational model of frontal lobe dysfunction: working memory and the Tower of Hanoi task

A symbolic computer model, employing the perceptual strategy, is presented for solving Tower of Hanoi problems. The model is calibrated—in terms of the number of problems solved, time taken, and number of moves made—to the performance of 20 normal subjects. It is then "lesioned" by increasing the decay rate of elements in working memory to model the performance of 20 patients with lesions to the prefrontal cortex. The model captures both the main effects of subject groups (patients and normal controls) performance, and the subject groups (patients and normal controls) by problem difficulty interactions. This leads us to support the working memory hypothesis of frontal lobe functions, but for a narrow range of problems.     

Effect of prefrontal cortex damage on resolving lexical ambiguity in text

The function of suppression of context-inappropriate meanings during lexical ambiguity resolution was examined in 25 adults with prefrontal cortex damage (PFCD) localized to the left (N=8), right (N=6), or bilaterally (N=11); and 21 matched Controls. Results revealed unexpected inverse patterns of suppression between PFCD and Control groups, with measures suggesting decreased interference across time in the PFCD group and increased interference in the Control group. The PFCD group, however, had significantly lower accuracy rates for the context-inappropriate condition. Results suggest a loss of the control aspects of inhibitory processes in lexical ambiguity resolution following PFCD. An aging effect on suppression function is also suggested.