Relation of maximal ankle dorsiflexion angle and passive resistive torque to passive-elastic stiffness of ankle dorsiflexion stretch

The maximal passive ankle dorsiflexion angle and the maximal passive resistive torque at this angle were measured for 81 women 20 to 84 years of age and correlated with the passive-elastic stiffness (stiffness) of an ankle dorsiflexion stretch. Pearson correlation coefficients and multiple regression analyses were used to examine whether the two clinical measurements could predict ankle stiffness. The maximal passive resistive torque showed a moderate correlation with stiffness in the full stretch range (r = .69) and high correlation with stiffness in the last half of the full stretch range (r = .84). The maximal dorsiflexion angle showed a low correlation with stiffness in the full stretch range (r = .27) and in the last half of the full stretch range (r = .36). The maximal passive resistive torque and the dorsiflexion angle together accounted for 54% of the stiffness variance in the full stretch range and 76% of the stiffness variance in the last half of the full stretch range. Thus, the clinical measurements of the maximal passive dorsiflexion angle and the maximal passive resistive torque were directly and significantly related to the ankle dorsiflexion passive-elastic stiffness and good predictors of stiffness in the last half of the passive ankle dorsiflexion stretch.     

Repetition blindness has a perceptual locus: evidence from online processing of targets in RSVP streams

Four experiments tested whether repetition blindness (RB; reduced accuracy reporting repetitions of briefly displayed items) is a perceptual or a memory-recall phenomenon. RB was measured in rapid serial visual presentation (RSVP) streams, with the task altered to reduce memory demands. In Experiment 1 only the number of targets (1 vs. 2) was reported, eliminating the need to remember target identities. Experiment 2 segregated repeated and nonrepeated targets into separate blocks to reduce bias against repeated targets. Experiments 3 and 4 required immediate "online" buttonpress responses to targets as they occurred. All 4 experiments showed very strong RB. Furthermore, the online response data showed clearly that the 2nd of the repeated targets is the one missed. The present results show that in the RSVP paradigm, RB occurs online during initial stimulus encoding and decision making. The authors argue that RB is indeed a perceptual phenomenon.     

Preference and resistance to change in concurrent variable-interval schedules

Pigeons were trained on a multiple schedule in which separate concurrent schedules were presented in the two components of the schedule. During one component, concurrent variable-interval 40-sec variable-interval 80-sec schedules operated. In the second component, concurrent variable-interval 40-sec variable-interval 20-sec schedules operated. After stable baseline performance was obtained in both components, extinction probe choice tests were presented to assess preference between the variable-interval 40-sec schedules from the two components. The variable-interval 40-sec schedule paired with the variable-interval 80-sec schedule was preferred over the variable-interval 40-sec schedule paired with the variable-interval 20-sec schedule. The subjects were also exposed to several resistance-to-change manipulations: (1) prefeeding prior to the experimental session, (2) a free-food schedule added to timeout periods separating components, and (3) extinction. The results indicated that preference and resistance to change do not necessarily covary.     

Psychiatric inpatients' perceptions of written no-suicide agreements: an exploratory study

One hundred thirty-five psychiatric inpatients admitted for suicidal danger were surveyed regarding their views on the benefits/limitations of written no-suicide agreements. A survey instrument developed for this study revealed that these inpatients, for the most part, rated written no-suicide agreements in a positive manner and in ways consistent with clinical opinion expressed in a number of qualitative/expert-opinion articles. Positive views of no-suicide agreements were not materially influenced by social desirability or age, nor were they moderated by gender, presence/absence of Axis II disorders, or admission suicidal danger. However, patient suicide attempt history (no attempts, one attempt, or more than one attempt) exerted a moderating effect on patients' ratings of the helpfulness of these contracts. Multiple attempters viewed written no-suicide agreements as less helpful than those patients with a single or no prior attempts. The methodological problems and generalizability concerns associated with these results are discussed and future research needs are suggested.     

Inhibition and superconditioning

Superconditioning is said to occur when learning an association between a conditioned stimulus (CS) and unconditioned stimulus (US) is facilitated by pairing the CS with the US in the presence of a previously established conditioned inhibitor. Previous demonstrations of superconditioning have been criticized because their control conditions have allowed alternative interpretations. Using a within–subjects autoshaping procedure, the present study unambiguously demonstrated superconditioning. The results support the view that superconditioning is the symmetric opposite of blocking.     

Recognition memory for single items and for associations is similarly impaired following damage to the hippocampal region

The formation of new associations between items is critical for establishing episodic memories. It has been suggested that the hippocampus is essential for creating such associations but is not involved, or is much less involved, in memory for single items. In Experiment 1, we tested controls and amnesic patients with bilateral lesions thought to be limited primarily to the hippocampal region in both single-item and associative recognition memory tasks. In the single-item task, a conventional recognition memory task was administered in which participants studied either houses or faces and were tested for their ability to recognize the individual items. In the associative task, participants studied paired pictures of houses and faces with instructions that encouraged associating the two stimuli, and were tested for their ability to recognize the specific pairings that were presented at study. Like the controls, the amnesic patients performed more poorly on the associative task. Relative to the controls, the amnesic patients were impaired to a similar extent on the single-item and associative tasks. In Experiment 2, the performance of the amnesic patients was improved by increasing the number of presentations of the study lists (eight presentations instead of one). On both the single-item and associative tests, the performance of the amnesic patients after eight presentations was now identical to the performance of the controls who had been given only one presentation of the study list. Thus, the associative condition was not disproportionally difficult for the amnesic patients. These results are consistent with the idea that the hippocampus is similarly involved in single-item and associative memory.     

A conceptual model of cultural predictors of anxiety among Japanese American and part-Japanese American adolescents

A model integrating Japanese ethnicity, cultural identity, and anxiety was developed and assessed in Japanese American and part-Japanese American high school seniors (N = 141). Using measures from the Hawaiian High Schools Health Survey, the model incorporated the State-Trait Anxiety Inventory, the Major Life Events Scale, and the Japanese Culture Scale (JCS). Japanese American adolescents scored higher on the JCS and reported fewer anxiety symptoms than part-Japanese American adolescents. Predictors for anxiety were being Japanese American versus part-Japanese American, income, and culturally intensified events. A significant interaction of behavior by self-identification was obtained. The model had good overall fit, suggesting that cultural identity formation may contribute to anxiety experienced particularly by adolescents of mixed heritage.     

Evaluating frequency proximity in stream segregation

Consecutive sounds of similar structure that are close in frequency or pitch are more likely to be perceived as part of the same sequence than those at greater frequency separations. The principle of grouping into such perceptual sequences, or auditory streams, is known as frequency proximity. However, the metric by which one frequency difference is judged to be greater or less than another in complex auditory scenes is not yet known. Two experiments explored the metric for frequency proximity. We presented repeating three-tone stimulus patterns at a rate where they are normally heard as two streams, one containing the highest tone and one containing the lowest. The middle tone joined one stream or the other depending on its frequency. Subjects reported the perceived allocation of the variable tone by responding on a 5-point scale. The frequency at which either of these two percepts was equally probable was found to be lower than a logarithmic midpoint or the midpoints on a cochlear map or the Mel scale; that is, it was unlike metrics arrived at by direct comparisons of tones. Further, the midpoint for high and low tones presented synchronously was lower than that for the same tones presented sequentially, demonstrating that in addition to a proximity factor, some additional factor or factors must operate differently when the lower and upper fixed tones are, or are not, presented simultaneously.     

Contextual effects on word production: A lifespan study

The effect of sentence priming on picture naming was investigated across the lifespan, from age 3 to 87 years. Names that are normally acquired before 3 years of age were presented in auditory contexts that were semantically congruent, incongruent, or neutral in relation to each picture and its name. Sentential priming was present at all age levels. Facilitation (neutral vs. congruent) was significantly by 4 years of age and did not vary significantly with age. Interference (incongruent vs. neutral) was significant at all age levels, but changed nonmonotonically with age (largest in the youngest children, stable from young adulthood through age 70, with a small increase in the oldest participants). We conclude that picture naming is a useful tool for the investigation of sentential priming effects across the lifespan and that it can reveal potentially interesting developmental changes in the effects of sentential context on word retrieval.     

Brief Strategic Family Therapy: Twenty-Five Years of Interplay Among Theory, Research and Practice in Adolescent Behavior Problems and Drug Abuse

This article describes a systematic program of research that focuses on Brief Strategic Family Therapy (BSFT) and the adaptations that were developed based on BSFT principles. The culture-specific origins of BSFT are reviewed, as well as its broader applications to the field of family therapy. Research is reviewed demonstrating that BSFT is a promising family-based approach to treating Hispanic youth behavior problems and drug abuse. Treatment innovations are described that address the combination of intergenerational and cultural differences that occur among youths and their Hispanic parents. Programmatic work is described that challenges basic principles of family therapy by expanding BSFT to a One Person modality and a strategic engagement procedure. Both of these novel approaches are intended to add tools to therapists' repertoire in working with difficult-to-engage families. A preview discussion of results is presented from a randomized clinical trial that is an application of an ecosystemic prevention version of BSFT. The implications of the work of the Center for Family Studies are discussed in the context of the broader service system. Ultimately, this article articulates a way of thinking about adolescent problem behavior, its social interactional determinants, and a range of theoretically consistent family-centered strategies that attempt to change social ecological processes that impact adolescent developmental trajectories.