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This study demonstrates that overtraining in temporal discrimination modifies temporal stimulus control in a bisection task and produces habitual responding, as evidenced through insensitivity to food devaluation. Rats were trained or overtrained in a 2-versus 8-sec temporal discrimination task, with each duration associated with a lever (left or right) and food (grain or sucrose). Overtraining produced a leftward shift in the bisection point. Devaluation treatment induced a differential loss of responding depending on stimulus duration (short versus long) and the level of training (training versus overtraining). The relationships between timing behavior and habitual behavior are discussed.

Introduction: Hospital-acquired infections (HAIs) after stroke are associated with additional morbidity and mortality, but whether HAIs increase long-term cognitive decline in stroke patients is unknown. We hypothesized that older adults with incident stroke with HAI experience faster cognitive decline than those having stroke without HAI and those without stroke. Methods: We performed a longitudinal analysis in the population-based prospective Cardiovascular Health Study. Medicare-eligible participants aged ≥65 years with and without incident stroke had cognition assessed annually. HAIs were assessed by hospital discharge codes. Global cognitive function was assessed annually by the Modified Mini-Mental State Examination (3MSE) and executive function by the Digit Symbol Substitution Test (DSST). We used linear mixed models to estimate the mean decline and 95% confidence intervals (95% CI) for 3MSE and DSST scores by incident stroke and HAI status, adjusted for demographics and vascular risk factors. Results: Among 5,443 participants ≥65 years without previous history of stroke, 393 participants had stroke with HAI (SI), 766 had a stroke only (SO), and 4,284 had no stroke (NS) throughout a maximum 9-year follow-up. For 3MSE, compared with NS participants, SO participants had a similar adjusted mean decline (additional 0.08 points/year, 95% CI: −0.15, 0.31), while SI participants had a more rapid decline (additional 0.28 points/year, 95% CI: 0.16, 0.40). Adjusted mean decline was 0.20 points/year faster (95% CI: −0.05, 0.45) among SI than SO participants. For DSST, compared with NS participants, SO participants had a faster adjusted mean decline (additional 0.17 points/year [95% CI: 0.003, 0.33]), as did SI participants (additional 0.27 points/year [95% CI: 0.19, 0.35]). Conclusion: Stroke, when accompanied by HAI, leads to a faster long-term decline in cognitive ability than in those without stroke. The clinical and public health implications of the effect of infection on post-stroke cognitive decline warrant further attention. [ABSTRACT FROM AUTHOR]

The accuracy of time judgments depends upon many factors, including the sensory properties of the to-be-timed stimulus. In auditory Pavlovian fear conditioning, an initially neutral tone (conditioned stimulus, CS) predicts the arrival of an aversive event (unconditioned stimulus, US) at a fixed time interval. The temporal relation between the CS and US events is encoded, leading to the development of a temporal pattern of responding. Little attention has been paid to the potential impact of the characteristics of the CS tone on the development of this temporal pattern. Here we compared the acquisition of the temporal pattern of conditioned responses of rats to different CS tone frequencies. Rats were first conditioned to lever press for food. Then, while lever pressing for food, they were presented with 60-s tones  of two very different frequencies 1kHz or 11kHz, each paired with a foot-shock given 30s after tone onset. This fear conditioning led to the appearance of conditioned suppression of the lever pressing. On probe trials the tone duration was 60 s, and the reinforcer was omitted. With training, a pattern of suppression evolved during the probe trials, showing a maximum of suppression near the programmed time of the shock US, however the 11kHz CS tone yielded better temporal control than did the 1kHz tone. A second experiment investigated rats’ abilities to discriminate between two times of shock arrival (10s or 30s) predicted by the different tone frequencies (1kHz or 11kHz), In this experiment, rats showed poorer discriminative timing performance when the lower frequency (1kHz) was associated with the longer duration (30s). Our results suggest a strong impact of the CS sensory properties on the expression of temporal learning within the context of auditory fear conditioning in rats.

The effects of two training procedures -- (a) modeling and praise and (b) self-instruction, modeling, and praise -- on complex gross-motor chain acquisition for preschool dance class students were evaluated. Six girls participated in the study. A multiple baseline design across six gross-motor chains with a secondary group comparison for treatment order effects was used. Both procedures were effective in teaching the gross-motor chains. Nevertheless, for 4 of the 6 participants, the self-instruction procedure produced a faster acquisition rate in at least two of the three comparable pairs of gross-motor chains. Furthermore, very early in gross-motor chain acquisition, for five of the six gross-motor chains, the self-instruction condition was associated with faster response acquisition.

The purpose of this study was to compare transformational and instructional leadership theories, examine the unique impact that school leaders have on student achievement, and determine which specific leadership practices are associated with increased student achievement. The sample for this study consisted of 590 teachers in 37 elementary schools in the Intermountain West of the United States. Teachers rated their principals' leadership style according to the Multifactor Leadership Questionnaire (Transformational Leadership) and the Principal Instructional Management Rating Scale (Instructional leadership). Student achievement was measured by a criterion referenced test. Hypotheses were tested using regression analysis. Results indicated that instructional leadership explained more of the variance in student achievement than did transformational leadership. Principals' leadership style tended to have a meaningful impact on student achievement beyond the impact of school context and principal demographics. Specific leadership functions associated with student achievement were also identified and reported. Conclusion, implications and limitations are also discussed.

Three children diagnosed with pervasive developmental disabilities emitted a high rate of mands and a low-to-zero rate of appropriate play responses when the two responses were reinforced on concurrent Fixed Ratio 1 (FR1) schedules. When mands were reinforced on an FR10 schedule and play responses were concurrently reinforced on an FR1 schedule, play responses increased. Two participants' mands decreased from baseline levels but were maintained, and the third participant's mands increased. Implications of the use of choice procedures for clinical settings are discussed. (Contains 2 figures.)

Recent advances in electronic data collection have opened broad new possibilities for educational assessment. Potentially significant savings in time, money, and effort make Web-based and e-mail-based surveys more and more attractive as alternatives to mail surveys and face-to-face interviews. Yet, as with any major change, questions and obstacles arise. Software packages require financial commitment, as well as hardware and programming support. There are also questions regarding the validity of electronically collected data. This study has two principal purposes. The first is to examine the practical, logistical advantages and disadvantages of electronic versus paper administration techniques for a large-scale survey project. The second is to evaluate the relative agreement of data received using electronic versus paper collection processes. The results of this research suggest that after the initial investment and learning curve, significant savings in time and effort, substantially quicker turn-around time and potentially richer data resulted from the electronic process. The main downsides include the initial cost of the software and greater technical support needed to configure and operate the programs successfully.

Pigeons were exposed to a random relation between a conditioned stimulus (CS) and an unconditioned stimulus (US) under the signaled random procedure. All US presentations that were unpaired with the CS were preceded by a second cue, a cover stimulus. Consistent with prior studies, the signaled random procedure supported responding during the CS; however, magnitude of this cover-stimulus effect varied with the duration of the CS relative to the cover-stimulus duration. Higher levels of responding were maintained when the CS and cover stimulus were equal versus unequal in duration. Experiment 1 provides a systematic replication of a study by Williams (1994), who used rat subjects. Higher levels of CS-directed responding were maintained when the cover stimulus was equal in duration to the CS versus when it was shorter. Experiment 2 provides the first demonstration of the effects of cover-stimulus durations that are both longer and shorter than the CS duration, compared to a procedure in which the durations are equivalent. In support of a stimulus-duration-equality effect, level of responding was higher for all equal stimulus-duration groups in comparison to unequal stimulus-duration comparison groups. These effects were accommodated by a common-elements generalization approach to the Rescorla-Wagner model.

Abstract Social anxiety disorder is associated with impairment in social and occupational functioning, significant personal distress and a possible economic burden, resulting in a reduction in quality of life. To [...]

The effects of two training procedures--(a) modeling and praise and (b) self-instruction, modeling, and praise--on complex gross-motor chain acquisition for preschool dance class students were evaluated. Six girls participated in the study. A multiple baseline design across six gross-motor chains with a secondary group comparison for treatment order effects was used. Both procedures were effective in teaching the gross-motor chains. Nevertheless, for 4 of the 6 participants, the self-instruction procedure produced a faster acquisition rate in at least two of the three comparable pairs of gross-motor chains. Furthermore, very early in gross-motor chain acquisition, for five of the six gross-motor chains, the self-instruction condition was associated with faster response acquisition. DESCRIPTORS: acquisition, dance, gross-motor chains, modeling, self-instruction, training procedures

Previous studies suggest that the effect of color on object identification differs depending upon the type of object identification response required of participants. In the present study, presence versus absence of color (chromaticity) was manipulated under two object identification tasks--speeded naming (priming) and recognition. In a replication and extension of Biederman and Cooper (1992), college students were exposed to a list of 28, 2-dimensional representations of common objects, presented two times in succession (Blocks 1 and 2). Participants orally named each stimulus in Block 1 as it appeared. Under a speeded naming task (Experiments 1 and 2), participants named each stimulus again in Block 2, whereas they produced a recognition response in Experiment 3. For the recognition task, participants were instructed to respond 'same' if an object had the same shape as one presented previously, and 'different' if it did not. Shape and/or size (Experiment 1) or shape and/or chromaticity (Experiments 2 and 3) of the objects could change between their first and second exposures. Changes in shape increased the latencies of correct speeded naming responses in both Experiments 1 and 2, whereas changes in size and chromaticity did not. In contrast, changes in chromaticity resulted in a sharp increase in recognition latencies for 'same' responses in Experiment 3. The results indicate that object chromaticity was incidentally coded during the first exposure even though this stimulus dimension did not affect speeded naming. The results are consistent with a history of differential reinforcement of stimulus response relationships for different object-identification responses., One objective of the present study was to systematically replicate Biederman and Cooper's research. A second objective was to extend that investigation to the stimulus attribute of color by evaluating [...]

Results of an experiment with pigeons tend to support memory retrieval theories in which unreinforced trials serve as a retrieval cue for not responding. Eliminating autoshaped responding by random or negatively-contingent response-reductive methods may not eliminate a previously acquired association. In two experiments, the autoshaped responding of pigeons was gotten rid of by a backward or negative contingency.