Changes in spinal reflex excitability in a countermanded timed response task

Subjects (N = 8) performed a timed response task in which they attempted to synchronize an impulsive foot-press response with the last in a series of four regularly spaced tones. In Experiment 1, the response was countermanded on one third of the trials (stop trials) by a stop signal that appeared at a predetermined delay after the third tone. No stop signal appeared on the remaining trials (go trials). All subjects showed a systematic transition from withholding the response on stop trials in which the stop signal appeared shortly after the third tone to executing the response on trials in which a single stop signal delay had been chosen so that a response would be made on about 50% of the stop trials. We elicited Hoffmann (H) reflexes from the soleus muscle on all trials to determine whether the reflexes were augmented on occasions on which a response was prepared but withheld. Mean H-reflex amplitudes on go trials and on stop trials on which the response was executed were similar and showed a marked augmentation beginning about 250 ms before response onset; mean H-reflex amplitudes on stop trials on which the response was withheld showed less pronounced augmentation. Inspection of individual H-reflex amplitudes revealed that on stop trials on which the response was withheld the reflexes could be augmented to the same extent as on trials on which the response was executed. This dissociation of H-reflex augmentation and response execution shows that H-reflex augmentation reflects a controlled response process. Ballistic response processes therefore must be limited to a brief duration.     

Spectral and pattern response in the rabbit retina.

The advantages of presenting sensory data in terms of stimulus variables are stressed. Spectral sensitivity plots of local electroretinograms and ganglion cell discharges from the dark-adapted rabbit retina illustrate the utility of using this kind of procedure. Spectral data agreed with the literature demonstrating two cone and one rod process in this animal. The spectral sensitivities of both the local electroretinogram and ganglion cell spikes were closely similar. Data pertaining to pattern vision may also be subjected to the same type of analysis and described in terms of stimulus variables.     

Exchange delays and impulsive choice in adult humans.

Choice responding by adult humans in a discrete-trial task was examined as a function of conditions that manipulated either the delay to point delivery or the delay between points and their exchange for money. In point-delay conditions, subjects chose between an "impulsive" alternative that provided a small amount of points immediately and a "self-control" alternative that provided a larger amount of points delayed by 15, 30, or 60 s. Points were exchanged for money immediately following the session. Subjects preferred the self-control alternative. In exchange-delay conditions, subjects chose between a small amount of points exchangeable for money immediately following the session and a larger amount of points exchangeable for money after 1 day, 3 weeks, or 6 weeks. A self-control preference observed for all subjects in the 1-day exchange-delay condition reversed to exclusive impulsive preference for 4 of the 6 subjects when choice conditions involved exchange delays of 3 or 6 weeks. These results show that human choice is sensitive to the manipulation of exchange delays and that impulsive preference can be obtained with exchange delays on the order of weeks.     

Varying the temporal placement of a drinking opportunity in a fixed-interval schedule.

Three rats, lever pressing for food delivered on a fixed-interval 128-s schedule, were presented with a 16-s opportunity to drink from a retractable water source. The temporal placement of the water probe within the reinforcement cycle was varied sequentially, in steps of 16 s. Although the lever-pressing pattern was modulated by the intercalated water probe, water consumption during the probe itself was a decreasing function of time from the following reinforcer. These results were interpreted as evidence against the notion that schedule-induced drinking is a "ubiquitous" phenomenon and are congruent with results from other "intruded stimulus" experiments.     

FACTORS INFLUENCING EMPLOYEES' PROPENSITY TO USE AN EMPLOYEE ASSISTANCE PROGRAM

Using data collected from 1,987 employees at several locations of a large firm, this study investigates relationships between these employees' cognitive and attitudinal perceptions of an employee assistance program (EAP) and their propensity to use it. Familiarity with the program, perceived accessibility of it, and perceived managerial support for it are hypothesized to affect both employees' confidence in the program and their propensity to use it, and confidence in the EAP is further hypothesized to affect propensity to use. LISREL analysis supported the overall model, but the direct paths from the cognitive variables to propensity to use were not supported and confidence in the program was therefore indicated to be an essential mediating variable. Propensity to use an EAP is argued to be an important indicator of effective EAP implementation and suggestions are offered to management for promoting employee confidence in an EAP and ultimately their propensity to use it.     

Acceptance and commitment therapy: Altering the verbal support for experiential avoidance

Acceptance and Commitment Therapy (ACT) is a behavior-analytically-based psychotherapy approach that attempts to undermine emotional avoidance and increase the capacity for behavior change. An overview of this approach is given, followed by several specific examples of the techniques used within ACT. In each instance the behavioral rationale of these techniques is described. A contemporary view of verbal relations provides the basis for new approaches to adult outpatient psychotherapy.     

Thinking About “Tests and Assessment” and the Career Beliefs Inventory

The author (a) comments briefly on the “Tests and Assessment” section of the Journal of Counseling & Development (JCD)—what it has covered and has not covered in recent years—and (b) introduces a set of articles that discuss a new career-oriented inventory of potential interest to counselors.     

The Older Native American Indian With Disabilities: Implications for Providers of Health Care and Human Services

This article presents a review of the literature as regards the older Native American Indian, as well as a report of health care and human service needs based on a recent study of urban Native American Indians with disabilities in the Denver metropolitan area.     

Pioneers of Multicultural Counseling: A Conversation With Clemmont E. Vontress

This article presents an interview conducted with Dr. Clemmont E. Vontress, a pioneering scholar in the field of multicultural counseling. In this interview. Dr. Vontress reflects on his long and distinguished career and the evolution of multicultural counseling as professional discipline.     

Print adverts: Not remembered but memorable

Attempts to measure advertising effectiveness have relied on explicit memory measures based on recall or recognition. However, recent cognitive research has shown that not only is it possible to measure unconscious effects of prior experience through implicit tests of memory, but that such performance is independent of explicit recollection. The present study sought to determine whether it is possible to demonstrate the same pattern of findings using print advertising in an ecologically valid situation. Eighty subjects saw 25 full-page colour magazine adverts in either a deliberate or incidental study condition and subsequently rated (on four salient dimensions) a set of 50 adverts, which included the target adverts. Following the ratings subjects were asked to indicate which of the adverts they recognized as having been in the original set. While the deliberate study group recognized around 60 per cent of the adverts, the incidental study group recognized only 11 per cent. However, both groups showed the same positive bias in attitudes towards the adverts they had been exposed to compared to the ones they had not seen before. Thus, in line with by the cognitive literature, it is possible to show shifts in attitudes that are independent of conscious recollection. This data questions advertisers' reliance one explicit memory tests as measures of advertising effectiveness.