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.     

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.     

Functions of the environment in behavioral evolution

This paper explores some of the ways in which the environment functions with respect to behavior within an explanatory framework analogous to that of evolutionary biology. In both the behavioral and organic domains, the environment functions differently with respect to individual occurrences and evolutionary units. Within the behavioral domain, the problem of accounting for an occurrence of an operant instance differs from that of accounting for the existence of the operant unit of which the instance is a part. Maintaining these distinctions in levels of analysis within the behavioral domain, we focus first on operant units and operant instances as products of evolutionary processes occurring in the behavioral domain and second upon the causal role of the environment with respect to the existence of operant units and the occurrence of operant instances. The environment's function is selective with respect to origin, maintenance, suppression, and extinction of behavioral populations. At the level of operant instances, the environment has instantiating functions-evocative or alterative. Evocative functions are exemplified by discriminative relations, and alterative functions include both conditional and motivative relations. Implications are considered regarding extension of the analogy to more complex behavior-environment relations.     

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.     

Hiding valuables: A questionnaire study of mnemonically risky behavior

A survey investigated incidences where individuals intentionally hid objects but later forgot the item's location. Surveys from 111 younger and 99 older adults yielded the following prototypical scenario: the person hid the valuable 1 year ago to prevent theft, and waited 1 month before an initial 30-minute search, which included looking in dresser drawers plus 1.5 other locations. The person made three additional searches (total searches = 4) for the missing valuable over a 2 week period. Three-quarters of the hidden valuables were eventually found (usually by accident) about 1 month after hiding the object. About half of the time, the person had already searched the hiding area. Older adults typically hid jewellery from thieves, while younger adults hid money from friends and relatives. Older adults searched more often for longer periods of time for the hidden object, and took longer to eventually find the object, compared with younger adults.     

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.     

CONSTRUCT ACCESSIBILITY AND THE MISATTRIBUTION OF AROUSAL:

Abstract— Schachter and Singer (1962) showed that people search the immediate environment for emotionally relevant cues to label and interpret unexplained physiological arousal We investigated how unobtrusively activated cognitions and physiological arousal interact to produce emotional experience when the immediate environment is devoid of relevant cues Subjects were primed with positive, negative, or neutral concepts They then either exercised or sat still and, either immediately or after a delay, rated their emotional state Consistent with what Schachter and Singer found, subjects in the exercise, delayed-rating condition, who lacked an obvious explanation for their arousal, made the most extreme affective self-ratings, which were consistent with the valence of the primed concepts These subjects apparently interpreted their residual arousal in terms of the primed concepts Subjects in the exercise, immediate-rating condition, who had an explanation for their arousal (i e, the exercise), were not influenced by the primes Subjects in the no-exercise condition showed typical priming effects, with prime-consistent self-ratings that decayed over time Implications for emotion formation, misattnbution of arousal, and cognition are discussed