Need probability affects retention: A direct demonstration

Recent memory theory has emphasized the concept ofneed probability—that is, the probability that a given piece of learned information will be tested at some point in the future. It has been proposed that, in real-world situations, need probability declines over time and that the memory-loss rate is calibrated to match the progressive reduction in need probability (J. R. Anderson & Schooler, 1991). The present experiments were designed to examine the influence of the slope of the need-probability curve on the slope of the retention curve. On each of several trials, subjects memorized a list of digits, then retained the digits in memory for 1, 2, 4, 8, or 16 sec. Some trials ended with a recall test; other trials ended with the message, “no test.” In Experiment 1, the likelihood of encountering a memory test (i.e., the need probability) was made to either increase or decrease as the retention interval increased; in Experiment 2, need probability either was flat (invariant across retention intervals) or decreased as the retention interval increased. The results indicated that the shape of the need-probability curve influenced the slope of the retention curve (Experiment 1) and that the effect became larger as the experimental session progressed (Experiment 2). The findings support the notion that memory adapts to need probabilities and that the rate of forgetting is influenced by the slope of the need-probability curve. In addition, all of the forgetting curves approximated a power function, suggesting that need probability influences the slope but not the form of forgetting.     

Hippocampal synaptic plasticity during instrumental learning

present research examined the role of hippocampal NMDA-dependent synaptic potentiation on appetitive instrumental conditioning under a continuous reinforcement schedule. In the first experiment, low (.025 mg.kg) or moderate (.05 mg/kg) dosages of the NMDA receptor antagonist, MK801, failed to increase the number of training days required to reach acquisition criterion; number of training days required to reach criterion for extinction were also unaffected. In the second experiment, a higher dosage (.10 mg/kg) of MK801 or induction of long-term potentiation failed to alter the number of responses occurring during acquisition. These data suggest that hippocampal synaptic potentiation does not play a prominent role in instrumental learning with simple contingency conditions. It is suggested that hippocampal LTP reflects a perceptual process that contributes differentially to spatial cognition, classical and instrumental conditioning.     

Evaluating the decay gradient for collinearity bias with lateral displacement from the axis of induction

The misperception of alignment which is found in many geometric illusions can be quantified using relatively simple stimulus configurations. Perceived collinearity of one segment (designated as the test segment) is biased by a second segment (designated as the induction segment), with the size of effect being a function of the relative angle between the two segments. The process can be described as angular induction. The strength of bias is greatest when the induction segment is centered at the tip of the test segment. Tong and Weintraub have reported that lateral displacement from the tip, i.e., at right angles to the axis of the induction segment, produces a sharp drop in the strength of effect. This decline is described as a decay gradient for the angular induction. One experiment replicates and provides better quantification of this decay gradient. Two other experiments examine the decay gradient using a pair of induction segments, one on each side of the tip of the test segment. Displacement of the segments (either in the same direction or in opposite directions) produces substantially the same gradient of effect. Therefore, previous evidence of tandem boosting of effect for segment pairs does not depend on collinearity among the stimulus components. Finally, a fourth experiment finds that an induction segment which is at a fixed position and orientation differentially affects the influence of a variable induction segment. At some angles the influence of the variable segment is augmented, and at others it is suppressed. These findings are discussed in a neuroreductionist context, and a simple model for angular induction is presented.     

The Role of Emotion in the Construction of Career in Parent—Adolescent Conversations

The role of emotion in the construction of career has not always been clear despite its importance in people's lives and in counseling. Recent conceptualizations suggest that emotion is a complex relational process that is socially constructed. This study illustrates the role of emotion in the construction of career from an action theory perspective. Two parent—adolescent conversations about career from a group of 14 conversations are analysed in detail to demonstrate the ways in which emotions serve to energise action and career and lend context and meaning to the process of constructing career in the family setting.     

Hippocampal synaptic plasticity during instrumental learning

present research examined the role of hippocampal NMDA-dependent synaptic potentiation on appetitive instrumental conditioning under a continuous reinforcement schedule. In the first experiment, low (.025 mg.kg) or moderate (.05 mg/kg) dosages of the NMDA receptor antagonist, MK801, failed to increase the number of training days required to reach acquisition criterion; number of training days required to reach criterion for extinction were also unaffected. In the second experiment, a higher dosage (.10 mg/kg) of MK801 or induction of long-term potentiation failed to alter the number of responses occurring during acquisition. These data suggest that hippocampal synaptic potentiation does not play a prominent role in instrumental learning with simple contingency conditions. It is suggested that hippocampal LTP reflects a perceptual process that contributes differentially to spatial cognition, classical and instrumental conditioning.     

Themes in Therapist Development During the First Three Months of Clinical Experience

The results of a qualitative research study designed to better understand the developmental processes active in beginning therapists during the first three months of clinical contact is reported. Thirteen beginning therapists were asked to complete a monthly log describing experiences impacting their clinical work and themselves as therapists during their first three months of client contact. Data analysis revealed that the primary developmental theme active during this period of time is the development of therapist confidence. Two additional themes, the development of an internal gauge on which to evaluate current experiences and the development of boundaries around the self as a professional, were also found to be active during this time. These additional themes support the development of therapist confidence. Implications for training and research are identified.     

EXAMINING THE THEORY AND CLINICAL UTILITY OF WRITING ABOUT EMOTIONAL EXPERIENCES

Abstract— Pennebaker's (this issue) intervention for writing about emotional experiences shows promise as a module for inclusion in therapeutic packages. There are conceptual, methodological ant practical issues to be considered, however. These issues are discussed, and parallels are drawn from the literatures on the moodregulatory function of dreams and on the effects of social support on health. Although there is evidence that anything about emotional experiences has beneficial effects on health, it is premature to recommend writing intervention as a treatment component for specific problems. What is needed at this point is systematic research to evaluate to clinical utility.     

New Roles for Rhetoric: From Academic Critique to Civic Affirmation

The classical conception of rhetoric as the method of reasoned political judgment survived into the Renaissance but was reduced to academic critiques of style and "empty" public rhetoric with the rise of modern science and its representationalist theories of language. Recently, however, rhetoric, textuality, and the "linguistic turn" generally, have become central metaphors in the human sciences. This renewed rhetorical perspective not only fosters a critique of positive philosophy and of scientism in public discourse, it also offers affirmative methods by which persons can construct their civic lives.