Reversal of Relative Thresholds for Synaptic Facilitation and Increased Excitability Induced by Serotonin and Tail Nerve Stimulation inAplysiaSensory Neurons

Tail shock induces reflex sensitization inAplysiaand, in parallel, induces a number of modulatory effects in central neurons, such as increased excitability in tail sensory neurons (SNs) and facilitation of synaptic transmission from SNs to motor neurons. Both of these modulatory effects are mimicked by exogenous application of serotonin (5HT) or electrical stimulation of the tail nerve P9. In the present study we examined the activation thresholds for increased excitability and synaptic facilitation induced by either 5HT or P9 stimulation. We found that the concentration of 5HT sufficient to produce a significant increase in excitability produced no significant synaptic facilitation and, conversely, that the intensity of nerve stimulation sufficient to produce significant synaptic facilitation produced no excitability changes. This reversal of relative thresholds for these modulatory effects may reflect the differential access of exogenous 5HT and endogenous 5HT (released by tail nerve stimulation) to the SN cell body and synaptic terminals, respectively.     

Isoluminance and contingent color aftereffects

In the typical induction of the orientation-contingent color aftereffect (CCAE), the stimuli are composed of elements that differ in both color and luminance. Three experiments are reported that show that chromatic contrast between stimulus elements is insufficient for the induction of the orientation-CCAE and that luminance contrast is necessary. These experiments expand on previous research concerned with the role of luminance contrast in the induction of orientation-CCAEs by eliminating alternative explanations.     

Causal Attributions for Poorly Performing Projects: Their Effect on Project Continuation Decisions

This study examined the escalation problem within an attribution theory framework. Students read a case scenario containing causal attribution information that described a poorly performing project under their supervision. They made estimates of its future success, as well as a decision whether to continue it. Perceived stability of causality had the primary effect on expectancy of success. A project whose performance downturn was attributed to a stable cause had a lower expectancy. Locus of causality had a smaller but still significant effect. Project downturns attributed to internal causes had a lower expectancy. Expectancy of success was significantly correlated with project continuation decisions. Discrepancies between these results and those reported by Staw and Ross (1978) are accounted for in terms of Weiner's (1985, 1986) attributional analysis.     

De Re Language,De Re Eliminability,and the Essential Limits of Both

De re modality is eliminable if there is an effective translation of all wffs into non-de re equivalents. We cannot have logical equivalence unless logic has odd theses, but we can have material equivalence by banning all essences, something the non-de re facts let us do, or by giving everything such humdrum essences as self-identity and banning the more interesting ones. Eliminability cannot be got from weaker assumptions, nor independent ones of even modest generality. The net philosophical import is that, quite apart from the merits of essentialism, de re language has scant utility.     

Politeness and memory for the wording of remarks

Three experiments were conducted to examine whether people spontaneously remember the wording used to convey politeness. In all experiments, subjects heard statements varying in politeness that had been made by either a high-status (e.g., a professor) or equal-status (e.g., another student) speaker. Subjects’ incidental memory for these statements was then tested with either a recognition (Experiments 1 and 3) or a recall (Experiment 2) procedure. As expected, there was evidence of significant memory for wording that conveyed politeness, and subjects were more likely to remember forms that were incongruous with the speaker’s status. There was also some evidence that subjects encoded the politeness of a remark even when they were unable to recall the specific remark. The results demonstrate the role of the interpersonal dimension in the processing of language in context.     

End-Weight from the Speaker's Perspective

Explanations of the tendency to put long, complex constituents at the ends of sentences (end-weight) usually take the listener's perspective, claiming it facilitates parsing. I argue for a speaker-oriented explanation of end-weight, based on how it facilitates utterance planning. Parsing is facilitated when as much tree structure as possible can be determined early in the string, but production is easiest when options for how to continue are kept open. That is, listeners should prefer early commitment and speakers should prefer late commitment. Corpus data show that different verbs exhibit different rates of word-order variation that are systematically related to differences in subcategorization possibilities in just the way predicted by a strategy of late commitment. Thus, a speaker-based account of lexical preferences in word ordering does a better job of explaining variation in weight effects than a listener-based account.     

Informal Caregiving to Persons with AIDS in the United States: Caregiver Burden Among Central Cities Residents Eighteen to Forty-Nine Years Old

Characteristics and caregiving experiences of friends and family members caring for people with AIDS (PWAs) were examined. Based on a probability sample of informal AIDS caregivers ages 18–49 living in central cities of the United States (n = 260), analyses were conducted to (a) identify the sociodemographic characteristics of young central city caregivers; and (b) examine the effects of caregiver characteristics (relationship to PWA, gender, race/ethnicity, income, sexual orientation, HIV status, perceived susceptibility), and level of objective caregiving demands, on subjective caregiver burden. Results indicate that the largest group of caregivers in this age category are male friends of the PWA—a group not typically found among caregivers to persons with other types of illnesses. In general, gay or bisexual caregivers, caregivers who have traditional family ties to the PWA, men relative to women, and lower income caregivers, report the greatest burden. While level of caregiving demands represents the most influential predictor of caregiver burden, white and male caregivers experience greater burden, independent of level of involvement and other caregiver characteristics. Receiving instrumental support with caregiving buffers the impact of high objective demands on subjective burden.     

Deconstructing Dispositional Bias in Clinical Inference: Two Interventions

In this study, the authors examined the effectiveness of instruction in attribution processes and practice in empathic perspective taking in deconstructing dispositional bias of counselor trainees. Videotaped stimulus cases and a clinical attribution scale were used to assess the treatment effects when compared with a placebo control condition. Results revealed significant differences among groups. Counselor trainees receiving either of the 2 interventions showed significantly lower dispositional bias in responding to videotaped clinical cases than did their counterparts in the placebo condition. The study points to a need for a paradigm shift from a person-focused to a system-focused approach in counseling practice. Implications also point to the need for including critical thinking and empathic experiencing in clinical training     

Evolutionary skepticism

International Journal for Philosophy of Religion -