Inhibition of the LH Surge by Restraint Stress in Cyclic Rats: Studies on the Role of GABAA and GABAB Receptors

There is evidence that stress can alter the activity in the brain of gamma-aminobutyricacid (GABA), a neurotransmitter that has been implicated in the regulation of LH secretion. In the present study the role of GABA in the restraint stress-induced inhibition of the LH surge was investigated in the intact cyclic rat. Intracerebroventricular (icv) administration of the GABAA receptor agonist muscimol (0.1, 0.5 or 1 μg) 5 min before the presumed onset of the pro-oestrous LH surge (at 0900 h) caused a dose dependent suppression of the surge. A single dose of the GABAB receptor agonist baclofen (1 μg; icv) injected at 0855 h postponed the onset of the LH surge, and repeated injections at 0855 and 1130 h suppressed the surge. These data indicate that GABA-ergic activity in the brain can inhibit the LH surge in the cyclic rat via GABAA and GABAB receptors. Pro-oestrous rats were subjected to 5 hrs of restraint starting at 0855 h. Pretreatment with the GABAA receptor antagonist bicuculine (1 μg; icv) at 0840, 0940 and 1040 h or pretreatment with the GABAB receptor antagonist phaclofen (10 μg; icv) at 0840 h were ineffective in preventing the restraint-induced inhibition of the LH surge. The results suggest that GABAA and GABAB receptors are not involved in the inhibitory effect of restraint stress on the LH surge.     

The role of proctoring in personalized instruction

The effect of amount of student-proctor interaction was investigated within the framework of Keller's (1968) method of personalized instruction. College students enrolled in introductory psychology were randomly assigned to five groups: 0%, 25%, 50%, 75%, and 100%, reflecting the percentage of units on which each student was proctored. The results indicated that (a) the proctored students were superior to the non-proctored students as measured by final examination performance, (b) for the proctored groups, the amount of proctoring did not differentially affect final examination performance, and (c) the major effect of increased proctoring was an acceleration of the rate of progress through the course.     

Empirical support for the gender‐as‐culture hypothesis.

This investigation provided a test of the gender‐as‐culture, or ‘two cultures’, hypothesis proposed by Maltz and Borker (1982) to explain male/female differences in language use. Analysis of previous empirical investigations located 16 language features that had consistently been shown to indicate communicator gender and these were tested within the framework of the four dimensions of intercultural style proposed by Gudykunst and Ting‐Toomey (1998): direct versus indirect, succinct versus elaborate, personal versus contextual and instrumental versus affective. Study 1 provided preliminary evidence supporting the hypothesized language‐feature‐by‐dimension relationships (e.g., male directives were rated more direct and female uncertainty verbs more indirect). In Study 2, respondents rated multiple exemplars of the 16 language features, as well as 16 contrasting foil sentences, on all four dimensions, finding that nearly all of the variables fell on the hypothesized intercultural dimensions. In Study 3, respondents rated four sets of naturally occurring target sentences and matching foil sentences, representing all language variables, on their appropriate intercultural dimensions in order to establish dimensional polarity. Results across the three studies supported the hypothesized language feature‐by‐stylistic dimension relationship for 15 of the 16 variables: The 6 male language features were rated as more direct, succinct, personal, and instrumental, whereas 9 of the 10 female features were perceived as more indirect, elaborate, and affective. The findings demonstrate that gender preferences for language use function in ways that are consistent with stylistic preferences that distinguish national cultures.     

Anticipatory Processing and Post‐Event Processing in Social Anxiety Disorder: An Update on the Literature

Two repetitive thinking processes that have been proposed in prominent maintenance models of social anxiety disorder (SAD) are anticipatory processing and post‐event processing. Research into these two processes has steadily increased over the last 20 years. This review highlights the main lines of existing research on anticipatory processing and post‐event processing, including studies on the nature of these processes, their association with social anxiety, the predictors, and consequences of these processes, as well as how these processes respond to treatments for SAD. The review also highlights some of the conceptual and methodological issues that have prevented the literature on anticipatory processing and post‐event processing from being more integrated and focused. Finally, the review draws together some new directions in terms of theory and research to further advance the field.     

An investigation of the alarm response in Bufo boreas and Rana cascadae tadpoles

Tadpoles of the western toad (Bufo boreas) and of the Cascades frog (Rana cascadae) show an alarm reaction to an extract containing chemical cues from damaged conspecifics. The mean time spent by individual B. boreas tadpoles in the half of the test tank to which the extract solution was added was significantly lower than expected by chance. Activity was also significantly greater in Bufo extract tests than in control tests. Tadpoles did not avoid an extract of another tadpole species (Hyla regilla). Rana cascadae tadpoles did not avoid areas containing Rana extract but did significantly increase their level of activity in response to the extract. These results suggest that the R. cascadae tadpole alarm reaction exists but differs from the B. boreas reaction.     

Kin recognition in Rana cascadae tadpoles: effects of rearing with nonsiblings and varying the strength of the stimulus cues

Experiments with two clutches of Rana cascadae tadpoles were undertaken to determine if (1) rearing tadpoles exclusively with nonkin affects sibling recognition behavior and (2) if tadpoles are capable of distinguishing between groups of varying sibling/nonsibling composition. Individual tadpoles reared from embryonic stages with 12 nonsiblings behaved as tadpoles reared with siblings by exhibiting a preference for siblings over nonsiblings in choice tests. This suggests that experience with siblings is not a necessary prerequisite for the development of sibling recognition in this species. Tadpoles reared with siblings preferred to associate with a group composed of 50% siblings and 50% nonsiblings over a group of 100% nonsiblings, but exhibited no preference for a group composed of 25% siblings and 75% nonsiblings versus one composed of nonsiblings only. Thus tadpoles are capable of discriminating between mixed groups of siblings and nonsiblings, but probably require some minimum proportion of siblings to do so.     

Vagueness as closeness

This paper presents and defends a definition of vagueness, compares it favourably with alternative definitions, and draws out some consequences of accepting this definition for the project of offering a substantive theory of vagueness. The definition is roughly this: a predicate ‘F’ is vague just in case for any objects a and b, if a and b are very close in respects relevant to the possession of F, then ‘Fa’ and ‘Fb’ are very close in respect of truth. The definition is extended to cover vagueness of many-place predicates, of properties and relations, and of objects. Some of the most important advantages of the definition are that it captures the intuitions which motivate the thought that vague predicates are tolerant, without leading to contradiction, and that it yields a clear understanding of the relationships between higher-order vagueness, sorites susceptibility, blurred boundaries, and borderline cases. The most notable consequence of the definition is that the correct theory of vagueness must countenance degrees of truth.