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The article discusses the role of learning in physiological regulation, specifically in the context of thermoregulation. The authors of the article argue that the discussion of learning in the previous review on thermoregulation was inadequate and misleading. They emphasize that learning plays a fundamental and major role in regulation, particularly in anticipatory learned regulatory responses that prevent or minimize adverse body temperature deviations. The authors also highlight that multiple mechanisms, including negative feedback, learned regulatory responses, and non-learned feedforward responses, contribute to achieving physiological regulation. They criticize the previous review for not adequately acknowledging the importance of learning and for misrepresenting a quote from their previous article. [Extracted from the article]

Background and aims: Conditioned Pain Modulation (CPM) is a measure of pain inhibition-facilitation in humans that may elucidate pain mechanisms and potentially serve as a diagnostic test. In laboratory settings, the difference between two pain measures [painful test stimulus (TS) without and with the conditioning stimulus (CS) application] reflects the CPM magnitude. Before the CPM test can be used as a diagnostic tool, its reliability on the same day (intra-session) and across multiple days (inter-session) needs to be known. Furthermore, it is important to determine the most reliable anatomical sites for both the TS and the CS. This study aimed to measure the intra-session and inter-session reliability of the CPM test paradigm in healthy subjects with the TS (pressure pain threshold-PPT) applied to three test sites: the face, hand, and dorsum of the foot, and the CS (cold pressor test-CPT) applied to the contralateral hand. Methods: Sixty healthy participants aged 18–65 were tested by the same examiner on 3 separate days, with an interval of 2–7 days. On each day, testing was comprised of two identical experimental sessions in which the PPT test was performed on each of the three dominant anatomical sites in randomized order followed by the CPM test (repeating the PPT with CPT on the non-dominant hand). CPM magnitude was calculated as the percent change in PPT. The Intraclass Correlation Coefficient (ICC), Coefficient of Variation (CV), and Bland-Altman analyses were used to assess reliability. Results: PPT relative reliability ranged from good to excellent at all three sites; the hand showed an intra-session ICC of 0.90 (0.84, 0.94) before CPT and ICC of 0.89 (0.83, 0.92) during CPT. The PPT absolute reliability was also high, showing a low bias and small variability when performed on all three sites; for example, CV of the hand intra-session was 8.0 before CPT and 8.1 during CPT. The relative reliability of the CPM test, although only fair, was most reliable when performed during the intra-session visits on the hand; ICC of 0.57 (0.37, 0.71) vs. 0.20 (0.03, 0.39) for the face, and 0.22 (0.01, 0.46) for the foot. The inter-session reliability was lower in all three anatomical sites, with the best reliability on the hand with an ICC of 0.40 (0.23, 0.55). The pattern of absolute reliability of CPM was similar to the relative reliability findings, with the reliability best on the hand, showing lower intra-session and inter-session variability (CV% = 43.5 and 51.5, vs. 70.1 and 73.1 for the face, and 75.9 and 78.9 for the foot). The CPM test was more reliable in women than in men, and in older vs. younger participants. Discussion: The CPM test was most reliable when the TS was applied to the dominant hand and CS performed on the contralateral hand. These data indicate that using the CS and TS in the same but contralateral dermatome in CPM testing may create the most reliable results. [ABSTRACT FROM AUTHOR]

Nitrous oxide (N2O) is a gaseous drug with abuse potential. Despite its common clinical use, little is known about whether N2O administration activates the HPA axis and/or the sympathetic adrenomedullary system. The goal of this study was to determine whether 60% N2O alters plasma concentrations of corticosterone (CORT), epinephrine (EPI), and norepinephrine (NE) in male Long-Evans rats. A gas-tight swivel assembly in the lid of a gas administration chamber allowed the remote collection of blood samples from an indwelling jugular vein catheter at four time-points: baseline and at 30, 60, and 120 min during a two-hour administration of 60% N2O. Relative to baseline, plasma CORT (n = 9) was significantly elevated at all three time-points during N2O inhalation (mixed model analysis, p = .001) and plasma EPI and NE levels were each significantly elevated (n = 8, p ≤ .001) at the 30 min assessment. EPI then declined and did not differ from baseline at the 60 and 120 min assessments (p > .05) whereas NE remained elevated (120 min, p = .001). Administration of 60% N2O increases circulating CORT, EPI, and NE, supporting N2O as a physiological stressor. An N2O-induced increase in CORT is consistent with the observation that addictive drugs typically activate the HPA axis causing increased plasma levels of glucocorticoids. Allostatic models of drug addiction typically involve stress systems and the possible role of stress hormones in N2O-induced allostatic dysregulation is discussed. [ABSTRACT FROM AUTHOR]

Background: Initial administration of ≥60% nitrous oxide (N2O) to rats evokes hypothermia, but after repeated administrations the gas instead evokes hyperthermia. This sign reversal is driven mainly by increased heat production. To determine whether rats will behaviorally oppose or assist the development of hyperthermia, we previously performed thermal gradient testing. Inhalation of N2O at ≥60% causes rats to select cooler ambient temperatures both during initial administrations and during subsequent administrations in which the hyperthermic state exists. Thus, an available behavioral response opposes (but does not completely prevent) the acquired hyperthermia that develops over repeated high-concentration N2O administrations. However, recreational and clinical uses of N2O span a wide range of concentrations. Therefore, we sought to determine the thermoregulatory adaptations to chronic N2O administration over a wide range of concentrations. Methods: This study had two phases. In the first phase we adapted rats to twelve 3-h N2O administrations at either 0%, 15%, 30%, 45%, 60% or 75% N2O (n = 12 per group); outcomes were core temperature (via telemetry) and heat production (via respirometry). In the second phase, we used a thermal gradient (range 8°C—38°C) to assess each adapted group’s thermal preference, core temperature and locomotion on a single occasion during N2O inhalation at the assigned concentration. Results: In phase 1, repeated N2O administrations led to dose related hyperthermic and hypermetabolic states during inhalation of ≥45% N2O compared to controls (≥ 30% N2O compared to baseline). In phase 2, rats in these groups selected cooler ambient temperatures during N2O inhalation but still developed some hyperthermia. However, a concentration-related increase of locomotion was evident in the gradient, and theoretical calculations and regression analyses both suggest that locomotion contributed to the residual hyperthermia. Conclusions: Acquired N2O hyperthermia in rats is remarkably robust, and occurs even despite the availability of ambient temperatures that might fully counter the hyperthermia. Increased locomotion in the gradient may contribute to hyperthermia. Our data are consistent with an allostatic dis-coordination of autonomic and behavioral thermoregulatory mechanisms during drug administration. Our results have implications for research on N2O abuse as well as research on the role of allostasis in drug addiction. [ABSTRACT FROM AUTHOR]

Considerable data suggest that individuals who appear minimally disrupted during an initial drug administration have elevated risk for abusing the drug later. A better understanding of this association could lead to more effective strategies for preventing and treating drug addiction. To investigate this phenomenon using a rigorous experimental model, we first administered the abused inhalant nitrous oxide (N2O) to rats in a total calorimetry and temperature system to identify groups that were sensitive or insensitive to the drug’s hypothermic effect. We then enrolled the two groups in a novel N2O self-administration paradigm. The initially insensitive rats self-administered significantly more N2O than sensitive rats, an important step in the transition to addiction. Continuous non-invasive measurement of core temperature and its underlying determinants during screening revealed that both groups had similarly increased heat loss during initial N2O administration, but that insensitive rats generated more heat and thereby remained relatively normothermic. Calorimetry testing conducted after self-administration revealed that whereas N2O’s effect on heat loss persisted comparably for both groups, initially insensitive rats actually over-responded by generating excess heat and becoming hyperthermic. Thus, rats with the greatest initial heat-producing compensatory response(s) appeared initially insensitive to N2O-induced hypothermia, subsequently self-administered more N2O, and developed hyperthermic overcompensation during N2O inhalation, consistent with increased abuse potential and an allostatic model of addictive vulnerability. [ABSTRACT FROM AUTHOR]

Objectives: The goal of this study was to investigate the association between tooth wear and salivary measures in a random sample of patients from practices of dentist members of a practice-based research network. Materials and methods: Patients completed a questionnaire on oral self-care, health, dietary habits, medications, and socio-demographic variables. Six salivary characteristics (consistency, resting salivary flow, resting salivary pH, stimulated salivary flow, stimulated salivary pH, and buffering capacity) were measured, and a dental examination included categorizing patients according to the dentist's judgment of the degree of tooth wear (i.e., none/minimal, some, or severe/extreme). Bivariate and multinomial logistic regression models were used to relate salivary characteristics and other factors to the outcome of tooth wear. Results: Data are reported from 1,323 patients (age range 16-97 years) from 61 practices. Patient age, gender, number of teeth, and perception of dry mouth were associated with tooth wear, but salivary and dietary factors were either weakly or not related. Conclusions: The findings of this cross-sectional assessment suggest that using these salivary tests and dietary assessments in real-life clinical settings is unlikely to be useful in assessing tooth wear risk. Suggestions are offered about risk assessment for tooth wear. Clinical relevance: Assessing a dental patient's risk of tooth wear using salivary measures and dietary assessments as described is not recommended for general dental practice until stronger evidence exists indicating its utility. [ABSTRACT FROM AUTHOR]

A technique to produce high-water alerts from coinciding high astronomical tide and high mean sea level anomaly is demonstrated for the Pacific Islands region. Low-lying coastal margins are vulnerable to episodic inundation that often coincides with times of higher-than-normal high tides. Prior knowledge of the dates of the highest tides can assist with efforts to minimize the impacts of increased exposure to inundation. It is shown that the climate-driven mean sea level anomaly is an important component of total sea level elevation in the Pacific Islands region, which should be accounted for in medium-term (1-7 months) sea level forecasts. An empirical technique is applied to develop a mean sea level-adjusted high-water alert calendar that accounts for both sea level components and provides a practical tool to assist with coastal inundation hazard planning and management. [ABSTRACT FROM AUTHOR]

Nitrous oxide (N2O) can initially lower core temperature ( T core), but hypothermic tolerance develops with chronic administration. Therefore, one or both of T core’s controlling determinants, heat production (HP) and heat loss (HL), must adapt across repeated N2O administrations. Simultaneous measurements of HP, HL, and T core during chronic N2O administrations will elucidate this adaptive process and constitute a rigorous model for studying the systems-level dynamics of tolerance in both mature and young animals. This approach is justified by the need to better understand the increased vulnerability to addiction associated with adolescent drug use. The objective of the study was to measure HL and HP across repeated steady-state administrations of 60% N2O in young and mature rats. Synchronous measurements of HP (indirect calorimetry), HL (direct calorimetry), and T core (telemetry) were obtained during 60% N2O administrations in adolescent (28–45 days, n = 11) and mature rats (>90 days, n = 8). Rats received five 90-min drug exposures (every other day). Compared to mature rats, adolescents initially exhibited greater hypothermia, but acquired tolerance more rapidly and actually developed hyperthermia during the fifth administration. In both groups, N2O consistently increased HL, but progressive increases of intrasessional HP over repeated administrations prevented hypothermia and subsequently promoted hyperthermia in adolescent rats. Adolescent rats hyper-adapt to N2O hypothermia. Increases of intrasessional HP across N2O administrations explained both tolerance to N2O hypothermia and the unexpected hyperthermia observed in adolescents. These findings raise the possibility that the increased vulnerability to addiction associated with adolescent drug use involves a hyper-adaptive tolerance mechanism. [ABSTRACT FROM AUTHOR]

Some argue that pharmacological effects trigger corrective regulatory responses of varying strength. If so, some commonly used in vivo measures of initial drug sensitivity are difficult to interpret because the measured effects represent a combination of underlying pharmacological effects and regulatory counter-responses with the relative contribution of each influenced by individual and dose-related factors. The objective of this study was determine if core temperature ( T core), a common measure in drug research, can mask the variability both in underlying pharmacological effects and physiological counter-responses during an initial administration of the hypothermia-promoting drug, nitrous oxide (N2O). T core was measured synchronously with its determinants, heat production (HP) and heat loss (HL) during steady-state N2O administration. Drug-naive rats received a 90-min exposure to 0, 15, 30, 50, 60, or 75% N2O plus a paired control gas exposure ( n ≥ 8 per group). HP was measured via indirect calorimetry, HL via direct calorimetry, and T core via telemetry. T core was unaltered by concentrations ≤50% N2O, but at 30 and 50% N2O, this stability masked significant increases of HL that were offset by increases of HP. On average, hypothermia accompanied 60 and 75% N2O inhalation owing to uncompensated increases of HL. However, some rats administered with these doses also exhibited T core stability via significant opposing changes of HL and HP. A common in vivo measure of initial drug sensitivity can fail to disclose underlying pharmacological sensitivity owing to regulatory counter-responses. This concept has implications for understanding relationships between phenotypic variation in initial drug sensitivity and subsequent drug-taking phenotypes. [ABSTRACT FROM AUTHOR]

This study examined the relation of anger and sadness to heart rate and cortisol in 4-month-old infants' (n = 56) response to a goal blockage. The blockage occurred during a contingency learning procedure where infants' response no longer produced a learned interesting event. Anger and sadness were the major emotional expressions to the blockage. The two emotional expressions were differentially related to heart rate and cortisol. Anger was related to increased heart rate, but not cortisol, whereas sadness was related to increased cortisol, but not heart rate. Along with other work, the present results support the view that infant anger in response to goal blockage involves autonomic as opposed to adrenocortical activation as a consequence of an expectation of control over the event. In contrast, sadness in response to goal blockage involves adrenocortical as opposed to autonomic activation stemming from the absence of an expectation of control. © 2006 Wiley Periodicals, Inc. Dev Psychobiol 48: 397–405, 2006. [ABSTRACT FROM AUTHOR]

Rationale: A preventive strategy for drug addiction would benefit from being able to identify vulnerable individuals. Understanding how an individual responds during an initial drug exposure may be useful for predicting how that individual will respond to repeated drug administrations. Objectives: This study investigated whether individual differences in initial drug sensitivity and acute tolerance can predict how chronic tolerance develops. Methods: During an initial 3-h administration of 60% nitrous oxide (N2O), male Long-Evans rats were screened for N2O's hypothermic effect into subsets based on being initially insensitive (II), sensitive with acute tolerance (AT), or sensitive with no intrasessional recovery (NR). Animals in each individual difference category were randomly assigned to receive six 90-min exposures of either 60% N2O or placebo gas. Core temperature was measured telemetrically. Results: Rats that exhibited a comparable degree of hypothermia during an initial N2O exposure, but differed in acute tolerance development, developed different patterns of chronic tolerance. Specifically, the NR group did not become fully tolerant over repeated N2O exposures while the AT group developed an initial hyperthermia followed by a return of core temperature to control levels indicative of full tolerance development. By the second N2O exposure, the II group breathing N2O became hyperthermic relative to the placebo control group and this hyperthermia persisted throughout the multiple N2O exposures. Conclusions: Individual differences in initial drug sensitivity and acute tolerance development predict different patterns of chronic tolerance. The hypothesis is suggested that individual differences in opponent-adaptive responses may mediate this relationship. [ABSTRACT FROM AUTHOR]

This study examined the relation of infant emotional responses of anger and sadness to cortisol response in 2 goal blockage situations. One goal blockage with 4-month-old infants (N = 56) involved a contingency learning procedure where infants' learned response was no longer effective in reinstating an event. The other goal blockage with 6-month-old infants (N = 84) involved the still face procedure where infants' reactions to their mothers' lack of responsivity were not effective in reestablishing interaction. For both blockages, sadness was related to cortisol response, though anger was not--the greater the sadness, the higher the cortisol response. This differential relation is consistent with other evidence indicating the more positive role of anger as opposed to sadness in overcoming an obstacle. [ABSTRACT FROM AUTHOR]

Studies using core temperature (Tc) have contributed greatly to theoretical explanations of drug tolerance and its relation- ship to key features of addiction, including dependence, withdrawal, and relapse. Many theoretical accounts of tolerance propose that a given drug-induced psychobiological disturbance elicits opponent responses that contribute to tolerance development. This proposal and its theoretical extensions (e.g., conditioning as a mechanism of chronic tolerance) have been inferred from dependent variables, such as Tc, which represent the summation of multiple underlying determinants. Direct measurements of determinants could increase the understanding of opponent processes in tolerance, dependence, and withdrawal. The proximal determinants of Tc are metabolic heat production (HP) and heat loss (HL). We developed a novel system for simultaneously quantifying HP (indirect calorimetry), HL (direct gradient layer calorimetry), and Tc (telemetry) during steady-state administrations of nitrous oxide (N2O), an inhalant with abuse potential that has been previously used to study acute and chronic tolerance development to its hypothermia-inducing property. Rats were administered 60% N2O (n = 18) or placebo gas (n = 16) for 5 h after a 2-h placebo baseline exposure. On average, N2O rapidly but transiently lowered HP and increased HL, each by ∼16% (P < 0,001). On average, rats reestablished and maintained thermal equilibrium (HP = HL) at a hypothermic Tc (-1.6°C). However, some rats entered positive heat balance (HP > HL) after becoming hypothermic such that acute tolerance developed, i.e., Tc rose despite continued drug administration. This work is the first to directly quantify the thermal determinants of Tc during administration of a drug of abuse and establishes a new paradigm for studying opponent processes involved in acute and chronic hypothermic tolerance development. [ABSTRACT FROM AUTHOR]

This study examined the relation of visual self-recognition to personal pronoun use and pretend play. For a longitudinal sample (N=66) at the ages when self-recognition was emerging (15, 18, and 21 months), self-recognition was related to personal pronoun use and pretend play such that children showing self-recognition used more personal pronouns and demonstrated more advanced pretend play than did children not showing self-recognition. The finding of a relation among these measures provides additional evidence that in the middle of the 2nd year of life a metarepresentation of self emerges in the human child. [ABSTRACT FROM AUTHOR]

This study examined relations between reactivity (i.e., peak response) and regulation (i.e., response dampening) in 6-month-old infants' cortisol and behavioral responses to inoculation (N = 62). Data showed that reactivity and regulation were unrelated for both cortisol and behavior. The independence of reactivity and regulation suggests that measures of both are needed to characterize infant cortisol or behavioral response to stress more completely. For both reactivity and regulation, cortisol and behavior were unrelated, suggesting that measures of both are needed to assess infant stress more adequately. There was considerable variation in the timing of the peak cortisol response, suggesting that obtaining only a single poststressor cortisol sample does not provide a sensitive measure of cortisol reactivity. [ABSTRACT FROM AUTHOR]

This study examined individual differences in 4-year-old children's (N = 60) expression of the self-conscious emotions of embarrassment and shame and their relation to differences in cortisol response to stress. Results indicated the presence of two different types of embarrassment--one that reflected negative evaluation of the self, and the other a nonevaluative type that reflected simply exposure of the self when the individual was the object of attention of others. Results also indicated a relation between a higher cortisol response to stress and the greater expression of the self-conscious emotions of evaluative embarrassment and shame that reflected negative self-evaluation. [ABSTRACT FROM AUTHOR]

Previous research has suggested that a relationship exists between craniofacial morphology and tooth wear. Theprimary objective of this study was to determine whether an individual's craniofacial morphology during childhood is relatedto the degree of tooth wear that occurs in that same individual's adult dentition. Pretreatment orthodontic records taken duringthe mixed dentition (T1) and follow-up records takenan average of 20years later (T2) were available for 165 orthodontic patients.Incisal/occlusal tooth wear was measured on a tooth-by-tooth basis from T1 and T2 casts using a four-category scoring system.Measures of craniofacial morphology were made from the T1 lateral cephalometric radiograph. Multiple regression analysisindicated that adult wear was associated with the T1 cephalometric measures of ANB (p = 0.017) and the interaction betweenramal height and sex (p = 0.039). These results suggest that the craniofacial morphology observed during childhood has a smallbut significant relationship to adult tooth wear. [ABSTRACT FROM AUTHOR]

Observation of cortisol and behavioral responses to routine inoculation was conducted at 18 months for infants in a longitudinal sample whose stress responses had been observed at 2, 4, and 6 months of age. At 18 months, infants showed an increase in cortisol level over base to the perturbation. The magnitude of this response did not differ from the 6-month response. Moreover, level of cortisol response at 18 months was related to level of cortisol response at 6 months, but not at 2 or 4 months of age. In light of previous findings for a decline in cortisol response between 2 and 6 months had for the emergence of consistent individual differences in cortisol response by 4 to 6 months, the present findings indicate that a developmental shift in adrenocortical functioning has occurred by 6 months of age. [ABSTRACT FROM AUTHOR]

Using the method of adjusted learning, subjects learned number-noun pairs while breathing either placebo or 30% nitrous oxide. Subjects breathing nitrous oxide required more acquisition trials to attain a learning criterion than did subjects breathing placebo. Two weeks later, half of the subjects from each group were administered either placebo or nitrous oxide and were asked to recall the noun that had accompanied each number cue. Results showed that: 1) nitrous oxide inhalation can decrease the accessibility of to-be-recalled material and 2) nitrous oxide administered during the acquisition of material can paradoxically improve the recall of that material 2 weeks later. The additional number of acquisition trials subjects received during nitrous oxide inhalation could potentially account for this paradoxical enhancement of delayed recall; however, correlational analyses suggest this was not the case. No evidence for any state-dependent effects of nitrous oxide on cued recall were found. [ABSTRACT FROM AUTHOR]

Examines infants' hand preference for removing toys from a box with a door. Bimanual strategies involving complete or incomplete differentiation of roles for the two hands; Strategies in opening the door and removing the toys; Handedness.

Assesses the quality of attachment relationships in adoptive and non-adoptive mother-infant using data from two separate samples with the Strange Situation paradigm. Absence of differences in mother-infant attachment between nonadopted and intraracial adopted subjects; Higher insecure attachment in interracial adoptive mother-infant pairs; Higher incidence of psychological problems among middle childhood adoptees.

3 studies examined the relation between the spontaneous occurrence in play of simple 2 part action sequences and the frequency of these sequences and their components following modeling at 12, 15, and 19 months of age. Play following modeling was typically more advanced than play preceding modeling. Moreover, imitation was tied to developmental level. Children at 19 months of age were generally able to imitate complete sequences, though only a few 19-month-olds performed such actions spontaneously. Children at 15 months of age typically did not imitate complete sequences except under simplified experimental conditions, and, even then, their ability to perform sequences was attenuated relative to the 19-month-olds. However, 15-month-olds did imitate many single components of the 2-part combinations and, to a lesser extent, exhibited these components spontaneously. A smaller number of 12-month-olds imitated components, which were rarely displayed spontaneously at this age. The results suggested that a general combinatorial capacity in play emerges between 15 and 19 months of age. [ABSTRACT FROM AUTHOR]

The purpose of this study was to validate a paradigm by which an infant's comprehension of concrete nouns could be assessed while controlling for (a) response bias, (b) stimulus preference, and (c) maternal cuing. More specifically, we sought to determine whether 11- and 13-month-old infants directed their eye fixations to the referent of an object word said by the mother and to determine whether there was a developmental shift in responding to object words at these 2 ages, as some previous research suggests. Duration of looking at each of 4 corners of an apparatus was measured while the mother (unable to see what the child was doing) uttered a word she felt the infant knew, 1 she felt he/she did not know, and a nonsense word. Analyses based on signal detection theory using "known" words as signal trials and nonsense words as noise revealed that 13-month-olds directed their looking time signifcantly longer at the referent of the known word when that word was uttered than when the nonsense word was uttered. At neither age did looking at the referent of the unknown word exceed control values. No significant effects were obtained at 11 months of age, nor were there any sex effects. [ABSTRACT FROM AUTHOR]

2 studies, 1 cross-sectional and 1 longitudinal, examined the relation between 2 developmental trends in play during the second year: the emergence of decentered acts, and the integration of separate acts into simple sequences. In both studies, infants were tested at 13, 19, and 24 months of age. Decentered acts directed toward inanimate as well as animate or lifelike objects had appeared for most children by 19 months. Sequences resulting from the repetition of a single theme generally emerged concurrently with the decentration measures. In contrast, sequences resulting from the coordination of 2 different acts did not emerge for most children until 24 months. It was suggested that the latter type of sequence may require an additional cognitive skill, specifically, the ability to mentally relate 2 different actions. [ABSTRACT FROM AUTHOR]

The effect of maternal soothing to infant inoculation as well as everyday distress on infant cortisol and behavioral responses to stress was examined in two longitudinal samples of 55 and 74 infants, respectively, between 2 and 6 months of age. There was no evidence that maternal soothing was effective in reducing infants' cortisol or behavioral responses to stress. The absence of this relation occurred despite evidence for cross-time stability and cross-situation consistency in maternal soothing. That maternal soothing plays little role in lowering infant responses to stress leaves open the possibilities that other maternal behaviors may mediate children's distress or that infant temperament may be related to infant stress. [ABSTRACT FROM AUTHOR]

Investigates whether early differences in reactivity to stress are related to self-recognition at 18 months of age. Information on adrenocortical and behavioral stress; What objective self-awareness involves; Role of maturational factors in the variation in the timing of self-recognition; Details on the relation between brain function and development.

Presents a longitudinal investigation of infants' cortisol and behavioral stress responses at two, four, and six months of age. Finding that cortisol level and cortisol response decreased with age; Indication of a developmental shift in adrenocortical functioning between two and six months of age.

Examines infant cortisol and behavioral responses to receiving inoculations during pediatric visits at two to six months of age in the United States. Pre- to post-stressor changes in cortisol levels; Effect of age and direction of cortisol response.

Studies the behavioral and cortisol responses of Japanese infants and Caucasian American infants during and following routine inoculation. Intense initial affective response showed by the Caucasian American group; Greater cortisol response showed by the Japanese group; Creation of a four-group taxonomy based on behavioral and cortisol responses.

SUMMARY After cockroaches were trained to traverse an illuminated runway with darkness as the rewarding event, they were given brief "primes" of darkness in the startbox. Runway performance was enhanced, but these priming effects declined as postprime delay (i.e., the delay before a roach was permitted to leave the startbox) was increased. A second experiment found that the response enhancement was greater after primes of long duration than after primes of short duration. The present work suggests a possible distinction between the priming properties of food and water on the other hand, and darkness, brain stimulation, and an imprinting object on the other. [ABSTRACT FROM AUTHOR]

We surveyed 350 University of Washington permanent employees chosen randomly from among both faculty and staff. The aim was to determine the extent and nature of dental anxiety in the university population potentially available for teaching clinics. In addition, the relationship of fears to self-reported dental health, utilization of dental care, and other general and mental health issues was examined. Dental anxiety was prevalent in this population; 13 percent of subjects reported high dental fear. In contrast to respondents with lower dental fear, subjects with clinically significant fear reported poorer perceived dental health, a longer interval since their last dental appointment, a higher frequency of past fear behaviors, more physical symptoms during last dental injection, and higher percentage of symptoms of anxiety and depression. Dental anxiety was not associated with poorer perceived general health or a longer interval since the last dental injection. University employees are a rich source of potential teaching patients for achieving curricular requirements for managing anxious patients. Student clinicians need guidance to be able to recognize fearful patients; they also need instruction about psychiatric conditions like anxiety and depression in order to be able to better manage and prevent dropouts in their patient roster. [ABSTRACT FROM AUTHOR]

Some shock-generator circuits may deliver large transient surges at onset and termination. The sources of these surges are derivable from electromagnetic analysis of the circuits employed. Virtual elimination of the surges may be accomplished by a simple rearrangement of the switching portion of the circuit. [ABSTRACT FROM AUTHOR]