d-cycloserine reverses the detrimental effects of stress on learning in females and enhances retention in males

Exposure to acute, inescapable stress produces a facilitation of subsequent classical eyeblink conditioning in male rats. The same stress exposure produces a profound deficit in classical eyeblink conditioning in females. Activation of N-methyl-d-aspartate receptors (NMDAr) is necessary for the effect of stress on learning in males while the contribution of NMDAr activation to the deficit in learning after stress is unknown. Here, we tested the influence of d-cycloserine (DCS), a positive modulator of the NMDAr, in stressed or unstressed male and female rats. Groups of males and females were exposed to an acute stressful event. One day later, they began training with four sessions of trace eyeblink conditioning. Each day before training, they were injected with DCS (15 mg/kg) or saline. Females treated with DCS during training responded similarly to those that were untreated. However, those that were stressed and the next day treated with the drug during training did not express the typical learning deficit, i.e. they learned to time the CR very well. Because the drug was administered well after the stressor, these data indicate that DCS reversed the negative effects of stress on learning in females. In males, the effect of DCS was subtle, resulting in higher asymptotic responding, and enhanced retention in a drug-free retention test. Thus, as shown previously, training in the presence of an NMDA receptor agonist enhances associative learning and memory retention. In addition, it can reverse learning deficits that have already been induced.     

Listeners’ perception of compensatory shortening

English exhibits compensatory shortening, whereby a stressed syllable followed by an unstressed syllable is measured to be shorter than the same stressed syllable alone. This anticipatory shortening is much greater than backward shortening, whereby an unstressed syllable is measured to shorten a following stressed syllable. We speculated that measured shortening reflects not true shortening, but coarticulatory hiding. Hence, we asked whether listeners are sensitive to parts of stressed syllables hidden by following or preceding unstressed syllables. In two experiments (Experiments 1A and 1B), we found the point of subjective equality—that is, the durational difference between a stressed syllable in isolation and one followed by an unstressed syllable—at which listeners cannot tell which is longer. In a third experiment (Experiment 2), we found the point of subjective equality for stressed monosyllables and disyllables with a weak-strong stress pattern. In all of the experiments, the points of subjective equality occurred when stressed syllables in disyllables were measured to be shorter than those in monosyllables, as if the listeners heard the coarticulatory onset or the continuation of a stressed syllable within unstressed syllables.     

Effect of chronic intermittent immobilization stress on Fos-like immunoreactivity in rat brain and adrenal medulla

The present study examined the influence of short- and long-term chronic intermittent immobilization stress throughout the brain and on the adrenal medulla of intact rats using Fos-like immunoreactivity (Fos-LI) as a marker of cellular activation. The effect of adreno-medullectomy on the central nervous system (CNS) response to chronic immobilization stress was also examined. It was found that control unoperated, unstressed rats had no Fos-LI cells in the brain or in the adrenal medulla. In intact rats, neither short term (1 week) nor long term (4 weeks) chronic intermittent immobilization stress produced significant increases in Fos-LI in the CNS compared with control animals. However, marked increase in the number of Fos-LI cells was observed in the adrenal medulla of animals stressed for 4 weeks compared with control, unstressed animals or those stressed for 1 or 2 weeks. In adreno-medullectomised rats, 4 weeks, but not 1 week, chronic immobilization stress produced significant increases in numbers of Fos-LI neurons in the paraventricular hypothalamic and supraoptic nuclei and the medial amygdala compared with intact animals stressed for a similar period of time. It is concluded that long term stress produces chronic Fos-LI in the adrenal medulla and that adreno-medullectomy increases the Fos response of the PVN, supraoptic nucleus and medial amygdala to long term stress.     

Induced motion and oculomotor capture

Three experiments investigating the basis of induced motion are reported. The proposition that induced motion is based on the visual capture of eye-position information and is therefore a subject-relative, rather than object-relative, motion was explored in the first experiment. Observers made saccades to an invisible auditory stimulus following fixation on a stationary stimulus in which motion was induced. In the remaining two experiments, the question of whether perceived induced motion produces a straight ahead shift was explored. The critical eye movement was directed to apparent straight ahead. Because these saccades partially compensated for the apparent displacement of the induction stimulus, and saccades to the auditory stimulus did not, we conclude that induced motion is not based on oculomotor visual capture. Rather, it is accompanied by a shift in the judged direction of straight ahead, an instance of the straight ahead shift. The results support an object-relative theory of induced motion.     

Chronic stress impairs recall of extinction of conditioned fear

Chronic restraint stress produces retraction of apical dendrites of pyramidal neurons in medial prefrontal cortex. To begin to examine the functional significance of this dendritic reorganization, we assessed the effects of chronic restraint stress on a prefrontally mediated behavior, extinction of conditioned fear. After bar press training to obtain a baseline of activity against which to measure freezing, rats were either unstressed or stressed via placement in a plastic restrainer (3 h/day for 1 week). After an additional day of bar press training, rats underwent fear conditioning and extinction. Rats received five habituation trials to a 30-s tone (4.5 kHz, 80 db) followed by seven pairings of tone and footshock (500 ms, 0.5 mA). One hour later, rats received tone-alone extinction trials to criterion. The next day, rats received 15 additional extinction trials. Percent freezing was assessed during all phases of training. Stress did not significantly affect unconditioned responding to tone, acquisition of conditioned fear, or initial extinction, but significantly increased freezing on extinction day 2. Thus, consistent with the regressive dendritic changes seen in medial prefrontal cortex, one week of restraint stress specifically impaired recall of extinction, a pattern of deficits typical of animals with impaired medial prefrontal function.     

Stressed and word-final syllables in infant-directed speech

Comparisons between infant-directed and adult-directed speech were conducted to determine whether word-final syllables are highlighted in infant-directed speech. Samples of adult-directed and infant-directed speech were collected from 8 mothers of 6-month-old and 8 mothers of 9- month-old infants. Mothers were asked to label seven objects both to an experimenter and to their infant. Duration, pitch, and amplitude were measured for whole words and for each of the target word syllables. As in prior research, the infant-directed targets were higher pitched and longer than adult-directed targets. The results also extend beyond previous results in showing that lengthening of final syllables in infant-directed speech is particularly exaggerated. Results of analyses comparing word-final versus nonfinal unstressed syllables in utterance-medial position in infant-directed speech showed that lengthening of unstressed word-final syllables occurs even in utterance-internal positions. These results could suggest a mechanism for proposals that word-final syllables are perceptually salient to young children.     

The effects of stress on the understanding of pronominal co-reference in children

Children aged 3, 4, and 5 years old were given sentences to act out in which the presence or absence of stress on a pronoun was critical to the reference of the pronoun. They were then divided up into three groups based on their proficiency in imitating sentences. Performance on unstressed pronouns was uniformly high in all three groups. Stressed pronouns were acted out like unstressed pronouns by the least advanced group, and improvement was radical from the lowest to highest groups. In the sentences used, unstressed pronouns could be interpreted by a natural cognitive strategy, in which the least change is required in the roles of the sentence actors. Early performance can be accounted for by use of this strategy. Interpretation of stressed pronouns required reversal of the role of one actor, which the less advanced children evidently found difficult. Results are discussed for their significance for theories of pronominal reference.This work was supported by the University of Minnesota Graduate School Grant #450-0350-4909-02.     

The duration component of the stress effect in stuttering

The purpose of the present study was to investigate whether there is a relationship between stuttering on stressed syllables and the duration of these syllables. Sixteen adults who stutter read a text consisting of 226 syllables. The relative stress of each syllable was rated, and syllables were categorized into long- and short-stressed syllables, unstressed syllables and intermediate syllables lying in-between. In order to isolate effects caused by within-word position from those caused by linguistic stress, syllables in initial and in subsequent positions were analyzed separately. In both word position categories stressed syllables were stuttered more often than unstressed syllables. Stuttering frequency of intermediate syllables seems to be in-between stressed and unstressed syllables, just as their stress level is rated in-between. Results regarding the duration of stressed syllables do not allow final conclusions.

Educational objectives: The reader will learn about and be able to describe (1) language factors related with stuttering events, (2) the stress effect in adults who stutter, and (3) methods to control for its confounding variables.     

汉语语句重音的分类和分布

通过两个独立进行的重音标注实验对汉语语句重音的分类和分布进行了初步探讨。实验l是由60位普通被试参加的音节重音突显度的知觉实验。实验2是由本文三位作者参加的重音类别标注实验,在此实验中语句重音被划分为节奏重音和语义重音。实验2中对于语句重音的分类性标注结果得到了实验l中普通被试对音节重音突显度知觉结果的支持,这说明人们确实能够感知到两种不同类型的重音。实验结果还表明,节奏重音倾向于出现在较大韵律单元内的最末韵律词的末音节上,并且与适当的停延相伴生,语义重音的分布则与语句的韵律结构的关系不大。     

On French listeners’ ability to use stress during spoken word processing

Previous studies have suggested that French listeners experience difficulties when they have to discriminate between words that differ in stress. A limitation is that these studies used stress patterns that do not respect the rules of stress placement in French. In this study, three stress patterns were tested on bisyllabic words (1) the legal stress pattern in French, namely words that were unstressed compared to words that bore primary stress on their last syllable (/?u?i/-/?u’?i/), (2) an illegal stress location pattern, namely words that bore primary stress on their first syllable compared to words that bore primary stress on their last syllable (/’?u?i/-/?u’?i/) and (3) an illegal pattern that involves an unstressed word, namely words that were unstressed compared to words that bore primary stress on their first syllable (/?u?i/-/’?u?i/). In an ABX task, participants heard three items produced by three different speakers and had to indicate whether X was identical to A or B. The stimuli A and B varied in stress (/?u’?i/-/?u?i/-/?u’?i/), in one phoneme (/?u’?i/-/?u’???/-/?u’?i/) or in both stress and one phoneme (/?u’?i/-/?u???/-/?u’?i/). The results showed that French listeners are fully able to discriminate between two words differing in stress provided that the stress pattern included an unstressed word. More importantly, they suggest that the French listeners’ difficulties mainly reside in locating stress within words.     

The cataphoric use of spoken stress in narratives

This study investigated the effects of introducing a concept into discourse either marked with spoken stress or in an unstressed form using a story continuation paradigm. Participants first listened to informal narratives and then continued them. The final phrase of the narratives introduced a new concept. If that concept had been introduced in a stressed form, participants referred to it more often and sooner. Also, there was a tendency towards using a higher proportion of pronominal references as opposed to NP references. These results closely resemble the findings of Gernsbacher and Shroyer, who, using the same experimental procedure, investigated the effect of marking a concept with the unstressed, indefinite article this as opposed to a/an. The two studies together support the notion of a common cataphoric function of the two linguistic devices; they mark concepts the speaker is likely to refer to again. Received: 10 August 1998 / Accepted: 9 December 1998     

Creating an Intersubjective Reality: Commentary on Paper by Arnold Rothstein

The author discusses Arnold Rothstein's paper “Compromise Formation Theory: An Intersubjective Dimension” and challenges his definition of intersubjectivity. She offers a perspective in which the import of intersubjectivity theory is less to dissolve the notion of objectivity than to grasp processes of mutual engagement, regulation, and recognition. While it is true that the recognition that the analyst is also a subject and therefore does not have exclusive knowledge is an important shift in the psychoanalytic paradigm, the author suggests that the intersubjective is far more encompassing than this. Intersubjective theory emphasizes the active creation of consensus or conflict about reality rather than merely the recognition that the analyst's perspective on reality is subjective. This cocreation produces a different emotional experience of connection, not merely a change in the quality of insight. Finally, Rothstein's case illustrates how he responds to the need for recognition and regulation. He shows us how focusing on the procedural allowed him to make an intersubjective shift, not simply an intrapsychic interpretation of compromise formation.     

Effects of sentential stress and word class upon comprehension in Broca's aphasics

The roles which word class (open/closed) and sentential stress play in the sentence comprehension processes of both agrammatic (Broca's) aphasics and normal listeners were examined with a word monitoring task. Overall, normal listeners responded more quickly to stressed than to unstressed items, but showed no effect of word class. Aphasics also responded more quickly to stressed than to unstressed materials, but, unlike the normals, responded faster to open than to closed class words regardless of their stress. The results are interpreted as support for the theory that Broca's aphasics lack the functional underlying open/closed class word distinction used in word recognition by normal listeners.     

A progressive model for teaching children with autism to follow gaze shift

Gunby, Rapp, Bottoni, Marchese and Wu (2017) taught three children with autism spectrum disorder to follow an instructor's gaze shift to select a specific item; however, Gunby et al. used different types of prompts with each participant. To address this limitation, we used a progressive training model for increasing gaze shift for three children with autism spectrum disorder. Results show that each participant learned to follow an adult's shift in gaze to make a correct selection. In addition, two participants displayed the skill in response to a parent's gaze shift and with only social consequences; however, the third participant required verbal instruction and tangible reinforcement to demonstrate the skill outside of training sessions.     

The use of rhythm in attending to speech

Three experiments examined attentional allocation during speech processing to determine whether listeners capitalize on the rhythmic nature of speech and attend more closely to stressed than to unstressed syllables. Ss performed a phoneme monitoring task in which the target phoneme occurred on a syllable that was either predicted to be stressed or unstressed by the context preceding the target word. Stimuli were digitally edited to eliminate the local acoustic correlates of stress. A sentential context and a context composed of word lists, in which all the words had the same stress pattern, were used. In both cases, the results suggest that attention may be preferentially allocated to stressed syllables during speech processing. However, a normal sentence context may not provide strong predictive cues to lexical stress, limiting the use of the attentional focus.     

Reaction time to temporally-displaced phoneme targets in continuous speech.

In seven experiments, reaction time (RT) was recorded to phoneme targets in sentences. By means of tape splicing or other experimental interventions preceding the target, speech information was or was not discarded, and targets were either temporally displaced "early" or "late" or remained on time." RT to displaced targets was slower than to on-time targets, except when the tape-splicing manipulation in effect presented coarticulatory target information in advance, in which case RT was faster than RT to on-time targets. The latter manipulation also produced faster RT than RT to the same targets in the original sentence, that is, that containing no experimental intervention at all. In three of the experiments, half the targets were contained in stressed syllables, half in unstressed syllables. Stressed and unstressed targets were affected differently, depending upon practice and other factors. Results were interpreted in terms of listener expectancies based on timing redundancy in continuous speech. They indicate an interaction between the effects of segmental and suprasegmental cues during ongoing perception.     

Cognitive activity shifts the attractors of bimanual rhythmic coordination

The attractors of bimanual rhythmic coordination are given as the solutions of a motion equation in relative phase. How are those attractors affected by cognitive activity? In 3 experiments, participants (N = 10 in Experiments 1 and 2; N = 5 in Experiment 3) were required to produce in-phase or antiphase coordination while they either did or did not perform an information-reduction task. The average absolute deviation from in-phase (0 degrees ) and antiphase (180 degrees ) satisfying a particular parameterization of the motion equation was amplified by cognitive activity. That amplification of absolute phase shift was the same for both in-phase and antiphase coordination. Furthermore, the amplification (in degrees) increased linearly with the magnitude of cognitive activity (in bits). Cognitive activity had limited influence on the variability of relative phase and did not affect its average signed deviation. Collectively, the results suggest that cognitive activity produces a shift in the attractors of bimanual coordination dynamics that is directionally nonspecific and is independent of movement speed, detuning, and the in-phase-antiphase distinction.     

Perception of a phonetic contrast in multisyllabic utterances by 2-month-old infants

In the present study, three aspects of the 2-month-old’s perception of multisyllabic utterances were explored. First, do infants perceive phonetic contrasts occurring either in the initial (Bada-Gada) or medial (Daba-Daga) positions of multisyllabic utterances? Second, are infants more likely to perceive these contrasts in stressed as opposed to unstressed syllables? Third, will infants detect a difference between two stress patterns? Our results indicate the following: (1) Two-month-olds are sensitive to place-of-articulation differences occurring in either the initial or medial positions of multisyllabic stimuli. (2) Whether the contrast occurred between stressed or unstressed syllables had little or no effect on the infant’s ability to detect it. (3) Infants as young as 2-months old respond to differences between stress patterns.     

Internal stress effect on grain-boundary diffusion in submicrocrystalline metals

Grain-boundary diffusion in the regime affected by internal stresses of triple-line disclinations is analysed. The concentration profiles in a stressed solid averaged over a distribution of hydrostatic stress gradients are calculated. It is shown that the stresses from triple-line disclinations in as-prepared submicrocrystalline metals can significantly increase the effective grain-boundary diffusion coefficient, which is obtained by fitting the concentration profiles to the solution of a diffusion equation for an unstressed polycrystal.     

The Donor's Dilemma: Recipient's Reactions to Aid from Friend or Foe1

Subjects participating as decision-makers in the Tactical and Negotiations Game experimental simulation encountered a programed emergency and then received an offer of aid from either an ally or an enemy donor. Findings indicate that recipients of aid from an ally donor perceived the donor to be more positively motivated and perceived the aid to reflect greater effort and to be of greater value than recipients of an equal amount of aid from an enemy donor. In addition, aid from an ally precipitated a positive shift in recipient perceptions of the donor and a negative shift in recipient perceptions of the enemy nondonor, while aid from an enemy had essentially no effects. The applied implications of these findings are discussed.