Some observations on control by spoken words in children's conditional discrimination and matching by exclusion

This study examined matching-to-sample procedures that might result in the emergence of conditional behavior never explicitly taught. Subjects were preschool children. Two pictures were displayed as comparisons on every trial, and samples were spoken words. In baseline training preceding each of three experiments, children learned to select pictures of a dog, a table, and a banana in response to their spoken English names. Thereafter, probe trials displayed novel comparisons with baseline comparisons: one novel comparison was displayed with the dog and another with the table. The three experiments differed primarily in the nature of the samples presented on probe trials. In Experiment 1, probe samples were novel words, "JAIJAI" and "BREEL." On the probes, each of seven subjects reliably selected the novel comparisons, apparently "excluding" the familiar ones. In Experiment 2, probe samples were from the subjects' baseline. On one probe, for example, the sample was "TABLE," and the subject had to choose either the dog or the novel picture. Exclusion was logically possible because the dog had always before been incorrect in the presence of "TABLE." Under these conditions, however, only two of nine children excluded reliably. In Experiment 3, probe samples were words that had never been samples on any matching-to-sample trial, but that had controlled the children's behavior in other settings. On one probe, for example, the sample was "PENCIL," and the subject had to choose either the dog or a novel picture. Subjects virtually always excluded the former and selected the latter. Unreliable exclusion in Experiment 2, therefore, apparently resulted because the probe samples had previously served also as samples on baseline trials. Spontaneous verbalizations recorded during probing provided further data consistent with this interpretation. The study helps to define variables controlling exclusion performances by showing that such performances are more likely to occur if the sample has no prior experimental history.     

Stimulus class membership established via stimulus-reinforcer relations

In an arbitrary matching-to-sample procedure, two mentally retarded subjects learned conditional discriminations with two sets of stimuli. Each set included a spoken name (N1 or N2), an object (O1 or O2), and a printed symbol (S1 or S2). One subject selected conditionally (a) O1 upon N1, and O2 upon N2, and (b) S1 upon O1, and S2 upon O2. The other subject selected conditionally (a) S1 upon N1, and S2 upon N2, and (b) O1 upon S1, and O2 upon S2. For both subjects, selections of O1 and S1 produced one type of food, F1; selections of O2 and S2 produced a different type of food, F2. Both subjects also learned identity-matching performances, selecting O1, O2, S1, S2, F1, and F2 conditionally upon those stimuli as samples; F1 followed selections of O1, S1, and F1; F2 followed selections of O2, S2, and F2. Matching performances consistent with stimulus class formation involving the names, objects, symbols, and foods were demonstrated on probe trials, even though these performances had not been taught explicitly. Next, new objects, X1 and X2, were presented on identity-matching trials, producing F1 and F2, respectively. Without further training, X1 was selected conditionally upon N1, S1, and O1, and X2 was selected upon N2, S2, and O2. When the contingencies were changed so that selections of X1 and X2 were now followed by F2 and F1, respectively, X2 was selected conditionally upon N1, S1, and O1, and X1 was selected upon N2, S2, and O2. Class membership of X1 and X2 had apparently changed. This study provides evidence that reinforcers may become members of stimulus classes, and that new stimuli may become class members through relations with reinforcers.     

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.     

Effects of Acute Stress or Centrally Injected Interleukin-1beta on Neuropeptide Expression in the Immune System

Acute stress stimulates the expression and release of corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP) from the hypothalamus, and the pro-opiomelanocortin products beta-endorphin and ACTH from the anterior pituitary. These neuropeptides are also expressed in immune tissues, and it has been proposed that they may modulate immune responses to stress through paracrine mechanisms. We subjected rats to restraint stress or central injection of interleukin (IL)-1beta to determine whether these acute stimuli can alter the expression of neuropeptides in the spleen and thymus. Restraint stress significantly increased the contents of all these neuropeptides in thymic, but not splenic, extracts. A single icv injection of IL-1beta increased contents of CRH, AVP, ACTH and beta-endorphin in the spleens of both sham-operated and adrenalectomised (ADX) rats. IL-1beta increased thymic contents of CRH and ACTH in sham-operated rats but these increases were not observed in ADX rats. These results suggest that the effects of IL-1beta on neuropeptide expression in the spleen are independent of glucocorticoids, whereas IL-1beta stimulation of neuropeptide expression in the thymus is dependent on circulating glucocorticoids. There were significant correlations between increases in CRH, ACTH and beta-endorphin in the spleen, and between CRH and ACTH in the thymus, consistent with the suggestion that IL-1beta-induced increases in ACTH and beta-endorphin may be mediated through CRH. These results provide evidence that stressors can directly influence neuropeptide expression in immune tissues. Thus stress may influence immune functions through paracrine mechanisms involving locally synthesised neuropeptides as well as through activation of the hypothalamo-pituitary-adrenal axis.     

A NOTE ON TRANSFER OF STIMULUS CONTROL IN THE DELAYED-CUE PROCEDURE: FACILITATION BY AN OVERT DIFFERENTIAL RESPONSE

This case study describes initially unsuccessful attempts to use the delayed-cue procedure to teach conditional discriminations to an individual with moderate mental retardation. The task was matching printed-word comparison stimuli to dictated-name sample stimuli. In three experiments, the subject typically waited for the delayed cue unless differential responses to the dictated samples (repeating the sample names) were required. Hence, the study provides an example of a way to make the delayed-cue method more effective. The stimulus control bases for the results are discussed.     

The Role of Probability and Intentionality in Preschoolers' Causal Generalizations

Three experiments examined whether preschoolers recognize that the causal properties of objects generalize to new members of the same set given either deterministic or probabilistic data. Experiment 1 found that 3- and 4-year-olds were able to make such a generalization given deterministic data but were at chance when they observed probabilistic information. Five-year-olds reliably generalized in both situations. Experiment 2 found that 4-year-olds could make some probabilistic inferences, particularly when comparing sets that had no efficacy with sets in which some members had efficacy. Children had some difficulty discriminating between completely effective sets and stochastic ones. Experiment 3 examined whether 3- and 4-year-olds could reason about probabilistic data when provided with information about the experimenter's beliefs about causal outcomes. Children who were more successful on standard false-belief measures were more likely to respond as if the data were deterministic. These data suggest that children's probabilistic inferences develop into early elementary school, but preschoolers might have some understanding of probability when reasoning about causal generalization.     

大学二年级学生人际宽恕与报复心理及其与抑郁的关系研究

采用沉思量表、报复动机量表、宽恕倾向量表、宽恕态度量表和流调中心用抑郁量表对236名大二学生进行问卷调查,综合探讨大学生人际宽恕和报复心理及其与抑郁的关系。研究发现:(1)男大学生的报复倾向显著高于女大学生。(2)宽恕倾向与报复倾向及对侵犯的沉思程度显著负相关。沉思程度和抑郁显著正相关。(3)沉思程度和宽恕倾向对抑郁分别具有显著的正向和负向的预测作用。(4)大学生的宽恕倾向和宽恕态度的相互作用以及宽恕倾向和报复倾向之间的交互作用对抑郁均没有显著预测作用。     

Salesperson characteristics affecting consumer complaint responses

The important relationship between consumer complaint behaviour and brand and store loyalty is well established. The range of factors that favourably influence the outcomes of complaining have received relatively less research attention. Therefore, this study tests the effects of two salesperson source characteristics: willingness to listen and product/store knowledge, on consumer complaint‐related perceptions and intentions in a retail setting. Mall shoppers participated in a consumer complaint experiment to test the hypothesised effects. The results indicate that both characteristics affect customer complaint responses, as well as consumer perceptions of the salesperson and the retail store. The findings of the study demonstrate that salesperson characteristics are important influences on positive or negative consumer complaint responses. Copyright © 2001 Henry Stewart Publications.     

An observation on stimulus control in a tilt discrimination by children

Most children who learned to discriminate opposing 45 degrees line tilts on a relational basis-oddity-did not learn the specific direction of the positive tilt. Most children who did not use oddity did discriminate the specific tilt.