Anisomycin impairs long-term working memory in a delayed alternation task

A long-term temporal component of working memory of rats trained on the radial maze has been shown to be susceptible to disruption by the protein synthesis inhibitor, anisomycin. It is not clear whether protein synthesis played a role in working memory because accurate performance on the radial maze required the storage of a large amount of information, or because the information was to be held in store for relatively long periods of time. This experiment tested these hypotheses by assessing the effect of anisomycin on choice accuracy in a comparatively simple spatial delayed alternation task. Results indicate that under the present training conditions, protein involvement in working memory is related more to the length of the retention interval than to the amount of information retained.     

Evidence for aggression-modulating pheromones in prepuberal pigs

A series of behavioral bioassays were conducted to determine the aggression-influencing properties of urine and other fluids. Subjects were prepuberal castrated male and female domestic pigs from commercial stocks. In the behavior assay, pigs were painted with a test fluid and grouped for a videotaped 90 min observation period. Experiment 1 validated use of videotape recording by showing that duration of aggressive behavior registered live was correlated with that obtained from video records (R = .98). In experiment 2, urine and plasma collected from actively aggressive pigs reduced the durations of aggressive behavior of test pigs compared with the effects of urine and plasma collected from socially stable, handled pigs. In Experiment 3, a new set of test pigs confirmed that urine from fighting pigs reduced the duration of attack by test pigs compared with urine from nonfighting, handled pigs. In addition, the suggested reproductive pheromone, 5 alpha-androst-16-en-3-one, substantially reduced the duration of attack. The effects of gender and aggressive state of urine-donor pigs on test pigs was determined in Experiment 4. Again, urine from castrated male and female aggressive pigs reduced attack by test pigs compared with the level of attack shown by test pigs coated with urine from handled castrated males and females. Urine from fighting and nonfighting intact males had similar effects on test pig aggression. In Experiment 5, urine was obtained from nonhandled, socially stable pigs in their home pens and again from the same pigs after they had been regrouped (aggressive). These urine types had no significant influence on test pigs' aggression over the entire 90-min observation. However, during the first 30 min nonhandled, nonfighting pigs' urine induced less aggression in test pigs than did urine from fighting pigs. Results indicate that urine and blood plasma from aggressive pigs reduces aggression by test pigs compared with the effects of urine from handled pigs. Handling may increase the aggression-promoting properties of urine, and aggression may inhibit this aggression-promoting property.     

Structure and process in semantic memory: new evidence based on speed-accuracy decomposition

Reaction-time and accuracy data obtained from studies of sentence verification have not been rich enough to answer certain important theoretical questions about structures and processes in human semantic memory. However, a new technique called speed-accuracy decomposition (Meyer, Irwin, Osman, & Kounios, 1986) may help solve this problem. The technique allows intermediate products of sentence verification to be analyzed more precisely. Three experiments with speed-accuracy decomposition indicate that verification processes produce useful partial information before they are completed. Such information appears to accumulate continuously at a rate whose magnitude depends on the degree of relatedness between semantic categories. This outcome is consistent with continuous computational (e.g., semantic-feature comparison) models of semantic memory. An analysis of reaction-time minima suggests that a discrete all-or-none search process may also contribute at least occasionally to sentence verification. Further details regarding the nature of these processes and the memory structures on which they operate can be inferred from additional results obtained through speed-accuracy decomposition.     

Hippocampal associative cellular responses: dissociation with behavioral responses revealed by a transfer-of-control technique

Multiunit activity was recorded in the CA3 field of the dorsal hippocampus in freely moving rats during classical conditioning and subsequent presentation of the CS on operant baselines for food reward as well as shock avoidance. Rats were first trained in a nonsignaled bar-pressing-dependent shock omission task and in a food-motivated lever-pressing task (60-s VI). Five sessions with presentations of a previously habituated tone as a CS paired with footshock as a US were then given. Testing was carried out by presenting the CS alone while behavioral responses were maintained by reinforcement in both instrumental tasks on alternate sessions. As expected, the CS induced a marked suppression of lever pressing for food reward and a marked enhancement of bar-pressing for shock avoidance. The analysis of the frequency of multiunit discharges to the CS revealed that the hippocampal cellular responses established during classical conditioning were maintained while two different behavioral responses were exhibited to the CS. The results showed that the associative response of hippocampal neurons may be dissociated from the Pavlovian conditioned responses the CS elicits. They support the hypothesis that hippocampal cellular responses represent a neural index of the acquired CS-US associative representation.     

Pavlovian analysis of interactions between hunger and thirst

In four experiments we examined the effect of an irrelevant drive on classical conditioning with food and water. In the first experiment the irrelevant drive weakened the conditioned response in extinction. In Experiments 2 and 3, this suppressive effect was found also in acquisition. Furthermore, the presence of an irrelevant drive during nonreinforced presentations of the conditioned stimulus was found to protect the conditioned response from extinction. Experiment 4 showed that the depressive effect of the irrelevant drive is manifested only when the relevant drive is present. Taken together, these results suggest that an irrelevant drive can influence conditioned responding by modulating the representation of the unconditioned stimulus.     

Effects of foveal priming and extrafoveal preview on object identification

The results of three different experiments suggested that the relation between an object in the fovea on fixation n and an object subsequently brought into the fovea on fixation n + 1 affects the time to identify the second object. In Experiment 1 we extended previous work by demonstrating that a previously seen related priming object speeded the time to name a target object even when a saccade intervened between the two objects. In Experiment 2 we replicated this result and further showed that the benefit on naming time was due to facilitation from the related object rather than inhibition from the unrelated object. In addition, naming of the target object was much slower in both experiments when there was not a peripheral preview of the target object on fixation n. However, because the effect of the foveal priming object was greater when the target was not present than when it was present, priming did not appear to make extraction of the extrafoveal information more efficient. In Experiment 3, fixation times were recorded while subjects looked at four objects in order to identify them. Fixation time on an object was shorter when a related object was fixated immediately before it, even though the four objects did not form a scene. The size of the facilitation was roughly comparable to that in several analogous experiments where scenes were used. The results suggest that the effects of a predictive scene context on object identification may be explainable in terms of an object-to-object or "intralevel" priming mechanism.     

Observed behaviors during clinical interviews predict improvement in depression

A considerable percentage of depressed patients do not respond to antidepressive treatment. Early indicators of prognosis are needed. The aims of this study are to examine (a) whether the interpersonal behavior of patients and psychiatrist, as assessed by means of direct observation of behavior during a baseline clinical interview, might have predictive value with respect to therapeutic outcome and (b) which predictive potency measures of psychomotor activation, as assessed by less refined methods, such as global clinical judgment, might have. In the analysis used, speech-pause behavior was taken as the basic structure of the interaction. The relations of other behaviors such as looking and hand and head movement with this structure were determined. Evidence is presented that in a group of 31 depressives, improvement after a period of 10 weeks was related to observed behaviors during a baseline interview. The behaviors of the patients are interpreted as relational or nonrelational. The relational behaviors (i.e., looking yesnodding, gesturing) occur less in patients who will improve, whereas the nonrelational behaviors (i.e., intensive body touching, head movements) occur more in these patients. The nonrelational behaviors are presumed to be indicative of the state of arousal. The predictive potency of these variables could not be explained by their relationship with the baseline severity of depression, which in itself also predicted improvement. Moreover, global clinical assessment of psychomotor activation (i.e., retardation and agitation) could not be related to outcome.     

Juvenile homicide: The need for an interdisciplinary approach

Most of the empirical literature on juvenile homicide has emerged from the clinical experience of mental health professionals who have diagnosed and/or treated youngsters who killed. After a critical review of this literature, data on 787 juvenile homicide offenders are presented and discussed. These data indicate that intrafamilial killings represent but a small fraction of all homicides perpetrated by juveniles and that there are clear differences between intrafamilial and extrafamilial juvenile homicides.     

Menstruation and crime: A critical review of the literature from the clinical criminology perspective

The authors review the literature on the relationship between menstruation and crime, focusing upon the methodological limitations of these studies in the broader context of criminological and menstruation research. Based on this review, they conclude: the present state of scientific knowledge is such that it is unknown whether there is an association between any phases of the menstrual cycle and crime; there is no evidence linking fluctuations in reproductive hormones to criminal behavior; and, this lack of scientific knowledge is so glaring that evidence regarding menstruation and crime should not be admissible in criminal trials.     

The effects of perceived parental rearing style on the development of Type A pattern

The aetiological antecedents of the Type A pattern have not been studied widely. In the present study the effects of parental rearing practices on the development of Type A pattern were evaluated. Perceived parental rearing style was assessed by the EMBU and Type A pattern by the JAS. Subjects were drawn from a random sample of residents (older than 21 years) of a Dutch community. Results suggested that a significant amount of variance of Type A behaviour can be accounted for by perceived parental characteristics, especially rejection and lack of emotional warmth. It is suggested that lack of emotional warmth and negative evaluation of children by their parents may lead to an internalized maladaptive cognitive set in the children which may be a developmental antecedent for eliciting the competitiveness, achievement striving, and sense of time urgency characteristic of Type A adults.