Visual discrimination by heifers (Bos taurus) of their own species

Species discrimination has been described in several taxa but rarely in domestic animals. In contrast to wild species, domestic species present a great phenotypic variety. This study investigated whether 10 Prim'Holstein heifers (Bos taurus) could discriminate images of cows from images of other domestic animals. The experiment was based on simultaneous discrimination. Responses were obtained through instrumental conditioning using a food reward. In Experiment 1, the reward was associated with a cow face and, in the reversal learning task, with faces of other domestic species. The results showed that in both tasks, cows were able to reach the criterion in few sessions. Therefore, despite great phenotypic variety (a cognitive challenge) cows were able to visually discriminate their own species from other domestic species.     

Sensory noise explains auditory frequency discrimination learning induced by training with identical stimuli

Thresholds in various visual and auditory perception tasks have been found to improve markedly with practice at intermediate levels of task difficulty. Recently, however, there have been reports that training with identical stimuli, which, by definition, were impossible to discriminate correctly beyond chance, could induce as much discrimination learning as could training with different stimuli. These surprising findings have been interpreted as evidence that discrimination learning can occur in the absence of perceived differences between stimuli and need not involve the fine-tuning of a discrimination mechanism. Here, we show that these counterintuitive findings of discrimination learning without discrimination can be understood simply by considering the effect of internal noise on sensory representations. Because of such noise, physically identical stimuli are unlikely to be perceived as being strictly identical. We show that, given empirically derived levels of sensory noise, perceived differences evoked by identical stimuli are actually not much smaller than those induced by the physical differences typically used in discrimination-learning experiments. We suggest that findings of discrimination learning with identical stimuli can be explained without implicating any fundamentally new learning mechanism.     

Is control a viable goal in the treatment of pathological gambling?

According to a report of National Gambling Impact Study Commission (National Gambling Impact Study Commission (1999). Final report. Washington, DC: Government Printing Office.), 97% of problem gamblers in the United States do not seek treatment. Within the small proportion of problem gamblers who enter into treatment, a high percentage drops out. Despite the fact that some researchers argue against abstinence as the only acceptable treatment goal and that regaining control over gambling behaviour appears to be possible for some pathological gamblers (PG), abstinence has been the only gambling intervention treatment goal. The primary goal of this study was to verify whether controlled gambling is a viable goal for pathological gamblers. The second goal was to identify the characteristics that predicted a successful outcome for treatment with a controlled gambling goal. Eighty-nine PGs were enrolled in cognitive-behavioural treatment aimed at controlled gambling. Six and twelve month follow-ups were conducted in order to evaluate the maintenance of therapeutic gains and to identify significant predictors of successful controlled gambling. Results showed that using the intent-to-treat procedure, 63% had a score of 4 or less on the DSM-IV at the end of treatment. That proportion was 56% and 51% at the 6- and 12-month follow-ups. If we retain only those who completed the treatment, these proportions increased to 92%, 80% and 71% at post-treatment, 6- and 12-month follow-ups, respectively. On the majority of the measures, significant improvements were found at post-treatment and the therapeutic gains were maintained at the 6- and 12-month follow-ups. However, few variables were identified to predict who would benefit from control rather than abstinence. The clinical and philosophical implications of these results are discussed in this paper.     

Nonstandard career paths and profiles of commitment to life roles: A complex relation

The career paths (ascending, interesting, uninteresting, descending) of 124 White Canadian francophones (62 men, 62 women) who had experienced nonstandard and precarious work for the last three years were examined in relation to the participants’ profiles of commitment to three life roles (work, family, and duality, that is, investment in both career and family). The paths were derived from the content analysis of the data collected through semi-structured individual interviews. Quantitative tools were used to assess the importance of life roles and to compare the career paths as well as the commitment profiles with respect to specific and general anxiety. Among other results, a significant relationship was found between unsatisfying career paths and the duality profile, on the one hand, and higher levels of specific and general anxiety, on the other. The results are discussed with respect to the scientific literature. Implications for career counseling are suggested.     

Language‐specific stress perception by 9‐month‐old French and Spanish infants

During the first year of life, infants begin to have difficulties perceiving non‐native vowel and consonant contrasts, thus adapting their perception to the phonetic categories of the target language. In this paper, we examine the perception of a non‐segmental feature, i.e. stress. Previous research with adults has shown that speakers of French (a language with fixed stress) have great difficulties in perceiving stress contrasts ( Dupoux, Pallier, Sebastián & Mehler, 1997 ), whereas speakers of Spanish (a language with lexically contrastive stress) perceive these contrasts as accurately as segmental contrasts. We show that language‐specific differences in the perception of stress likewise arise during the first year of life. Specifically, 9‐month‐old Spanish infants successfully distinguish between stress‐initial and stress‐final pseudo‐words, while French infants of this age show no sign of discrimination. In a second experiment using multiple tokens of a single pseudo‐word, French infants of the same age successfully discriminate between the two stress patterns, showing that they are able to perceive the acoustic correlates of stress. Their failure to discriminate stress patterns in the first experiment thus reflects an inability to process stress at an abstract, phonological level.     

Forest chimpanzees (Pan troglodytes verus) remember the location of numerous fruit trees

It is assumed that spatial memory contributes crucially to animal cognition since animals’ habitats entail a large number of dispersed and unpredictable food sources. Spatial memory has been investigated under controlled conditions, with different species showing and different conditions leading to varying performance levels. However, the number of food sources investigated is very low compared to what exists under natural conditions, where food resources are so abundant that it is difficult to precisely identify what is available. By using a detailed botanical map containing over 12,499 trees known to be used by the Taï chimpanzees, we created virtual maps of all productive fruit trees to simulate potential strategies used by wild chimpanzees to reach resources without spatial memory. First, we simulated different assumptions concerning the chimpanzees’ preference for a particular tree species, and, second, we varied the detection field to control for the possible use of smell to detect fruiting trees. For all these assumptions, we compared simulated distance travelled, frequencies of trees visited, and revisit rates with what we actually observed in wild chimpanzees. Our results show that chimpanzees visit rare tree species more frequently, travel shorter distances to reach them, and revisit the same trees more often than if they had no spatial memory. In addition, we demonstrate that chimpanzees travel longer distances to reach resources where they will eat for longer periods of time, and revisit resources more frequently where they ate for a long period of time during their first visit. Therefore, this study shows that forest chimpanzees possess a precise spatial memory which allows them to remember the location of numerous resources and use this information to select the most attractive resources.     

Emotion and motor preparation: A transcranial magnetic stimulation study of corticospinal motor tract excitability

In the present study, we examined whether preparing motor responses under different emotional conditions alters motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation delivered to the motor cortex. Analyses revealed three findings: (1) Reaction times were expedited during exposure to unpleasant images, as compared with pleasant and neutral images; (2) force amplitude was greater during exposure to unpleasant images, as compared with pleasant and neutral images; and (3) MEPs were larger while participants viewed unpleasant images, as compared with neutral images. Hence, coupling the preparation of motor responses with the viewing of emotional images led to arousal-driven changes in corticospinal motor tract excitability, whereas movement speed and force production varied as a function of emotional valence. These findings demonstrate that the effects of emotion on the motor system manifest at varying sensitivity levels across behavioral and neurophysiological measures. Moreover, they validate the action readiness component of emotional experience by demonstrating that emotional states influence the execution of future movements but, alone, do not lead to overt movement.     

Impact of Co-Therapy Teams on Client Outcomes and Therapist Training in Marriage and Family Therapy

This study of 33 student therapists, 402 client systems, and three supervisors tested the efficacy of using student co-therapy teams as an aspect of clinical training in a marriage and family therapy program. This study utilizes both quantitative and qualitative methodology. Two research questions were addressed: “Do different pairings of co-therapists affect client outcomes?” and “Is co-therapy a viable option for a training program?” The results indicate that client outcomes using co-therapy are at least as effective as treatment using one therapist and in some circumstances produce more positive outcomes for both clients and student therapists.     

Jung’s Axioms: An Introduction to Jung’s “Note on Number”

This article is an introduction to C. G. Jung’s handwritten note on natural numbers (in this issue), which became the basis of Marie-Louise von Franz’s book Number and Time. I present the historical background of Jung’s note and discuss part of its content using mostly Jung’s own words.