SAVING THE BEST FOR LAST? A CROSS-SPECIES ANALYSIS OF CHOICES BETWEEN REINFORCER SEQUENCES

Two experiments were conducted to compare choices between sequences of reinforcers in pigeon (Experiment 1) and human (Experiment 2) subjects, using functionally analogous procedures. The subjects made pairwise choices among 3 sequence types, all of which provided the same overall reinforcerment rate, but differed in their temporal patterning. Token reinforcement schedules were used in both experiments and the type of exchange schedule varied across blocks of sessions. Some conditions permitted immediate exchange of tokens for consumable reinforcers (food for pigeons, video access for humans); in other conditions, tokens accumulated and were exchanged for consumable reinforcers only at the end of the sequence. Choice patterns in the immediate-exchange conditions were generally similar across species, with both pigeons and humans preferring sequences with the shortest delay to the initial reinforcer in the series. The results are broadly consistent with models of temporal discounting expanded to include the impact of sequences of delayed reinforcers acting in parallel from the time of the choice. Preferences were less consistent with discounting models in the delayed exchange conditions. Questionnaire data gathered at the end of the experiment were consistent with prior results of questionnaire studies, but showed no straightforward relation to the observed choice patterns, urging caution in the extrapolation of results from one decision-making domain to the other.     

RELATIONS AMONG ACUTE AND CHRONIC NICOTINE ADMINISTRATION,SHORT-TERM MEMORY,AND TACTICS OF DATA ANALYSIS

Emerging evidence suggests that nicotine may enhance short‐term memory. Some of this evidence comes from nonhuman primate research using a procedure called delayed matching‐to‐sample, wherein the monkey is trained to select a comparison stimulus that matches some physical property of a previously presented sample stimulus. Delays between sample stimulus offset and comparison stimuli onset are manipulated and accuracy is measured. The present research attempted to systematically replicate these enhancement effects with pigeons. In addition, the effects of nicotine were assessed under another, more dynamic, memory task called titrating‐delay matching‐to‐sample. In this procedure, the delay between sample offset and comparison onset adjusts as a function of the subject's performance. Correct matches increase the delay, mismatches decrease the delay, and titrated delay values serve as the primary dependent measure. Both studies examined nicotine's effects under acute and chronic administration. Neither provided clear or compelling evidence of memory enhancement following nicotine administration despite reliable and systematic dose‐related changes in response latency measures. A modest dose‐related effect on accuracy was found, but the magnitude of the effect appears to be directly related to tactics of data analysis involving best‐dose analyses of a very circumscribed subset of trial types.     

EFFECTS OF A SIGNALED DELAY TO REINFORCEMENT IN THE PREVIOUS AND UPCOMING RATIOS ON BETWEEN-RATIO PAUSING IN FIXED-RATIO SCHEDULES

Domestic hens responded under multiple fixed‐ratio fixed‐ratio schedules with equal fixed ratios. One component provided immediate reinforcement and the other provided reinforcement after a delay, signaled by the offset of the key light. The components were presented quasirandomly so that all four possible transitions occurred in each session. The delay was varied over 0, 4, 8, 16, and 32 s with fixed‐ratio 5 schedules, and over 0, 8 and 32 s with fixed‐ratio 1, 15 and 40 schedules. Main effects of fixed‐ratio value and delay duration were detected on between‐ratio pauses. Pauses were longer when the multiple‐schedule stimulus correlated with a delayed‐reinforcer component was presented, with the longest pauses occurring at the transition from a component with an immediate reinforcer to one with a delayed reinforcer. Pause durations were shortest during immediate components. Overall, both the presence or absence of a delay in the upcoming component, and the presence or absence of a delay in the preceding component affected pause length, but the upcoming delay had the larger effect. Thus changes in delay had similar effects to past reports of the effects of changes in response force, response requirement, and reinforcer magnitude in multiple fixed‐ratio fixed‐ratio schedules.     

The relationship between performance-based self-esteem and self-reported work and health behaviors among Danish knowledge workers

Since knowledge intensive work often requires self-management, one might fear that persons who are dependent on work success for self-esteem will have difficulties in finding a healthful and sustainable balance between internal needs and external demands. Accordingly, we examined to what degree work-related performance-based self-esteem (PBS) was linked to work and health behaviors in 392 knowledge workers (226 women, 166 men). In the women group, multiple binary logistic regression analyses with repeated measurements showed that the PBS score was associated with 10 of the 17 examined work and health behaviors. For men the corresponding figure was 3 of 17. In both men and women, higher PBS scores were positively associated with reports of efforts and strivings for work as well as attending work while ill. In conclusion, statistically significant relationships between PBS and work and health behaviors were more clearly visible among women than men. Whether this gender difference is dependent on the study design, or on true inherent differences between women and men, cannot be concluded with any certainty. However, persons who described themselves as being relatively more dependent on work accomplishments for a high self-esteem, as expressed by the PBS score, seem to display work behaviors that may lessen their restitution time. In addition, they also seem to be more prone to work while sick.     

Cross-contextual stability of bullying victimization: a person-oriented analysis of cyber and traditional bullying experiences among adolescents

Using a person-oriented approach the study examined whether bullying victimization at school continued into cyberspace victimization in a large sample of high school students in Lithuania (N = 1667, 58% girls), age 15-19 (M = 17.29, SD = 0.95). Three forms of traditional bullying (verbal, physical and relational) and seven forms of cyberbullying victimization through cell phones and computers were included in the analysis. The findings revealed that 35% of traditional bullying victims were also bullied in cyberspace. In particular, adolescents who experienced predominantly verbal and relational bullying at school, showed a higher risk of victimization in cyberspace a year later, while this was not observed for predominantly physical forms of traditional bullying. The findings point to the importance of a cross-contextual perspective in studies on stability of bullying victimization.     

Disruption of writing processes by the semanticity of background speech

Previous studies have noted that writing processes are impaired by task-irrelevant background sound. However, what makes sound distracting to writing processes has remained unaddressed. The experiment reported here investigated whether the semanticity of irrelevant speech contributes to disruption of writing processes beyond the acoustic properties of the sound. The participants wrote stories against a background of normal speech, spectrally-rotated speech (i.e., a meaningless sound with marked acoustic resemblance to speech) or silence. Normal speech impaired quantitative (e.g., number of characters produced) and qualitative/semantic (e.g., uncorrected typing errors, proposition generation) aspects of the written material, in comparison with the other two sound conditions, and it increased the duration of pauses between words. No difference was found between the silent and the rotated-speech condition. These results suggest that writing is susceptible to disruption from the semanticity of speech but not especially susceptible to disruption from the acoustic properties of speech.     

Mental health problems and post-migration stress among multi-traumatized refugees attending outpatient clinics upon resettlement to Norway

Refugees have often been exposed to multiple traumas making them prone to mental health problems later. The aim of this study is to describe the prevalence and symptom load of psychiatric disorders in refugees admitted to psychiatric outpatient clinics and to investigate the relationship between multiple exposure to traumatic events, the severity of traumatic symptoms and post-migration stressors. A clinical sample of 61 refugee outpatients from psychiatric clinics in Southern Norway was cross-sectionally examined using three structured clinical interviews (SCID-PTSD, SIDES and MINI) and self-report psychometric instruments (HSCL-25, IES-R). Post-traumatic Stress Disorder (PTSD) was diagnosed in 82% of the patients, while Disorders of Extreme Stress Not Otherwise Specified (DESNOS) was present in 16% of them. Comorbidity was considerable; 64% of the patients had both PTSD and major depression disorder (MDD) and 80% of those who had PTSD had three or more additional diagnoses. Multi-traumatized refugees in outpatient clinics have high prevalence of PTSD, DESNOS, comorbid depression and anxiety disorders. A more severe symptomatology was found in patients diagnosed with both PTSD and DESNOS, than in those diagnosed with only PTSD. Higher rates of unemployment, weak social network and weak social integration were also prevalent in these outpatients, and related to increased psychiatric comorbidity and severity of symptoms. Further research may clarify the existence of a cumulative relationship between pre-resettlement traumas and post-resettlement stressors in the mental health of refugees, which in turn may help to improve therapeutic interventions.     

Locus of control as a contributing factor in the relation between self-perception and adolescent aggression

Researchers continue to debate the role of self-esteem in aggression, but research has shown a consistent association between narcissism and aggression in adults and adolescents [e.g., Barry et al., 2007; Bushman and Baumeister, 1998; Stucke, 2007]. The primary aim of the current study was to examine whether locus of control (LOC) moderated the relation between self-perception variables (i.e., self-esteem and narcissism) and aggression in adolescents. Participants were 174 youth (145 males, 26 females) between the ages of 16 and 19 who were enrolled in a voluntary residential program for youth who have dropped out of school. The results showed that LOC moderated the association between self-esteem and aggression such that low self-esteem was associated with higher levels of aggression for individuals with an external LOC. Contrary to expectations, LOC failed to moderate the narcissism-aggression relation. The implications of this study for understanding how self-perception is related to adolescent aggression are discussed.     

Stress in Clinical Psychology Trainees: Current Research Status and Future Directions

The purpose of this article is to present the current status of the literature related to stress in clinical psychology trainees (CPTs), and to offer research directions for investigating stress in this population and ways to enhance self‐care in these individuals. The following conclusions emerge from the review: (1) CPTs are vulnerable to elevated stress; (2) undue stress can negatively impact CPTs' personal and professional functioning and, in turn, result in less than optimal standards of care for clients; (3) there is a dearth of studies on stress in this population and no published intervention studies; (4) incorporating self‐care strategies into clinical psychology training is recommended; and (5) “third‐wave” cognitive behaviour therapy stress management interventions have been efficacious in comparable populations. In view of the potential costs of elevated stress to trainees themselves and their clients, research on stress and stress management in this population is of a high priority. Broad research agendas are proposed for these two domains. Modifications to clinical training programmes to reduce trainee stress are required and should be evidence‐based and systematically revaluated.     

Independent race of colour and word can predict the Stroop effect

Mainstream theories of the Stroop effect suggest that faster colour classification on congruent trials (say, the word RED printed in red colour) relative to incongruent trials (GREEN in red) is due to channel interaction. Namely, information from the irrelevant word channel perturbs processing of the print colour, causing in turn slower processing of incongruent displays. In this note, I advance a new model in which colour and word are processed in parallel and completely independent channels. The Stroop effect is then the outcome of signal redundancy in congruent displays, where both colour and word contribute to the same response. Numerical computations show that the model can produce the Stroop effect (along with high accuracy rates) for a subset of parameter values. Thus, it provides a proof of existence for a separate channel theory, and a challenge to many existing theories.