Bouts of responding from variable-interval reinforcement of lever pressing by rats

Four rats obtained food pellets by lever pressing. A variable-interval reinforcement schedule assigned reinforcers on average every 2 min during one block of 20 sessions and on average every 8 min during another block. Also, at each variable-interval duration, a block of sessions was conducted with a schedule that imposed a variable-ratio 4 response requirement after each variable interval (i.e., a tandem variable-time variable-ratio 4 schedule). The total rate of lever pressing increased as a function of the rate of reinforcement and as a result of imposing the variable-ratio requirement. Analysis of log survivor plots of interresponse times indicated that lever pressing occurred in bouts that were separated by pauses. Increasing the rate of reinforcement increased total response rate by increasing the rate of initiating bouts and, less reliably, by lengthening bouts. Imposing the variable-ratio component increased response rate mainly by lengthening bouts. This pattern of results is similar to that reported previously with key poking as the response. Also, response rates within bouts were relatively insensitive to either variable.     

Changing perspectives on frontotemporal dementia: A review

This article examines the evolution in understanding of frontotemporal dementia (FTD) during the last four decades. A central theme is the recognition of heterogeneity. Originally construed as a disorder of behaviour and executive impairment, FTD is now known also to be associated with alterations in language, conceptual knowledge and praxis. An absence of neurological signs is the hallmark of many FTD patients, but there is also an established association with motor neurone disease (MND), progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). FTD is commonly defined as an early onset dementia, yet about a quarter of patients present after the age of 65. The underlying pathological protein is tau, TDP-43 or more rarely fused-in-sarcoma (FUS). Distinct genetic mutations have been identified in familial FTD. There are predictable relationships between clinical phenotype, pathological substrate and genetic mutation. For example, a circumscribed semantic disorder predicts TDP-43 pathology, and speech or limb apraxia tau pathology. The co-occurrence of MND predicts TDP-43 pathology, and PSP and CBD tau pathology. FUS pathology is associated with very youthful onset, stereotyped behaviours and caudate atrophy. Non-fluent aphasia is linked to progranulin (GRN) mutations and MND and psychosis to repeat expansions in the C9orf72 gene. Despite striking worldwide consensus in findings there remain some issues of contention, largely related to the classification of FTD and its sub-variants. Understanding the diverse nature of FTD is crucial for effective diagnosis, management and the development of targeted therapies.     

Defensive pessimism and precautionary action during the COVID pandemic

The purpose of this research was to test, in the context of the COVID-19 pandemic, the hypothesis that individuals who use defensive pessimism as a strategy to manage anxiety are likely to act to prevent or mitigate negative outcomes. Across three crowd-sourced samples (Total N = 1416), defensive pessimism was correlated with self-reports of more precautionary behavior (Studies 1, 2, & 3) and fewer COVID-positive results (Study 3).     

Actual and Perceived Group Performance as a Function of Group Composition: The Moderating Role of the Type A and B Behavior Patterns1

This study examined the moderating influence of the Type A and B behavior patterns on group performance and group functioning. Type As and Bs were assigned to different roles in groups given the task of deciding what items to transfer from a sinking ship to a life raft. Results indicated that groups with Type A leaders in conflict with a Type A group member arrived at relatively poor decisions. Type A leaders, however, also were perceived by their groups to be more competent than were Type B leaders. These results suggested that the Type A behavior pattern can have the paradoxical effects of hindering group problem-solving and of leading others to view Type As as more competent than Type Bs because of their active dynamic style.     

Citizen participation in police crisis intervention activities

A naturalistic experiment tested the proposition that police time could be saved in nondangerous crisis intervention calls through the use of citizen participants. Results showed that police officers who used citizen intervention spent less time per call than officers who did not. However, police time was not saved in family disturbance calls. Family disturbance control group calls were rated by police as having a higher degree of physical danger present than other calls.     

Teenagers and illicit drug use—expanding the ‘user vs non-user’ dichotomy

The present study examines proximal and distal factors associated with the use and non-use of illegal substances within a sample of 860 teenagers in North Wales. Arguing that there is predictive utility in expanding the traditional ‘users vs non-users’ design dichotomy, four groups are identified — resistant and vulnerable non-users and experimental and repeated users. ‘Person’ variables (life satisfaction, deviance, hopelessness and drug-related attributions) appeared to primarily differentiate the vulnerable group from their resistant counterparts and identify this, as yet non-using group, with user samples. It is suggested that these variables might represent ‘risk’ factors for illicit substance use and that the group design employed suggests they precede, rather than follow as a consequence of, illicit drug use. Like their resistant counterparts however, the vulnerable group are differentiated from user samples on some lifestyle and context indices. It is argued that these represent ‘protective’ influences in an otherwise at-risk group of non-users. Variables associated with an escalation of illicit drug use are discussed in considering the differences between the experimental and repeated user groups. Apart from the more proximal factor of drug-related attributions, ‘person’ variables appeared less involved here. Repeated users did however, tend to use a greater number of drugs, have a greater proportion of friends who also used illegal substances and significantly fewer had a Welsh cultural identity.     

Teaching preschoolers to avoid abduction by strangers: Evaluation of maintenance strategies

The purpose of this study was to evaluate the use of effective training procedures for teaching preschoolers to avoid abduction by strangers and to evaluate strategies to promote maintenance of the acquired skills. The study was conducted in three Head Start classrooms with a total of 46 children. A multiple probe design across groups within each class and replicated across the three classrooms was used to evaluate two strategies for promoting maintenance: (a) monthly reviews involving verbal rehearsal, modeling, and feedback; and (b) monthly reviews involving verbal rehearsal, modeling, feedback, and in-class role play. The findings of the study indicate: (a) classroom teachers implemented the training procedures with a high degree of procedural fidelity, (b) all children were taught to resist the lures of strangers, (c) children maintained the critical abduction avoidance behavior (moving away from a stranger) while the maintenance promotion strategies were used, and (d) minimal differences were noted in the effectiveness of the two maintenance promotion strategies for the critical abduction avoidance behavior.     

Matching Messages to Motives in Persuasion: A Functional Approach to Promoting Volunteerism1

This study examined a functional strategy for investigating audience responses to motivationally-based persuasive appeals. It was predicted that people exposed to advertisements informing them how they could satisfy personally relevant motivations through volunteering (i.e., functionally matched messages) would judge these ads to be more persuasive, more emotionally positive, and would report being more likely to volunteer than people exposed to advertisements unrelated to their personally relevant motivations (i.e., functionally mismatched messages). These predictions were confirmed in an experiment wherein participants whose attitudes toward volunteerism served a Social Adjustive, Value Expressive, Utilitarian, Knowledge, or Ego Defensive function viewed advertisements promoting volunteerism that either matched or mismatched their personally relevant motivations. Results confirmed predictions as participants responded more favorably to the functionally matched than mismatched messages. The implications of this research for understanding the mechanisms by which functionally matched messages exert persuasive influence and the ramifications of the research for the practice of volunteerism are discussed.