Resistance to extinction in the steady state and in transition

Three experiments with pigeons explored the constancy of reinforcer omission during extinction conjectured by rate estimation theory. Experiment 1 arranged 3-component multiple variable-interval (VI) schedules with a mixture of food and extinction trials within each session. Reinforcers omitted to an extinction criterion increased with food-trial reinforcer rate. Experiment 2 arranged 3-component multiple VI schedules where components differed in rate or number of reinforcers. Resistance to extinction depended on the training reinforcer rate but not on the number of reinforcers omitted. Experiment 3 replicated the partial-reinforcement extinction effect within subjects in a discrete-trial procedure and found that more reinforcers were omitted in continuous- than in partial-reinforcement trials. A model of extinction based on behavioral momentum theory accounted for all the data.     

What does it mean that an issue is conceptual in nature?

McGrath (2005/this issue) argues that "the conceptual complexity [italics added] of the constructs psychologists choose to measure and the scales they use to measure them has played an important role in the failure to develop more accurate measurement systems" (p. 112). Although we agree with this, we argue, in this commentary, that McGrath has misdiagnosed the source of these difficulties and that this misdiagnosis originates with an unresolved articulation of the nature of a conceptual issue and of the relationship between conceptual and empirical issues in science.     

Activation of adenosine receptors in the posterior cingulate cortex impairs memory retrieval in the rat

Adenosine A1 and A2A receptor agonists and antagonists have been reported to alter learning and memory. The aim of our study was to investigate the involvement of adenosinergic system in memory retrieval into posterior cingulate cortex (PCC) of Wistar rats. To clarify this question, we tested specifics agonist and antagonists of adenosine A1 and A2A receptors in rats submitted to a one-trial inhibitory avoidance task. The stimulation of adenosine A1 and A2A receptors by CPA and CGS21680, respectively, impaired memory retrieval for inhibitory avoidance task, into PCC. These findings provide behavioral evidence for the role of adenosinergic system in the memory retrieval into PCC.     

Factor analysis of the frontal systems behavior scale (FrSBe)

The Frontal Systems Behavior Scale (FrSBe), formerly called the Frontal Lobe Personality Scale (FLOPS), is a brief behavior rating scale with demonstrated validity for the assessment of behavior disturbances associated with damage to the frontal-subcortical brain circuits. The authors report an exploratory principal factor analysis of the FrSBe-Family Version in a sample including 324 neurological patients and research participants, of which about 63% were diagnosed with neurodegenerative diseases (Huntington's, Parkinson's, and Alzheimer's diseases). The three-factor solution accounted for a modest level of variance (41%) and confirmed a factor structure consistent with the three subscales proposed on the theoretical basis of the frontal systems. Most items (83%)from the FrSBe subscales of Apathy, Disinhibition, and Executive Dysfunction loaded saliently on three corresponding factors. The FrSBe factor structure supports its utility for assessing both the severity of the three frontal syndromes in aggregate and separately.     

Issues and considerations regarding the use of assessment instruments in the evaluation of competency to stand trial

Since the early 1960s, a number of instruments, reflecting a broad range of assessment methods, have been developed to assist in the evaluation of competency to stand trial. These instruments have taken various forms including checklists, self-report questionnaires, sentence-completion tasks, and interview-based instruments with and without criterion-based scoring. This article reviews these assessment instruments with a specific focus on their contribution to the competency evaluation process. Furthermore, relevant issues and considerations regarding the use of these instruments are outlined, including a comparison of screening versus assessment applications of these instruments, balancing standardized approaches with individualized assessments, the integration of instrumentally derived data with other components of a competency evaluation, and the communication of results to the fact finder. Each of these issues is discussed in relation to specific competency assessment instruments. Overall, we argue that each of the competency assessment instruments developed to date can make a contribution to the competency evaluation process and this article serves to delineate those areas in which these contributions are made.     

A prospective study of memory for child sexual abuse: new findings relevant to the repressed-memory controversy

Previous research indicates that many adults (nearly 40%) fail to report their own documented child sexual abuse (CSA) when asked about their childhood experiences. These controversial results could reflect lack of consciously accessible recollection, thus bolstering claims that traumatic memories may be repressed. In the present study, 175 individuals with documented CSA histories were interviewed regarding their childhood trauma. Unlike in previous studies, the majority of participants (81%) in our study reported the documented abuse. Older age when the abuse ended, maternal support following disclosure of the abuse, and more severe abuse were associated with an increased likelihood of disclosure. Ethnicity and dissociation also played a role. Failure to report CSA should not necessarily be interpreted as evidence that the abuse is inaccessible to memory, although inaccessibility or forgetting cannot be ruled out in a subset of cases.     

Remote Odor Memory in Alzheimer's Disease: Deficits as Measured by Familiarity

Deficit in olfaction and remote nonolfactory memory in Alzheimer's disease (AD) motivated the present study of remote memory for odors and faces, operationally defined as rated familiarity, in patients with AD and controls. Uncommon engineering symbols were rated for familiarity to ensure task comprehension. Results showed that patients with AD rate odors, but not faces, as significantly less familiar than do controls, which is indicative of deficit in remote odor memory. Follow-up testing 1 year later again showed this result. Poor odor-detection sensitivity in patients, with AD, but lack of significant correspondence between sensitivity and familiarity, suggests an existing but limited effect of sensitivity on familiarity. The findings provide further evidence that olfaction may be a useful modality for early identification of AD.     

REEMERGENCE AND EXTINCTION OF SELF-INJURIOUS ESCAPE BEHAVIOR DURING STIMULUS (INSTRUCTIONAL) FADING

Based on results of a functional analysis indicating that the self-injurious behavior (SIB) of 3 individuals was maintained by negative reinforcement (escape from instructional situations), the effects of stimulus (instructional) fading were evaluated in a multiple baseline design across subjects. The rate of instructions was reduced to zero at the beginning of treatment and was gradually increased (faded in) across sessions as long as SIB remained low. However, if SIB remained high for 10 consecutive sessions, extinction was implemented until SIB decreased, at which point extinction was withdrawn and fading was resumed. Treatment was completed when the rate of instructions was the same as in baseline (two per minute), and SIB remained below 0.5 responses per minute for two consecutive sessions. Results showed that instructional fading (without extinction) virtually eliminated SIB initially, but these effects were not maintained. All 3 subjects required multiple exposures to extinction and over 150 treatment sessions in order to meet the end-of-treatment criteria. Advantages and limitations of fading procedures without an extinction component, as well as extensions of both interventions to other clinical problems, are discussed.