Place learning in scopolamine-treated rats: the roles of distal cues and catecholaminergic mediation

Experiments 1 and 2 tested the hypothesis that cholinergic receptor antagonists impair place learning in a water maze by interfering with the processing of distal, visual cues. Extramaze cues were offered to rats in the form of geometrical patterns arranged on the inner circumference of a curtain surrounding the water maze. In Experiment 1 the animals were offered both the distal cues and proximal cues in the form of pingpong balls in fixed positions on the surface of the water while only distal cues were present in Experiment 2. Animals were injected with either scopolamine (0.5 mg/kg body wt) or saline 20 min prior to the daily place learning sessions. Upon reaching criterion level performance the animals were tested on "rotation" sessions on which the distal cues were displaced. The outcome of such "rotations" demonstrated that-regardless of the presence or absence of proximal cues-scopolamine-treated rats relied at least as much as normal animals on the distal cues. The acquisition phase of both Experiments 1 and 2 demonstrated an almost complete lack of scopolamine-associated impairment in acquisition and performance of the place learning task. In Experiment 3 (when scopolamine was no longer administered) the subjects of Experiment 2 were exposed to a series of pharmacological "challenges" of their place learning performance and eventually to surgical ablation of the anteromedial prefrontal cortex. The outcome of the pharmacological challenges and the postoperative test of task performance demonstrated that the place learning performance of animals which had acquired the task under scopolamine was mediated by a neural substrate dissimilar to the substrate of task performance in normal animals. Rats acquiring the task while deprived of the cholinergic system demonstrated above-normal contributions to task mediation from catecholaminergic-probably dopaminergic-mechanisms and tentative results pointed to a "shift" toward prefrontal task mediation.     

The myth of technology in health care

Technology is believed to have liberated health care from dogmas, myths and speculations of earlier times. However, we are accused of using technology in an excessive, futile and even detrimental way, as if technology is compelling our actions. It appears to be like the monster threatening Dr. Frankenstein or like the socerer’s broom in the hand of the apprentice. That is, the same technology that should liberate us from myths, appears to be mythical. The objective of this article is to investigate the background for the re-entrance of the myth: How we encounter it and how we can explain it. The main point is that a myth of technology is normative: it relates ‘is’ and ‘ought’ and directs our actions. This becomes particularly clear in health care. Hence, if there is a myth of technology, it is an ethical issue, and should be taken seriously.     

Descartes's Regulae, mathematics, and modern psychology: "the Noblest example of all" in Light of Turing's (1936) On computable Numbers

There are surprisingly strong connections between the philosophy of mind and the philosophy of mathematics. One particular important example can be seen in the Regulae (1628) of Descartes. In "the noblest example of all," he used his new abstract understanding of numbers to demonstrate how the brain can be considered as a symbol machine and how the intellect's algebraic reasoning can be mirrored as operations on this machine. Even though his attempt failed, it is illuminating to explore it because Descartes launched 2 traditions--mechanistic philosophy of mind and abstract mathematics--that would diverge until A. Turing (1936) approached symbolic reasoning in a similar "symbol machine-existence proof" way. Descrates's and Turing's thought experiments, which mark the beginning of modern psychology and cognitive science, respectively, indicate how important the development of mathematics has been for the constitution of the science of mind.     

When false memories do not occur: not thinking of the lure or remembering that it was not heard?

The aim of the present study was to evaluate two explanations for the non-occurrence of false memories in the Deese-Roediger-McDermott (DRM) paradigm. One explanation was that a critical lure is not recalled because the list failed to evoke it in the participant's mind. Another possible explanation was that the participant would identify the critical lure and would remember, at the time of recall, that the lure was not produced by an external source. In order to explore these two possible explanations for the non-occurrence of false memories, an experimental phase was added to the usual DRM paradigm: participants were asked to recall items they thought of but did not recall because these items were not members of the list presented by the experimenter. Among participants who did not recall the critical lure during the standard recall task, those who recalled the critical lure during the additional phase outnumbered those who did not recall it. This result is more consistent with the second explanation than with the first one.     

Metacognitions in proneness towards hallucinations and delusions

The objectives of the present study were to examine the degree of co-existence of hallucinations and delusions in the nonclinical population. In addition, we wished to investigate the role of metacognitions in hallucinations and delusions. Finally, we explored the relative roles of positive and negative metacognitive beliefs in proneness to hallucinations and delusions. Three hundred and thirty-one nonclinical participants completed instruments assessing: hallucination-proneness (Launay-Slade Hallucinations Scale; LSHS), delusion-proneness (21-item version of the Peters et al. Delusions Inventory; PDI-21) and metacognitive beliefs (Meta-Cognitions Questionnaire; MCQ). Participants were successively grouped according to their scores on the LSHS and the PDI-21. Results revealed that hallucination-proneness was positively and significantly associated with delusion-proneness. Furthermore, hallucination-prone and delusion-prone participants scored significantly higher on some sub-scales of the MCQ compared to non-prone participants. Finally, multiple regression analysis revealed that positive and negative beliefs were good predictors of proneness towards hallucinations and delusions.     

Is the unilateral lesion of the left substantia nigra pars compacta sufficient to induce working memory impairment in rats?

Adult male Wistar rats with a substantia nigra pars compacta (SNc) lesion induced by intranigral administration of 1 micromol 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) were used as a model of early phase Parkinson's disease (PD). This lesion caused a partial depletion of striatal dopamine (DA). The animals were submitted to a spatial working memory version of the water maze task in which they had to find a hidden (submersed) platform using online-maintained information that the platform remains in the same place during four consecutive trials, but that it is moved to another place every training day. Left, but not right SNc-lesioned rats were impaired in finding the platform in the second trial. This result suggests that the left SNc plays a key role in spatial working memory. Control experiments ruled out the possibility that motor impairment, sensory neglect, and/or impairment in the mental representation of the contralateral spatial environment had affected performance of the SNc-lesioned rats.     

Behavioral treatment of insomnia in older adults: an open clinical trial comparing two interventions

Fifty-five insomniacs, 60 years or above, participated in a behavioral treatment program, comparing two interventions (sleep hygiene+stimulus control vs sleep hygiene+relaxation tape). Half of the subjects were randomized to a waiting-list condition prior to treatment. No significant changes were observed during the waiting-list period. During the treatment period however, the subjects improved on several sleep parameters, and treatment gains were maintained at a 6-month follow-up. The effects of treatment were greater for nocturnal measures (e.g. sleep onset latency and total sleep time) as compared to daytime measures (e.g. life satisfaction, daytime alertness) and not-targeted behavior (medication use). There were no differences in treatment effects for the two interventions.     

Day treatment of patients with personality disorders: experiences from a Norwegian treatment research network

This study sought to investigate the following research questions: Are time-limited day treatment programs for patients with personality disorder (PD) effective outside resourceful university settings, and what are the overall treatment results when the program is implemented on a larger scale? Do all categories and subtypes of PDs respond favorably to such treatment? How intensive should such day treatment programs be? All patients (n = 1,244) were consecutively admitted to eight different treatment programs in the Norwegian Network of Psychotherapeutic Day Hospitals from 1993 to 2000. Altogether, 1,010 patients were diagnosed with PD. Avoidant, borderline, not otherwise specified (NOS), and paranoid PD were the most common conditions. SCID-II and MINI were used as diagnostic instruments. Outcome measures included GAF Global Assessment of Functioning, (GAF; American Psychiatric Association, 1994), SCL-90R, CIP, Quality of Life, work functioning and parasuicidal behavior, measured at admittance, discharge and 1-year follow up. The attrition rate was 24%. The number of dropouts did not improve over time. As a group, completers with PD improved significantly on all outcome variables from admittance to discharge and improvement was maintained or increased at follow up. Treatment results were best for borderline PD, cluster C patients, PD NOS and No PD, and poorer for cluster A patients. Units with a high treatment dosage did not experience better outcomes than those with a low treatment dosage (10 hours per week). Results from the University unit were not better than those from units at local hospitals or mental health centers.     

Phenomenal characteristics of cryptomnesia

Qualitative characteristics of cryptomnesia, or unintentional plagiarism were investigated. In Experiment 1 we compared accurate and inaccurate source attributions in terms of their level of confidence using instructions that did not require a fixed number of responses. Confidence was lower for plagiarised responses than for correct responses. Nevertheless, participants provided high ratings of certainty for a large proportion of their plagiarised responses. In Experiment 2 the phenomenological differences between plagiarised recall and veridical recall were compared by using an adaptation of the memory characteristics questionnaire (Johnson, Foley, Suengas, & Raye, 1988). Correct responses were associated with more experiential detail than plagiarised responses. However, a considerable number of plagiarised responses were accompanied by a confident memory of at least one qualitative characteristic. Results are discussed in terms of the source monitoring framework developed by Johnson, Hashtroudi, and Lindsay (1993).     

Grandiose-Manipulative,Callous-Unemotional,and Daring-Impulsive: the Prediction of Psychopathic Traits in Adolescence and their Outcomes in Adulthood

There has been much debate about how to measure psychopathic traits in adolescence. One of the main issues is whether one should focus on callous-unemotional (CU) traits alone, or CU traits in combination with Grandiose-Manipulative (GM) and Daring-Impulsive (DI) traits. The current study first investigates the extent to which youth who are high on CU traits are also high on GM and DI traits. In addition, the study investigates if being high on both CU and GM, and high on both CU and DI, identify groups that are particularly characterized by past and future impairments. To investigate this, data from the Cambridge Study in Delinquent Development (CSDD) was analyzed. The CSDD is a prospective longitudinal study of 411 English boys spanning over 50 years. The information available at age 12–14 was coded on the Antisocial Process Screening Device (APSD). Childhood risk factors were measured at age 8–10 and later life outcomes were measured at age 32. The results indicate that being high on CU in combination with DI delineates a clinically interesting group who are characterized by high childhood risk and poorer adult life outcomes. The same applied to the high CU/high GM group, but to a lesser extent.