Consolidation of long-term memory: evidence and alternatives

Memory loss in retrograde amnesia has long been held to be larger for recent periods than for remote periods, a pattern usually referred to as the Ribot gradient. One explanation for this gradient is consolidation of long-term memories. Several computational models of such a process have shown how consolidation can explain characteristics of amnesia, but they have not elucidated how consolidation must be envisaged. Here findings are reviewed that shed light on how consolidation may be implemented in the brain. Moreover, consolidation is contrasted with alternative theories of the Ribot gradient. Consolidation theory, multiple trace theory, and semantization can all handle some findings well but not others. Conclusive evidence for or against consolidation thus remains to be found.     

Lesion analysis of the brain areas involved in language comprehension

The cortical regions of the brain traditionally associated with the comprehension of language are Wernicke's area and Broca's area. However, recent evidence suggests that other brain regions might also be involved in this complex process. This paper describes the opportunity to evaluate a large number of brain-injured patients to determine which lesioned brain areas might affect language comprehension. Sixty-four chronic left hemisphere stroke patients were evaluated on 11 subtests of the Curtiss-Yamada Comprehensive Language Evaluation - Receptive (CYCLE-R; Curtiss, S., & Yamada, J. (1988). Curtiss-Yamada Comprehensive Language Evaluation. Unpublished test, UCLA). Eight right hemisphere stroke patients and 15 neurologically normal older controls also participated. Patients were required to select a single line drawing from an array of three or four choices that best depicted the content of an auditorily-presented sentence. Patients' lesions obtained from structural neuroimaging were reconstructed onto templates and entered into a voxel-based lesion-symptom mapping (VLSM; Bates, E., Wilson, S., Saygin, A. P., Dick, F., Sereno, M., Knight, R. T., & Dronkers, N. F. (2003). Voxel-based lesion-symptom mapping. Nature Neuroscience, 6(5), 448-450.) analysis along with the behavioral data. VLSM is a brain-behavior mapping technique that evaluates the relationships between areas of injury and behavioral performance in all patients on a voxel-by-voxel basis, similar to the analysis of functional neuroimaging data. Results indicated that lesions to five left hemisphere brain regions affected performance on the CYCLE-R, including the posterior middle temporal gyrus and underlying white matter, the anterior superior temporal gyrus, the superior temporal sulcus and angular gyrus, mid-frontal cortex in Brodmann's area 46, and Brodmann's area 47 of the inferior frontal gyrus. Lesions to Broca's and Wernicke's areas were not found to significantly alter language comprehension on this particular measure. Further analysis suggested that the middle temporal gyrus may be more important for comprehension at the word level, while the other regions may play a greater role at the level of the sentence. These results are consistent with those seen in recent functional neuroimaging studies and offer complementary data in the effort to understand the brain areas underlying language comprehension.     

An overview on Primary Progressive Aphasia and its variants

We present a review of the literature on Primary Progressive Aphasia (PPA) together with the analysis of neuropschychological and neuroradiologic profiles of 42 PPA patients. Mesulam originally defined PPA as a progressive degenerative disorder characterized by isolated language impairment for at least two years. The most common variants of PPA are: 1) Progressive nonfluent aphasia (PNFA), 2) semantic dementia (SD), 3) logopenic progressive aphasia (LPA). PNFA is characterized by labored speech, agrammatism in production, and/or comprehension. In some cases the syndrome begins with isolated deficits in speech. SD patients typically present with loss of word and object meaning and surface dyslexia. LPA patients have word-finding difficulties, syntactically simple but accurate language output and impaired sentence comprehension. The neuropsychological data demonstrated that SD patients show the most characteristic pattern of impairment, while PNFA and LPA overlap within many cognitive domains. The neuroimaging analysis showed left perisylvian region involvement. A comprehensive cognitive, neuroimaging and pathological approach is necessary to identify the clinical and pathogenetic features of different PPA variants.     

ADHD and DCD: a relationship in need of research

Although the connection between attention deficit hyperactivity disorder (ADHD) and developmental coordination disorder (DCD) has been recognized for several decades, little research has examined the relationship between these two disorders. This paper draws attention to the contribution the cognitive-energetic model (CEM) can make in determining the specific nature of these two disorders. An information processing approach such as the CEM is a useful model to identify specific and overlapping mechanisms that are disrupted in these two disorders. This paper describes the CEM and reviews the research so-far in relation to the model. The CEM has several advantages over other models: First, it predicts which task variables will be independent or may interact, thus enabling the investigator to determine the success/failure of the task manipulation(s) and identify spurious findings. Second, the CEM links energetic factors to task variables and predicts both additive and interactive effects. Third, the CEM enables executive processes such as selective attention, working memory and inhibition to be related to both energetic and lower level processes. Fourth, by employing the CEM in clinical research, taxonomy of deficits can be derived enabling further insight into the nature of the disorders and their specific neuropsychological dysfunction. Suggestions are made for future research into the neuropsychological deficits associated with ADHD and DCD.     

How to overcome the detrimental effects of noise in social interaction: the benefits of generosity

Interpersonal misunderstanding is often rooted in noise, or discrepancies between intended and actual outcomes for an interaction partner due to unintended errors (e.g., not being able to respond to an E-mail because of a local network breakdown). How can one effectively cope with noise in social dilemmas, situations in which self-interest and collective interests are conflicting? Consistent with hypotheses, the present research revealed that incidents of noise exert a detrimental effect on level of cooperation when a partner follows strict reciprocity (i.e., tit for tat) but that this effect can be overcome if a partner behaves somewhat more cooperatively than the actor did in the previous interaction (i.e., tit for tat plus 1). Also, when noise was present, tit for tat plus 1 elicited greater levels of cooperation than did tit for tat, thereby underscoring the benefits of adding generosity to reciprocity in coping with noise in social dilemmas. The Discussion outlines implications of the present work for theories focusing on self-presentation and attribution, communication, and trust and prorelationship behavior.     

A silent antipode: The making and breaking of psychoanalyst Wilhelm Stekel

Wilhelm Stekel, one of Freud's earliest followers , was expelled from the psychoanalytic movement in 1912 ostensibly because he did not know how to behave himself. Although he remained active as a psychoanalyst, his post-1912 work was mostly neglected, and consequently his historic import is seriously undervalued. The author reviews recent literature, reexamines the Freud-Stekel break, and focuses on Stekel's role as silent antipode. Freud's reference to an unnamed individual in his 1907 Gradiva paper (S. Freud, 1907/1959b) - commonly believed to be Jung - is now identified as Stekel. This not - unimportant correction of the historical record begins the exploration of a hitherto-undocumented antagonistic dialogue between Stekel and Freud.     

Effects of Reward and Response Cost on Response Inhibition in AD/HD, Disruptive, Anxious, and Normal Children

In previous research, children with attention deficit/hyperactivity disorder (AD/HD) have demonstrated impaired response inhibition on the stop paradigm. In this study we examined whether this impairment in fact reflects a motivational deficit. Four groups of children (age range 7–13 years) participated in the study: 14 AD/HD children, 21 normal controls, 14 disruptive children, and 14 anxious children. The psychopathological groups were recruited from special educational services and mental health outpatient clinics. Parent, teacher, and child questionnaires were used to select children with pervasive disorders. Normal controls attended regular classes and scored low on all questionnaires. Children were tested once with reward contingencies and once with response cost contingencies in a randomized cross-over design. We hypothesized that if a motivational deficit underlies poor response inhibition in AD/HD children, this deficit will be remedied by response contingencies. Despite the presence of response contingencies, AD/HD children showed poor response inhibition compared with normal controls. Findings argue against a motivational explanation for the response inhibition deficit in AD/HD children     

Focused attention in pervasively hyperactive children

This experiment was designed to investigate the hypothesized distractibility of hyperactive children in a focused attention task. Distractibility was defined in terms of Shiffrin and Schneider's model of focused attention as the ability to ignore irrelevant in favor of relevant information. Failure to inhibit processing of irrelevant information indicates a focused attention deficit. Task efficiency in all children decreased when irrelevant information was presented. The mean reaction time, within-subject variance of reaction time, and error percentage all increased compared with a nondistraction condition. Thus, the demands of focused attention, as formulated in the model, were measured optimally. Since hyperactives and controls did not differ significantly with respect to task efficiency in the distraction condition, a focused attention deficit in hyperactives was not demonstrated. The hyperactives did nevertheless make more errors and their responding was more variable than the controls. However, the difference in error percentages between hyperactives and controls was associated with the difference in IQ. It is speculated that the variable responding in hyperactives is caused by a less optimal state of performance unrelated to distractibility.The authors wish to thank L. Leertouwer for making the drawings. This research was supported by grants from the Netherlands Foundation for the Advancement of Pure Research (ZWO) and the Professor Duijker Fund.     

Counsellors' focus on competitive employment for people with severe mental illness: an application of the theory of planned behaviour in vocational rehabilitation programmes

Although the evidence-based Individual Placement and Support programme highlights the importance of the vocational rehabilitation (VR) counsellors' focus on competitive employment during career counselling, studies have shown that counsellors do not always target such jobs. This study examines which determinants affect the counsellors' intentions using an extended version of the Theory of Planned Behaviour. Cross-sectional data of 263 VR counsellors of three public employment services were analysed using structural equation modelling. A path model comprising attitudes, prior behaviour, and subjective and moral norms explained 69% of the variance in intentions. The findings indicate that counsellors focus more on competitive employment when they (1) view the placement in a competitive job as positive, (2) experience support and (3) have prior relevant experiences.