Working Memory and Learning in Early Alzheimer’s Disease

Cognitive deficits associated with early Alzheimers disease (AD) have been recently operationalised in terms of an acquisition deficit and the research supporting this view is presented. However, there is still debate concerning the nature of this deficit and how underlying cognitive processes may be detrimentally affecting the ability to acquire new information in early AD. This review argues that the pattern of cognitive deficits contributing to the acquisition impairment in early AD patients may be readily interpreted within the context of a working memory model. Isolating the component processes of working memory that underlie the acquisition deficit in early AD patients will aid in the design of clinical applications that are focussed at enhancing the ability to acquire new information in everyday life.     

Acquired distinctiveness and equivalence in human discrimination learning: Evidence for an attentional process

In a first stage of training, participants learned to associate four visual cues (two different colors and two different shapes) with verbal labels. For Group S, one label was applied to both colors and another to both shapes; for Group D, one label was applied to one color and one shape, and the other label to the other cues. When subsequently required to learn a task in which a given motor response was required to one of the colors and one of the shapes, and a different response to the other color and the other shape, Group D learned more readily than Group S. The task was designed so that the associations formed during the first stage of training could not generate differential transfer to the second stage. The results are consistent, however, with the proposal that training in which similar cues are followed by different outcomes will engage a learning process that boosts the attention paid to features that distinguish these cues.     

Identification of tone duration, line length, and letter position: an experimental approach to timing and working memory deficits in schizophrenia

Patients with schizophrenia display numerous cognitive deficits, including problems in working memory, time estimation, and absolute identification of stimuli. Research in these fields has traditionally been conducted independently. We examined these cognitive processes using tasks that are structurally similar and that yield rich error data. Relative to healthy control participants (n = 20), patients with schizophrenia (n = 20) were impaired on a duration identification task and a probed-recall memory task but not on a line-length identification task. These findings do not support the notion of a global impairment in absolute identification in schizophrenia. However, the authors suggest that some aspect of temporal information processing is indeed disturbed in schizophrenia.     

Prediction of adolescent and adult delinquency from childhood Rorschach ratings

Relatively few studies have predicted adolescent or adult delinquency from childhood Rorschach data. Incremental validity of Rorschach measures over other known consistent and more easily obtained predictors has typically not been investigated. We addressed Rorschach data's incremental validity over mother's reports of externalizing behavior and mother-child relations for predicting officially registered adolescent and adult delinquency in a longitudinal study of 122 Swedish men. The Rorschach measures we used were aggregates of blind, prospectively performed, global expert ratings based on a holistic evaluation of protocols. An aggregate of Rorschach-based ratings of ego strength significantly improved the prediction of delinquency in adolescence and adulthood over and above earlier identified best predictors (mother's ratings of mother-child relations and externalizing problem behavior).     

The role of locomotion in the acquisition and transfer of spatial knowledge in children

The role of locomotion in the acquisition and transfer of spatial knowledge was investigated in 144 five-, seven- and eleven-year-old children. Two experiments were conducted in the Kiel locomotor maze. In the first experiment, one group of children explored the spatial layout by walking through the maze, while another learned the maze by surveying the layout. In the second experiment, children were exposed to one of two orientation tests in the maze, one of which could be solved using "landmark orientation", the other only using a "relational place orientation". Children sitting by the side of the experimental chamber surveying the maze needed fewer trials to learn the spatial layout than children exploring the environment in the locomotion condition, but in the orientation test demanding the "relational place orientation" children who had explored the maze in the locomotion condition outperformed the children in the non-locomotion condition. Results are discussed in the context of cognitive mapping models.     

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.     

Functional neuroanatomy of altered states of consciousness: the transient hypofrontality hypothesis

It is the central hypothesis of this paper that the mental states commonly referred to as altered states of consciousness are principally due to transient prefrontal cortex deregulation. Supportive evidence from psychological and neuroscientific studies of dreaming, endurance running, meditation, daydreaming, hypnosis, and various drug-induced states is presented and integrated. It is proposed that transient hypofrontality is the unifying feature of all altered states and that the phenomenological uniqueness of each state is the result of the differential viability of various frontal circuits. Using an evolutionary approach, consciousness is conceptualized as hierarchically ordered cognitive function. Higher-order structures perform increasingly integrative functions and thus contribute more sophisticated content. Although this implies a holistic approach to consciousness, such a functional hierarchy localizes the most sophisticated layers of consciousness in the zenithal higher-order structure: the prefrontal cortex. The hallmark of altered states of consciousness is the subtle modification of behavioral and cognitive functions that are typically ascribed to the prefrontal cortex. The theoretical framework presented yields a number of testable hypotheses.     

On weighted exponential entropies

As an alternative to Shannon's classical entropy measure of information, an exponential entropy function was proposed by Pal and Pal in 1989 and 1991. To generalize Pal's entropy further, this author introduced two different families of exponential entropies that are one-parameter generalizations of Pal's entropy. The purpose of the present paper is to define weighted entropies corresponding to those one-parameter generalizations. Some properties and examples of such weighted exponential entropies are discussed.     

Methodology in subliminal psychodynamic activation: the next step in the debate

Subliminal psychdynamic activation methodology has recently been the subject of an exchange of views between Birgeg?rd and Sohlberg (1999) and Fudin (2000). The agreements and some remaining points of contention are summarized here. The main difference of opinion appears to concern unconscious verbal encoding in relation to subjective experience in subliminal stimulation and whether subliminal psychodynamic activation results are unreliable until a full explanation of how verbal encoding works is at hand. We conclude that clarifying perspectives is important and that those suggesting alternative explanations of results on subliminal psychodynamic activation must now empirically investigate their claims.