Paired associate learning in reading-disabled children: evidence for a rule-learning deficiency

Two experiments examined whether normal and disabled readers differed in the utilization of rules in a paired associate learning task. Experiment 1 required children to learn symbol-word associates. Children were assigned to one of three conditions: nonrule, consistent rule, or inconsistent rule. When present, the rule was based on semantic opposites. Subjects benefited from having the rule, but disabled readers showed less improvement across four test blocks than both chronological age (CA) controls and reading age (RA) controls, particularly in the inconsistent condition. Experiment 2 required subjects to learn symbol-symbol associations in one of three conditions: nonrule, consistent rule, or inconsistent rule. When present, the rule specified the locations of a subsidiary figure in each symbol according to the pattern top-right, bottom-left. Disabled and normal readers did not differ in the nonrule condition where reliance on visual memory would be an effective strategy. Normal readers were superior to disabled readers in both rule conditions. In addition, disabled readers in the inconsistent rule condition were less able than normal readers to apply the rule in a generalization task where memory demands were reduced. Results supported the hypothesis that disabled readers have greater difficulty than normal readers inducing and/or using rules, particularly when they are inconsistent. It is suggested that difficulties in acquiring or using complex and inconsistent rules may be one important source of problems learning spelling-sound correspondence rules, which in English are complex and inconsistent.     

Cognitive theory,cognitive impairment and clinical practice

The aim of this paper is to present a practical model for investigating cognitive impairment which integrates the experimental-cogaitive-information processing-theory and the psychometric-intellectual-abilities-tradition in psychology to understanding cognitive functioning. It reviews developments in cognitive theory in terms of Processes, complex and simple, such as Intelligence and Information Processing, and Factors of attained Level and Learning ability in the Verbal and Performance modalities. The Savage Cognitive Impairment Model (SCIM) is outlined and types of cognitive impairment defined. Measures of cognitive impairment relevant to clinical practice and research are presented.     

Processing power and delay—Limits on human performance

A computational approach to cognition is developed that has both broad scope and precision. The theory is based on a few simple assumptions and draws its conclusions from an analysis of limits on computational activity. These limits are a delay limit and a processing power limit. The theory explains published findings on memory span, measurement of spatial numerosity (and subitization), total-time effects, and the behavior of RT curves for the Sternberg item recognition experiment.     

Exploring Traumas in the Development of Talent: What Are They,What Do They Do,and What Do They Require?

It has recently been argued that performers benefit from trauma (i.e., memorable challenges) during development. To deepen knowledge in this area, we explored perceived traumas in the development of 20 senior-international performers with a multimethods, temporal-based design. Results showed that perceived traumas were primarily sports based, recognized from onset of investment, associated with immediately negative but ultimately positive impact, and negotiated through skills that were brought to, rather than generated by, these experiences. The findings provide an interesting contrast to messages in other early trauma-focused research and promote focus on the process and mechanisms of responding to and recovering from traumatic experiences.     

Relationship between nicotinic receptors and cognitive function in early Alzheimer's disease: a 2-[18F]fluoro-A-85380 PET study

Neuronal nicotinic acetylcholine receptors (nAChRs) are critical for higher order cognitive processes. Post-mortem studies suggest reductions in nAChRs (particularly the alpha(4)beta(2) subtype) with ageing and in Alzheimer's disease (AD). This study aimed to; (1) quantify nAChR distribution in vivo with 2-[18F]fluoro-A-85380 (2-FA) in 15 early AD patients compared to 14 age-matched, healthy controls (HC) and (2) correlate nAChR distribution with cognitive performance in both groups. All participants were non-smokers and underwent cognitive testing along with a dynamic PET scan after injection of 200 MBq of 2-FA. Brain regional 2-FA binding was assessed through a simplified estimation of Distribution Volume (DV(S)). The AD group differed significantly from HC on all cognitive measures employed, with impairments on measures of attention, working memory, language, executive function, visuospatial ability, verbal learning and verbal memory (p<.05). Contrary to post-mortem data this study found no evidence of in vivo nAChR loss in early AD despite significant cognitive impairment. Furthermore, no correlation between nAChR and cognitive performance was found for either group. The findings of the current study suggest preservation of nAChRs early in AD supporting previous studies. It is possible that while the clinical 2-FA PET method described here may be insensitive in detecting changes in early AD, such changes may be detected in more advanced stages of the illness.     

Neuropsychological impairment associated with compulsive hoarding

A group of patients with compulsive hoarding (n=30) was compared to a mixed clinical group (n=30) and a nonclinical community group (n=30) on laboratory tests of information-processing features hypothesized to be central to hoarding (memory, attention, and decision-making). Hoarding patients demonstrated slower and more variable reaction time, increased impulsivity, greater difficulty distinguishing targets and nontargets, and worse spatial attention relative to comparison groups. Multiple regression analyses demonstrated that slower reaction time and increased impulsivity were significantly related to hoarding symptoms over and above the effect of depression, schizotypy, and other obsessive-compulsive disorder (OCD) symptoms. There were no group differences on a test of emotion-based decision-making. Results are discussed in terms of previous findings and theoretical models of compulsive hoarding.     

Blunted hippocampal, but not striatal, acetylcholine efflux parallels learning impairment in diencephalic-lesioned rats

A rodent model of diencephalic amnesia, pyrithiamine-induced thiamine deficiency (PTD), was used to investigate the dynamic role of hippocampal and striatal acetylcholine (ACh) efflux across acquisition of a nonmatching-to-position (NMTP) T-maze task. Changes in ACh efflux were measured in rats at different time points in the acquisition curve of the task (early=day 1, middle=day 5, and late=day 10). Overall, the control group had higher accuracy scores than the PTD group in the latter sessions of NMTP training. During the three microdialysis sampling points, all animals displayed significant increases in ACh efflux in both hippocampus and striatum, while performing the task. However, on day 10, the PTD group showed a significant behavioral impairment that paralleled their blunted hippocampal--but not striatal--ACh efflux during maze training. The results support selective diencephalic-hippocampal dysfunction in the PTD model. This diencephalic-hippocampal interaction appears to be critical for successful episodic and spatial learning/memory.     

Effort,play, and sport

The effort involved in playing sports calls for a hermeneutical reflection on the power that we have to move our bodies. Drawing on Paul Ricoeur’s phenomenology of the lived body and his later ontology of the flesh, I explore how athletic displays of agility, strength, and speed within the theater of sporting competitions exemplify the way that the effort made by athletes attests to their will and desire to succeed. The agonistic spirit of the Greek Olympics is evident in sporting events where competitors or teams strive against one another. At the same time, the players’ willingness to enter the field of play has a counterpart in real-life situations over which we cannot exert complete control. The contingencies of the game in which the players are caught up are a model of the absence of aseity that is a mark of all human existence. By setting the playing field off from the concerns of everyday life, the game places this feature of the human condition on stage. The players’ physical exertion is the sign of a form of consent that sets the will, desire, and effort to exist against the wish for absolute freedom. Sporting competitions are therefore a theater for dramatizing the misery and grandeur of a specifically human freedom.