Visual searh through word lists as a function of grade level,reading ability,and target repetition

Second-, fourth-, and sixth-grade students of high or low reading ability and college students carried out a visual-search task in which they scanned a list of 10 words, looking for a target word which was changed every trial or remained constant during an entire session. Search time increased linearly with serial position, consistent with a serial self-terminating model of visual search. The search rate increased from 3.3 words/sec in the second grade to 8.4 words/sec in college. Reading ability was not a significant factor in any comparisons. These results on the development of visual-search ability agree with others in showing that with increasing age there is a marked increase in search speed. However, retarded readers are as competent as their age peers on this task, suggesting that reading dysfunction must be traced to other deficiencies.     

Effect of dopamine on diuresis and its role in forming a renal CR

Four female mongrel dogs were used. Three had both ureters transplanted to the surface of the abdomen and one had a unilateral nephrectomy on the left and the right ureter transplanted to the abdomen. In dogs with externalized ureters our results with dopamine show changes in cardiac rate and renal secretion. The method used was 1) injection of dopamine, 2) measurement of subsequent changes in renal secretions (unconditional reflex), 3) and heart rate (HR). After 40 daily injections im of 2.5 mg/kg in normal saline the possible production of a diuretic CR was tested by injecting normal saline im and a tone was used as a signal. The control for normal saline showed no change in HR nor any of the constituents measured. The dopamine injection resulted in an increase of epinephrine in the urine of 300–600 per cent for 45 minutes; of norepinephrine of 200–500 per cent for 45 minutes; of an increase of 50 per cent in urine volume for 45 or more minutes; of absolute Na secretion of 49 per cent, of K, 20 per cent; of creatinine, 39 per cent (average in 3 dogs for 45 minutes diuresis). When the conditional stimulus (normal saline and tone) was given after several months training with the conditional signal and the injection of dopamine, there was no significant CR change to the HR nor any of the above components of urine. The conclusion is that in spite of the great increase of urine volume and composition of above substances there was no significant increase to the signals for the im injection of dopamine,i.e., no conditioning to dopamine.     

Advanced training in child psychology: Key elements in offering a Doctor of Psychology (DPsych) programme in South Africa

The aim of this article is to propose some benchmarks for a Doctor of Psychology (DPsych) in advanced training in Child Psychology in South Africa, and to highlight key elements in offering such a programme. In doing so, we use as case illustration an existing DPsych programme currently being offered at the University of the Free State, South Africa. We consider advanced child psychology training to registered psychologists in the clinical, counselling and educational categories. The DPsych option encompasses clinical practice, research, training, selection, and student outcomes in the context of theory as well as evidence-based practices. A wider adoption of a DPsych, focusing on child psychology, would add value to the integration of the best available research and clinical expertise in child mental health care in South Africa.     

Quantification of swim patterns in the morris water maze

Spatial learning and memory in rodents is most often assessed in the Morris water maze. Neurobiologists have to distinguish behavioral patterns to unravel underlying neuronal systems. We analyzed swim patterns of mice videotaped before and after training with a multitrial procedure in the water maze. In addition to traditional parameters, the animals’ position in relation to trained and other possible platform locations was estimated five times per second by an image analysis system. This parameter,cumulative distance to platform, was correlated with time spent in the platform quadrant but not with latency to and crossings of the platform location. We detected a subgroup of animals with concentric patterns within the group of spatial/persistent patterns. Random patterns were classified as well. Swim patterns before training were not predictive for the one after training. In summary, image analysis systems have made it very convenient to quantify behavior. Using their capacity, we have further improved the analysis of swim patterns, revealing animals’ different approaches to solve a problem.     

Similes on the Internet have explanations

We searched the Internet for expressions linking topics, such as crime, and vehicles, such as disease, as similes (crime is like a disease) and as metaphors (crime is a disease). We counted the number of times the expressions were accompanied by explanations (crime is like a disease because it spreads by direct personal influence). Similes were more likely than metaphors to be accompanied by explanations. Similes may be preferred if a writer wants to express an out-of-the-ordinary relation between the topic and the vehicle.     

More than meets the eye: Context effects in word identification

The influence of semantic context on word identification was examined using masked target displays. Related prime words enhanced a signal detection measure of sensitivity in making lexical decisions and in determining whether a probe word matched the target word. When line drawings were used as primes, a similar benefit was obtained with the probe task. Although these results suggest that contextual information affects perceptual encoding, this conclusion is questioned on the grounds that sensitivity in these tasks may be determined by independent contributions of perceptual and contextual information. The plausibility of this view is supported by a simulation of the experiments using a connectionist model in which perceptual and semantic information make independent contributions to word identification. The model also predicts results with two other analytic methods that have been used to argue for priming effects on perceptual encoding.     

Memory systems within a cognitive architecture

This article addresses the division of memory systems in relation to an overall cognitive architecture. As understanding the architecture is essential to understanding the mind, developing computational cognitive architectures is an important enterprise in computational psychology (computational cognitive modeling). The article proposes a set of hypotheses concerning memory systems from the standpoint of a cognitive architecture, in particular, the four-way division of memory (including explicit and implicit procedural memory and explicit and implicit declarative memory). It then discusses in detail how these hypotheses may be validated through examining qualitatively the literature on memory. A quick review follows of computational simulations of a variety of quantitative data (which are not limited to narrowly conceived “memory tasks”). Results of accounting for both qualitative and quantitative data point to the promise of this approach.     

Broca's aphasia, verbs and the mental lexicon

Verb production is notoriously difficult for individuals with Broca's aphasia, both at the word and at the sentence level. An intriguing question is at which level in the speech production these problems arise. The aim of the present study is to identify the functional locus of the impairment that results in verb production deficits in Broca's aphasia. Levelt's (1989) model is used as a theoretical framework for this study. Two experiments have been conducted, one on verb movement and one on verbs with alternating transitivity. The results suggest that the functional impairment in Broca's aphasia should be located in Levelt's "grammatical encoder."