Metric unfolding: Data requirement for unique solution & clarification of Schönemann's algorithm

The object of this paper is to clarify Schönemann's unfolding algorithm and, in particular, to make it clear that the equations numbered (3.2) in Schönemann's [1970] article, which define Schönemann's solutions, are not a complete set of restraints for the purpose of defining metric unfoldings. Namely, Schönemann has transformed the original equations which define an unfolding to a set of linear and non-linear equations of which he uses only the linear equations to define his solutions. Given infallible data (solution(s) exist) Schönemann's solutions will include the correct solutions. If enough data are available so that there are enough linear equations to uniquely determine a single solution, then Schönemann's solution will coincide with the correct solution. LetP andQ denote the number of elements in the two sets of points, the interset distances of which are specified by the data in the unfolding problem. Letm denote the dimensionality of the Euclidean space into which these points are to be imbedded. If only the linear equations, numbered (18) herein, are to be used, then Schönemann gives the following data requirement for the solution to be uniquely determined: Max {P – 1,Q – 1} m(m + 3)/2. If the full set of linear and nonlinear equations (18–20) are used, then the amount of data required for a solution to be locally unique is relaxed toP +Q – 1 m(m + 3)/2. Both of these results assume that the equations are independent, which has not been proved.This study was supported by General Research Support Grant RR 5612 of the Division of Research Facilities and Resources, National Institutes of Health, U.S. Public Health Service.     

The role of verbalization in the Rorschach response process: a review

Traditional Rorschach theory has consistently overlooked the linguistic aspect of the response process. Most conceptualizations focus on the perceptual and cognitive aspects of the process, never examining the subject's need to find a linguistic representation for the inner, perceptual process. This review examines the traditional formulations and suggests that new research from information-processing, neuropsychological, and dual-coding memory theory paradigms offer new possibilities for Rorschach research that would incorporate an appreciation of the unique cognitive demand of the test--the linking of percept with language.     

The effects of training, epinephrine, and glucose injections on plasma glucose levels in rats

Recent findings indicate that a post-training injection of glucose enhances memory storage, suggesting that release of glucose into plasma may mediate the effects of epinephrine and perhaps other treatments on memory. The present experiment examined the effects of handling, inhibitory (passive) avoidance training, epinephrine and glucose injections on plasma glucose levels in Sprague-Dawley rats. Handling produced a small, but significant, transient increase in plasma glucose above basal levels. Saline injections caused a similar increase in circulating glucose levels. Inhibitory avoidance training with high footshock (2.0 mA, 2.0 s) resulted in significant increases in plasma glucose levels above those of low (0.5 mA, 0.75 s) and unshocked animals suggesting that glucose release is responsive to inhibitory avoidance training. Subcutaneous injections of epinephrine (0.01-1.0 mg/kg), or glucose (10-1000 mg/kg) significantly elevated glucose levels above those of saline-injected animals in a dose-dependent manner. Memory facilitating doses of epinephrine and glucose resulted in increases in plasma glucose levels similar to those seen in rats trained with high footshock. Higher doses of epinephrine and glucose resulted in further increases in circulating glucose, to levels significantly greater than those of memory facilitating doses. These results suggest that memory modulation, both endogenous and in response to epinephrine injections, may be mediated in part by circulating glucose levels. Thus, the findings of these experiments support the view that circulating glucose levels regulate the efficacy of neural memory storage processes.     

Medical Education for Social Justice: Paulo Freire Revisited

Although social justice is an integral component of medical professionalism, there is little discussion in medical education about how to teach it to future physicians. Using adult learning theory and the work of Brazilian educator Paulo Freire, medical educators can teach a socially-conscious professionalism through educational content and teaching strategies. Such teaching can model non-hierarchical relationships to learners, which can translate to their clinical interactions with patients. Freirian teaching can additionally foster professionalism in both teachers and learners by ensuring that they are involved citizens in their local, national and international communities.     

Order of question presentation and correlation between judgments of comparative and own risk

Unrealistic optimism is often assessed using a single question asking for an estimate of comparative risk. However, it has been proposed that individuals treat such a question essentially as though it were only about their own risk. This proposal leads to the prediction that, when the questions about own risk and comparative risk are asked in sequence, the correlation between the resulting estimates should be lower if the question about own risk comes first than if the question about comparative risk comes first. This prediction was tested using a student sample (N=68). Participants answered the two types of question in sequence, with order of presentation being counterbalanced. Results were in accord with the prediction. Possible reasons are advanced for individuals' answering questions about comparative risk as if the questions concerned their own risk.     

The anatomy of amnesia: neurohistological analysis of three new cases

The most useful information about the anatomy of human memory comes from cases where there has been extensive neuropsychological testing followed by detailed post-mortem neurohistological analysis. To our knowledge, only eight such cases have been reported (four with medial temporal lobe damage and four with diencephalic damage). Here we present neuropsychological and post-mortem neurohistological findings for one patient (NC) with bilateral damage to the medial temporal lobe and two patients (MG, PN) with diencephalic damage due to bilateral thalamic infarction and Korsakoff's syndrome, respectively. All three patients exhibited a similar phenotype of amnesia with markedly impaired declarative memory (anterograde and retrograde) but normal performance on tests of nondeclarative memory (e.g., priming and adaptation-level effects) as well as on tests of other cognitive functions. Patient NC had damage to the hippocampus (dentate gyrus and the CA1 and CA3 fields) and layer III of the entorhinal cortex, but with relative sparing of the CA2 field and the subiculum. Patient MG had damage to the internal medullary lamina and mediodorsal thalamic nuclei. Patient PN had damage to the mammillary nuclei, mammillothalamic tracts, and the anterior thalamic nuclei. These findings illuminate several issues regarding the relation between diencephalic and medial temporal lobe amnesia, the status of recognition memory in amnesia, and the neuroanatomy of memory.     

Single-item memory, associative memory, and the human hippocampus

We tested recognition memory for items and associations in memory-impaired patients with bilateral lesions thought to be limited to the hippocampal region. In Experiment 1 (Combined memory test), participants studied words and then took a memory test in which studied words, new words, studied word pairs, and recombined word pairs were presented in a mixed order. In Experiment 2 (Separated memory test), participants studied single words and then took a memory test involving studied word and new words. In a separate test, they studied word pairs and then took a memory test involving studied word pairs and recombined word pairs. In both experiments, patients were impaired at memory for single items as well as memory for associations, suggesting that the hippocampus is important for both of these memory functions. In Experiment 1, patients appeared to be more impaired at associative memory than item memory. In Experiment 2, patients were similarly impaired at associative memory and item memory. These different findings are considered, including the fact that in Experiment 1 the results depended on the fact that controls produced unexpectedly low false-alarm rates to recombined pairs. We discuss single-item and associative memory from the perspective that the hippocampus and adjacent cortex work cooperatively to signal recognition and that simple dichotomies do not adequately describe the division of labor within the medial temporal lobe.     

The effects of haloperidol on thought disorder and IQ in schizophrenia

The impact of haloperidol treatment on the Wechsler Adult Intelligence Scale (WAIS) and the Thought Disorder Index was investigated in a group of 19 patients with schizophrenia tested both before and after 26 days of treatment with haloperidol. Thought disorder scores declined significantly over the course of treatment and fewer patients demonstrated severe forms of thought disorder at the end of the trial. WAIS performance improved significantly but the magnitude of change was consistent with the literature on expected practice effects. Thought disorder scores were negatively correlated with IQ at baseline, but not at Day 26. The results suggest a partial dissociation of thought disorder and other cognitive functions in schizophrenia.     

EQUATING INVERSE PROBABILITIES IN IMPLICIT PERSONALITY JUDGMENTS

Abstract— Meehl and Rosen (1955) observed that their colleagues tended to equate the sensitivity of a sign (its probability given a diagnostic category) with its predictive accuracy (the probability of the diagnostic category given the sign). Such equating of inverse probabilities implies ignoring base rates. Later, many researchers demonstrated such neglect in a number of experimental contexts involving hypothetical judgments; others have found some use of base rates—but only when base rates were supplied by the experimenter, in which case even irrelevant base rates influenced judgment. The present study tested for equating conditional probabilities in a context similar to the contexts involved in the initial observations—that is, subjects strove for accuracy rather than attempted to make good judgments about hypothetical problems, and the base rates were generated by the subjects themselves. Neglect of base rates was revealed by within-individual comparisons showing subjects equated inverse probabilities without equating the corresponding unconditional ones.