Search

Background: There are no studies on adults with unilateral brain lesions regarding story reading with incidental/implicit comprehension and memory, in which memory is only assessed through delayed recall. There is a need for validation of cerebral laterality in this type of verbal recall, which includes spontaneous performance (free or uncued condition (UC)), and induced-through-question performance regarding the forgotten units (cued condition (CC)). Objectives: To explore the effects of unilateral brain lesions, of oral reading with expression (RE) and comprehension (RC) on delayed recall of a story, as either UC or CC; and to validate the ability of UC and CC to discriminate the side of brain injury. Methods: Data were obtained from 200 right-handed volunteers, among whom 42 had left-hemisphere injury (LHI), 49 had right-hemisphere injury (RHI) and 109 were demographically-matched healthy participants (HP). Patients who were unable to read, understand or speak were excluded. Results: LHI individuals presented impairment of both UC and CC, in relation to the other two groups (non-LHI) with sensitivity and specificity above 70%. LHI and RHI individuals were not significantly different in RE and RC, but they were both different from HP in all the assessments except CC, in which RHI individuals resembled HP. Despite this lack of abnormality in RHI individuals during CC, about half of this group showed impairment in UC. Additionally, whereas RE had a significant effect on UC, the moral of the story (RC) had a significant effect on both UC and CC. Conclusions: The left hemisphere was dominant for this memory task involving implicit processing. RESUMEN Antecedentes: No existen estudios en adultos con lesiones cerebrales unilaterales sobre la lectura de una historia, con comprensión y memoria incidental/implícita, midiendo sólo el recuerdo diferido. Se necesita validar la lateralidad cerebral en este tipo de recuerdo verbal que incluye: desempeño espontáneo (condición sin claves (CS) o libre) y desempeño inducido con preguntas sobre las unidades olvidadas (condición con claves (CC)). Objetivos: Explorar el efecto de las lesiones cerebrales unilaterales, la lectura expresiva (LE) y la comprensiva (LC), sobre el recuerdo diferido de una historia, sea CS o CC. Validar CS y CC en su capacidad para discriminar el lado de la lesión cerebral. Métodos: Los datos se obtuvieron de 200 voluntarios diestros, 42 con lesiones del hemisferio izquierdo (LHI), 49 con lesiones del hemisferio derecho (LHD), y 109 participantes sanos (PS), equiparados demográficamente. Se excluyeron los pacientes que no pudieron leer, entender o hablar. Resultados: LHI resultó perjudicado respecto de los otros dos grupos (no-LHI) en CS y CC, con una sensibilidad y especificidad superior al 70%. LHI y LHD no se diferenciaron significativamente en LE ni LC, pero ambos fueron diferentes de los PS en todas las evaluaciones excepto CC, en donde LHD se asemejó a los PS. A pesar de esta ausencia de anomalía en LHD durante CC, aproximadamente la mitad de LHD mostró deterioro en CS. Además, mientras que LE tuvo un efecto significativo en CS, la moraleja de la historia (LC) tuvo un efecto significativo tanto en CS como en CC. Conclusiones: El hemisferio izquierdo fue dominante para esta tarea de memoria que involucró procesamiento implícito.

Objective Posterior cortical atrophy (PCA) is a neurodegenerative syndrome characterised by progressive impairment in visuospatial and perceptual function. Recent findings show that memory functioning can also be compromised early in the course of disease. In this study, we investigated the neural basis of memory impairment in PCA, and hypothesised that correlations would be observed with parietal cortex rather than classic medial temporal memory structures. Methods Eighteen PCA patients, 15 typical Alzheimer's disease (tAD) patients and 21 healthy controls underwent memory testing with the Rey Auditory Verbal Learning Test (RAVLT) word list and MRI. Voxel-based morphometry (VBM) was used to identify regions in the parietal and medial temporal lobes that correlated with memory performance. Results Compared with controls, PCA patients were impaired at learning, immediate and delayed recall and recognition of the RAVLT. Learning rate and immediate recall was significantly better in PCA compared to tAD, whereas there was no difference in delayed recall. Recognition memory also was not statistically different between patient groups, but PCA patients made significantly more false positive errors than tAD patients. VBM analysis in the PCA patients revealed a significant correlation between total learning and grey matter density in the right supramarginal gyrus, right angular gyrus and left postcentral gyrus. The left post central gyrus also significantly correlated with immediate and delayed recall and with recognition memory. No correlations were detected in the medial temporal lobe. Conclusions The findings provide novel evidence that early verbal memory impairment is frequently observed in PCA, and is associated with damage to lateral parietal structures. The results have implications for the diagnosis and management of PCA., Highlights • PCA patients were impaired in learning, recall and recognition memory. • Deficits were evident in the early stages of disease. • Memory impairment was associated with damage to lateral parietal structures. • No correlations were detected in the medial temporal lobe.

International audience; To examine the short-term impact of the WIXX multimedia communication campaign on children's physical activity (PA) beliefs and behaviors, 3 repeated cross-sectional telephone surveys were conducted before, 9 months after, and 21 months after the launch of the campaign. A random-digit dialing procedure was used to recruit children ages 9 to 13 years. Children's PA beliefs, behaviors, and recall of the WIXX ads were self-reported. Logistic regression models showed that girls exposed to the WIXX ads were more likely to believe that PA would help to make new friends (odds ratio [OR] = 1.4, 95% confidence interval [CI] [1.0, 1.9]) and that they can be active even if too busy (OR = 1.4, 95% CI [1.0, 1.8]) compared to girls not exposed. Boys exposed were more likely to believe that PA would help to spend time with friends (OR = 1.4, 95% CI [1.1, 1.9]). Boys (OR = 1.5, 95% CI [1.1, 2.0.]) and girls (OR = 1.4, 95% CI [1.1, 1.8]) exposed were more likely to report having tried new PAs. No significant impact of the campaign was observed on overall PA after we controlled for confounders. Recall of the WIXX ads was associated with a significant, albeit modest, impact on some PA beliefs and intermediate PA behaviors.

BackgroundPrior research on the nature of the vulnerability of neuroticism to psychopathology suggests biases in information processing towards emotional rather than neutral information. It is unclear to what extent this relationship can be explained by genetic or environmental factors.MethodThe genetic relationship between a neuroticism composite score and free recall of pleasant and unpleasant words and the reaction time on negative probes (dot-probe task) was investigated in 125 female twin pairs. Interaction effects were modelled to test whether the correlation between neuroticism and cognitive measures depended on the level of the neuroticism score.ResultsThe only significant correlation was between neuroticism and the proportion of recalled unpleasant words (heritability is 30%), and was only detectable at the higher end of the neuroticism distribution. This interaction effect seems to be due to environmental effects that make people in the same family more similar (e.g. parental discipline style), rather than genetic factors. An interesting sub-finding was that faster reaction times for left versus right visual field probes in the dot-probe task suggest that cognitive processing in the right hemisphere is more sensitive to subliminal (biologically relevant) cues and that this characteristic is under substantial genetic control (49%). Individual differences in reaction times on right visual field probes were due to environmental effects only.ConclusionsThere is no evidence that the predisposition of individuals to focus on negative (emotional) stimuli is a possible underlying genetic mechanism of neuroticism.

In this paper, we describe a patient (LI) suffering from semantic dementia who showed a category-specific naming impairment for living things over and above the effects of several nonsemantic confounding variables. We investigated the characteristics of LI's impairment to address the following three issues raised in three different accounts of category-specific impairments: (i) the role of an imbalance in the loss of sensory compared to nonsensory features (assumed by the Sensory Functional Theory [Warrington, E. K., & Shallice, T. (1984). Category-specific semantic impairments. Brain, 107, 829-859]); (ii) the role of cross domain differences in Feature Correlation (assumed by the Conceptual Structure Account [Moss, H., Tyler, L. K., & Devlin, J. T. (2002). The emergence of category-specific deficits in a distributed semantic system. In: E. M. E. Forde & G. W. Humphreys (Eds.), Category Specificity in Brain and Mind (pp. 115-147). New York: Psychology Press]); (iii) the role of semantic distance (proposed by Cree and McRae [Cree, G. S., & McRae, K. (2003). Analyzing the factors underlying the structure and computation of the meaning of chipmunk, cherry, chisel, cheese, and cello (and many other such concrete nouns). Journal of Experimental Psychology: General, 132, 163-201]). We found that semantic distance was the only factor causally linked to LI's poorer performance on living things. In fact, her naming performance was less accurate on items that had many semantic neighbours, which is typical of living things. On the contrary, a feature listing task revealed that the features available to LI were not predicted by their level of correlation, as expected by the Conceptual Structure Account. Finally, at variance with the Sensory Functional Theory, although LI quoted sensory features less accurately than nonsensory ones, this did not give rise to a disproportionate loss of semantic features in the living domain.

Objectives: As a fundamental element of medical practice, clinical reasoning should be cultivated in courses of study in human medicine. To date, however, no conclusive evidence has been offered as to what forms of teaching and learning are most effective in achieving this goal. The Diagnostic Thinking Inventory (DTI) was developed as a means of measuring knowledge-unrelated components of clinical reasoning. The present pilot study examines the adequacy of this instrument in measuring differences in the clinical reasoning of students in varying stages of education in three curricula of medical studies. Methods: The Diagnostic Thinking Inventory (DTI) comprises 41 items in two subscales (“Flexibility in Thinking” and “Structure of Knowledge in Memory”). Each item contains a statement or finding concerning clinical reasoning in the form of a stem under which a 6-point scale presents opposing conclusions. The subjects are asked to assess their clinical thinking within this range. The German-language version of the DTI was completed by 247 student volunteers from three schools and varying clinical semesters. In a quasi-experimental design, 219 subjects from traditional and model courses of study in the German state of North Rhine-Westphalia took part. Specifically, these were 5th, 6th and 8th semester students from the model course of study at Witten/Herdecke University (W/HU), from the model (7th and 9th semester) and traditional (7th semester) courses of study at the Ruhr University Bochum (RUB) and from the model course of study (9th semester) at the University of Cologne (UoC). The data retrieved were quantitatively assessed. Results: The reliability of the questionnaire in its entirety was good (Cronbach’s alpha between 0.71 and 0.83); the reliability of the subscales ranged between 0.49 and 0.75. The different groups were compared using the Mann-Whitney test, revealing significant differences among semester cohorts within a school as well as between students from similar academic years in different schools. Among the participants from the model course of study at the W/HU, scores increased from the 5th to the 6th semester and from the 5th to the 9th semester. Among individual cohorts at RUB, no differences could be established between model and traditional courses of study or between 7th and 9th semester students in model courses of study. Comparing all participating highest semester students, the 8th semester participants from the W/HU achieved the highest scores – significantly higher than those of 9th semester RUB students or 9th semester UoC students. Scores from the RUB 9th semester participants were significantly higher than those of the 9th semester UoC participants. Discussion: The German-language version of the DTI measures self-assessed differences in diagnostic reasoning among students from various semesters and different model and traditional courses of study with satisfactory reliability. The results can be used for discussion in the context of diverse curricula. The DTI is therefore appropriate for further research that can then be correlated with the different teaching method characteristics and outcomes of various curricula.

Many clinical decisions are made in uncertainty. When the diagnosis is uncertain, the goal is to establish a diagnosis or to treat even if the diagnosis remains unknown. If the diagnosis is known (e.g., breast cancer or prostate cancer) but the treatment is risky and its outcome uncertain, still a choice must be made. In researching the psychology of clinical judgment and decision making, the major strategy is to compare observed clinical judgments and decisions with the normative model established by statistical decision theory. In this framework, the process of diagnosing is conceptualized as using imperfect information to revise opinions; Bayes' theorem is the formal rule for updating a diagnosis as new data are available. Treatment decisions should be made so as to maximize expected value. This essay uses Bayes' theorem and concepts from decision theory to describe and explain some well-documented errors in clinical reasoning. Heuristics and biases are the cognitive factors that produce these errors.

Background Is there evidence for expertise on collaboration and, if so, is there evidence for cross-domain application? Recall of stimuli was used to measure so-called internal collaboration scripts of novices and experts in two studies. Internal collaboration scripts refer to an individual’s knowledge about how to interact with others in a social situation. Method—Study 1 Ten collaboration experts and ten novices of the content domain social science were presented with four pictures of people involved in collaborative activities. The recall texts were coded, distinguishing between superficial and collaboration script information. Results—Study 1 Experts recalled significantly more collaboration script information (M = 25.20; SD = 5.88) than did novices (M = 13.80; SD = 4.47). Differences in superficial information were not found. Study 2 Study 2 tested whether the differences found in Study 1 could be replicated. Furthermore, the cross-domain application of internal collaboration scripts was explored. Method—Study 2 Twenty collaboration experts and 20 novices of the content domain medicine were presented with four pictures and four videos of their content domain and a video and picture of another content domain. All stimuli showed collaborative activities typical for the respective content domains. Results—Study 2 As in Study 1, experts recalled significantly more collaboration script information of their content domain (M = 71.65; SD = 33.23) than did novices (M = 54.25; SD = 15.01). For the novices, no differences were found for the superficial information nor for the retrieval of collaboration script information recalled after the other content domain stimuli. Discussion There is evidence for expertise on collaboration in memory tasks. The results show that experts hold substantially more collaboration script information than did novices. Furthermore, the differences between collaboration novices and collaboration experts occurred only in their own content domain, indicating that internal collaboration scripts are not easily stored and retrieved in memory tasks other than in the own content domain.

Aim of the present review paper was to evaluate the hypothesis (included in the proposal of new research criteria for Alzheimer's disease; Dubois et al., Lancet Neurology, 6, 734-746, 2007) that a neuropsychological tool which provides support for the semantic encoding of memorandum at the time of study and supplies category cues at the time of retrieval (i.e. the Grober-Buschke paradigm) is more effective than traditional measures of free recall in 1) differentiating patients affected by the amnestic form of Mild Cognitive Impairment (MCI) or by mild to moderate forms of Alzheimer's disease (AD) from healthy matches, 2) predicting the conversion of individuals with MCI to AD, and 3) differentiating AD patients from individuals affected by other forms of dementia. Results of the review are controversial regarding the superiority of the Grober-Buschke procedure in differentiating individuals affected by AD or MCI from healthy individuals. The only study that evaluated this issue directly found that the Grober-Buschke procedure was more sensitive and specific than more traditional memory tests in predicting the conversion of MCI patients to AD. Finally, two studies reported that patients affected by AD or other forms of dementia showed different performance patterns in the free and cued recall tasks of the Grober-Buschke procedure. In conclusion, although encouraging results are reported in the few studies that investigated the ability of this procedure to predict the evolution of individuals with amnestic MCI and to differentiate AD patients from patients with other forms of cortical and subcortical dementia, more experimental work is needed to confirm these positive findings.

We investigated whether MCI patients with hippocampal atrophy or multiple subcortical infarcts demonstrate neuropsychological patterns and markers considered typical of Alzheimer's disease (AD) and of vascular dementia (VD), respectively. An extensive neuropsychological battery, including tests of memory, visual-spatial and executive functions, language, attention, praxis and psychomotor speed, was administered to 36 mild cognitive impairment (MCI) patients with hippocampal atrophy and 41 MCI patients with multiple subcortical infarcts. Both groups of MCI patients were very mildly impaired and well matched in terms of MMSE scores. A clear, disproportionately severe, episodic memory disorder was observed in MCI patients with hippocampal atrophy. A less specific neuropsychological profile, consisting of impairment on an Action Naming task that is sensitive to frontal lobe lesions, was observed in MCI patients with multiple subcortical infarcts. In MCI patients, a disproportionately severe episodic memory impairment strongly points to an Alzheimer's type brain pathology, whereas the prevalence of executive deficits and other frontal lobe symptoms are a much weaker diagnostic marker of small vessel subcortical disease. (JINS, 2008, 14, 611–619.)

Most studies on medical expertise research have focused on diagnostic performance, whereas patient management has been largely ignored. According to knowledge encapsulation theory, applying encapsulated knowledge is a characteristic of expert doctors' diagnostic reasoning, but it is unclear whether or not encapsulated knowledge also plays a prominent role when processing a clinical case with a management focus.The participants were 40 medical students (20 in Year 4 and 20 in Year 6) and 20 expert doctors (internists). Participants were asked to study the cases with either a diagnostic (Dx) or a management (Mx) focus. Subsequently, participants were asked to write down what they remembered from the case.In both conditions, experts recalled fewer propositions and used more high-level inferences than medical students. Furthermore, they processed the cases faster and more accurately than medical students, but no significant difference between Mx and Dx conditions was found. Year 4 students also showed no significant differences in recall and processing speed between conditions. By contrast, Year 6 students recalled more in a Dx than in an Mx condition, but there was no significant difference in processing speed between conditions.In both conditions, findings indicate that the experts' and Year 4 students' performance was not affected by processing focus. The fact that only Year 6 students were affected by processing focus might be explained by the assumption that their diagnostic knowledge and management knowledge are not fully integrated yet, a process that has already taken place in the expert's knowledge structure.

Guidelines are presented to facilitate the use of the WAIS Digit Symbol measure of paired associate recall as a neuropsychological instrument. Currently three formal variants of the test exist with accompanying normative data (the original WAIS-R-NI form; a WAIS-R Short Form; a longer WAIS-III form), providing a potential source of confusion which may limit its application. To circumvent this, the present article critically evaluates: (i) variations in test forms and their advantages; (ii) available norms in terms of age and education, with pointers for more differentiated guidelines in this regard; and (iii) the desirability of incorporating a delayed recall variant of the test. Finally, a synopsis of data is presented that supports the screening potential of Digit Symbol paired associate recall in cases of mild neurocognitive dysfunction. For the purposes of this paper, the term WAIS is used with broad reference to all variations of the original Wechsler Adult Intelligence Scale (1955) upon which they were based, including the WAIS-R (1981) and WAIS-III (1997) updated editions, and the South African WAIS (1969). The terms South African WAIS (South African Wechsler Adult Intelligence Scale), WAIS-R (Wechsler Adult Intelligence Scale - Revised), and WAIS-III (Wechsler Adult Intelligence Scale-III), refer to these specific versions of the test.

Medical students and experts were given head-and-shoulder photographs of patients, each showing a key feature of the patient's problem. Three quarters of these pictures were taken from textbooks. Noticing these supposedly obvious features was difficult and strongly influenced by contextual factors. Both experts and students gained about 20% in diagnostic accuracy by having the key features verbally described for them, although these were clearly visible on the photographs. Conversely, both experts and students reported seeing more of these features when the correct diagnosis was suggested to them. This facilitation resulted from an increase in sensitivity to depicted features, rather than a response bias. The properties of these features that allow such failures of noticing are discussed.

In this study we explored the rate of forgetting from long-term memory in Alzheimer's (AD) and multi-infarct (MID) dementia. For this purpose, we administered to 15 AD, 15 MID, and 22 control subjects two tasks exploring, respectively, long-term verbal and long-term visuo-spatial memory. The absolute rate of forgetting in both tasks was computed as the difference between immediate and delayed recall of memorandum. Since level of immediate recall was significantly different between groups, a proportional rate of forgetting (percentage of memorandum lost passing from immediate to delayed recall) was computed for each patient. In the verbal task (Rey's 15 words) AD patients displayed significantly larger absolute and proportional rates of forgetting than MID and control subjects. In the spatial task (Corsi block supraspan), the absolute rate of forgetting was only marginally different between groups. Nevertheless, AD patients demonstrated a larger proportional rate of forgetting than MID and normal subjects. These results point out an exalted decay of information from long-term memory store in AD patients. In the light of previous data (Corkin et al., 1984; Kopelman, 1985) we propose that long-term memory deficits in AD is due, at least in part, to an abnormal forgetting of information within the first few minutes following acquisition. Information still present in the subsequent period (10 min to several days) is retained normally. The normal rate of forgetting in MID patients, further, suggests different mechanisms underlying memory disorders in vascular and degenerative dementias.

In two experiments, the effects of level of medical expertise and study time on free recall of a clinical case were assessed. In Experiment 1, a nonmonotonic relationship between level of ex­ pertise and recall was found: Subjects of intermediate levels of expertise remembered more in­ formation from the case than both experts and novices. This "intermediate effect" disappeared, however, when study time was restricted. Analysis of post hoc acquired protocols ofpathophysio­ logical knowledge active during case processing suggested that this phenomenon could be at­ tributed to the nature of the pathophysiological knowledge mobilized to comprehend the case. In Experiment 2, this assumption was directly tested by priming relevant pathophysiological knowledge for either a short or a longer period, before enabling subjects to study the case briefly. Free-recall data confirmed and extended the results of Experiment 1. Again, an intermediate effect was found; this time, however, it was generated experimentally. The findings were inter­ preted in terms of qualitative differences in the nature of the knowledge structures underlying performance between novices, advanced students, and medical experts: Experts use knowledge in an encapsulated mode while comprehending a case, whereas students use elaborated knowledge. The intermediate effect in clinical case representation studies is among the best-known, stable, and hitherto un­ explained phenomena in medical expertise research. The quasi-experimental paradigm that produces this phenom­ enon is described as follows: Subjects differing in level of expertise are requested to study, for about 2 or 3 min, half a page oftext describing a patient's history, present­ ing complaint and some additional findings such as re­ sults of laboratory tests and physical examination. The text is removed, and the subjects are asked to recall every­ thing they can remember from the text. Subjects of inter­ mediate levels of expertise consistently produce more elaborate recalls than either experts (e.g., experienced physicians) or novices. This phenomenon has been dem­ onstrated under various conditions, with different cases and in different populations (Claessen & Boshuizen, 1985; Hassebrock, Bullemer, & Johnson, 1988; Muzzin, Nor­ man, Feightner, & Tugwell, 1983; Patel & Groen, 1986b). The intermediate effect has also been demon­ strated in expertise-related tasks other than text process­ ing (Grant & Marsden, 1988; Patel, Evans, & Kaufman, 1988). These findings appear to be counterintuitive. Spilich, Vesonder, Chiesi, and Voss (1979), for instance, have

Few studies of problem-solving expertise in professional domains have undertaken independent assessments of how domain-specific knowledge contributes to the development of problem representations as well as subsequent memory for task information. These issues were investigated in the present study by asking participants at three levels of training and experience (novice, trainee, and expert) in a medical specialty to solve two complex diagnostic problems (patient cases) selected from medical records of a university hospital. The subjects were also asked to provide an incidental free recall of the patient information contained in each case immediately after problem solving and one week later. Problem representations (identified as "lines of reasoning") used by each subject in each case were determined from an analysis of thinking-aloud protocols generated during problem solving. The three groups did not differ on the overall amount of case information recalled at the immediate retention test and did not show selective recall for information statements that were directly relevant to the lines of reasoning used during problem solving. After one week, however, the expert physicians remembered fewer information units than novices but showed selective retention for case information contained in the lines of reasoning used to reach a diagnosis. Experts also increased their recall of specific diagnostic interpretations contained in their initial problem-solving experience while novices did not demonstrate evidence of their problem representations in recalling case information.

Many studies dealing with differences between students' and doctors' memory for clinical cases have yielded puzzling results. In this paper it is claimed that these are due to the use of inadequate techniques for isolating chunks inherent in the stimuli and the data. The purpose of this paper is to investigate whether the techniques of propositional analysis yield a clearer picture. Using this technique, the analysis of two sets of data is presented. The results show a clear difference between doctors and students when relevant clinical information is isolated from irrelevant information. This supports the notion that the process involved in the memory for clinical cases is far more complex and involves the ability to make inferences from a highly developed knowledge base.

Exemplar-memory and adaptive network models were compared in application to category learning data, with special attention to base rate effects on learning and transfer performance. Subjects classified symptom charts of hypothetical patients into disease categories, with informative feedback on learning trials and with the feedback either given or withheld on test trials that followed each fourth of the learning series. The network model proved notably accurate and uniformly superior to the exemplar model in accounting for the detailed course of learning; both the parallel, interactive aspect of the network model and its particular learning algorithm contribute to this superiority. During learning, subjects' performance reflected both category base rates and feature (symptom) probabilities in a nearly optimal manner, a result predicted by both models, though more accurately by the network model. However, under some test conditions, the data showed substantial base-rate neglect, in agreement with Gluck and Bower (1988b).

Two experiments tested the hypothesis that laypeople cognitively organize and recall information about physical symptoms according to prototyped conceptions they have of physical diseases. Based on pilot studies that identified the extent to which subjects associated specified symptoms with specific diseases, symptom sets were assembled to vary in the extent to which the symptoms were perceived to be associated with (to be prototypical of) a given disease. Experiment 1 asked subjects to indicate whether a given set of symptoms indicated a disease and, if so, which one. Experiment 2 tested subjects' recall for symptom sets varying in prototypicality for given diseases and also tested the effects on recall of giving subjects a diagnosis. Results of both experiments support the prototype hypothesis that information about physical symptoms is organized and processed according to people's preexisting beliefs about the association between particular symptoms and diseases. Implications for illness behavior and help seeking are discussed.

According to Feltovich & Barrows (1984), the general frame used by medical experts to construct a mental representation of a particular patient problem contains a component part for those illness features that are associated with the acquisition of the illness. These 'enabling conditions' are related in several ways to the patient's disease. Examples are conditions like sex and age, or risk factors originating from work, behaviour and hereditary taint. Because of the sequential nature by which patient data become available during a clinical interview, contextual information is expected to play an important role in the generation of initial diagnostic hypotheses. To investigate the hypothesis that experienced doctors better utilize this kind of information, a group of 18 experts and 17 novices was confronted with 32 short case histories each presented on three slides: a portrait of the patient, the patient chart containing previous disease history, and a slide with the presenting complaint. It was hypothesized that differences in the number of correct diagnoses would emerge between the two groups, because the experts would use the contextual information, implicitly provided by picture and patient chart, in a more extensive way. If so, this would show in the amount of information that is explicitly recalled later. The data confirmed these predictions. The experts produced almost 50% more correct hypotheses as compared to the novices and were able to reproduce a larger amount of contextual information in particular information that was directly relevant to the patient's problem. Only the expert group showed a high correlation between accuracy of diagnoses and recall measures.