Problems for clinical judgement: 5. Principles of influence in medical practice.
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The basic science of psychology has identified specific ingrained responses that are fundamental elements of human nature, underpin common influence strategies and may apply in medical settings. People feel a sense of obligation to repay a perceived debt. A request becomes more attractive when preceded by a marginally worse request. The drive to act consistently will persist even if demands escalate. Peer pressure is intense when people face uncertainty. The image of the requester influences the attractiveness of a request. Authorities have power beyond their expertise. Opportunities appear more valuable when they appear less available. These 7 responses were discovered decades ago in psychology research and seem intuitively understood in the business world, but they are rarely discussed in medical texts. An awareness of these principles can provide a framework for physicians to help patients change their behaviour and to understand how others in society sometime alter patients' choices. (+info)
Middle temporal visual area microstimulation influences veridical judgments of motion direction.
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Microstimulation of direction columns in the middle temporal visual area (MT, or V5) provides a powerful tool for probing the relationship between cortical physiology and visual motion perception. In the current study we obtained "veridical" reports of perceived motion from rhesus monkeys by permitting a continuous range of possible responses that mapped isomorphically onto a continuous range of possible motion directions. In contrast to previous studies, therefore, the animals were freed from experimenter-imposed "categories" that typify forced choice tasks. We report three new findings: (1) MT neurons with widely disparate preferred directions can cooperate to shape direction estimates, inconsistent with a pure "winner-take-all" read-out algorithm and consistent with a distributed coding scheme like vector averaging, whereas neurons with nearly opposite preferred directions seem to compete in a manner consistent with the winner-take-all hypothesis, (2) microstimulation can influence direction estimates even when paired with the most powerful motion stimuli available, and (3) microstimulation effects can be elicited when a manual response (instead of our standard oculomotor response) is used to communicate the perceptual report. (+info)
Neural correlates of recency judgment.
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The prefrontal cortex plays a critical role in recollecting the temporal context of past events. The present study used event-related functional magnetic resonance imaging (fMRI) and explored the neural correlates of temporal-order retrieval during a recency judgment paradigm. In this paradigm, after study of a list of words presented sequentially, subjects were presented with two of the studied words simultaneously and were asked which of the two words was studied more recently. Two types of such retrieval trials with varied (high and low) levels of demand for temporal-order retrieval were intermixed and compared using event-related fMRI. The intraparadigm comparison of high versus low demand trials revealed brain regions with activation that was modulated on the basis of demand for temporal-order retrieval. Multiple lateral prefrontal regions including the middle and inferior lateral prefrontal cortex were prominently activated. Activation was also observed in the anterior prefrontal cortex and the medial temporal cortex, regions well documented to be related to memory retrieval in general. The modulation of brain activity in these regions suggests a detailed pathway that is engaged during recency judgment. (+info)
Neuroanatomical correlates of episodic encoding and retrieval in young and elderly subjects.
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Lesion studies have shown convincingly that the medial temporal lobes (MTL) and frontal lobes are critical to episodic memory. Ageing generally has been found to have a generally negative effect on episodic memory performance, which might relate to neurofunctional changes in the frontal and medial temporal brain regions. In the present study, we used functional MRI (fMRI) to investigate separately the contributions of encoding and retrieval to the age-related decline in memory. To this end, we compared brain activity patterns obtained during incidental encoding (pleasant/unpleasant judgements about nouns) and subsequent retrieval (recognition) in three groups: a group of young subjects, a group of elderly subjects showing reduced memory performance (ELD-RED), and a group of elderly subjects who still performed in the normal range (ELD-NORM). This allowed us to differentiate between age-related changes in brain activity that affect memory function and those that do not have an apparent effect on memory function, because they are found in both elderly groups. Contrary to previous imaging studies on this topic, we used (self-paced) event-related fMRI to control for differences in performance level across groups by including correct responses only. Comparing the encoding of successfully remembered items with baseline (press left/press right), the young subjects showed a significant increase in brain activation in the left anterior MTL compared with the ELD-RED but not the ELD-NORM subjects. Comparing correctly rejected items (retrieval attempt) with baseline, the ELD-RED group showed much increased overall activity throughout the brain compared with the other groups. However, when correctly recognized items (retrieval attempt + success) were compared directly with correctly rejected items (retrieval attempt), these differences were greatly reduced, revealing common activity in the left parietal, retrosplenial and left anterior prefrontal regions. Therefore, we conclude that the reduced performance in the ELD-RED group is likely to be due to MTL dysfunction during encoding. The differences observed during retrieval attempts may reflect strategic differences. The lack of differences observed in relation to retrieval success suggests that ageing does not affect the processes that support the actual recovery of information. (+info)
Neural basis for semantic memory difficulty in Alzheimer's disease: an fMRI study.
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Patients with probable Alzheimer's disease are thought to have a semantic memory deficit. We used functional MRI to evaluate the neural basis for impaired semantic memory for ANIMALS and IMPLEMENTS in 11 patients with Alzheimer's disease and 16 healthy seniors. For both categories of knowledge, Alzheimer's disease patients show reduced activation in the left posterolateral temporal-inferior parietal cortex compared with healthy seniors. Activation changes in this heteromodal association region may be related to an impairment of the category-neutral semantic processes involved in integrating feature knowledge that is represented in modality-specific association cortices. We also found increased activation of an area of the left temporal cortex for both categories of knowledge in Alzheimer's disease that was not activated in healthy seniors. Category-specific changes were also seen in Alzheimer's disease compared with healthy seniors that may be related to the neural representation of category-specific feature knowledge represented in semantic memory. For ANIMALS, the left ventral temporal cortex was activated in Alzheimer's disease in an anatomical distribution that was posterior to the left ventral recruitment for this category in healthy seniors. For IMPLEMENTS, frontal-striatal regions were activated in Alzheimer's disease in a manner that was displaced from the locus of recruitment for this category in healthy seniors. Our findings are consistent with a two-component model of semantic memory involving category-neutral processes operating on category- specific knowledge, and both components appear to be compromised in Alzheimer's disease. Components of the large-scale neural network underlying semantic memory may modify themselves to maintain performance in the face of a neurodegenerative disease. (+info)
Curriculum evaluation of ethical reasoning and professional responsibility.
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This exploratory study evaluated curricular content and evaluation mechanisms related to ethics and professionalism in the baccalaureate dental hygiene program at Idaho State University. Competency-based education requires enhanced student preparation in ethical reasoning, critical thinking, and decision-making. Graduates must integrate concepts, beliefs, principles, and values to fulfill ethical and professional responsibilities. Methods included 1) development of five supporting competencies defining ethics and professionalism to provide a framework for curricular evaluation; 2) assessment of all course content and evaluation methods for each supporting competency; 3) evaluation of students' clinical performance based on professional judgment grades; and 4) survey of junior (n=30) and senior (n=27) students' attitudes about dental hygiene practice related to ethics and professionalism. Results revealed that most courses include content and evaluation related to at least one supporting competency; however, authentic evaluation is weak. Clinical instructors rarely relate evaluations to ethical principles or values. Surveys showed significant differences between junior and senior students' attitudes about ethics and professionalism in six of thirty-four areas (the six were laws and regulations; communication and interpersonal skills; problem solving; professional activities/programs; integrity; and safe work environment). This article shares one approach for evaluating curricular content and evaluation methods designed to develop student competence in ethical reasoning and professionalism. Based upon the study's findings, recommendations are made for curricular enhancement via authentic evaluation and faculty training. (+info)
Alcohol intoxication reduces impulsivity in the delay-discounting paradigm.
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AIMS: To examine the moderating effects of alcohol myopia on cognitive impulsivity in humans using the delay-discounting paradigm. METHODS: Seventy-six male undergraduate students were randomly assigned to sober, placebo or alcohol conditions. In the delay-discounting task, participants made a series of hypothetical choices between a small, immediate reward and a large, delayed reward. To test the predictions of alcohol myopia theory, participants completed a standard version of the task or one containing cues which impelled the impulsive choice (i.e. preference for the small, immediate reward). Participants also completed a personality measure of impulsivity and the go/no-go task, which assesses motor impulsivity. RESULTS: Intoxicated participants tended to discount delayed rewards at lower rates than sober participants, and blood alcohol level was inversely correlated with delay discounting. The impelling cues did not moderate the effects of alcohol on delay discounting. CONCLUSIONS: Alcohol intoxication does not always increase cognitive impulsivity and may lead to more cautious decision-making under certain conditions. (+info)
Effects of nicotine deprivation on craving response covariation in smokers.
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Most models of craving propose that when cravings are strong, diverse responses--thought to index an underlying craving state--covary. Previous studies provided weak support for this hypothesis. The authors tested whether nicotine deprivation affects degree of covariation across multiple measures related to craving. Heavy and light smokers (N = 127) were exposed to smoking cues while either nicotine deprived or nondeprived. Measures included urge ratings, affective valence, a behavioral choice task assessing perceived reinforcement value of smoking, and smoking-related judgment tasks. Results indicated higher correlations in the nicotine-deprived than in nondeprived group. The measures principally responsible for this effect loaded onto a single common Craving factor for nicotine-deprived but not nondeprived smokers. These findings suggest that, under certain conditions, measures of craving-related processes covary. (+info)