Why are medical students 'checking out' of active learning in a new curriculum?

OBJECTIVES: The University of Virginia School of Medicine recently transformed its pre-clerkship medical education programme to emphasise student engagement and active learning in the classroom. As in other medical schools, many students are opting out of attending class and others are inattentive while in class. We sought to understand why, especially with a new student-centred curriculum, so many students were still opting to learn on their own outside of class or to disengage from educational activities while in class. METHODS: Focus groups were conducted with students from two classes who had participated in the new curriculum, which is designed to foster small-group and collaborative learning. The sessions were audio-recorded and then transcribed. The authors read through all of the transcripts and then reviewed them for themes. Quotes were analysed and organised by theme. RESULTS: Interview transcripts revealed candid responses to questions about learning and the learning environment. The semi-structured nature of the interviews enabled the interviewers to probe unanticipated issues (e.g. reasons for choosing to sit with friends although that diminishes learning and attention). A content analysis of these transcripts ultimately identified three major themes embracing multiple sub-themes: (i) learning studio physical space; (ii) interaction patterns among learners, and (iii) the quality of and engagement in learning in the space. CONCLUSIONS: Students' reluctance to engage in class activities is not surprising if classroom exercises are passive and not consistently well designed or executed as active learning exercises that students perceive as enhancing their learning through collaboration. Students' comments also suggest that their reluctance to participate regularly in class may be because they have not yet achieved the developmental level compatible with adult and active learning, on which the curriculum is based. Challenges include helping students better understand the nature of deep learning and their own developmental progress as learners, and providing robust faculty development to ensure the consistent deployment of higher-order learning activities linked with higher-order assessments.

Teaching and Practicing Cultural Competency Skills with Medical Students Using Nutrition-Focused Case Scenarios.

Cultural competency is a required standard for American medical students, but it can be challenging to effectively engage students with this topic. Because nutrition and culture are inherently intertwined in patient care, classroom role-play with nutrition-focused case scenarios enables students to practice strategies for navigating cultural barriers with patients.

Using Instrument-Guided Team Reflection and Debriefing to Cultivate Teamwork Knowledge, Skills, and Attitudes in Pre-Clerkship Learning Teams.

Drawing on the science of teamwork and the science of learning, we designed an instrument-guided team reflection and debriefing activity to foster teamwork knowledge, skills, and attitudes (KSAs) in medical students. We then embedded this activity within and between a biweekly series of pre-clerkship Team-Based Learning sessions with the goal of encouraging medical students to cultivate a practical and metacognitive appreciation of eight foundational teamwork KSAs that are applicable to both healthcare teams and classroom learning teams. On evaluations, 144 learners from a class of 156 reported increased appreciation for and team improvement with these teamwork KSAs.

Temperature dependent modulation of lobster neuromuscular properties by serotonin.

In cold-blooded species the efficacy of neuromuscular function depends both on the thermal environmental of the animal's habitat and on the concentrations of modulatory hormones circulating within the animal's body. The goal of this study is to examine how temperature variation within an ecologically relevant range affects neuromuscular function and its modulation by the neurohormone serotonin (5-HT) in Homarus americanus, a lobster species that inhabits a broad thermal range in the wild. The synaptic strength of the excitatory and inhibitory motoneurons innervating the lobster dactyl opener muscle depends on temperature, with the strongest neurally evoked muscle movements being elicited at cold (<5 degrees C) temperatures. However, whereas neurally evoked contractions can be elicited over the entire temperature range from 2 to >20 degrees C, neurally evoked relaxations of resting muscle tension are effective only at colder temperatures at which the inhibitory junction potentials are hyperpolarizing in polarity. 5-HT has two effects on inhibitory synaptic signals: it potentiates their amplitude and also shifts the temperature at which they reverse polarity by approximately +7 degrees C. Thus 5-HT both potentiates neurally evoked relaxations of the muscle and increases the temperature range over which neurally evoked muscle relaxations can be elicited. Neurally evoked contractions are maximally potentiated by 5-HT at warm (18 degrees C) temperatures; however, 5-HT enhances excitatory junction potentials in a temperature-independent manner. Finally, 5-HT strongly increases resting muscle tension at the coldest extent of the temperature range tested (2 degrees C) but is ineffective at 22 degrees C. These data demonstrate that 5-HT elicits several temperature-dependent physiological changes in the passive and active responses of muscle to neural input. The overall effect of 5-HT is to increase the temperature range over which neurally evoked motor movements can be elicited in this neuromuscular system.

Temperature and acid-base balance in the American lobster Homarus americanus.

Lobsters (Homarus americanus) in the wild inhabit ocean waters where temperature can vary over a broad range (0-25 degrees C). To examine how environmental thermal variability might affect lobster physiology, we examine the effects of temperature and thermal change on the acid-base status of the lobster hemolymph. Total CO(2), pH, P(CO)2 and HCO(-)(3) were measured in hemolymph sampled from lobsters acclimated to temperature in the laboratory as well as from lobsters acclimated to seasonal temperatures in the wild. Our results demonstrate that the change in hemolymph pH as a function of temperature follows the rule of constant relative alkalinity in lobsters acclimated to temperature over a period of weeks. However, thermal change can alter lobster acid-base status over a time course of minutes. Acute increases in temperature trigger a respiratory compensated metabolic acidosis of the hemolymph. Both the strength and frequency of the lobster heartbeat in vitro are modulated by changes in pH within the physiological range measured in vivo. These observations suggest that changes in acid-base status triggered by thermal variations in the environment might modulate lobster cardiac performance in vivo.

Dual inhibition of the dactyl opener muscle in lobster.

The dactyl opener neuromuscular system of crayfish and lobster has long been a popular model system for studies of synaptic physiology and its modulation. Previous studies of its neural innervation in both species have reported that whereas the opener excitor axon (OE) and the specific opener inhibitor (OI) innervate the entire muscle, the common inhibitor (CI) is restricted to a small number of the most proximal muscle fibers and is the physiologically weaker of the two inhibitors. Here, we show in the lobster that, contrary to previous reports, CI innervates fibers along the entire extent of the dactyl opener muscle and thus shares the innervation targets of OE and OI. To characterize the physiological function of CI in the lobster dactyl opener system, we independently stimulated both OI and CI and compared their effects. The physiological impact of each inhibitor was similar: inhibitors elicit inhibitory junction potentials of similar sizes, both trigger muscle relaxations and both inhibit excitatory junction potentials and muscle contractions to a comparable extent. Thus, in the periphery, CI and OI appear to be equally powerful inhibitors with similar physiological roles, both in suppressing contractions triggered by the excitor OE and in directly relaxing muscle tension. In light of these observations, our understanding of the physiological roles of specific and common inhibitors in crustacean motor control requires reevaluation.

Temperature acclimation alters cardiac performance in the lobster Homarus americanus.

The American lobster is a poikilotherm that inhabits a marine environment where temperature varies over a 25 degrees C range and depends on the winds, the tides and the seasons. To determine how cardiac performance depends on the water temperature to which the lobsters are acclimated we measured lobster heart rates in vivo. The upper limit for cardiac function in lobsters acclimated to 20 degrees C is approximately 29 degrees C, 5 degrees C warmer than that measured in lobsters acclimated to 4 degrees C. Warm acclimation also slows the lobster heart rate within the temperature range from 4 to 12 degrees C. Both effects are apparent after relatively short periods of warm acclimation (3-14 days). However, warm acclimation impairs cardiac function at cold temperatures: following several hours exposure to frigid (<5 degrees C) temperatures heart rates become slow and arrhythmic in warm acclimated, but not cold acclimated, lobsters. Thus, acclimation temperature determines the thermal limits for cardiac function at both extremes of the 25 degrees C temperature range lobsters inhabit in the wild. These observations suggest that regulation of cardiac thermal tolerance by the prevailing environmental temperature protects against the possibility of cardiac failure due to thermal stress.

Neuromuscular synapses on the dactyl opener muscle of the lobster Homarus americanus.

The crustacean dactyl opener neuromuscular system has been studied extensively as a model system that exhibits several forms of synaptic plasticity. We report the ultrastructural features of the synapses on dactyl opener of the lobster (Homarus americanus) as determined by examination of serial thin sections. Several innervation sites supplied by an inhibitory motoneuron have been observed without nearby excitatory innervation, indicating that excitatory and inhibitory inputs to the muscle are not always closely matched. The ultrastructural features of the lobster synapses are generally similar to those described previously for the homologous crayfish muscle, with one major distinction: few dense bars are seen at the presynaptic membranes of these lobster synapses. The majority of the lobster neuromuscular synapses lack dense bars altogether, and the mean number of dense bars per synapse is relatively low. In view of the finding that the physiology of the lobster dactyl opener synapses is similar to that reported for crayfish, these ultrastructural observations suggest that the structural complexity of the synapses may not be a critical factor determining synaptic plasticity.

Temperature dependence of cardiac performance in the lobster Homarus americanus.

The lobster Homarus americanus inhabits ocean waters that vary in temperature over a 25 degrees C range, depending on the season and water depth. To investigate whether the lobster heart functions effectively over a wide range of temperatures we examine the temperature dependence of cardiac performance of isolated lobster hearts in vitro. In addition, we examined whether modulation of the heart by serotonin depends on temperature. The strength of the heartbeat strongly depends on temperature, as isolated hearts are warmed from 2 to 22 degrees C the contraction amplitude decreases by greater than 60%. The rates of contraction and relaxation of the heart are most strongly temperature dependent in the range from 2 to 4 degrees C but become temperature independent at warmer temperatures. Heart rates increase as a function of temperature both in isolated hearts and in intact animals, however hearts in intact animals beat faster in the temperature range of 12-20 degrees C. Interestingly, acute Q10 values for heart rate are similar in vivo and in vitro over most of the temperature range, suggesting that temperature dependence of heart rate arises mainly from the temperature effects on the cardiac ganglion. In contrast to earlier reports suggesting that the strength and the frequency of the lobster heartbeat are positively correlated, we observe no consistent relationship between these parameters as they change as a function of temperature. Stroke volume decreases as a function of temperature. However, the opposing temperature-dependent increase in heart rate partially compensates to produce a relationship between cardiac output and temperature in which cardiac output is maximal at 10 degrees C and significantly decreases above 20 degrees C. Serotonin potentiates contraction amplitude and heart rate in a temperature-independent manner. Overall, our results show that although the parameters underlying cardiac performance show different patterns of temperature dependence, cardiac output remains relatively constant over most of the wide range of environmental temperatures the lobster inhabits in the wild.