Pre-service and In-service Teachers’ Metacognitive Knowledge of Learning Strategies

Research in cognitive psychology has suggested that difficulties are often desirable for learning: learning strategies that create difficulties for learners during practice often produce durable learning. Prominent examples of effective learning strategies that introduce desirable difficulties are testing as a means of learning, spacing study sessions over time, and interleaving practice of different topics. Previous research has suggested that, generally, undergraduates’ metacognitive knowledge about the effectiveness of these learning strategies is inaccurate. The goal of the current study was to extend the examination of metacognitive knowledge of learning strategies to pre-service and in-service teachers, and further examine whether teachers’ metacognitive knowledge is related to their teaching experience. Pre-service teachers enrolled in a university teacher training program (N = 83) and in-service elementary, junior-high, and high school teachers (N = 82) were presented with learning scenarios and predicted which of two learning strategies would yield the better outcome. Results suggested that, overall, both pre-service and in-service teachers failed to predict the advantages of testing, spacing, and interleaving as learning strategies. Furthermore, their knowledge of learning strategies failed to increase with teaching experience. It is, therefore, recommended that explicit instruction about the benefits of empirically supported learning strategies should be included in teacher training and development programs

Synthesis and properties of conjugates between silver nanoparticles and DNA-PNA hybrids

We describe the preparation and properties of a stable conjugate between two 15 nm silver nanoparticles (AgNPs) and a DNA-PNA hybrid composed of 10 guanine-cytosine base pairs. We show that the conjugate is spontaneously formed during incubation of a DNA-PNA hybrid, containing phosphorothioate residues at both ends of the DNA strand with AgNPs. The conjugate molecules were separated from individual AgNPs and multiparticle structures by gel electrophoresis. We demonstrate that the absorption spectrum of the conjugate is broader than that of AgNPs, due to the interparticle plasmon coupling

The Effect of Testing on the Retention of Coherent and Incoherent Text Material

Research has shown that testing during learning can enhance the long-term retention of text material. In two experiments, we investigated the testing effect with a fill-in-the-blank test on the retention of text material. In Experiment 1, using a coherent text, we found no retention benefit of testing compared to a restudy (control) condition. In Experiment 2, text coherence was disrupted by scrambling the order of the sentences from the text. The material was subsequently presented as a list of facts as opposed to connected discourse. For the incoherent version of the text, testing slowed down the rate of forgetting compared to a restudy (control) condition. The results suggest that the connectedness of materials can play an important role in determining the magnitude of testing benefits for long-term retention. Testing with a completion test seems most beneficial for unconnected materials and less so for highly structured materials

Effects of age on goal-dependent modulation of episodic memory retrieval

Retrieval gating refers to the ability to modulate the retrieval of features of a single memory episode according to behavioral goals. Recent findings demonstrate that younger adults engage retrieval gating by attenuating the representation of task-irrelevant features of an episode. Here, we examine whether retrieval gating varies with age. Younger and older adults incidentally encoded words superimposed over scenes or scrambled backgrounds that were displayed in one of three spatial locations. Participants subsequently underwent fMRI as they completed two memory tasks: the background task, which tested memory for the word's background, and the location task, testing memory for the word's location. Employing univariate and multivariate approaches, we demonstrated that younger, but not older adults, exhibited attenuated reinstatement of scene information when it was goal-irrelevant (during the location task). Additionally, in younger adults only, the strength of scene reinstatement in the parahippocampal place area during the background task was related to item and source memory performance. Together, these findings point to an age-related decline in the ability to engage retrieval gating