Korean deaf adolescents' recognition of written words for taxonomic categories of different levels

Deaf college students seem to have relatively stronger associations from words for taxonomic categories of basic (e.g., snake) to those of super-ordinate (e.g., reptiles) level than vice versa compared with hearing students in word association (Marschark, Convertino, McEvoy & Masteller, 2004). In deciding whether two sequentially presented words for taxonomic categories of different levels are conceptually related, deaf adolescents might therefore have a poorer performance when they see a category name before than when they see it after one of the corresponding exemplar words. Deaf Korean adolescents were found to recognize words for taxonomic categories of super-ordinate level with lower efficiencies than those of basic level. Their accuracy seemed to reflect a reversed typicality effect when they decided that first-presented words for taxonomic categories of basic level were conceptually related to second-presented words for those of super-ordinate level. It was argued that deaf Korean adolescents went through a temporary stage of having iconic representations of several exemplars of the category aroused in working memory before the abstract semantic representation was fully activated when they saw the word for a taxonomic category of super-ordinate level.     

Asymmetrical stimulus generalization following differential fear conditioning

Rodent ultrasonic vocalizations (USVs) are ethologically critical social signals. Rats emit 22 kHz USVs and 50 kHz USVs, respectively, in conjunction with negative and positive affective states. Little is known about what controls emotional reactivity to these social signals. Using male Sprague–Dawley rats, we examined unconditional and conditional freezing behavior in response to the following auditory stimuli: three 22 kHz USVs, a discontinuous tone whose frequency and on–off pattern matched one of the USVs, a continuous tone with the same or lower frequencies, a 4 kHz discontinuous tone with an on–off pattern matched to one of the USVs, and a 50 kHz USV. There were no differences among these stimuli in terms of the unconditional elicitation of freezing behavior. Thus, the stimuli were equally neutral before conditioning. During differential fear conditioning, one of these stimuli (the CS⁺) always co-terminated with a footshock unconditional stimulus (US) and another stimulus (the CS⁻) was explicitly unpaired with the US. There were no significant differences among these cues in CS⁺-elicited freezing behavior. Thus, the stimuli were equally salient or effective as cues in supporting fear conditioning. When the CS⁺ was a 22 kHz USV or a similar stimulus, rats discriminated based on the principal frequency and/or the temporal pattern of the stimulus. However, when these same stimuli served as the CS⁻, discrimination failed due to generalization from the CS⁺. Thus, the stimuli differed markedly in the specificity of conditioning. This strikingly asymmetrical stimulus generalization is a novel bias in discrimination.     

Morphological changes in dendritic spines of Purkinje cells associated with motor learning

Experience-dependent changes of spine structure and number may contribute to long-term memory storage. Although several studies demonstrated structural spine plasticity following associative learning, there is limited evidence associating motor learning with alteration of spine morphology. Here, we investigated this issue in the cerebellar Purkinje cells using high voltage electron microscopy (HVEM). Adult rats were trained in an obstacle course, demanding significant motor coordination to complete. Control animals either traversed an obstacle-free runway or remained sedentary. Quantitative analysis of spine morphology showed that the density and length of dendritic spines along the distal dendrites of Purkinje cells were significantly increased in the rats that learned complex motor skills compared to active or inactive controls. Classification of spines into shape categories indicated that the increased spine density and length after motor learning was mainly attributable to an increase in thin spines. These findings suggest that motor learning induces structural spine plasticity in the cerebellar Purkinje neurons, which may play a crucial role in acquiring complex motor skills.     

Magic Learning Pill: Ontological and Instrumental Learning in Order to Speed Up Education

The purpose of this research is to investigate the phenomenology of learning — people”s attitudes toward their learning experiences that have inherent worth in themselves (i.e., ontological learning) or have value outside of the learning itself (i.e., instrumental learning). In order to explore this topic, 58 participants from the U.S., Russia, and Brazil were interviewed with a central question derived from the science fiction writer Isaac Asimov’s short story “Profession”: whether participants would take a “Magic Learning Pill” (MLP) to avoid the process of learning, and instead magically acquire the knowledge. The MLP would guarantee the immediate learning by skipping the process of learning while achieving the same effect of gaining skills and knowledge. Almost all participants could think of some learning experiences for which they would take MLP and others for which they would not. Many participants would not take MLP for ontological learning, which is learning experiences that have inherent value for the people, while they would take MLP for instrumental learning, which is learning that mainly serves some other non-educational purposes. The main finding suggests that both instrumental and ontological types of learning are recognized by a wide range of people from diverse cultures as present and valued in their lives. This is especially significant in light of the overwhelmingly instrumental tone of public discourse about education. In the context of formal education, ontological learning was mentioned 35 times (28.0%) while instrumental learning was mentioned 74 times (60.2%). Although ontological learning was often mentioned as taking place outside of school, incorporating pedagogy supporting ontological learning at school deserves consideration.     

Specificity of learning through memory retrieval practice: The case of addition and subtraction

The identical elements (IE) model (Rickard, Healy, & Bourne, Learning, Memory, and Cognition 32:734–748, 1994) of fact representation predicts that, in both verbal and numerical domains, performance gains with retrieval practice on multielement items will be specific to the practiced stimulus–response combinations, failing to transfer even to altered stimulus–response mappings of practiced items. In the case of arithmetic, the model predicts no transfer across either complementary operations (e.g., 4 × 7 to 28 / 4) or complementary division or subtraction problems (e.g., 28 / 4 to 28 / 7). Although that model has successfully described transfer effects in the domains of multiplication–division and episodic cued recall, it is challenged by a recent demonstration of positive cross-operation transfer for addition and subtraction (Campbell & Agnew, Psychonomic Bulletin & Review 16:938–944, 2009). We report results of a new addition–subtraction transfer experiment, the design of which closely matched that of a prior multiplication–division experiment that supported the model. The transfer results were consistent with the IE model. A two-component model of memory retrieval practice effects is proposed to account for the discrepant experimental results for addition and subtraction and to guide future work.