1,721,137 research outputs found
Children's competence or adults' incompetence? Different developmental trajectories in different tasks
No full textResearch has shown that adults often make judgments inconsistent with the laws of probability. Furthermore, some studies have shown that children seem to reason better than adults in typical judgment tasks.
Classical theories of cognitive development cannot explain these counterintuitive findings. Dual-process theories attempt to account for these findings by proposing two distinct systems of reasoning. Research exploring the development of the two systems, however, has yielded inconsistent results.
The purpose of this research is to shed light on factors that have led to such inconsistencies. We expect to identify task-specific factors involved in decision making problems that constitute the reason for conflicting evidence.
In Experiment 1 participants were 90 fifth graders, 99 seventh graders and 153 adults. The if-only task was used varying superstitious belief (present or absent). In Experiment 2 participants were 276 fifth graders, 344 seventh graders and 90 adults. The contingency detection problem was used varying: a) probability ratios (equal probability or different probability) and b) superstitious belief (present or absent).
In Experiment 1 the age of participants significantly predicts whether they gave a heuristic or a normative response. Interestingly, the heuristic responses increased with age, suggesting adults are more prone to the if-only fallacy than children. The superstitious belief manipulation did not influence the proportion of heuristic responses.
In Experiment 2 the interaction between the age of participants and the probability ratios was significant. When ratios were equal only fifth graders focused on the greater number as having a more probable outcome. Instead, when ratios were different, fifth graders gave a higher proportion of correct responses.
The different developmental trajectories observed in these experiments are due to task-specific factors. Understanding development of decision making requires understanding how task properties engage the two reasoning systems
Fooled by probabilities: developmental trends in superstitious beliefs and numeracy
No full textPeople persist in confounding random processes with naïve conceptions of chance and luck; at the same time children have early and correct intuitions about probabilities. This research focuses on these developmental inconsistencies under the theoretical background of dual-process theories. Numeracy and superstitious beliefs are investigated in two typical judgment tasks.
Words such as chance, luck and probability are terms that people use in everyday life. On the one hand research has shown that adults often make judgments inconsistent with the laws of probability. On the other hand, some studies have shown that 8-10 year olds seem to reason in a more “rational” way than adults in typical judgment tasks.
Classical theories of cognitive development cannot explain these counterintuitive findings. Dual-process theories attempt to account for these findings by proposing two distinct systems of reasoning (the analytical and heuristic systems). However, their dissemination within developmental psychology has been limited and the results are mixed.
The purpose of this research is to shed light on factors that have led to such inconsistencies. We expect to identify task-specific factors involved in decision making problems that constitute the reason for the present conflicting evidence. Individual beliefs play a role when numerical information and beliefs are in conflict.
In Study 1 participants were 90 fifth graders, 99 seventh graders and 153 adults. The if-only task was used varying the superstitious belief (present or absent). No numerical information was provided.
In Study 2 participants were 276 fifth graders, 344 seventh graders and 90 adults. The contingency detection problem was used varying: a) probability ratios (equal probability or different probability); b) superstitious belief (present or absent).
In Study 1 the age of participants significantly predict whether they gave a heuristic or a normative response. Interestingly, the heuristic responses increased with age, suggesting adults as more prone to the if-only fallacy than children. The superstitious belief did not influence the proportion of heuristic responses.
In Study 2 the interaction between the age of participants and the probability ratios was significant. When ratios were equal only fifth graders were influenced by absolute numbers and they focused on the greater number as having a more probable outcome. Instead, when ratios were different, fifth graders gave a higher proportion of correct responses; at the same time the performance of seventh graders and adults decreased. For all the age groups the proportion of atypical responses increased, in particular in adults. This effect was due to the presence of the superstitious belief that influenced the performance paradoxically when the problem is easily solved.
These results emphasize the relevance of understanding the developmental trajectory of decision making and these two studies underline the necessity to investigate the task-specific factors that are involved in the interaction between the two systems of reasoning.
A specific dual-process account can explain our counterintuitive findings: the Fuzzy-Trace Theory (Brainerd & Reyna, 2001). According to this theory, intuition develops into adulthood and represents an advanced form of mature reasoning. Moreover, results in Study 2 give support to an early development of the interaction between the two systems of reasoning
Mass spectrometry analysis of complexes formed by myotonic dystrophy protein kinase (DMPK)
No full textMyotonic dystrophy type 1 (DM1) is caused by an expansion of CTG repeats at the 3'-UTR of the serine/threonine protein kinase DMPK. Expanded CTG repeats are toxic since they are transcribed into an RNA molecule which is then sequestered within the nucleus in the form of foci. RNA cytotoxicity is linked to the aberrant splicing of several developmentally regulated genes. DMPK transcripts undergo alternative splicing giving rise to many isoforms but do not seem to be involved in the splicing dysregulation of DM1. However, decreased levels of DMPK in DM1 patients and DMPK involvement in muscle weakness and cardiac dysfunction in animal models have been reported. The variability in phenotypic expression of DMPK together with its differential subcellular targeting, suggests that different splicing isoforms may be involved in different signalling pathways, possibly through DMPK-interacting proteins. To gain better insight into the DMPK function, we used mass spectrometry to identify proteins co-segregating with DMPK in soluble complexes isolated from high-speed supernatant of rat muscles. We carried out experiments with native DMPK to preserve the physiological stoichiometry with potential partners. DMPK-containing complexes were isolated and immuno-detected by non-denaturing electrophoresis, gel filtration, ionic-exchange chromatography and immunoprecipitation. DMPK peptides were identified by high-resolution mass spectrometry together with several putative DMPK-binding proteins, including several heat shock proteins such as HSP20/HSPB6, HSP60/CPN60, HSP70 and HSP90. We also obtained evidence of a direct interaction of DMPK with alphaB-crystallin/HSPB5 and HSP25/HSPB1
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Density Functional calculations of photoionization with an exchange – correlation potential with the correct asymptotic behaviour
No full textWhen context overrides numerical evidence: Ratio bias in the development of probability judgments
No full textPURIFICATION AND CHARACTERIZATION OF CALSEQUESTRIN FROM CHICKEN CEREBELLUM
No full textChicken cerebellum microsomal fractions contain a protein tentatively identified as calsequestrin (CS) (Volpe et al., Neuron 5, 713-721, 1990). Here we report, for the first time, the purification of cerebellum CS from whole tissue homogenate by DEAE-Cellulose chromatography and Ca(2+)-dependent elution from phenyl-Sepharose. The purified cerebellum CS displays the shift and increase in intrinsic fluorescence characteristic of skeletal muscle CS, and is shown to be a high-capacity, low-affinity Ca2+ binding protein (Kd = 1 mM)
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