An investigation of Taiwanese early adolescents' views about the nature of science

This study developed a Pupils' Nature of Science Scale, including the subscales of the invented and changing nature of science, the role of social negotiation on science, and cultural context on science, to assess early adolescents' views about the nature of science. More than 6,000 fifth and sixth graders in Taiwan responded to the Scale. The study revealed that the adolescents had quite different perspectives toward different subscales of the nature of science. Moreover, male adolescents tended to express more constructivist-oriented views toward the nature of science than did their female counterparts. The adolescents of different grades and races also displayed varying views toward the nature of science.     

Recognizing faces defined by texture gradients

Texture gradients can reveal surface orientation in a manner similar to shape from shading, and therefore provide an important cue for object recognition. In this study, we tested whether a complex 3-D object, such as a face, can be identified from texture gradients alone. The stimuli were laser-scanned faces for which the texture element was a fractal-noise pattern mapped onto the 3-D surface. An eight-alternative forced choice task was used in which participants matched a face defined by texture gradients to one of eight faces defined by shape from shading (Experiment 1) or by texture gradients (Experiment 2). On average, participants scored 24% and 18%, respectively, above chance in these experiments. Although this performance was much poorer than the performance based entirely on shape-from-shading stimuli (Experiment 3), the results suggest that texture gradient information may be used to recover surface geometry of complex objects.     

Evaluation and classification of types of Chinese handwriting deficits in elementary schoolchildren

The handwriting problems of elementary schoolchildren were investigated in this study. A questionnaire for evaluation of Chinese handwriting was developed and then administered to 165 children with handwriting deficits. Factor analysis indicated that the questionnaire has six major dimensions, including construction of characters, accuracy, developmental delay, pencil grip, gross movement, and emotional reaction. These six dimensions were utilized to search for subtypes of handwriting deficits. By further sampling, another 209 children were administered the handwriting evaluation questionnaire to classify their handwriting deficits. According to the severity of deficits on different dimensions of the questionnaire, K-means clustering was utilized to classify the children into four subtypes of mild, severe, motor-originated, and academic learning dysfunction subtypes. The classification by subtype might be helpful in planning interventions for children with handwriting deficits.     

Acetylcholine release in the hippocampus and striatum during place and response training

These experiments examined the release of acetylcholine in the hippocampus and striatum when rats were trained, within single sessions, on place or response versions of food-rewarded mazes. Microdialysis samples of extra-cellular fluid were collected from the hippocampus and striatum at 5-min increments before, during, and after training. These samples were later analyzed for ACh content using HPLC methods. In Experiment 1, ACh release in both the hippocampus and striatum increased during training on both the place and response tasks. The magnitude of increase of training-related ACh release in the striatum was greater in rats trained on the response task than in rats trained on the place task, while the magnitude of ACh release in the hippocampus was comparable in the two tasks. Experiment 2 tested the possibility that the hippocampus was engaged and participated in learning the response task, as well as the place task, because of the availability of extra-maze cues. Rats were trained on a response version of a maze under either cue-rich or cue-poor conditions. The findings indicate that ACh release in the hippocampus increased similarly under both cue conditions, but declined during training on the cue-poor condition, when spatial processing by the hippocampus would not be suitable for solving the maze. In addition, high baseline levels of ACh release in the hippocampus predicted rapid learning in the cue-rich condition and slow learning in the cue-poor condition. These findings suggest that ACh release in the hippocampus augments response learning when extra-maze cues can be used to solve the maze but impairs response learning when extra-maze cues are not available for use in solving the maze.     

A confirmatory model for depression among Japanese American and part-Japanese American adolescents

A confirmatory model integrating Japanese ethnicity, cultural identity, and depression was developed (N = 140). The model incorporated the Center for Epidemiologic Studies-Depression Scale (CES-D), Major Life Events Scale, and Japanese Cultural Scale. Japanese American adolescents scored higher on the Japanese Cultural Scale and reported fewer depressive symptoms on the CES-D total and on 2 of the 3 CES-D factors than part-Japanese American adolescents. Predictors for depression were being Japanese American vs. part-Japanese American, female gender, and culturally intensified events. A significant interaction of behavior by self-identification was noted. The model had good overall fit and suggested that the formation of cultural identity may contribute to depressive symptoms experienced by adolescents, particularly adolescents of mixed heritage.     

A psychophysical measure of attention deficit in children with attention-deficit/hyperactivity disorder

The authors explored the temporal mechanism of attention deficit in children with attention-deficit/hyperactivity disorder (ADHD). In rapid serial visual presentation tasks in which two targets (T-sub-1 and T-sub-2) were presented in close temporal proximity among distractors, participants tried to identify T-sub-1 and detect T-sub-2 in one (dual-task) experiment and only to detect T-sub-2 in a second control (single-task) experiment. The sensitivity of T-sub-2 detection was analyzed using signal detection theory. The attentional blink--the impairment in T-sub-2 detection following the identification of T-sub-1--was increased in magnitude and protracted in the patients. Moreover, some ADHD children appeared to have a blink largely normal in magnitude but temporally displaced toward a later time. The authors hypothesize that a slower closing of the attention gate may mediate this specific attention impairment in ADHD children.     

Hand movements deviate toward distracters in the absence of response competition

In a series of experiments, participants reached to targets in the presence of visual distracters that were either adjacent to the target or located along the reach path. The reaching movements were affected by the presence of the distracters, with the movement paths deviating toward the distracters. Those deviations were observed under two different conditions: (a) one in which the distracter could potentially have been a movement target; and (b) another in which the distracter never was a possible target. Because the movement was affected by the distracter in both situations, the results suggested that response competition is not necessary for distracter-induced reach-path deviations. Instead, the authors propose that attention to a distracter is sufficient to affect the to-target movement. The movement deviations may reveal an effective mechanism for coping with stimulus-rich environments.     

Trial spacing is a determinant of cue interaction

Four conditioned lick suppression experiments with rats examined the effect of trial spacing on cue interaction. Experiments 1 and 2 found overshadowing to be eliminated with massed compound stimulus-outcome pairings and the usual trial spacing effect to be reversed with compound acquisition trials. Experiment 3 found that whether acquisition compound-outcome pairings were massed or spaced determined the effect of posttraining extinction treatment. Extinction of the overshadowing cue reduced responding following massed training and increased responding following spaced training. Extinction of the context decreased responding following massed training. Experiment 4 found the conditioning and devaluation results to be associative and stimulus specific. These results are in accord with the extended comparator hypothesis (J. C. Denniston, H. I. Savastano, & R. R. Miller, 2001).     

Diencephalic damage decreases hippocampal acetylcholine release during spontaneous alternation testing

A rodent model of diencephalic amnesia, pyrithiamine-induced thiamine deficiency (PTD), was used to investigate diencephalic-hippocampal interactions. Acetylcholine (ACh) release, a marker of memory-related activation, was measured in the hippocampus of PTD-treated and control rats prior to, during, and after spontaneous alternation test. During behavioral testing, all animals displayed increases in ACh release. However, both the percent increase of ACh release during spontaneous alternation testing and the alternation scores were higher in control rats relative to PTD-treated rats. Thus, when rats are tested on a task with demands dependent on the hippocampus, it appears that the hippocampus is not fully activated after diencephalic damage.