Difference threshold for stimulus length under simultaneous and nonsimultaneous viewing conditions

The present study was concerned with Weber’s Law as it is related to the discriminability of the lengths of lines. Experiments were conducted to investigate three questions: (I) Is Weber’s Law equally applicable to simultaneous and nonsimultaneous viewing conditions? (2) Is the relationship between the stimulus sizes and the values ofDLs described more adequately by the function proposed by Weber or a generalized Weber’s Law stated by Miller? and (3) Is Weber’s Law better approximated by proximal or distal size? It was demonstrated that the discriminability of the lengths of lines follows Weber’s Law under the nonsimultaneous viewing condition, but not under the simultaneous viewing condition. Under the nonsimultaneous viewing condition, it was noted that the generalized Weber’s Law as stated by Miller described the relationship between the DL and stimulus size significantly better than the function proposed by Weber. From the results pertaining to the third question, it was not possible to determine whether the proximal or the distal size follows Weber’s Law more closely.     

On the semantic duplicity of the first person pronoun “I”

Continental Philosophy Review -     

Recent Learned Helplessness/Irrelevance Research in Japan: Conceptual Framework and Some Experiments on Learned Irrelevance

In Section 1, a conceptual framework within which to study learned helplessness (LH), learned irrelevance (LI) and the related phenomena is introduced. In Section 2, three rat experiments on LI conducted in our laboratory using a conditioned suppression of licking preparation are introduced. In Experiment 1, the phenomena of LI and general LI were confirmed. In Experiment 2, random presentations of CST/US were found to interfere with subsequent initial excitatory conditioning to CSL under random CSL/US presentations. In Experiment 3, pre-paired presentations of CSN or CST with US before random CST/US presentations was found to have an attenuating effect on the development of general LI.     

A static geometrical illusion contributes largely to the footsteps illusion

When a black and a white rectangle drifts across a stationary striped background with constant velocity, the rectangles appear to alternately speed up and slow down. Anstis (2001, Perception 30 785-794; 2004, Vision Research 44 2171-2178) suggested that this 'footsteps' illusion is due to confusion between contrast and velocity signaling in the motion detectors of the human visual system. To test this explanation, three experiments were carried out. In experiment 1, the magnitudes of the footsteps illusion in dynamic and static conditions was compared. If motion detectors play an important role in causing the illusion, it should be reduced in the static condition. Remarkably, however, we found that the illusory misalignment between the black and the white rectangle was even more prominent in the static condition than in the dynamic condition. In experiment 2, we measured the temporal-frequency properties of the footsteps illusion. The results showed that the footsteps illusion was tuned to low temporal frequencies. This suggests that the static illusory misalignment can contribute sufficiently to the dynamic illusory misalignment. In experiment 3, the magnitude of the illusion was measured with the rectangles drifting on a temporally modulated background instead of a spatially modulated background. If contrast affects the apparent velocity of the rectangles, temporal modulation of a uniform background should also cause the footsteps illusion. However, the results showed that the magnitude of the illusion was much reduced in this condition. Taken together, the results indicate that the footsteps illusion can be regarded as a static geometrical illusion induced by the striped background and that motion detectors play a minor role at best.     

Shared minds: Effects of a mother's imitation of her child on the mother–child interaction

Children with Autistic Spectrum Disorders (ASD) have impaired social interaction right from early development. Previous studies (Dawson & Adams, 1984; Tiegerman & Primavera, 1981, 1984) have suggested that imitating children with ASD is effective in facilitating their social behaviors. The present case report, through a 6‐month intervention, investigated how a home‐based intervention of helping a mother imitate her 21‐month‐old child with ASD impacted the child's development of social communication outside the experimental settings. Our results show that the mother's imitation of her child might be associated with the development of nonverbal joint attention skills. Positive changes in the mother's emotion towards her child and the mother–child interaction also were noted and represent other important effects of parental involvement in therapeutic interventions for children with ASD.     

Brain mechanisms for predictive control by switching internal models: implications for higher-order cognitive functions

Humans can guide their actions toward the realization of their intentions. Flexible, rapid and precise realization of intentions and goals relies on the brain learning to control its actions on external objects and to predict the consequences of this control. Neural mechanisms that mimic the input–output properties of our own body and other objects can be used to support prediction and control, and such mechanisms are called internal models. We first summarize functional neuroimaging, behavioral and computational studies of the brain mechanisms related to acquisition, modular organization, and the predictive switching of internal models mainly for tool use. These mechanisms support predictive control and flexible switching of intentional actions. We then review recent studies demonstrating that internal models are crucial for the execution of not only immediate actions but also higher-order cognitive functions, including optimization of behaviors toward long-term goals, social interactions based on prediction of others’ actions and mental states, and language processing. These studies suggest that a concept of internal models can consistently explain the neural mechanisms and computational principles needed for fundamental sensorimotor functions as well as higher-order cognitive functions. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Computer‐based teaching of Kanji construction and writing in a student with developmental disabilities

Students with developmental disabilities often have difficulty with writing skills such as tracing, copying, and dictation writing. A student with writing difficulties participated in the present study, which used computer‐based teaching applied in the home. We examined whether a student could copy Japanese Kanji characters after training with a constructed response matching‐to‐sample (CRMTS) procedure. The procedure was designed to teach identity Kanji construction. The results showed that the student not only acquired the constructed responses through this procedure but also to spelling generalized to copy trained and untrained Kanji characters. The results are discussed in terms of the effect of the CRMTS procedure on the acquisition and transfer of writing characters and the applicability of computer‐based home teaching. Copyright © 2008 John Wiley & Sons, Ltd.     

Random Walker Test: A computerized alternative to the Road-Map Test

The Road-Map Test (RMT) is a popular neurological assessment of left-right orientation, using a simplified road map. Inspired by the RMT, we developed a new computerized navigation test, the Random Walker Test (RWT), for further quantitative assessment of left-right orientation ability. RWT provides verbal or nonverbal instructions for the direction (left, right, or front) in which to proceed, and participants must judge the spatially correct direction. Perspectives rotate by 90° during navigation. Verbal judgments demand verbal-to-spatial mapping of left/right/front and, if necessary, egocentric perspective rotation. Using the RWT, we evaluated the left-right orientation of normal male participants. The RWT reliably recorded the response times and error rates for participant performance and also revealed egocentric perspective rotation as an unreliable mental process with large intra- and interpersonal variability. These results indicate that the RWT may be useful in investigating left-right orientation and/or egocentric perspective rotation in both normal participants and neuropathological patients.     

Hitting the target: relatively easy, yet absolutely difficult

It is generally agreed that absolute-direction judgments require information about eye position, whereas relative-direction judgments do not. The source of this eye-position information, particularly during monocular viewing, is a matter of debate. It may be either binocular eye position, or the position of the viewing-eye only, that is crucial. Using more ecologically valid stimulus situations than the traditional LED in the dark, we performed two experiments. In experiment 1, observers threw darts at targets that were fixated either monocularly or binocularly. In experiment 2, observers aimed a laser gun at targets while fixating either the rear or the front gunsight monocularly, or the target either monocularly or binocularly. We measured the accuracy and precision of the observers' absolute- and relative-direction judgments. We found that (a) relative-direction judgments were precise and independent of phoria, and (b) monocular absolute-direction judgments were inaccurate, and the magnitude of the inaccuracy was predictable from the magnitude of phoria. These results confirm that relative-direction judgments do not require information about eye position. Moreover, they show that binocular eye-position information is crucial when judging the absolute direction of both monocular and binocular targets.     

Computer‐based teaching of word construction and reading in two students with developmental disabilities

Students with developmental disabilities often have difficulty in learning the systematic relations between syllables (auditory stimuli) and characters (visual stimuli) required for reading. Two students with developmental disabilities participated in the present study which used computer‐based teaching applied in the home. We examined whether the students could read individual Japanese Hiragana characters after training with a constructional MTS procedure with differential outcome (DO) that was designed to teach word‐construction for pictured sample stimuli. The DO procedure provided the differential stimulus (in this case spoken syllables) after response selection. The results showed that the students not only acquired appropriate word‐construction responses through this task, they also learned to read Hiragana characters without direct training of this skill. The results are discussed in terms of the effect of the constructional MTS procedure with DO on the acquisition and transfer of reading characters and the applicability of computer‐based home teaching. Copyright © 2007 John Wiley & Sons, Ltd.