Dual-egocentre hypothesis on angular errors in visually directed pointing

We examined the hypothesis that angular errors in visually directed pointing, in which an unseen target is pointed to after its direction has been seen, are attributed to the difference between the locations of the visual and kinesthetic egocentres. Experiment 1 showed that in three of four cases, angular errors in visually directed pointing equaled those in kinesthetically directed pointing, in which a visual target was pointed to after its direction had been felt. Experiment 2 confirmed the results of experiment 1 for the targets at two different egocentric distances. Experiment 3 showed that when the kinesthetic egocentre was used as the reference of direction, angular errors in visually directed pointing equaled those in visually directed reaching, in which an unseen target is reached after its location has been seen. These results suggest that in the visually and the kinesthetically directed pointing, the egocentric directions represented in the visual space are transferred to the kinesthetic space and vice versa.     

Working memory in spatial knowledge acquisition: Differences in encoding processes and sense of direction

This study examined how different components of working memory are involved in spatial knowledge acquisition for good and poor sense‐of‐direction (SOD) people. We employed a dual‐task method, and asked participants to learn routes from videos with verbal, visual and spatial interference tasks and without any interference. Results showed that participants with a good SOD encoded landmarks and routes verbally and spatially, and integrated knowledge about them into survey knowledge with the support of all three components of working memory. In contrast, participants with a poor SOD encoded landmarks only verbally, and tended to rely on the visual component of working memory in the processing of route knowledge. Based on the results, a possible model for explaining the differences in spatial knowledge acquisition and SOD was proposed. Copyright © 2010 John Wiley & Sons, Ltd.     

Individual differences in ego depletion: The role of sociotropy-autonomy

In his cognitive theory of depression, Beck (1987) suggested that highly sociotropic individuals have a strong need for social acceptance whereas highly autonomous individuals have an excessive need for achievement. Research by Baumeister (2000) has suggested that a phenomenon known as ego depletion, the weakening of performance on tasks following active self-control, occurs because it depletes a limited inner resource. The present study examined whether individuals who are highly sociotropic or autonomous would respond differently when faced with tasks requiring self-control. Participants completed the Sociotropy-Autonomy Scale (Clark et al. 1995) and engaged in two active self-control tasks. The results revealed that sociotropy levels were negatively correlated with persistence on tasks that require self-control whereas autonomy was positively correlated to persistence on the same task. In addition, the results suggested that, following a task requiring self-control, highly sociotropic individuals expend less effort, whereas highly autonomous individuals expend more effort on subsequent tasks requiring self-control.     

Dynamic facial expressions of emotion induce representational momentum

Two experiments were conducted to explore whether representational momentum (RM) emerges in the perception of dynamic facial expression and whether the velocity of change affects the size of the effect. Participants observed short morphing animations of facial expressions from neutral to one of the six basic emotions. Immediately afterward, they were asked to select the last images perceived. The results of the experiments revealed that the RM effect emerged for dynamic facial expressions of emotion: The last images of dynamic stimuli that an observer perceived were of a facial configuration showing stronger emotional intensity than the image actually presented. The more the velocity increased, the more the perceptual image of facial expression intensified. This perceptual enhancement suggests that dynamic information facilitates shape processing in facial expression, which leads to the efficient detection of other people's emotional changes from their faces.     

Dynamic fearful gaze does not enhance attention orienting in individuals with Asperger’s disorder

Although impaired joint attention is one of the core clinical features of pervasive developmental disorder including autistic disorder and Asperger’s disorder, experimental studies failed to report its impairment. This discrepancy might be the result of differences between real-life and experimental situations. The present study examined joint attention in 11 individuals with Asperger’s disorder and 11 age-matched controls under naturalistic conditions using a target detection paradigm with dynamic emotional gaze cues. Although both groups showed gaze-triggered attention orienting as assessed by the differences in reaction time for invalid minus valid cues, enhancement of joint attention by fearful (vs. neutral) gaze was observed in the control, but not in the Asperger group. This suggests that the integration of emotion and gaze direction that elicits strong joint attention is impaired in individuals with Asperger’s disorder.     

Occlusion as a depth cue in the Wheatstone-Panum limiting case

We examined the hypothesis (Ono & Wade, 1985) that occlusion of far stimuli by a near one on the same visual line can operate as a depth cue in stereograms containing different numbers of targets in the two eyes. By controlling eye positions, we created conditions in which the visual system could interpret the retinal images as originating from stimuli on the visual axis of one eye and also created other conditions in which the origin of the retinal images was ambiguous. In Experiment 1, we presented two lines to one eye and a single line to the other eye. When the image of the line on the temporal side of the line pair on one retina fused with the image of the single line on the other retina, the nonfused line appeared farther away more often than it did when the image on the nasal side fused. In Experiment 2, we used two differently shaped stimuli. In the condition in which the nonfused stimulus represented an object being occluded, it appeared farther away more often than in the four conditions in which it did not. In Experiment 3, we extended the idea to three different objects. When the middle of the three images fused with the single image, the nonfused stimulus appeared farther when it could be interpreted as being occluded than when it could not. In the condition in which the most temporal image fused with the single image, the nonfused stimuli appeared farther than in the condition in which the most nasal one fused. The results supported the hypothesis that occlusion plays a role in depth perception in the Wheatstone-Panum limiting case.     

The interaction of perceived distance with the perceived direction of visual motion during movements of the eyes and the head

A horizontally moving target was followed by rotation of the eyes alone or by a lateral movement of the head. These movements resulted in the retinal displacement of a vertically moving target from its perceived path, the amplitude of which was determined by the phase and amplitude of the object motion and of the eye or head movements. In two experiments, we tested the prediction from our model of spatial motion (Swanston, Wade, & Day, 1987) that perceived distance interacts with compensation for head movements, but not with compensation-for eye movements with respect to a stationary head. In both experiments, when the vertically moving target was seen at a distance different from its physical distance, its perceived path was displaced relative to that seen when there was no error in pereived distance, or when it was pursued by eye movements alone. In a third experiment, simultaneous measurements of eye and head position during lateral head movements showed that errors in fixation were not sufficient to require modification of the retinal paths determined by the geometry of the observation conditions in Experiments 1 and 2.     

A quantitative near-infrared spectroscopy study: a decrease in cerebral hemoglobin oxygenation in Alzheimer's disease and mild cognitive impairment

A newly developed quantitative near-infrared spectroscopy (NIRS) system was used to measure changes in cortical hemoglobin oxygenation during the Verbal Fluency Task in 32 healthy controls, 15 subjects with mild cognitive impairment (MCI), and 15 patients with Alzheimer's disease (AD). The amplitude of changes in the waveform, which was quantitatively calculated by a signal processing method, was significantly lower in the frontal, and the bilateral parietal areas in the AD group, whereas that in the MCI group was significantly lower only in the right parietal area. The NIRS system may be a potential tool for the primary screening of AD.     

Effects of acute simulated microgravity on nocturnal sleep, daytime vigilance, and psychomotor performance: comparison of horizontal and 6 degrees head-down bed rest

This study examined the effect of acute simulated microgravity on nocturnal sleep, daytime vigilance, and psychomotor performance. Each of 7 volunteers were maintained for 3 days of head-down and horizontal bed rest in a counter-balanced design. Assessment measures were polysomnographic recordings on the first night and performance on psychophysiological tasks on the second day involving subjective and objective vigilance, P300, simple reaction time tasks, and dual performance tasks. No clear difference in sleep structure was observed between the head-down and horizontal conditions, except for a slight decrease in Stage 4 for head-down. Both subjective and objective daytime vigilance, P300, and the simple RT task showed no statistical difference, although tracking performance on the dual task showed deterioration at 10:00 for the head-down condition. These results suggest that nocturnal sleep, daytime vigilance, and psychophysiological functions were not disturbed in head-down sleep conditions, although there was a mild deterioration of higher attentional function in the morning.     

Remembering a nuclear accident in Japan: did it trigger flashbulb memories?

Flashbulb memories are vivid memories of the details surrounding the discovery of an emotional event. We investigated whether the nuclear accident that occurred in Japan in 1999 produced flashbulb memories among people who lived near the accident site. A questionnaire was distributed twice (approximately 3 weeks after the accident and 1 year later) to (1) the residents of the communities surrounding the accident site, (2) the students at a university near the accident site, and (3) the students at two universities far away from the accident site. Flashbulb memory holders were defined as those individuals who showed consistent memories between test and retest. The results indicated that only a small percentage of participants formed flashbulb memories. Further, no age-related decline was found. Flashbulb memories were distinguished by perfect or near perfect scores on four attributes: source, place, activity, and people. The results also indicated that the ratings on emotional reactions, personal consequentiality, and surprise did not differentiate between the flashbulb and non-flashbulb memory holders. In contrast, the flashbulb memory holders reported rehearsing more than the non-flashbulb memory holders. These results supported the notion that flashbulb memories are formed through rehearsal rather than at encoding. However, it is also possible that rehearsal was a result of the flashbulb memory.