Action control: independent effects of memory and monocular viewing on reaching accuracy

Evidence suggests that perceptual networks in the ventral visual pathway are necessary for action control when targets are viewed with only one eye, or when the target must be stored in memory. We tested whether memory-linked (i.e., open-loop versus memory-guided actions) and monocular-linked effects (i.e., binocular versus monocular actions) on action arise from a common mechanism as suggested by evidence from neuropsychology and psychophysics. Participants viewed targets with either one eye or two (vision: monocular versus binocular) and then reached to touch targets in open-loop and memory-guided conditions (condition: open-loop versus 0, 500, 1000, and 1500 ms delays). Results showed that memory-linked and monocular-linked increases in radial and variable movement error were additive (i.e., main effects of vision and condition, but no interaction). This suggests that the two effects on visuomotor control arise from separate mechanisms, in contrast to evidence from psychophysics and neuropsychology suggesting a common underlying mechanism.     

无限慈悲的观音菩萨

菩萨是梵文音译“菩提萨”的简称,其菩提汉译为觉悟,萨汉译为众生,或有情(一切有感情之物),全译为觉有情、觉悟的众生之意。根据修行的层次,菩萨可分为胁侍菩萨和供养菩萨。胁侍菩萨是修行层次最高的菩萨,其修行觉悟仅次于佛或等同于佛。每尊佛都有两位或几位胁侍菩萨。在石窟壁画中经常画的“八大菩萨”,即是释迦牟尼佛左右的胁侍菩萨——文殊菩萨、普贤菩     

医疗纠纷处理中若干伦理问题的思考

医疗纠纷的增势和处理难已成为众所周知的事实。但是,在医疗纠纷处理中存在着医患关系的信任性、医疗事故鉴定的公正性和经济裣的合理笥是思考的伦理问题。只要医患双方、乃至社会对诸如医疗行为是否等同于一般的服务行为、病人权益是否等同于消费者权益、医疗事故鉴定是不是医医相护、经济裣能不能实行等价赔偿原则、医疗差错要不要给予经济补偿等有效为统一的认识,就会有利于医疗纠纷的处理,有利于维护医患双方的合法权益,有利     

The accuracy of reaching movements in brief delay conditions.

We tested the hypothesis that a highly accurate target representation is available to the visuomotor system in brief (< 2 s) delay conditions. Participants reached to single midsagittal targets (20, 25, 30, 35, 40 cm amplitude) in full vision, open-loop and delay conditions (500, 1,000, 1,500 or 2,000 ms). Radial endpoint error was significantly greater for open-loop than full vision reaches, and was greater still for all delay conditions, which did not differ from one another. Radial error was greater for farther targets, although this tended to hold only for delayed reaches. These data suggest that the visuomotor system switches from on-line visual information to a degraded, stored representation very soon (< 500 ms) if not immediately after target occlusion.     

The effect of pictorial content on attention levels and alcohol‐related beliefs: An eye‐tracking study

To examine attention levels to different types of alcohol warning labels. Twenty‐two participants viewed neutral or graphic warning messages while dwell times for text and image components of messages were assessed. Pre and postexposure outcome expectancies were assessed in order to compute change scores. Dwell times were significantly higher for the image, as opposed to the text, components of warnings, irrespective of image type. Participants whose expectancies increased after exposure to the warnings spent longer looking at the image than did those whose positive expectancies remained static or decreased. Images in alcohol warnings appear beneficial for drawing attention, although findings may suggest that this is also associated with heightened positive alcohol‐related beliefs. Implications for health intervention are discussed and future research in this area is recommended.     

Religion,sexuality, and (in)equality in the lives of older lesbian,gay, and bisexual people in the United Kingdom

This article explores how older lesbian, gay, and bisexual (LGB) people in the United Kingdom engage with religion in later life. Drawing on research with older persons who are LGB and with activists, it explores religious spaces as sites of both inclusion and exclusion, historically and in the present day. Particular consideration is given to the equality implications, in the form of parity of participation, including in the context of religious-based social care provision for older people. Future research implications are addressed.     

Manipulability and living/non-living category effects on object identification

Object naming studies have generally observed that both normal and brain damaged individuals are faster and more accurate at identifying non-living objects than living objects (). However, a potential confounding variable, manipulability, has been present in past studies that may mediate this effect. Previous studies that have observed a non-living advantage have often used manipulable and non-manipulable exemplars to represent the non-living and living groups, respectively. Under conditions which controlled for object manipulability and familiarity, results demonstrated advantages for the identification of non-manipulable and for living objects.     

Divided attention,memory, and spatial discrimination in food-storing and nonstoring birds,black-capped chickadees (Poecile atricapilla) and dark-eyed juncos (Junco hyemalis)

Food-storing birds, black-capped chickadees (Poecile atricapilla), and nonstoring birds, dark-eyed juncos (Junco hyemalis), matched color or location on a touch screen. Both species showed a divided attention effect for color but not for location (Experiment 1). Chickadees performed better on location than on color with retention intervals up to 40 s, but juncos did not (Experiment 2). Increasing sample-distractor distance improved performance similarly in both species. Multidimensional scaling revealed that both use a Euclidean metric of spatial similarity (Experiment 3). When choosing between the location and color of a remembered item, food storers choose location more than do nonstorers. These results explain this effect by differences in memory for location relative to color, not division of attention or spatial discrimination ability.     

Patterns of apraxia associated with the production of intransitive limb gestures following left and right hemisphere stroke

The model of apraxia proposed by Roy (1996) states that three patterns of apraxia should be observed across pantomime and imitation conditions. In the present analysis the frequency and severity of each pattern of apraxia were examined in a consecutive sample of left-(LHD) and right-hemisphere-damaged (RHD) patients during the production of intransitive limb gestures. The results indicated that a significant proportion of LHD and RHD patients were selectively impaired in formulating the ideational component of intransitive limb gestures.     

Posture and target location effects on manual preference

Twenty-nine right-handed participants made unimanual movements to 5 target locations while standing and while balancing on a rocker platform. Manual preference was affected by target location (p < .001; manual preference tended to be concordant with target hemispace) and posture (p < .05; responses from the rocker platform were associated with a lower level of right-hand responding). A location by posture interaction (p < .05) indicated that the effect of posture was present only for targets in left hemispace; the right hand was used less frequently in the rocker condition than simple standing. Manual preference is viewed as a process of response selection motivated by an effort to minimize neural processing and mechanical costs.