7 国際: 2014年6月アーカイブ

Authors:
Kenri Kodaka and Yuki Ishihara

Title:
Crossed hands strengthen and diversify proprioceptive drift in the
self-touch illusion

Journal(書誌情報）:
Frontiers in Human Neuroscience, 8, 422, 2014

doi:
10.3389/fnhum.2014.00422

論文URL:
http://www.frontiersin.org/Journal/10.3389/fnhum.2014.00422

Abstract:
In the self-touch illusion (STI), some can feel that both hands are
touching each other even when they are separated actually. This is achieved
by giving synchronized touches to both hands. Because the STI involves both
hands (an administrating hand and a receptive hand) of a single person, two
types of proprioceptive drifts (PDs) simultaneously occur in such a way
that both hands are attracted to each other. It is known that the PD
distance is generally larger for the administrating hand than for the
receptive hand when the two hands are uncrossed. However, it remains
unclear why such an asymmetrical relationship is observed universally. In
this study, we conducted two types of experiment to induce the STI. The
first experiment involved four conditions combining a factor of "whether
the hands are uncrossed or crossed" and a factor of "whether the
administrating hand is resting or active on the surface," with the
receptive (left) hand located at the body's midline. The result
demonstrated that crossing hands and resting on surface (ROS) induced the
STI. Specifically, crossing hands enhanced the amount of PD distance by
more than two or three times. Moreover, it is interesting that strong PD
with dominance of the receptive hand, which did not appear in the uncrossed
condition, was observed frequently. The second experiment collected seven
"illusion-sensitive" participants from the first experiment, all of whom
had a strong tendency to feel the self-touch, and examined the effect of
the location of the body midline on the PD when hands are crossed with the
administrating hand ROS. The result demonstrated that the dominant hand on
the PD completely differed among participants, but was relatively stable
over the midline position and time in the same person. We also found that a
small number of participants exhibited quite a different pattern of the PD
in the identical posture. On the basis of the results, we analyze in detail
how the dominant hand on the PD is determined in the STI.


著者Contact先の email:
kenri@sda.nagoya-cu.ac.jp

日本語によるコメント：
関連の映像を以下で公開しています。
https://www.youtube.com/watch?v=EkmVnUVs7PE

Authors:
Matsuyoshi, D., Osaka, M., Osaka, N.

Title:
Age and individual differences in visual working memory deficit induced by overload

Journal:
Frontiers in Psychology, 5, 394、2014

doi:
10.3389/fpsyg.2014.00384

論文URL:
http:// www.frontiersin.org

Abstract:
Many studies on working memory have assumed that one can determine an
individual's fixed memory capacity. In the current study, we took an individual
differences approach to investigate whether visual working memory (VWM) capacity
was stable irrespective of the number of to-be-remembered objects and participant age.
Younger and older adults performed a change detection task using several
objects defined by color. Results showed wide variability in VWM capacity across
memory set sizes, age, and individuals. A marked decrease in the number of objects
held in VWM was observed in both younger and older adults with low memory capacity,
but not among high-capacity individuals, when set size went well beyond the limits of
VWM capacity. n addition, a decrease in the number of objects held in VWM was
alleviated among low-capacity younger adults by increasing VWM encoding time; however,
increasing encoding time did not benefit low-capacity older adults. These findings
suggest that low-capacity individuals are likely to show decreases in VWM capacity
induced by overload, and aging exacerbates this deficit such that it can not be
recovered by simply increasing encoding time. Overall, our findings challenge the
prevailing assumption that VWM capacity is fixed and stable, encouraging are
vision to the strict view that VWM capacity is constrained by a fixed number of
distinct "slots" in which high-resolution object representations are stored.

著者Contact先の email:
matsuyoshi@fennel.rcast.u-tokyo.ac.jp

Authors:
Tanabe-Ishibashi, A., Ikeda, T., Osaka, N

Title:
Raise two effects with one scene: Scene contexts have two separate effects in
visual working memory of target faces

Journal:
Frontiers in Psychology, 5, 400, 2014

doi:
10.3389/fpsyg.2014.00400

論文URL:
http:/ www.frontiersin.org

Abstract
Many people have experienced the inability to recognize a familiar face
in a changed context, a phenomenon known as
the "butcher-on-the-bus "effect. Whether this context effect is
a facilitation of memory by old contexts or a disturbance of
memory by novel contexts is of great debate. Here, we investigated
how two types of contextual information associated with target faces
influence the recognition performance of the faces using
meaningful (scene) or meaningless (scrambled scene) backgrounds.
The results showed two different effects of contexts: (1) disturbance on
face recognition by changes of scene backgrounds and (2) weak
facilitation of face recognition by there-presentation of the same
backgrounds, be it scene or scrambled. The results indicate that the
facilitation and disturbance of context effects are actually caused by
two different subcomponents of the background information: semantic
information available from scene backgrounds and visual array
information commonly included in a scene and its scrambled picture.
This view suggests visual working memory system can control such
context information, so that it switches the way to deal with the contexts
information; inhibiting it as a distracter or activating it as a cue for
recognizing the current target.

著者Contact先の email:
tanabe.azumi.2n@kyoto-u.ac.jp