基于N2pc成分的视觉空间注意功能老化机制

视觉空间注意是人的一种基本认知功能,对老年人的生活有重要影响。N2pc作为一种与注意选择相关的ERP成分,可以反映注意资源在空间上的分配,是研究视觉空间注意的一个良好指标。本文对此前基于N2pc成分的注意功能老化研究进行了综述。前人研究主要采用视觉搜索范式与空间线索范式。采用视觉搜索范式的研究发现,当目标周围有干扰子时,目标诱发的N2pc在老年人中振幅减小,潜伏期延迟,同时在行为上老年人与年轻人相比,正确率更低,反应时更长; 当目标周围无干扰子时,目标诱发的N2pc振幅老年人与年轻人相当或比年轻人更大,老年人的正确率与年轻人无显著差异。采用空间线索范式的研究发现,与目标无相同特征的线索奇异子(singleton cue)不会诱发N2pc,与目标有相同特征的线索奇异子诱发的N2pc未表现出年龄差异,差异体现在一种反映抑制的ERP成分—Pd上(年轻人有Pd而老年人没有),此时老年人在行为上表现出比年轻人更强的空间线索效应。这些研究共同说明,视觉空间注意功能的老化是一个复杂的过程,涉及到搜索目标时注意分配速度的减慢,对干扰子抑制能力的下降以及基于特征的注意捕获能力的良好保持。     

Walking through doorways causes forgetting: active and passive interaction

ABSTRACT

The current study explored the location updating effect when people passively interacted with an environment. This was assessed experimentally by having one person actively navigate through a virtual environment while picking up and putting objects down. A second person passively viewed the movement. Both participants responded to memory probes for objects they encountered. Probes appeared when the active participant moved halfway across a room or immediately after moving into a new room. Consistent with previous research, a location updating effect was found. That is, memory was worse following a shift to a new room. This effect was found for both active and passive participants but was smaller for the passive group. Thus, the shift from one event to another causes information to be harder to remember, reinforcing the importance of event cognition in memory. However, the more involved a person is in the interactive event, the more pronounced the effects.     

Inhibition within a reference frame during the interpretation of spatial language

Spatial terms such as right are potentially ambiguous because they can refer to different regions of space when defined by competing reference frames (e.g., my right within a relative reference frame versus an object's right within an intrinsic reference frame). In such situations, previous research has suggested that multiple reference frames are initially activated, followed by inhibition of the reference frame that is not ultimately selected to define the spatial term. Reference frames are complex multi-component representations, raising the question of exactly which components of the non-selected frame are inhibited. It is possible that the whole frame may be inhibited, including all axes and endpoints, or that only select endpoints and axes may be inhibited. Three experiments conducted using a negative priming paradigm revealed that only certain components of the non-selected reference frame were inhibited, consistent with the idea that some axes are privileged. These results also suggest that the components of a reference frame can be independently accessed. Implications for representing and accessing spatial information are discussed.     

How robust are the deviations in haptic parallelity?

Several studies have shown that physically parallel bars do not feel parallel and vice versa. The most plausible cause of this deviation is the biasing influence of an egocentric reference frame. The aim of the present study was to assess the strength of this egocentric contribution. The deviations from veridicality were measured in six experiments where subjects were presented with either haptic or visual information about parallelity or their deviations. It was found that even direct error feedback (either haptically or visually) did not even nearly result in veridical performance. The improvements found were attributed to a shift in focus towards a more allocentric reference frame, possibly reflecting the same mechanisms as found in delay and noninformative vision studies. We conclude that the illusionary percept of haptic parallelity is rather robust and is indeed caused by a strong reliance on an egocentric reference frame.     

情境和任务对空间认知参考框架选择的影响

通过运动迷津和语言描述任务,考察情境和任务对大学生空间参考框架选择的影响。结果表明,开放空间和目标物同背景融为一体有利于被试选择绝对参考框架。习惯空间术语对空间参考框架选择有影响,但影响程度视情境和任务之间关系而定。     

The development of categorical and coordinate spatial relations

Two classes of spatial relations can be distinguished in between and within object representations. Kosslyn [Kosslyn, S. M. (1987). Seeing and imagining in the cerebral hemispheres: A computational approach. Psychological Review, 94, 148–175] suggested that the right hemisphere (RH) is specialized for processing coordinate (metric) spatial information and the left hemisphere (LH) processes categorical (abstract) information more effectively. The present study examined the developmental pattern of spatial relation processing in 6–8-year old, 10–12-year old and adults. Using signal detection analyses we calculated sensitivity and bias scores for all age groups. The results indicated that older children and adults showed a greater response bias than younger children. Also, discrimination sensitivity for spatial relation changes clearly improved with age. For the oldest children (10–12-year old) and adults this improvement was accompanied by a RH specialization. In contrast with Kosslyn's claim, this RH advantage also applied to the processing of categorical spatial information. The results are discussed in terms of a right hemispheric specialization for spatial relation processing which matures with age.     

类别空间关系加工系统和数量空间关系加工系统的分离 ——来自多领域的研究证据

Kosslyn认为人类的空间关系加工系统分为类别空间关系加工子系统和数量空间关系加工子系统,这两个子系统不仅存在功能上的分离,并且存在大脑神经水平的分离,这种神经水平的分离表现为两种空间关系加工的大脑半球偏向,即类别空间关系加工的左半球偏向与数量空间关系加工的右半球偏向。对两种空间关系加工的研究,涉及的领域从低水平的空间知觉,至表象、记忆、语言、行动及物体识别等,涉及的研究方法包括半视野速示法,神经网络模拟,PET, fMRI, ERP, rTMS,脑损伤病人的研究及比较动物研究。综合现有研究,虽然大多数研究中得到的脑半球偏向为两种加工子系统在神经水平的分离提供了证据,但不同研究中脑半球偏向的获得是相当不稳定的,并且受到研究方法因素的影响。尽管造成神经水平的分离似乎与大脑左右半球对具有不同感受野特征的神经元输出的偏向有一定的关系,但这仍需要进一步的研究证据     

负数的空间表征引起的空间注意转移

本研究采用数字线索提示的刺激探测任务, 通过三个实验探讨负数的低水平加工能否,以及怎样引起空间注意的转移。实验一探讨只有负数单独呈现作为线索时能否引起空间注意的转移。结果表明：对负数绝对值大小的加工能引起空间注意的转移。实验二进一步探讨在正数、负数和零混合作为线索时能否引起空间注意的转移。结果表明：对负数数量大小的加工能引起空间注意的转移。实验三再次用正数, 负数和0三种数字混合作为探测刺激前的线索, 但仅对负数和零作为提示线索之后的探测刺激进行反应, 又一次得到了由有效提示线索所引发的对数字数量大小加工引起的空间注意的转移。本研究表明, 对负数的低水平加工可以引起空间注意的转移, 然而, 是对绝对值的加工还是数量大小的加工引起注意转移依赖于共同参与的其它数字加工产生的影响。     

自我面孔对空间注意的调控：来自Posner空间线索范式的证据

利用Posner的空间线索范式,三个实验意在探寻自我面孔作为特殊的刺激对空间注意的调控作用。在实验一中,自我或者熟悉的面孔作为内源性线索出现在视野中央,通过朝左或者朝右来提示目标出现的位置。在实验二（小图）和实验三（大图）中,自我或熟悉的面孔与目标同时呈现,作为与任务无关的刺激出现在视野的左侧或右侧。实验一的结果发现,与熟悉的面孔相比较,自我面孔产生了更大的提示效应。这意味着当自我面孔与任务相关时,对提示位置易化优于熟悉的面孔。与之相反的是,在实验二和实验三中,自我面孔和熟悉的面孔同样捕获目标位置的空间注意。然而,研究并没有发现自我面孔与熟悉面孔在捕获注意上的差异。这一结果也许暗示着在注意捕获的过程中,面孔效应足够大而掩盖了自我效应的出现。这些发现表明自我面孔之所以是具有特殊性的刺激不仅受感知过程的影响,还依赖于与任务的关系。