Developmental changes in infants’ visual short-term memory for location

To examine the development of visual short-term memory (VSTM) for location, we presented 6- to 12-month-old infants (N = 199) with two side-by-side stimulus streams. In each stream, arrays of colored circles continually appeared, disappeared, and reappeared. In the changing stream, the location of one or more items changed in each cycle; in the non-changing streams the locations did not change. Eight- and 12.5-month-old infants showed evidence of memory for multiple locations, whereas 6.5-month-old infants showed evidence of memory only for a single location, and only when that location was easily identified by salient landmarks. In the absence of such landmarks, 6.5-month-old infants showed evidence of memory for the overall configuration or shape. This developmental trajectory for spatial VSTM is similar to that previously observed for color VSTM. These results additionally show that infants’ ability to detect changes in location is dependent on their developing sensitivity to spatial reference frames.     

Continuous visual cues trigger automatic spatial target updating in dynamic scenes

Dynamic tasks often require fast adaptations to new viewpoints. It has been shown that automatic spatial updating is triggered by proprioceptive motion cues. Here, we demonstrate that purely visual cues are sufficient to trigger automatic updating. In five experiments, we examined spatial updating in a dynamic attention task in which participants had to track three objects across scene rotations that occurred while the objects were temporarily invisible. The objects moved on a floor plane acting as a reference frame and unpredictably either were relocated when reference frame rotations occurred or remained in place. Although participants were aware of this dissociation they were unable to ignore continuous visual cues about scene rotations (Experiments 1a and 1b). This even held when common rotations of floor plane and objects were less likely than a dissociated rotation (Experiments 2a and 2b). However, identifying only the spatial reference direction was not sufficient to trigger updating (Experiment 3). Thus we conclude that automatic spatial target updating occurs with pure visual information.     

Spatial reasoning in Tenejapan Mayans

Language communities differ in their stock of reference frames (coordinate systems for specifying locations and directions). English typically uses egocentrically-defined axes (e.g., “left–right”), especially when describing small-scale relationships. Other languages such as Tseltal Mayan prefer to use geocentrically-defined axes (e.g., “north–south”) and do not use any type of projective body-defined axes. It has been argued that the availability of specific frames of reference in language determines the availability or salience of the corresponding spatial concepts. In four experiments, we explored this hypothesis by testing Tseltal speakers’ spatial reasoning skills. Whereas most prior tasks in this domain were open-ended (allowing several correct solutions), the present tasks required a unique solution that favored adopting a frame-of-reference that was either congruent or incongruent with what is habitually lexicalized in the participants’ language. In these tasks, Tseltal speakers easily solved the language-incongruent problems, and performance was generally more robust for these than for the language-congruent problems that favored geocentrically-defined coordinates. We suggest that listeners’ probabilistic inferences when instruction is open to more than one interpretation account for why there are greater cross-linguistic differences in the solutions to open-ended spatial problems than to less ambiguous ones.     

Plasticity of human spatial cognition: spatial language and cognition covary across cultures

The present paper explores cross-cultural variation in spatial cognition by comparing spatial reconstruction tasks by Dutch and Namibian elementary school children. These two communities differ in the way they predominantly express spatial relations in language. Four experiments investigate cognitive strategy preferences across different levels of task-complexity and instruction. Data show a correlation between dominant linguistic spatial frames of reference and performance patterns in non-linguistic spatial memory tasks. This correlation is shown to be stable across an increase of complexity in the spatial array. When instructed to use their respective non-habitual cognitive strategy, participants were not easily able to switch between strategies and their attempts to do so impaired their performance. These results indicate a difference not only in preference but also in competence and suggest that spatial language and non-linguistic preferences and competences in spatial cognition are systematically aligned across human populations.     

On using Vernier acuity to assess magnocellular sensitivity

A recent study [Keri, S., & Benedek, G. (2009). Visual pathway deficit in female fragile × premutation carriers: A potential endophenotype. Brain and Cognition, 69, 291–295] has found Vernier acuity deficiencies together with contrast sensitivity defects consistent with a magnocellular deficit in female fragile × premutation carriers. This may appear to support the notion that Vernier acuity may serve as a test of magnocellular sensitivity. However, Vernier acuity deficiencies have been reported in other conditions (e.g., schizophrenia, amblyopia and cortical visual impairment) where there is little evidence for magnocellular deficits. The observation that Vernier acuity deficiencies can occur without magnocellular deficits indicates that Vernier acuity is not a reliable test of magnocellular sensitivity.     

Role of motor processes in extrinsically encoding mental transformations

Previous research has shown that imagined perspective rotations elicit spatial and low-level cortical motor areas of the brain when participants rely on knowledge of their physical body, or body percept (Wraga, Flynn, Boyle, & Evans, 2010). The current study used functional magnetic resonance imaging (fMRI) to investigate whether recruitment of the body percept would activate low-level cortical motor areas of the brain within other classes of mental transformations. Participants performed imagined object and perspective rotations of three-dimensional Shephard-Metzler (1971) stimuli. For each task, participants used button presses serving as virtual pointers to locate a prescribed portion of the stimuli with respect to their "right" and "left." We found low-level cortical motor activation (M1) for both mental transformations; however, the degree to which such activation related to participants' performance differed, as well as the recruitment of additional nonmotoric strategies. The results are discussed in terms of recent hypotheses regarding the role of the body percept in extrinsically encoded mental transformations.     

运动轨迹和方向对视觉空间关系加工的影响

视觉空间关系分为类别与数量两种表征。研究通过控制起参照作用的运动客体消失状态与定位客体出现时间,分析客体运动信息对两种关系判断的影响。结果发现:运动信息在各间隔时间对类别任务影响呈序列排列,运动方向较轨迹信息有优势,轨迹较法线信息有优势;数量表征仅在0ms间隔受运动方向促进,在其他间隔下,三种位置上的判断均无差异。结果表明运动客体类别表征比数量表征更持久;且相对类别表征,数量判断作为精确距离表征不易受运动方向和轨迹信息影响。     

面孔参照或观察者参照：性别二态线索、面孔吸引力与表情对正视面孔偏好的影响

本研究探讨了性别二态线索、面孔吸引力和表情对正视面孔偏好的影响。实验1基于面孔参照,被试普遍偏好正视面孔;相对男性化/厌恶和生气/低吸引力的面孔,被试更偏好女性化/高兴和中性/高吸引力的正视面孔;实验2基于观察者参照,总体并未表现出正视偏好;对低吸引力/中性表情/男性化面孔更偏好斜视面孔。     

Paradoxical cross-over due to attention to high or low spatial frequencies

The mechanisms underlying the right hemisphere's dominance for spatial and attentional functions lacks a comprehensively explanation. For example, perceptual biases, as observed in line bisection and related tasks, might be caused by an attentional asymmetry or by perceptual processes such as a specialization of the left and right hemisphere for high and low spatial frequencies (SFs), respectively. Here we used the gratingscales task to measure perceptual bias in SF judgements, and we cued participants' attention either to high or low SFs. Participants showed a leftward bias when comparing the high SF components of the stimulus, and a rightward bias when comparing the low SF components-opposite to what would be expected from a hemispheric lateralization for SFs. Two control experiments used different strategies to manipulate the width of the attentional window. However, we observed no influence on perceptual bias, thus ruling out the possibility that the results in Experiment 1 were due to differences in attentional window size. These data support the idea of an attentional asymmetry underlying perceptual bias. Our results provide novel support for the role of attentional asymmetry in perceptual biases.