Viewing direction and pictorial representation

During prolonged monocular observation from afar, an upright wire cube (Necker cube) or a drawing of such a cube inverts continuously so that the lower of the two frontal faces appears to be either in front (version A) or in back (version B). Version A is perceived as if it were viewed obliquely from above and version B as if seen from below. In our experiments, timing the durations of the versions showed that version A lasted longer than version B. When a wire cube was shifted upward so that it was actually viewed slightly from below, version B lasted longer than version A. The actual viewing direction was apparently taken into account by the subjects, which was not the case when the cube was replaced by a drawing showing the projection of the cube. In that case, version A always lasted longer, regardless of the actual viewing direction. This finding conforms with picture viewing in general, where a three-dimensional object’s orientation does not change when the observer’s viewing direction changes.     

Conventional naturalism: A perceptualist account of pictorial representation

This paper proposes that pictures are functional objects which figure in norm‐governed practices of usage yet whose specific function is to present the world as it looks to acculturated perceivers. Pictorial content presents the way the world looks to a subject's acculturated perceptual grasp. Hence, pictorial content needs to be explained in terms of a theory of perceptual content, but a novel theory which departs from the two‐stage sensation‐based approach to perception and the polarization between naturalism and conventionalism that it engenders. Following a diagnosis of this polarization, I invoke a novel theory of perception that explains perceptual content as conceptually articulated and determinate in character. I show that (1) pictures present content of the same distinctive determinate type as perceptual content; and that (2) pictures do so by invoking perceptual experience and perceptual processes that are of the same kind as those invoked by actual scenes. This perceptualist approach considers and explains the role of norms as well as of the nature of our visual processes, allowing us to allocate the insights of both conventionalism and naturalism to their proper theoretical roles.     

The cognitive and neural architecture of sequence representation

The authors theorize that 2 neurocognitive sequence-learning systems can be distinguished in serial reaction time experiments, one dorsal (parietal and supplementary motor cortex) and the other ventral (temporal and lateral prefrontal cortex). Dorsal system learning is implicit and associates noncategorized stimuli within dimensional modules. Ventral system learning can be implicit or explicit It also allows associating events across dimensions and therefore is the basis of cross-task integration or interference, depending on degree of cross-task correlation of signals. Accordingly, lack of correlation rather than limited capacity is responsible for dual-task effects on learning. The theory is relevant to issues of attentional effects on learning; the representational basis of complex, sequential skills; hippocampal-versus basal ganglia-based learning; procedural versus declarative memory; and implicit versus explicit memory.     

Constraining the neural representation of the visual world

Understanding the perception of all but the most impoverished and artificial scenes presents a different and probably far greater challenge from understanding face recognition, reading, or identification (or even categorization) of single objects. Central issues in the interpretation of structured objects and scenes are reviewed, starting with fundamentals such as the meaning of seeing. A theoretical approach to this formidable task is outlined, motivated by some recent developments in neuroscience and neurophilosophy.     

Memory search and the neural representation of context

A challenge for theories of episodic memory is to determine how we focus memory search on a set of recently learned items. Cognitive theories suggest that the recall of an item representation is driven by an internally maintained context representation that integrates incoming information with a long time-scale. Neural investigations have shown that recalling an item revives the pattern of brain activity present during its study. To link these neural and cognitive approaches, we propose a framework in which context is maintained and updated in prefrontal cortex, and is associated with item information through hippocampal projections. The proposed framework is broadly consistent with neurobiological studies of temporal integration and with studies of memory deficits in individuals with prefrontal damage.     

A depictive neural model for the representation of motion verbs

In this paper, we present a depictive neural model for the representation of motion verb semantics in neural models of visual awareness. The problem of modelling motion verb representation is shown to be one of function application, mapping a set of given input variables defining the moving object and the path of motion to a defined output outcome in the motion recognition context. The particular function-applicative implementation and consequent recognition model design presented are seen as arising from a noun-adjective recognition model enabling the recognition of colour adjectives as applied to a set of shapes representing objects to be recognised. The presence of such a function application scheme and a separately implemented position identification and path labelling scheme are accordingly shown to be the primitives required to enable the design and construction of a composite depictive motion verb recognition scheme. Extensions to the presented design to enable the representation of transitive verbs are also discussed.     

The origins of pictorial competence

Pictorial competence , which refers to the many factors involved in perceiving, interpreting, understanding, and using pictures, develops gradually over the first few years of life. Although experience is not required for accurate perception of pictures, it is necessary for understanding the nature of pictures. Infants initially respond to depicted objects as if they were real objects, and toddlers are remarkably insensitive to picture orientation. Only gradually do young children figure out the nature of pictures and how they are used.     

Generation of a pictorial code

In Experiments I and II direct measures were obtained of the time required to convert a picture or a sentence to a report of visualization or to a simple drawing, latencies were faster for pictures than for sentences and were affected by the surface form of the sentence. In Experiment Ill, Ss matched pictures or sentences against a test picture under conditions of simultaneous or successive presentation. “Yes” and “No” response times were affected by sentence form under both conditions, although the difference between sentence-picture and picture-picture comparisons was virtually eliminated under the successive condition. In Experiment IV, Ss held a sentence or picture in memory over a 1,500-msec interval at the end of which a test picture or an instruction to draw the design was presented. Construction latencies were shorter in response to pictures than sentences, and there were effects of sentence form on verification time. Some implications of these results are discussed.     

Multidimensional scaling of pictorial informativeness.

The dimensions used in the judgment of the informativeness of picture sections were investigated by means of a recently proposed methodology, multidimensional similarity analysis. 10 judges (college students) rated the informational similarity of 32 areas within a single picture. The five extracted dimensions accounted for 86% of the judgmental variance and were all readily interpretable. These dimensions were discussed with respect to an earlier study in which eye movements of subjects viewing this picture were recorded.     

探究事件相关脑电/脑磁信号中的神经表征模式：基于分类解码和表征相似性分析的方法

探究不同心智活动下的神经表征差异, 是认知神经科学关注的核心问题之一。早期的脑电/脑磁分析方法主要关注组平均后的神经响应水平, 这要求在关注的时间进程上, 各个被试在相同刺激条件下事件相关电位/事件相关磁场的振幅大小和方向、以及地形图分布和极性均要有较高的一致性。近些年来, 研究者们将功能性磁共振成像研究中常用到的两种技术——机器学习中的分类算法(即基于分类的解码)和表征相似性分析——引入到了脑电/脑磁数据分析中。这两种新技术可以克服传统脑电/脑磁数据基于具体电压/磁感应强度波形平均分析的缺点, 具有在个体水平上探究神经表征编码的特点, 为人们探究大脑在不同时间进程上如何对特定的神经表征信息进行动态编码提供了新的思路。两种技术基于不同的方法学原理来抽提个体间一致的脑认知加工机制, 还为脑电/脑磁研究开展跨时域、跨任务、跨模态、跨群体比较不同认知过程中的表征差异提供了更多新颖的途径。我们首先通过与传统的脑电/脑磁分析方法进行比较, 系统性介绍了基于分类的解码和表征相似性分析的原理和操作流程, 之后对两种方法的应用场景进行了梳理, 并在最后对未来可供研究的方向提出了我们的见解。     

大脑腹侧视觉通路知觉表征神经机制研究

大脑腹侧视觉通路知觉表征的神经机制是认知神经科学研究面临的基本问题。本文系统介绍了该问题研究中比较有影响力的理论模型,归纳分析了模型之间的分歧与各自的局限。文章分析指出大脑自上而下的调控机制是腹侧视觉通路神经表征机制问题研究的另一重要维度,如何有效整合知觉表征模型与大脑调控机制的相关研究是进一步深化知觉表征神经机制问题研究的关键。     

Judging pictorial and linguistic aspects of space

A test is made of the notion that Stroop-like interference and facilitation effects arise from two different sources, one pictorial and the other linguistic. It was hypothesized that when irrelevant information is pictorial, it interferes with a pictorial code used in the processing of the relevant information; when it is linguistic, it interferes with a linguistic code. The experiment required subjects to respond to (1) the meaning of a spatial word, t2) its absolute position, or (3) its relative position, while attempting to ignore the two irrelevant dimensions of the display. It was found that word meaning and absolute position information affected the speed of relative position judgments in an additive manner. No other Stroop-like effects were found. The results supported the hypothesis under test. It was concluded that the existence of different kinds of Stroop effect must be accommodated by current models of the phenomenon.     

Perception of pictorial depth cues by pigeons

Pigeons were trained to discriminate pictures of intact objects from pictures of objects in which both depth from shading and depth from perspective cues were manipulated. Depth from shading was manipulated either by scrambling or by removing three-dimensional shading cues. Depth from perspective was manipulated either by presenting pictures of objects with a two-dimensional outline (i.e., a square) or with a three-dimensional outline (i.e., a cube). Transfer tests with novel images suggest that pigeons perceive and utilize both types of pictorial depth cues. The implications of these results for our understanding of picture perception in pigeons are discussed.     

Free recall and complexity of pictorial stimuli

In order to explore variables underlying primacy and recency effects in free recall of pictorial material, norms were developed using 120 subjects who rated the vividness and complexity of slides. Two experiments were then run in which two levels of each of these variables (extreme high and low ratings) were factorially combined. In the first experiment 24 subjects were shown three mixed lists, two short and one long (consisting of materials of all four combinations of vividness and complexity), and in the second experiment 12 subjects were shown four pure lists (consisting of materials of a single type). Analysis of variance showed list length in the mixed list experiment and complexity in both experiments to be strong determinants of recall. Greatest recall was for items of low complexity in short lists. Weak, but statistically significant, serial position effects were evident, particularly for less complex items. The effects of primacy and recency seem to decrease with increasing complexity of visual materials, perhaps because of the greater difficulty in rehearsing more complex pictures either verbally or iconically.