Decrement of the Müller-Lyer illusion with saccadic and tracking eye movements

Subjects viewed the Müller-Lyer illusion, making either saccadic or smooth tracking eye movements between the apexes of the arrow heads. The decrement in the magnitude of the illusion was significantly greater for Ss in the saccadic viewing condition. Saccadic and smooth tracking eye movements are separately controlled,and information about eye position is more readily available from the efferent signals issued to control a saccadic eye movement. The experimental findings were consistent with the hypothesis that Ss in the saccadic condition learned a new afferent efferent association. The results support a theory that visual perception is determined by efferent readiness activated by visual afferent stimulation.     

On nystagmus,saccades, and fixations

Investigations of the ways in which the eyes move came to prominence in the 19th century, but techniques for measuring them more precisely emerged in the 20th century. When scanning a scene or text the eyes engage in periods of relative stability (fixations) interspersed with ballistic rotations (saccades). The saccade-and-fixate strategy, associated with voluntary eye movements, was first uncovered in the context of involuntary eye movements following body rotation. This pattern of eye movements is now referred to as nystagmus, and involves periods of slow eye movements, during which objects are visible, and rapid returns, when they are not; it is based on a vestibular reflex which attempts to achieve image stabilisation. Post-rotational nystagmus was reported in the late 18th century (by Wells), with afterimages used as a means of retinal stabilisation to distinguish between movement of the eyes and of the environment. Nystagmus was linked to vestibular stimulation in the 19th century, and Mach, Breuer, and Crum Brown all described its fast and slow phases. Wells and Breuer proposed that there was no visual awareness during the ballistic phase (saccadic suppression). The saccade-and-fixate strategy highlighted by studies of nystagmus was shown to apply to tasks like reading by Dodge, who used more sophisticated photographic techniques to examine oculomotor kinematics. The relationship between eye movements and perception, following earlier intuitions by Wells and Breuer, was explored by Dodge, and has been of fundamental importance in the direction of vision research over the last century.     

Perception of self-motion from visual flow

Accurate and efficient control of self-motion is an important requirement for our daily behavior. Visual feedback about self-motion is provided by optic flow. Optic flow can be used to estimate the direction of self-motion (‘heading’) rapidly and efficiently. Analysis of oculomotor behavior reveals that eye movements usually accompany self-motion. Such eye movements introduce additional retinal image motion so that the flow pattern on the retina usually consists of a combination of self-movement and eye movement components. The question of whether this ‘retinal flow’ alone allows the brain to estimate heading, or whether an additional ‘extraretinal’ eye movement signal is needed, has been controversial. This article reviews recent studies that suggest that heading can be estimated visually but extraretinal signals are used to disambiguate problematic situations. The dorsal stream of primate cortex contains motion processing areas that are selective for optic flow and self-motion. Models that link the properties of neurons in these areas to the properties of heading perception suggest possible underlying mechanisms of the visual perception of self-motion.     

Must we measure what we mean?

This paper excavates a debate concerning the claims of ordinary language philosophers that took place during the middle of the last century. The debate centers on the status of statements about ‘what we say’. On one side of the debate, critics of ordinary language philosophy argued that statements about ‘what we say’ should be evaluated as empirical observations about how people do in fact speak, on a par with claims made in the language sciences. By that standard, ordinary language philosophers were not entitled to the claims that they made about what we would say about various topics. On the other side of the debate, defenders of the methods of ordinary language philosophy sought to explain how philosophers can be entitled to statements about what we would say without engaging in extensive observations of how people do in fact use language. In this paper, I defend the idea that entitlement to claims about what we say can be had in a way that doesn’t require empirical observation, and I argue that ordinary language philosophers are (at least sometimes) engaged in a different project than linguists or empirically minded philosophers of language, which is subject to different conditions of success.     

A revised analysis of the role of efference in motion perception

The analysis of motion perception historically has included efferent as well as afferent mechanisms to account for the perception of motion during eye movement. The application of efferent mechanisms to motion perception has been limited, however, by several illusions which are apparently inconsistent with the notion that oculomotor mechanisms contribute to motion perception. An alternative account is presented of the manner in which efference may contribute to the perception of motion. It is proposed that distinct smooth eye-movement systems contribute differentially to object motion perception. Specifically, activity in the smooth pursuit system gives rise to the perception of object motion, whereas activity in the smooth component of reflexive eye movements does not. Tracking of a moving object results in object motion perception as a result of efference in the pursuit system. However, the pursuit system may be activated to oppose the smooth component of reflexive eye movements in order to preserve fixation on a stationary object. In such cases neither the fixated object nor the eye is moving but illusory movement results from the efference in the pursuit system. A number of illusory movement phenomena are interpreted in terms of this model.     

One ring to rule them all: Master discourses of enlightenment—and racism—from colonial to contemporary New Zealand

We interrogated historical continuity and change in discourses of enlightenment and racism through the analysis of 160 years of New Zealand Speeches from the Throne (1854–2014, 163 speeches). Enlightenment discourses of benevolence and perfectibility were prevalent in all periods, much more so than racism. ‘Old‐fashioned’ racism took the form of an assumed civilizational superiority (including accusations of ‘barbarism’) during colonization, with ‘modern’ racism taking forms like blaming Māori for not ‘productively’ using the land. Both declined to almost zero by the 20th century, undermining the idea of ‘old‐fashioned’ versus ‘modern’ racism. Utilitarian discourses peaked in the late 19th to early 20th centuries as justification for Māori land alienation. ‘Master discourses of enlightenment’ consisted of a central core of social representations that changed at the periphery, with a gradual expansion of symbolic inclusion of Māori in discourses of national identity to the point where biculturalism is the dominant discourse for elites today.     

视觉运动追踪的加工过程

视觉运动追踪是运动知觉研究的一个重要领域。通过构建视觉运动追踪的过程模型和分析每个阶段的认知加工任务, 可以帮助人们认识运动物体识别的本质。视觉运动追踪包括目标获取和运动追踪两个加工过程：目标获取阶段的主要任务是将目标与背景分离, 集中注意力加工追踪目标; 运动追踪阶段的主要任务是启动平滑追踪眼动和追赶性眼跳, 并发挥行为水平、眼动水平和神经活动水平的预测机制。目标获取同时受背景和目标的运动特征和身份特征影响; 运动追踪系统发挥预测机制的基础是客体表征连续性, 而客体表征连续性的建立同时依赖于目标时空属性和身份特征的编码加工。因此, 视觉运动追踪是视觉系统对客体运动信息和身份语义信息整合的结果。其中, 客体运动信息的加工特性已经获得了比较广泛的研究, 而语义信息加工机制还有待进一步加强。     

On agency and body-ownership: phenomenological and neurocognitive reflections

The recent distinction between sense of agency and sense of body-ownership has attracted considerable empirical and theoretical interest. The respective contributions of central motor signals and peripheral afferent signals to these two varieties of body experience remain unknown. In the present review, we consider the methodological problems encountered in the empirical study of agency and body-ownership, and we then present a series of experiments that study the interplay between motor and sensory information. In particular, we focus on how multisensory signals interact with body representations to generate the sense of body-ownership, and how the sense of agency modulates the sense of body-ownership. Finally, we consider the respective roles of efferent and afferent signals for the experience of one's own body and actions, in relation to self-recognition and the recognition of other people's actions. We suggest that the coherent experience of the body depends on the integration of efferent information with afferent information in action contexts. Overall, whereas afferent signals provide the distinctive content of one's own body experience, efferent signals seem to structure the experience of one's own body in an integrative and coherent way.     

Visual and verbal coding in the interhemispheric transfer of information

A manual response was used to record a decision of ‘same’ or ‘differ’ on two visual signals which were presented simultaneously, either both to the same hemisphere or each to different hemispheres. The signals were drawn from the set of letters A, B, a, b. Eight subjects were required to match on the basis of the names of the letters (irrespective of whether they were capitals or lower case) and eight subjects were required to match on the basis of the visual identity of the signals.Reaction times were measured for ‘same’ and ‘differ’ decisions.This experiment extends a previous study by the same authors (Davis and Schmit 1971). The previous finding, that when two signals are presented each to different hemispheres, reaction times are shorter than when both are presented to the same hemisphere, was confirmed for both visual and name matching. New evidence is provided on the role of each hemisphere in the analysis and comparison of signals, on either a visual or a verbal basis, for ‘same’ and ‘differ’ decisions. A model to explain the results in terms of the different functions of the two hemispheres is proposed.     

Interaction of afferent and efferent signals underlying joint position sense: empirical and theoretical approaches

A model of joint position sense is considered based on the concept that central motor commands are adequately expressed in terms of shifts of the so-called invariant length-tension characteristics for agonist and antagonist muscles. The main points of this concept are discussed to clarify them and to prevent misunderstanding. The basic idea of the model is that the efferent copy of the central motor commands plays the role of a reference frame for evaluation of afferent proprioceptive discharges. An experiment with reproduction of constrained movements was performed in order to investigate the influence of voluntary flexor or extensor muscle tension on position sense in the elbow joint. The results demonstrate adequate perception of joint position on the background of voluntary muscle tension and thus are quite consistent with the model. The role of afferent and efferent signals in position sense is discussed with special reference to views expressed recently by different authors. The interrelation between position sense and sense of effort is considered, based on a concept of senso-motor space.     

Interaction of Afferent and Efferent Signals Underlying Joint Position Sense

A model of joint position sense is considered based on the concept that central motor commands are adequately expressed in terms of shifts of the so-called invariant length-tension characteristics for agonist and antagonist muscles. The main points of this concept are discussed to clarify them and to prevent misunderstanding. The basic idea of the model is that the efferent copy of the central motor commands plays the role of a reference frame for evaluation of afferent proprioceptive discharges. An experiment with reproduction of constrained movements was performed in order to investigate the influence of voluntary flexor or extensor muscle tension on position sense in the elbow joint. The results demonstrate adequate perception of joint position on the background of voluntary muscle tension and thus are quite consistent with the model. The role of afferent and efferent signals in position sense is discussed with special reference to views expressed recently by different authors. The interrelation between position sense and sense of effort is considered, based on a concept of senso-motor space.     

空间知觉的透视理论

空间知觉与人在观察时的认知过程和透视结构有关,它还涉及不同参照系统信号之间的连续转换,运动自我透视和运动时间透视与整体和局部透视类似。视觉输入以视网膜协调的方式进行编码,来自每只眼睛的网膜中心值需要整合并与眼睛位置和眼动的信号相混合,形成自我中心信号。自我中心信号进一步转化为一个三维协调系统——自我中心参照系统。视觉系统的神经输出是地球中心信号。     

The vicissitudes of metaphysics in the Modern Age

Following Hans Blumenberg and others, an account is given of the coming about of Modernity and of its major characteristics. The aim of the paper is to show that, from the very beginning, a restricted number of philosophical reactions are developed towards the phenomenon of Modernity. These reactions are represented in the major ‘modern’ philosophers: Descartes, Spinoza, Hume (and Kant) and French Enlightenment thinkers (as, e.g., Condorcet). These major reactions repeat themselves mutatis mutandis well into the 20th century. The paper ends with a brief discussion of the possibility of (modern) metaphysics at the present moment.     

Ocular motility and cognitive process

This study investigates the amount of ocular motility occuring in response to questions varying the kind of cognitive process required for answer. Fewer eye movements occur in response to questions designed to elicit visuo-spatial as compared to verbal-conceptual processes, a finding consistent with our earlier observation of more ‘stares’ occuring with the former than with the latter questions. The results are inconsistent with the traditional hypothesis that visual imagery involves an increase in scanning eye movements. The findings are interpreted in terms of a model postulating an interaction of the form of visual information processing and the type of cognitive activity subjects engage in.     

Justice as the Practice of Non-Coercive Action: A Study of John Dewey and Classical Daoism

In this essay, I will argue for an understanding of justice that is grounded in our imperfect world by drawing upon the works of John Dewey and the Classical Daoist philosophers. It will require a reconstructed understanding of persons as a field/continuum of interrelations and an updated understanding of human action and agency. This understanding of justice takes the form of non-coercive action, interaction that respects the particularity of each lived situation. The practice culminates in an ability to respond to the environment considered to be ziran (自然) or ‘self-so’ by the Daoist Philosophers. As described in the Dao De Jing, it is the cultivation of the ‘Three Jewels of the Dao’, the most central of them being compassion making, this practice of justice as non-coercive action also understandable as the practice of compassion as described by the Classical Daoist philosophers.     

The rhetorical power of naming: The case of regicide

The traditional reading of ancient Chinese texts focuses on their content rather than their modes of expression: truth is considered a given, of which language is merely the expression. This approach misses out on a predominant way of arguing in Chinese texts, namely to evaluate the situation by (re) naming it. A discussion of four textual fragments (up to the 2nd century BC) concerning the topic of regicide illustrates different degrees of this type of argumentation. Among philosophers discussion occurs in a subtle play of specifying terms such as ‘regicide’ or ‘reign’, rather than in an explicit defence of regicide by appeal to higher principles.     

The influence of eye movements and illumination on auditory localization

A critical analysis of a recent paper by Shelton and Searle (1980) on the visual facilitation of auditory localization is presented. The author claims that Shelton and Searle fail to make the relevant distinction between Warren’s (1970) frame of reference hypothesis and Jones’s (1975) spatial memory hypothesis. Shelton and Searle’s claim that they have demonstrated the existence of two distinct forms of visual facilitation is questioned. Data from an experiment in which auditory localization was tested under two levels of illumination (light and dark) and with two kinds of eye movement instructions (fixed and movement) are presented. The results show that facilitation occurs only when eye movements take place in a lighted environment. This is interpreted as supporting Warren’s frame of reference hypothesis.     

A further empirical evaluation of neurolinguistic primary representational systems (PRS)

Neurolinguistic programmers claim that individuals have preferred (primary) representational systems. These may be auditory, visual or kinesthetic and determine how a person views/deals with the world. Systems can be identified by observation of eye movements. In workshops programmers demonstrated strong associations between eye movements following questioning and types of questions and eye movement categories (assumed to identify systems) and other assessments of systems. Studies have evaluated these ‘workshop’ associations and found little support for their general occurrence. In these studies, it is possible that eye movements following questioning were influenced by artifacts which influence predicted association between these and other variables. An attempt was made to exclude these artifacts in this study. Except for subjects who had attended neurolinguistic workshops, results supported those obtained elsewhere. Possibly, associations in workshops occur as a result of expectational-contextual variables.     

Relying on Intuitions: Where Cappelen and Deutsch Go Wrong

Abstract

In Philosophy without Intuitions (Oxford: Oxford University Press, 2012), Herman Cappelen challenges the ‘almost universally accepted’ thesis of ‘Centrality’: ‘philosophers rely on intuitions as evidence (or as a source of evidence) for philosophical theories’. Cappelen takes there to be two arguments for Centrality and rejects both. According to the first, Centrality is supported by the way philosophers characterize key premises in their arguments as ‘intuitive’. Central to Cappelen’s rejection of this is his lengthy argument that philosophers’ ‘intuition’-talk is very hard to interpret, indeed often ‘meaningless’. I argue, in contrast, that this talk is easy to interpret. The great mass of philosophers who would endorse Centrality mean by ‘intuition’ just what it ordinarily means: ‘immediate judgment, without reasoning or inference’. Cappelen claims further that philosophers’ ‘intuition’-talk, however it is interpreted, does not support Centrality. I argue that this talk, interpreted in the ordinary way, does indeed support Centrality. According to the second argument, Centrality is supported by the very practice of philosophy. Cappelen rejects this with a thorough examination of several philosophical arguments. Deutsch has attacked Centrality similarly, in effect, with a thorough examination of one famous argument from Kripke. How are we to tell whether philosophical practice relies on intuitions? Cappelen, and Deutsch to some extent, answer by looking to the opinions of intuition-theorists about the nature of intuitions. This approach is quite mistaken. Rather, we should look to our ordinary ability to recognize intuitions. Adopting this approach, and discussing Deutsch’s Kripke example in most detail, I argue that Centrality gets support from all of these examples of philosophical practice.