Similar effects of visual perception and imagery on simple reaction time

A longstanding issue is whether perception and mental imagery share similar cognitive and neural mechanisms. To cast further light on this problem, we compared the effects of real and mentally generated visual stimuli on simple reaction time (RT). In five experiments, we tested the effects of difference in luminance, contrast, spatial frequency, motion, and orientation. With the intriguing exception of spatial frequency, in all other tasks perception and imagery showed qualitatively similar effects. An increase in luminance, contrast, and visual motion yielded a decrease in RT for both visually presented and imagined stimuli. In contrast, gratings of low spatial frequency were responded to more quickly than those of higher spatial frequency only for visually presented stimuli. Thus, the present study shows that basic dependent variables exert similar effects on visual RT either when retinally presented or when imagined. Of course, this evidence does not necessarily imply analogous mechanisms for perception and imagery, and a note of caution in such respect is suggested by the large difference in RT between the two operations. However, the present results undoubtedly provide support for some overlap between the structural representation of perception and imagery.     

视觉表象眼动的变化：知识还是技能表征的差异？

以表象看到一个运动员完成三级跳远项目为实验任务,对表象任务的信息通达水平、眼动注视点的活动位置和被试对三级跳远项目的知识水平和技能水平进行系统的操纵,通过2个实验探讨了视觉表象眼动的变化是基于知识学习表征差异还是技能训练表征差异的问题。实验1以没有三级跳远运动专业技能知识且对该运动的认知水平也较低的大学生为被试,结果表明,在完成高信息通达水平的表象任务时,注视点需要较短的持续时间,但眼跳距离会增大,眼跳频率会变低;实验2对表象任务的知识学习表征水平和技能训练表征水平进行操纵,分别以对实验任务进行过知识学习和专业技能训练的人为被试,结果表明,随着被试知识习得水平和技能水平表征能力的提高,不同表象任务信息通达水平间的眼动差异将消失,但知识学习和技能表征的差异在平均眼跳时间上有差异,技能训练型的被试其平均眼跳时间要短于知识学习型被试,达到临界水平显著,注视点平均持续时间和平均眼跳距离等均没有差异。     

Abilities and strategies of blind and sighted subjects in visuo-spatial imagery

An active visuo-spatial memory task was used in order to determine the characteristics of mental imagery in subjects with and without visual experience. Subjects were instructed to generate a mental representation of verbally presented 2D patterns that were placed in a grid and to indicate how many pattern elements were in corresponding positions in the two halves of the grid according to a specific grid axis (vertical or horizontal). Unexpectedly, results showed a similar performance in early blind, late blind and sighted subjects. However, subjects' debriefing showed that the three groups used different strategies. The sighted and the late blind subjects took advantage of a visuo-spatial strategy. They generated a mental image of the matrix and they simplified this image to maintain only the relevant information in memory. In contrast, the early blind subjects encoded each pattern element by its location in a (X,Y) coordinate system without visual representation. This indicates that both early and late blind subjects are able to perform an active visuo-spatial imagery task as well as sighted subjects although they use different strategies.     

Imagery Value,Subjective and Objective Frequency,Date of Entry into the Language,and Degree of Polysemy in a Sample of 998 French Words

A random sample of 998 lexical words was drawn from a dictionary of the French language. Two groups of subjects rated the words for imagery value (IV) and subjective frequency (SF). Despite substantial individual differences in the ratings, the subjective measures were highly reliable (α = 0.98 for both IV and SF). The relation between the standard deviation and the mean of the ratings can be described by a quadratic function (R = 0.93 for IV and R = 0.75 for SF). The independence of IV and frequency was confirmed. IV was found to be partially dependent on grammatical category (η = 0.50) and slightly dependent on polysemy. Date of entry into the language (DE) was correlated with objective and subjective frequency. The correlation between DE and IV was weak. The words and their characteristics are presented in the Appendix.     

生物反馈放松训练和表象训练在飞行训练中的应用研究

本研究试用生物反馈放松训练和表象训练相结合方法,减轻飞行学员的精神紧张及有关的生理反应、２６名２０—２２岁的男性飞行学员,实验、对照组各１３名、实验组学员每次飞行后进行一次肌电生物反馈放松训练和起落航线表象训练,共１６次;对照组学员参加日常飞行训练不加任何干预。实验前后实验组及对照组学员进行黑红数字测试,记录其测试前后的血压、心率;第一次升空及单飞考核飞行后也记录他们的血压和心率。结果表明,实验组学员的单飞考核成绩优于对照组;实验织学员单飞考核后的收缩压及第二次黑红数字测试后的收缩压比实验前显著降低;而对照组的前述生理指标无变化。生物反馈放松训练和表象训练能有效地减轻飞行中的紧张情绪及其生理反应,适于在飞行部队应用。     

Object imagery and object identification: object imagers are better at identifying spatially-filtered visual objects

Object imagery refers to the ability to construct pictorial images of objects. Individuals with high object imagery (high-OI) produce more vivid mental images than individuals with low object imagery (low-OI), and they encode and process both mental images and visual stimuli in a more global and holistic way. In the present study, we investigated whether and how level of object imagery may affect the way in which individuals identify visual objects. High-OI and low-OI participants were asked to perform a visual identification task with spatially-filtered pictures of real objects. Each picture was presented at nine levels of filtering, starting from the most blurred (level 1: only low spatial frequencies—global configuration) and gradually adding high spatial frequencies up to the complete version (level 9: global configuration plus local and internal details). Our data showed that high-OI participants identified stimuli at a lower level of filtering than participants with low-OI, indicating that they were better able than low-OI participants to identify visual objects at lower spatial frequencies. Implications of the results and future developments are discussed.     

Analogue Mental Transformations in 3‐Year‐Olds: Introducing a New Mental Rotation Paradigm Suitable for Young Children

Until now, a successful application of the mental rotation paradigm was restricted to children 5 years or older. By contrast, recent findings suggest that even infants can perform mental rotation. Unlike the methods used in infant studies (looking time), our new research paradigm allows for the measurement and interpretation of reaction times. Kindergartners (aged 3–6 years) were presented with a stimulus configuration on a touchscreen and asked to bring a rotated stimulus into an upright position using the shortest path. Mean reaction time (RT) increased linearly with angular disparity. The ensuing linear trend was significant not only for the entire sample but also for the youngest age group analysed separately. To exclude the possibility that linearity was due to movement planning, 3‐year‐olds had to manually rotate a stimulus about the same trajectory without the need for a corresponding mental transformation in a second experiment. Here, no linear trend was observed. These results are interpreted as evidence for an analogue mental transformation in 3‐year‐olds, equal to the transformation processes in older children's and adults' mental rotation. Copyright © 2013 John Wiley & Sons, Ltd.     

Generate,maintain, manipulate? Exploring the multidimensional nature of motor imagery

Motor imagery (MI), the mental rehearsal of a motor task, is thought to be a synergistic interaction between processes that allow for the generation, maintenance, and manipulation, of motor images. While our understanding of the multidimensional nature of MI stems from research examining various methods to assess MI ability, limited research has been conducted employing multiple assessments across participants to probe the underlying dimensions of MI. Accordingly, the current study sought to explore the multidimensional nature of MI using an exploratory approach that would allow for the dimensions of imagery to be examined and linked to each assessment measure. Specifically, participants (N = 81) underwent a battery of MI-assessments (including questionnaires, mental chronometry, a hand laterality judgment task, and a MI-based learning task), and data was analyzed via principal component analysis (PCA). Three components resulted, which were named based on which outcome measures loaded on to the component: generation, maintenance, and manipulation of motor images. We further discuss a fourth component, named ‘temporal sequencing’ of motor images, identified via the initial component solution. Concordant with previous research, we highlight the importance of employing multiple measures when assessing imagery ability prior to its use in training. Notably, this work allowed us to link assessments of MI to the different dimensions of MI, informing on the nature of MI.