A systematic, large-scale study of synaesthesia: implications for the role of early experience in lexical-colour associations

For individuals with synaesthesia, stimuli in one sensory modality elicit anomalous experiences in another modality. For example, the sound of a particular piano note may be 'seen' as a unique colour, or the taste of a familiar food may be 'felt' as a distinct bodily sensation. We report a study of 192 adult synaesthetes, in which we administered a structured questionnaire to determine the relative frequency and characteristics of different types of synaesthetic experience. Our data suggest the prevalence of synaesthesia in the adult population is approximately 1 in 1150 females and 1 in 7150 males. The incidence of left-handedness in our sample was within the normal range, contrary to previous claims. We did, however, find that synaesthetes are more likely to be involved in artistic pursuits, consistent with anecdotal reports. We also examined responses from a subset of 150 synaesthetes for whom letters, digits and words induce colour experiences ('lexical-colour' synaesthesia). There was a striking consistency in the colours induced by certain letters and digits in these individuals. For example, 'R' elicited red for 36% of the sample, 'Y' elicited yellow for 45%, and 'D' elicited brown for 47%. Similar trends were apparent for a group of non-synaesthetic controls who were asked to associate colours with letters and digits. Based on these findings, we suggest that the development of lexical-colour synaesthesia in many cases incorporates early learning experiences common to all individuals. Moreover, many of our synaesthetes experienced colours only for days of the week, letters or digits, suggesting that inducers that are part of a conventional sequence (e.g. Monday, Tuesday, Wednesday...; A, B, C...; 1, 2, 3...) may be particularly important in the development of synaesthetic inducer-colour pairs. We speculate that the learning of such sequences during an early critical period determines the particular pattern of lexical-colour links, and that this pattern then generalises to other words.     

Exploring visuomotor priming following biological and non-biological stimuli

Observation of human actions influences the observer’s own motor system, termed visuomotor priming, and is believed to be caused by automatic activation of mirror neurons. Evidence suggests that priming effects are larger for biological (human) as opposed to non-biological (object) stimuli and enhanced when viewing stimuli in mirror compared to anatomical orientation. However, there is conflicting evidence concerning the extent of differences between biological and non-biological stimuli, which may be due to stimulus related confounds. Over three experiments, we compared how visuomotor priming for biological and non-biological stimuli was affected over views, over time and when attention to the moving stimulus was manipulated. The results indicated that the strength of priming for the two stimulus types was dependent on attentional location and load. This highlights that visuomotor priming is not an automatic process and provides a possible explanation for conflicting evidence regarding the differential effects of biological and non-biological stimuli.     

计算机通过样例学习解二元一次联立方程

本文介绍一个通过样例来学习解二元一次联立方程的计算机学习系统。系统根据人提供的各种样例,建立一系列产生式规则。这些规则组成了解方程组的知识,从而达到了学习和获得知识的目的。建立和应用产生式规则,也是人类学习和解决问题的一般形式。因此,关于计算机学习问题的研究,也将有助于理解人类学习的心理机制。     

A guide to norms,ratings, and lists

A catalog of 119 studies, mostly post-1960 except for a few important and well-controlled earlier ones, is listed. The studies provide norms, scales, ratings, or lists of verbal material for use in experiments investigating aspects of cognitive psychology, memory, psycholinguistics, neuropsychology, etc. The catalog is preceded by an outline index.     

The information conveyed by varying the dimensions of features in human outline faces

Outline drawings of human faces were presented for rating as to a number of dichotomous attributes, while the dimensions of the four constituent features were varied sysrematically. It was found that people act in a regular and predictable fashion in attributing characterisrics to certain of these features. When independently significant features appear in combination, there is a lawful increase in such characterizing responses. Subsidiary findings related to a halo effect between certain attributes, differential employment of some attributes, and a difference in overall strength of effect between certain features.     

Serial,parallel, or holistic identification of single words in the two visual fields?

Subjects made timed manual responses in judging whether laterally presented four-letter words were identical to targets. In Experiment 1, nontargets differed by a single letter from targets. A right-field superiority occurred only for targets (which were detected fastest of all) and for nontargets where a letter changed at Position 2 or Position 3. Changes at initial and final positions were detected faster than the two middle positions, and there were no significant field differences. In Experiment 2, ascenders and descenders were controlled and changes were made in nontargets at all four letter positions, at Positions 1 and 4, at Positions 2 and 3, or at 2 alone. Response times for nontargets varied inversely with the number of differing letters, regardless of position. Significant field differences again only appeared for changes in the two middle positions. Letters at the beginning and end of a word seem to be processed faster than and differently from those within, where field differences are strongest. Vowel-consonant differences probably do not account for these effects, which are more compatible with some form of parallel, rather than either serial or holistic, processing.     

Effects of auditory feedback on a musical performance task

Two experiments examined the effects of various feedback conditions on performance by 12 Ss on an electronic organ. Playing time scores showed complete absence of auditory feedback to have little or no detrimental effect; in fact, some Ss played fastest under this condition. Delayed auditory feedback (DAF), as expected, caused considerable performance decrement when compared with immediate auditory feedback (IAF). Extraneous prerecorded input as a distractor in the absence of auditory feedback ranked between mixed DAF-with-IAF, and pure DAF, which showed the greatest disruption. The possible role of auditory imagery in musical performance was discussed, together with four components which perhaps contribute to the standard DAF effect: distraction, error repetition, conflict with expectancies and auditory imagery, and presentation of two competing and conflicting signals (IAF and DAF).     

A system for accurately measuring articulatory durations which is not reset by any included silent periods

A device is described that accurately measures duration of phonation or articulation without being reset by intervening silent periods or pauses, which may be within the range of 10 to 1,000 msec. Thus, it is possible to time the overall duration of single sounds, syllables, single or multiple words, even though periods of silence are included. Input can be direct or recorded, the ancilliaries being a voice-operated switch and a chronoscope.     

The effect of punishment on free-operant choice behavior in humans

During Phase I, three female human subjects pressed a button for monetary reinforcement in five variable-interval schedules specifying different frequencies of reinforcement. On alternate days, responding was also punished (by subtracting money) according to a variable-ratio 34 schedule. In the absence of punishment, response rates conformed to Herrnstein's equation for single variable-interval schedules. Punishment suppressed responding at all frequencies of reinforcement. This was reflected in a change in the values of both constants in Herrnstein's equation: the value of the theoretical maximum response-rate parameter was reduced, and the parameter describing the reinforcement frequency corresponding to the half-maximal response rate was elevated. During Phase II, the same five schedules (A) were in operation (without punishment), but in addition, a concurrent variable-interval schedule (B) of standard reinforcement frequency was introduced. On alternate days, responding in Component B was punished according to a variable-ratio 34 schedule. In the absence of punishment, absolute response rates conformed to equations proposed by Herrnstein to describe performance in concurrent schedules; the ratios of the response rates in the two components and the ratios of the times spent in the two components conformed to the Matching Law. When responding in Component B was punished, response rates in Component B were reduced and those in Component A were elevated, these changes being reflected in distortions of the matching relationship.     

Lexical discrimination and letter-string identification in the two visual fields.

Right-handed subjects were tachistoscopically presented three-letter words and nonword permutations in a single visual field for 20 msec. Although the subjects were unable to identify the stimuli at this exposure duration, their lexical decisions were better than chance, and were superior in the left visual field. When the exposure duration was increased, subjects demonstrated superior identification of the words in the right visual field. Results are discussed within an information processing framework.