On the perception of symmetrical and repeated patterns

Four experiments investigated rapid perceptual judgments about tachistoscopically presented patterns that were either symmetrical about or repeated across a vertical axis. The same patterns were presented under two different instructional conditions; some Ss were to judge the two halves of each pattern “same” or “mirror,” others were to judge each pattern as a whole “symmetrical” or “asymmetrical.” With dot patterns, RTs were faster for symmetrical than for repeated patterns when the two halves were close together, but not when they were separated, regardless of instructions. With simpler patterns made up of arrowheads and C-shapes, however, “same” RTs were faster than “mirror,” but “asymmetrical” RTs were marginally slower than “symmetrical,” regardless of spatial separation. The advantage of “same” over “mirror” did not seem to be simply a labeling effect. The results suggest that left-right symmetry is perceptually more salient than left-right repetition when the patterns are perceived holistically. By contrast, distinct patterns can be matched more rapidly when they are the same than when they are left-right mirror images.     

Pattern redundancy and detection in very short-term memory

A tachistoscopically presented target letter is detected better in a background of redundant items than in nonredundant material. The present experiment extended this finding by showing that detection rate increased systematically across three levels of background letter redundancy. A conclusion based on the earlier findings was that a serial process of letters in memory could not account for the effects of background redundancy on detection accuracy. Contrary to this conclusion, the present analysis showed that detection for semiredundant displays was successfully predicted by two variants of a serial process model. One model assumed that the scan of a letter is faster when the letter is the same as any prior letter scanned in the matrix. The other model assumes that nonredundant letters are processed serially and that redundant letters are processed all at once, i.e., in parallel.     

Young children's processing of asymmetrical and symmetrical patterns

Dot patterns varying in type of symmetry (double symmetry, vertical symmetry, horizontal symmetry, and asymmetry) were presented tachistoscopically for 200 msec, followed by a patterned mask, to kindergarten, second-grade, and fourthgrade children. All subjects reported symmetrical patterns more accurately than asymmetrical patterns. Double symmetry patterns were reproduced more accurately than vertical symmetry patterns, and vertical symmetry patterns were reproduced more accurately than horizontal symmetry patterns. These results stand in marked contrast to previous research by demonstrating that the ability to process symmetrical relationships evolves early in perceptual development. There was a suggestion that subjects of all ages perceived information about the type of symmetry presented in the display, but there were agerelated differences in subjects' abilities to use this knowledge in constructing their responses. Additionally, analyses revealed no age-related biases toward imposing symmetrical responses on asymmetrical patterns.     

Evidence in support of word unitization

In each of five experiments, the subjects viewed tachistoscopically presented pairs of letters and made speeded comparison judgments on the basis of name identity. On most trials, a noise letter string (word or anagram) was placed directly between the target letters. The results indicated that correct “same” RTs were a function of noise item type and its relation to target letters. Anagrams increased RTs more than their counterpart words, except when the noise word was either unmeaningflul or response incompatible with respect to the target letters (e.g., B Tea b). The interference effects were also found to be independent of sequence length. It was posited that the subjects were unable to completely ignore the irrelevant attributes of the displays and that under certain conditions, the subjects were able to identify the noise items in a holistic fashion. The data were interpreted in terms of a unitization hypothesis of word recognition, response competition, and a continuous-flow conception of information processing.     

Perception of geometrical arrays tachistoscopically exposed in right and left visual fields.

Geometrical stimuli (48 6-item arrays of familiar forms, e.g., circle), tachistoscopically presented in the right or left visual field, were more accurately perceived in the right than left visual field by 15 college students. Targets about half the length of the displays exposed here were perceived with equal facility in both visual fields (Bryden, 1960). Results suggest that length of array might affect the difference in perceptual accuracy of forms shown in the right and left visual fields. Figures in the right visual field were predominantly processed from left to right, and forms in the left visual field from right to left. Since more symbols were identified in the right than left visual field, the left to right encoding sequence may be more efficient than a right to left movement. Limited experience of most Ss in reading symbols from left to right is probably only one factor. Extensive experience reading alphabetical material from left to right might have developed the physiological mechanism underpinning this sequence more than the one serving the opposite movement.     

The memorial structure of organized sequences

Subjects were asked to memorize a sequence of nine consonants which were grouped into three groups of three letters each (e.g., SBJ FQL ZNG). After learning the sequence, they were presented with single letters, letter pairs, or letter triples and asked to indicate if the probe item appeared in the memorized sequence. The latency results suggest that subjects engage in a linear self-terminating memory search in which the items from one chunk are retrieved from memory as the items from the immediately preceding chunk are being scanned. When the probe consisted of more than one item, the subjects were slowed in their comparison if the letters came from different chunks (e.g., JF vs. FQ in the above illustration), and the number of letters in the probe also influenced the reaction time. Neither of those effects were obtained if all the letters in the probe came from the same chunk, and that would seem to suggest that the probe items from the same chunk were compared in parallel to the letters in the memory item, while items from different chunks were compared serial.     

Orthographic directionality and thematic role illustration in English and Arabic

This study tested the hypotheses that people had a bias for drawing agents on the left of a picture when given a verb stimulus targeting an active or passive event (e.g., "kicked" or "is kicked") and that orthographic directionality would influence the way events were illustrated. Monolingual English speakers, who read and write left-to-right, and Arabic speakers, who read and write right-to-left, drew agents and patients in response to verb stimuli. We found no significant orthographic directionality effects and no preference for positioning agents on the left of pictures in either group or sentence type. Instead, participants drew agents on the right regardless of language or sentence type, and this was exaggerated in English speakers illustrating passive verbs. These findings support the existence of a preference for placing agents in the right hemispace that may result from asymmetrical hemispheric (i.e., left>right) activation induced by language processing. Our results are consistent with findings that people prefer pictures in which focus is on the right, a preference strongest in pictures with no implicit directionality of movement. This suggests that the methodology of the current study encouraged a static rather than dynamic interpretation of the verb in most participants.     

Groups perform better than the best individuals on Letters-to-Numbers problems

Eighty-two four-person cooperative groups and 328 independent individuals solved a random coding of the letters A–J to the numbers 0–9. On each trial the group or individual proposed an equation in letters (e.g., A + D=?), received the answer in letters (e.g., A + D=B), proposed one specific mapping (e.g., A=3), received the answer (e.g., True, A=3), and proposed the full mapping of the 10 letters to the 10 numbers. As predicted, the groups had fewer trials to solution, proposed more complex equations, and identified more letters per equation than each of the best, second-best, third-best, and fourth-best individuals. We interpret the group superiority as due to the highly intellective nature of Letters-to-Numbers problems, which entail demonstrable recognition of correct answers, demonstrable rejection of erroneous answers, and multiple insights into effective collective information processing strategies.     

Identification of symmetry: Effects of stimulus orientation and head position

It has been argued that the perceptual advantage of symmetry depends upon the essentially symmetrical properties of the visual system. According to this explanation, the ease of identification of symmetries about different axes of orientation should decrease with increasing distance from the vertical: Reaction times to vertical symmetry should be faster than those to diagonal symmetry, which in turn should be faster than those to horizontal symmetry. Previous research demonstrating this pattern of responding employed stimuli with linear axes. In the present study, the subjects viewed tachistoscopically presented symmetrical and asymmetrical dot patterns (which had no explicit axes) in one of three head positions: upright, 45 deg left, and 45 deg right. The subjects’ performance failed to support the structural explanation: Identification of symmetry is equivalently fast for vertical and horizontal; vertical and horizontal show strong advantages over obliques, and this general advantage follows retinal coordinates. Findings are discussed in light of alternative theories of symmetry processing.     

Subsyllabic units in computerized reading instruction: onset-rime vs. postvowel segmentation

Previous studies suggest that adults and children divide spoken syllables into subsyllabic onset-rime units more readily than into any other kind of subsyllabic unit. We asked whether this same onset-rime segmentation might also be beneficial in teaching children to read. That is, can children learn more words segmented at the onset-rime boundary (e.g., CL-AP, D-ISH) than words segmented after the vowel (CLA-P, DI-SH)? In three experiments, first-grade students studied single words presented by a computer connected to a high-quality speech synthesizer. Experiment 1 used words of four letters but only three phonemes apiece (e.g., WHIP, DISH). In some of these words the onset-rime segmentation corresponded to the initial bigram (e.g., WH-IP); in some it did not (e.g., D-ISH). Experiments 2 and 3 used words of four letters and four phonemes (e.g., CLAP, CORN). In all three experiments, onset-rime segmentation proved more helpful than postvowel segmentation in short-term learning of the words.     

Eye movements when reading transposed text: the importance of word-beginning letters

Participants' eye movements were recorded as they read sentences with words containing transposed adjacent letters. Transpositions were either external (e.g., problme, rpoblem) or internal (e.g., porblem, probelm) and at either the beginning (e.g., rpoblem, porblem) or end (e.g., problme, probelm) of words. The results showed disruption for words with transposed letters compared to the normal baseline condition, and the greatest disruption was observed for word-initial transpositions. In Experiment 1, transpositions within low frequency words led to longer reading times than when letters were transposed within high frequency words. Experiment 2 demonstrated that the position of word-initial letters is most critical even when parafoveal preview of words to the right of fixation is unavailable. The findings have important implications for the roles of different letter positions in word recognition and the effects of parafoveal preview on word recognition processes.     

The effect of set size on hemifield asymmetries in letter recognition

Single letters were presented tachistoscopically in the left or right hemifield to right-handed observers. Superior recognition of letters on the right was found for letters chosen from subsets containing four items, but no differences were found when any letter, or any symmetrical letter, could appear. In a second experiment, the right hemifield advantage was found under conditions requiring the subject to determine the subset only when the subset chosen was appropriate. Results were discussed in terms of the adequacy of language-based explanations of hemifield asymmetries in letter recognition.     

复合字母刺激心理旋转加工中的整体优先效应

采用复合字母材料结合正镜像判断任务,首次揭示了心理旋转加工中的整体优先效应。实验一延长复合字母材料的呈现时间,检验心理旋转实验常用的正/镜像判断任务中的视知觉整体优先效应;实验二将实验一的复合字母材料旋转一定角度,考察心理旋转加工中的整体优先效应。结果发现：（1）延长复合字母呈现时间后的字母正镜像判断任务中,被试判断大字母和判断小字母的时间没有显著差异,并且大小字母是否一致对大字母判断和小字母判断的影响无显著差异;（2）在排除了视知觉的整体优先效应存在的情况下,发现心理旋转加工中存在明显的整体优先效应,大字母（整体）旋转条件下的反应时显著短于小字母（局部）旋转条件下的反应时;（3）旋转角度一致性对大字母旋转和小字母旋转条件下的反应时均无显著影响,表明心理旋转的整体优先效应模式可能有别于视知觉加工的整体优先效应模式     

Elicitation of spontaneous mirror reversal drawing on the forehead

32 Japanese participants drew symmetrical and asymmetrical letters on their own foreheads. By observing their drawing strokes, it was judged that 29 of them drew symmetric letters in reverse, that is, as if these were viewed from inside the head. However, 14 of these 29 seemed to have noticed their reversed perception because they drew asymmetric letters intentionally reversed so they would appear correct when viewed from outside. Only three participants drew the letters in a normal way irrespective of the letter symmetry.     

Color singleton pop-out does not always poop out: An alternative to visual search

Folk psychology suggests that when an observer views a scene, a unique item will stand out and draw attention to itself. This belief stands in contrast to numerous studies in visual search that have found that a unique target item (e.g., a unique color) is not identified more quickly than a nonunique target. We hypothesized that this finding is the result of task demands of visual search, and that when the task does not involve visual search, uniqueness will pop out. We tested this hypothesis in a task in which observers were presented an array of letters and asked to respond aloud, as quickly as possible, with the identity of any one of the letters. The observers were significantly more likely to respond with a uniquely colored letter than would be expected by chance. In a task in which observers blurt out the first thing that they see, unique pop-out does not poop out.     

Aftereffects for face attributes with different natural variability: Children are more adaptable than adolescents

Adults can be adapted to a particular facial distortion in which both eyes are shifted symmetrically (Robbins, R., McKone, E., & Edwards, M. (2007). Aftereffects for face attributes with different natural variability: Adapter position effects and neural models. Journal of Experimental Psychology: Human Perception and Performance, 33, 570–592), but they do not show as great adaptation to an asymmetrical eye distortion. We adapted children and adolescents to symmetrical and asymmetrical eye distortions and measured the aftereffects. Children (aged 6–12, mean age 9 years) showed larger aftereffects than adolescents (aged 13–18, mean age 15 years) and demonstrated aftereffects of a similar magnitude for both asymmetrical and symmetrical distortions. Adolescents only showed aftereffects for symmetrical distortions. We propose that children may have a more flexible face norm and neural responses that allow a broader range of adapted states compared to adolescents.     

The word superiority effect: Dependence on short-term memory factors

Two experiments were conducted to test whether the word superiority effect, that letters in words are perceived more accurately than letters in nonwords, could be attributed to short-term memory (STM) factors. One hypothesis attributed the word superiority effect to superior maintenance of words in STM. Another hypothesis was that letters in STM have considerable positional uncertainty which is overcome by the orthographic characteristics of the words. Both experiments utilized a simultaneous same-different task, where subjects compared two four-letter strings, one on top of the other, which were presented tachistoscopically. In Experiment I, the two presented strings were either both words or both nonwords and a word superiority effect was obtained. This result was interpreted as disconfirming the STM maintenance hypothesis. In Experiment II, letters were removed from one of the two letter strings, making the serial position of the comparison unambiguous. The word superiority effect disappeared. This result was interpreted as supporting the positional uncertainty hypothesis.     

Symmetry and asymmetry in interpersonal relations--with implications for the concept of projection

This paper first reviews evidence for some proposals about interpersonal relations These relations tend to be “symmetrical” or “asymmetrical”—i.e, involve similar or dissimilar characteristics for the two parties—depending on what the characteristics are. Certain characteristics (eg., love-hate) are—and are perceived to be—symmetrical, and others (eg, dominance-submission) asymmetrical The implications are then illustrated for the concept of projection A process of attributing to others characteristics that “explain” one's own would account for symmetrical projection for certain characteristics and asymmetrical projection for others This reformulation can provide a simpler and more unified account for cases that are traditionally treated separately as “supplementary” and “complementary” projection