The "saw-it-all-along" effect: demonstrations of visual hindsight bias

The authors address whether a hindsight bias exists for visual perception tasks. In 3 experiments, participants identified degraded celebrity faces as they resolved to full clarity (Phase 1). Following Phase 1, participants either recalled the level of blur present at the time of Phase 1 identification or predicted the level of blur at which a peer would make an accurate identification. In all experiments, participants overestimated identification performance of naive observers. Visual hindsight bias was greater for more familiar faces--those shown in both phases of the experiment--and was not reduced following instructions to participants to avoid the bias. The authors propose a fluency-misattribution theory to account for the bias and discuss implications for medical malpractice litigation and eyewitness testimony.     

"Seeing things in my head": a synesthete's images for music and notes

We explored synesthetic experiences (photisms) elicited by music and notes for GS, a 22-year-old female college student, who is a genuine digit synesthete (Mills et al 1999 Cognitive Neuropsychology 16 181-191). After extensive interviews, we conducted five studies using synthesizer notes in different octaves and in different instrument sounds. GS described, drew, or selected her photisms from alternatives. The results were: (a) her photisms had shape, color, movement, and texture: (b) different instruments had photisms with different shapes and families of instruments had similar shapes; (c) low-pitched notes were darker and larger than high notes; (d) instrument and pitch affected each other; (e) a given note was perceived as darker after a high note than after a low note; and (f) GS's drawings of notes became more consistent with repeated trials. Theoretical observations are discussed on the basis of these results.     

The perception of short phrases presented simultaneously for visual & auditory reception

Subjects were provided with outline maps that were incomplete in several details. Brief, simultaneous, visual and auditory instructions were given for completing some of the missing details. Certain items could be completed on the basis of direct information contained in one or other of the sensory modalities. Others, however, could be completed only because of their relation to details capable of location by direct instruction. Information important for the completion of map details was distributed randomly among short passages of unconnected words. All relevant visual and aural clues were presented simultaneously in every case. Opportunities for alternations of attention were curtailed.

Thirty-six subjects were randomly assigned to three experimental conditions, and to two groups that were given different instructions. One group was told that relevant information would always appear simultaneously, while the other group was not allowed this information.

The number of successfully located simultaneous pairs of items presented for direct location was found to be no greater than could be expected by chance. The total number of correctly located items was less than 50 per cent of the possible items. There was no difference in the number of correctly located simultaneous pairs of items between the “instructed” and the “uninstructed” groups. The “uninstructed” group did not learn in the course of the experiment that all relevant material was presented simultaneously. Significantly more correct completions were made with the visual material than with the auditory. It is concluded that successful division of attention did not occur.     

Selective interference during the retrieval of visual images

Twenty-six subjects memorized lists of (low I and high I) noun pairs under imagery or verbal mediation instructions. At recall the subjects were presented a digit (“1” or “2”) either auditorily or visually as an interfering stimulus.

Visual interference was found to selectively affect the retrieval of high I response terms. Also, the retrieval of nouns studied by imagery mediation was found to be selectively disrupted by visual interference.

These results suggest that the qualities of a visual image are retained all the way from image acquisition to retrieval, and that the visual components of images generated at the acquisition stage are probably not lost by subsequent coding processes.     

Selective interference with the use of visual images in the symbolic distance paradigm

Eight experiments investigated the effects of visual, spatial, auditory, and executive interference on the symbolic comparison of animal size and ferocity, semantic goodness of words, and numbers. Dynamic visual noise (DVN) and the reading of visually presented stimulus items were shown to selectively interfere with response times on the animal size comparison task, though the slope of the symbolic distance function remained unchanged. Increased change of DVN significantly increased interference, but interference was reduced by equiluminant DVN. Spatial tracking reduced the slope of the symbolic distance function in contrast to an executive task that only increased mean latency and errors for all comparisons. Results suggest that the generation of an image is necessary for size comparison, but neither imagery nor executive function is responsible for the frequently observed distance-time function.     

Attenuating the visual suffix effect with color

In previous studies using a short-duration visual presentation (200-340 msec), presentation of a different colored suffix did not attenuate the visual suffix effect. In Experiment 1, color attenuated the suffix effect for a longer duration visual presentation (approximately 3-4 sec) during which the subject engaged in articulatory suppression to prevent auditory recoding. Experiments 2 and 3 confirmed that color does not attenuate the suffix effect for the short-duration presentations. In Experiment 4, recall of a long-duration presentation was not improved when the last digit was a different color, suggesting that the different color of the suffix improves recall by allowing the suffix to be excluded from visual short-term memory. The attenuation by color is consistent with the hypothesis that preattentive grouping governs the entry of information into visual short-term memory.     

音乐学习对语言加工的促进作用

音乐学习可以增强个体的艺术素养,同时,音乐学习对其他认知加工过程尤其是语言学习还有正面的促进作用。近年来国内外学者主要围绕着音乐家、音乐学习障碍个体开展了一系列相关工作,同时还进行了相关的追踪研究。值得注意的是,有关音乐学习促进语言加工的实证依据主要来自横断研究,还需要更多的纵向追踪研究来进一步提供因果关系的证据。这方面的工作将最终促进音乐学习与训练在教育与医疗领域的广泛应用。     

Factors affecting reports of fragmenting visual images

Seven experiments employing simulation as well as actual voluntary stabilization were performed to study the reporting of fragmenting visual images. The results indicated a significant bias toward the reporting of meaningful fragments when verbal reports were used throughout each trial. Moreover, tracings of fragments were completely accurate only when one line segment of the original pattern remained, with errors becoming increasingly likely as the number of segments remaining increased. Diagonally oriented line segments disappeared more frequently than those oriented either vertically or horizontally. Locus of fixation proved important, but Hebb’s hypothesis concerning the preponderance of meaningful fragments was not supported.     

Sex bias in visual images evoked by generics: A new zealand study

Male biases are known to exist in the usage, evaluation, and interpretation of masculine generics. This study explored, by means of a tachistoscope, sex-specific biases in visual images evoked by masculine (All men are created equal, At university a student can study whatever he wants) and feminine (The feminists protested outside the town hall, At university a student can study whatever she wants) generics. Photographs of male and female faces were presented in a deliberately ambiguous (subthreshold) viewing field while maintaining the masculine or feminine generic sentence on constant view. It was predicted and found in a sample of 48 university students that if generics invoked sex-specific images, the images would affect the direction in which the viewer would resolve the ambiguous faces, resulting in more reported male faces in the masculine than in the feminine generic condition.Preparation of this article was supported by a New Zealand Social Sciences Research Fund Committee grant (8632/21/24/8604) to S. H. Ng.     

The effects of music and task difficulty on performance at a visual vigilance task

Forty subjects performed a visual vigilance task in music or noise and when the task was difficult or easy. Response measures taken were: correct detections, commission errors, detection latencies and d' values. For the difficult version of the task a significant increase in detection latencies was found which music prevented. Broadly similar findings were obtained for correct detections. The results are compared with other studies of detection latency and task difficulty and are discussed in terms of arousal.     

Dissociation between the mental rotation of visual images and motor images in unilateral brain-damaged patients

Deficits in the mental rotation of body parts and of external objects can be doubly dissociated (Rumiati, Tomasino, Vorano, Umiltà, & De Luce, 2001; Sirigu & Duhamel, 2001; Tomasino, Rumiati, & Umità, in press). The aim of this study was to replicate this finding and to then investigate the relevance of the specific hemispheres in these deficits. Nine patients with unilateral lesions (five in the Left Hemisphere and four in the Right) and 20 control subjects, performed a single task requiring mental rotation of hands, and two tasks requiring mental rotation of external objects. RH patients were impaired in the rotation of external objects, but showed intact performance on the rotation of hands; the opposite pattern was found for LH patients. These results support the view that the LH contributes to the mental rotation of hands, recruiting processes specific to motor preparation, while the RH is specialized for mental rotation of external objects.