Abstract: Perceptual organization during short tachistoscopic presentation of stimulus patterns formed by ten moving bright spots, representing a human body in walking, running, etc. was investigated. Exposure times were .1 sec to .5 sec. The results reveal that in all Ss the dot pattern is perceptually organized to a “gestalt”, a walking, running, etc., person at an exposure time of .2 sec. 40% of Ss perceived a human body in such motion at presentation times as short as 0.1 sec. Under the experimental conditions used the track length of the bright spots at the threshold of integration to a moving unit was of the size order 10′ visual angle. This result is regarded as indicating that a complex vector analysis of the proximal motion pattern is accomplished at the initial stage of physiological signal recording and that it is a consequence of receptive field organization. It is discussed in terms of vector calculus.

Abstract: The visual response properties of single neurons in the owl's visual Wulst suggest that this forebrain structure is an analog of the mammalian visual cortex. Features in common with the cat and the monkey visual cortex include a precise topographic organization, a high degree of binocular interaction, and selectivity for orientation, direction of movement, and binocular disparity of straight-line contours.

Abstract: Visual information processing in the nervous system of flies begins with a large array of photoreceptors, which transduce a light intensity pattern, and culminates in a behavioural response that depends on that pattern.In the previous paper we have given a quantitative description of visual control of flight orientation in the fly. This description can account for fixation, tracking and some instances of spontaneous pattern preference behaviour. The phenomenological theory outlines the basic logical organization of the visual control system of the fly. It requires the neural network between the receptors and the flight muscles to perform two main computations on the visual input. One computation extracts movement information (the term r(ψ)ψ b of the phenomenological equation). The other provides position information (the term D(ψ)).

Abstract: Music bears formal relations to language which suggest that perceptual processes in the two modes may also be similar. These experiments examined the way in which experienced musicians differed from non-musicians in their recognition of briefly exposed pitch notation. Experiments I and II together demonstrated that musicians are superior to non-musicians in their immediate written recall of stimuli containing more than three notes, but only when the stimulus is available to them for 150 ms or more. These results are accounted for well by a model proposed by Coltheart (1972) for letter perception under conditions of brief exposure. In this model, two coding processes act simultaneously on the stimulus, one a fast visual coding, and the other a slower, but more permanent abstract (or name) coding. In this case non-musicians appear to be lacking a second, abstract, coding which musicians possess. Experiments III and IV attempted to investigate the nature of the abstract code for musicians by presenting vario...

Abstract: Four studies were conducted to investigate the relation between audition and vision in the human newborn. In all four studies visual activity was recorded with infrared corneal-reflection technqiues in 1- to 4-day-old infants. Study 1 concerned the effects of sound at midline on scanning in darkness and in a lit but formless field. In the dark compared to light, newborns maintained better eye control, centralized fixations, scanned with smaller eye movements, scanned less dispersely, and were wider-eyed. In a blank field, sound caused newborns to maintain better eye control, centralize fixations, scan with small eye movements, constrain fixations, and be wider-eyed than in silence. Sound had little effect on scanning in the dark beyond constraining fixations. Study 2 concerned the effects of sound at midline on scanning vertical and horizontal edges. Visual activity was different for the two visual stimuli. While viewing a vertical rather than a horizontal edge, newborns maintained better eye control and fixated closer to the position of the vertical edge. Newborns crossed the position of the horizontal edge when that edge was present. Sound affected scanning in general, centralizing fixations for newborns not already looking centrally, but sound did not affect the frequency of edge crossing. Study 3 concerned the effects of laterally presented sound on scanning spatially consonant or dissonant vertical bars. The major finding was that infants were sensitive to the spatial property of sound. Infants shifted fixations first toward and then gradually away from sound. Study 4 was an attempt to determine whether there is an effort constraint on the simultaneous functioning of auditory and visual systems. The effects of two differentially salient sounds on scanning two differentially salient visual stimuli were examined. Although the results appeared to support the idea of an effort constraint, the data were accounted for parsimoniously in terms of the spatial influence of sound of scanning. The data on visual activity were discussed in terms of the presence of inherent information-acquisition routines in the newborn. It was concluded that sound influences visual epistemic behavior even at birth.

Abstract: Patients with unilateral brain lesions were given a task requiring exploration of space with the hand in order to assess the visual dependency of unilateral spatial neglect. The task was carried out both without visual control and under visual control. Performances were compared with that of normal subjects. Results were :(1) patients with right brain damage with no visual field defect demonstrated left-sided neglect only when the exploration was not controlled visually; (2) patients with left and right brain damage with visual field defect demonstrated contralateral neglect only when the exploration was under visual guidance. The performance of the patients with right brain damage without visual field defect in not clearly understood. The other results suggest that inner spatial representation remains intact in most cases of spatial neglect. The role of parietal lobe damage in the development of this visually induced phenomenon is hypothesised. The dominant position of vision among the senses is indicated.

Abstract: Combining psychology, art theory and cross-cultural study, this book explores the ways that our minds construct meaning from visual information. There are chapters on how the mind attributes meaning to things and events, the structure and functioning of the eye and the brain, how we perceive colour, space, depth and distance, motion, the development and mechanics of photography and how the camara effects our perception of reality and the way we think about the world, the incursion of electronic and mass-communication media, and finally, on making and looking at works of art and learning to see more creatively.

Abstract: Sex differences were investigated in two experiments on visual persistence: the Ganzfeld and the afterimage. Males were found to hold visual sensation longer than females, particularly in the Ganzf...

Abstract: Verbal reaction times to identify and to calssify 20 traffic sign messages were measured under three conditions - sign alone, sign plus visual loading task, and sign plus visual loading task plus visual distraction. Similar trends were found in the three experiments: reaction times were smaller for the classification task than for the identification task, smaller for warning than for regulatory signs, and smaller for verbal than for symbolic messages. Comparison of these reaction time data with on-the-road measures of legibility distance revealed significant correlations. The correlational data add credibility to laboratory measures of reaction times as valid of traffic sign perception. /Author/

Abstract: Perception is generally thought to occur centrally in the nervous system as a result of information which flows unidirectionally through a hierarchy of sensory processors. Such a view is in conflict with recent experimental evidence for a centrifugal control capable of enhancing particular features of the sensory input. Certain phenomena in human perception, resembling order-disorder transitions in physics, also suggest the existence of a positive feedback mechanism in the sensory pathway. A mechanism of perception is proposed in which unstructured feedback can accomplish the desired feature-specific enhancement of the input. The principle used here — the Alopex principle — is one that was devised in this laboratory for the experimental determination of visual receptive fields. The biological requirements for the operation of the principle are discussed, and a possible site in the thalamic relay nuclei is suggested.

Abstract: The reaching behavior of some 60 infants between 7 and 23 days of age was studied. Contrary to some other reports, the infants did not respond differently to a visually presented, graspable, solid object than to its two-dimensional representation.

Abstract: 1. The persistence of visual perception was investigated under conditions of visual fixation as well as eye movement. The Ss' task was to discriminate brief double light impulses; their responses were recorded as a function of the duration of the interstimulus interval. Based on these data the critical interstimulus interval was calculated, which yielded equal response frequencies for the perception of one or two stimuli upon presentation of double light pulses.

Abstract: Summary. The intent of this study was to explore several segments of divergent intelligence, visual stimulus complexity as a cognitive style, and auditory acuity, that presumably characterise the artistically expressive person. The sample population was comprised of 34 visual artists, 32 musical artists, and a normative group of 30 undergraduate university students. Between-group differences were examined by way of ANOVA, multiple discriminant function analysis, and then by a principal components solution (with varimax rotation). Preference for visual stimulus complexity was upheld as a cognitive style dimension common to both artistic and musical personalities. Substantive evidence was found to confirm the ‘divergent auditory figural memory factor’ (DFS-A) posited by Guilford in his SI model. As conjectured, visual artists displayed a superior propensity on the triadic divergent abilities subsumed under fluency, flexibility, and originality of thinking, while musical and control subjects were undifferentiated on these cognitive parameters. More importantly, the heightened auditory acuity and aesthetic judgment of visual artists over that of controls, as measured by the pilot auditory discrimination test, indicates the existence of a general intersensory factor among creative artists. Similarly, the musician's sensibility and attraction to complex abstract imagery beyond that of their non-artistic peers further strengthens the notion of possible shared perceptual features by creative individuals across discretesensory modalities. Overall, the selected variables were shown to be reliable predictors for identifying the artistically gifted individual.

Abstract: The importance of vision to man was used as a basis for a possible link between vision and sleep. A physiological approach to the human visual system identified several factors which might produce a visual load. Five subjects were exposed to high and low levels of visual load on two different occasions. Exercise and noise were controlled. Sleep EEGs were taken for 3 baseline nights and for 2 nights following each condition. The only significant changes were for SWS stages, which increased after the high load condition. These increases were particularly prominent on the second night. There were no significant changes fallowing the low condition. On all nights RKM remained constant: this was contrary to the cognitive theories of REM. Although the findings indicate that visual load can affect SWS. this interpretation is qualified.

Abstract: Dynamic retinoscopy has suggested that near vision may be more acute than far vision during early infancy. To test this, acuity thresholds were determined by presenting square wave gratings in a preference paradigm to 1- and 2-month-old human infants at 4 viewing distances. Gratings were paired with unpatterned fields; direction of first fixation was the dependent measure. Infants exhibited the same acuity at each of the distances at which gratings were presented. The results were interpreted as compatible with the fact that considerable optical defocusing does not seriously affect a visual system, such as the infant's, that is sensitive only to low spatial frequencies.

Abstract: To the Editor.— Dr Denny-Brown's highly personal view of the primate visual system as propounded in his Bennett lecture (Arch Neurol33:219, 1976) is sufficiently at variance with other work in the field that some comment is necessary. The division of visual perception into object vision-vision for cognitive detail-and panoramic vision-vision for spatial localization and behavioral import-is heuristically useful, and has been discussed in detail.However, the bulk of behavioral and physiological evidence must assign the superior colliculus to participation in "panoramic" rather than "object" vision. Dr Denny-Brown's arguments hinge on the drastic effects of collicular ablation in his hands. He argues that "complete removal of the superior colliculus resulted in the same loss of visual object identification, binocular fixation, and visuosocial behavior that followed removal of area 17." Most other investigators have failed to show such dramatic deficits from collicular ablation. Thus, Rosvold et al2showed that monkeys with

Abstract: Intersensory integration has been extensively explored in relation to reading and its developmental anomalies. Since matching across sensory modalities also involves different modes of presentation (auditory-sequential vs. visual-spatial), we tested the ability of normal and learning disabled children to match spatially arranged patterns of dots as well as sequences of light flashes within a single modality, vision. Normal and experimental subjects found it easiest to match spatial patterns with each other, and that task did not distinguish between the two groups. The other tasks were more difficult for both, particularly when sequential flashes of light were presented first and had to be matched to other flashes of light or to a spatial pattern. On these tasks the performance of normal children was significantly better than that of the learning disabled. Only the condition which required matching from sequence to pattern correlated with reading age among the learning disabled: possibly it is a process si...

Abstract: Threshold luminance necessary to evoke an eye movement was evaluated as a function of age (6-21 years) and visual angle (6 degrees-42 degrees from the fovea). Results were comparable to those of static perimetry in older subjects but showed little narrowing of the visual field in younger children.