Problems of Visual Culture in the Light of Modern Investigations of Visual Perception and Visual Thinking

The problem of visual and esthetic training has many facets, among which the psychological are obviously not the least important. The results of long years of studying the psychology of the child (2) lead to the conclusion that:

Human consciousness and the mechanisms of conscious control of human actions represe it a hierarchical system, like a building constructed of many superimposed psychophysiological levels, of many floors rising above one another. Somewhere in the basement are the prepsychological instinctive processes of receiving and using unconditioned reflex signals; the lower floors form the elementary sensations and implement the elementary types of individually discovered sensorimotor coordinations; the next floor is where the synthetic perceptions of space and time are formed along with the mechanisms for controlling locomotion and object manipulation; above them is the floor housing visual thinking and the processes for regulating play and productive activities; and, finally, above all these is the floor of symbolic, abstract, logical operations and the most complex instances of control exerted by the most complex information- seeking and labor activities. It should be emphasized that in its developed form this hierarchical system operates as a single entity, and the control of complex operations requires agreement between the operations of the psychophysiological mechanisms located at all these levels or floors. Each age level in the child's development erects the next floor of the overall psychophysiological building, and our task is mainly to build it in the best possible way, without senseless haste and taking heed not to erect the next floor before the one below is finished. (4)     

Quality of Visual Cue Affects Visual Reweighting in Quiet Standing

Sensory reweighting is a characteristic of postural control functioning adopted to accommodate environmental changes. The use of mono or binocular cues induces visual reduction/increment of moving room influences on postural sway, suggesting a visual reweighting due to the quality of available sensory cues. Because in our previous study visual conditions were set before each trial, participants could adjust the weight of the different sensory systems in an anticipatory manner based upon the reduction in quality of the visual information. Nevertheless, in daily situations this adjustment is a dynamical process and occurs during ongoing movement. The purpose of this study was to examine the effect of visual transitions in the coupling between visual information and body sway in two different distances from the front wall of a moving room. Eleven young adults stood upright inside of a moving room in two distances (75 and 150 cm) wearing a liquid crystal lenses goggles, which allow individual lenses transition from opaque to transparent and vice-versa. Participants stood still during five minutes for each trial and the lenses status changed every one minute (no vision to binocular vision, no vision to monocular vision, binocular vision to monocular vision, and vice-versa). Results showed that farther distance and monocular vision reduced the effect of visual manipulation on postural sway. The effect of visual transition was condition dependent, with a stronger effect when transitions involved binocular vision than monocular vision. Based upon these results, we conclude that the increased distance from the front wall of the room reduced the effect of visual manipulation on postural sway and that sensory reweighting is stimulus quality dependent, with binocular vision producing a much stronger down/up-weighting than monocular vision.     

Visual Search Elicits the Electrophysiological Marker of Visual Working Memory

Background

Although limited in capacity, visual working memory (VWM) plays an important role in many aspects of visually-guided behavior. Recent experiments have demonstrated an electrophysiological marker of VWM encoding and maintenance, the contralateral delay activity (CDA), which has been shown in multiple tasks that have both explicit and implicit memory demands. Here, we investigate whether the CDA is evident during visual search, a thoroughly-researched task that is a hallmark of visual attention but has no explicit memory requirements.

Methodology/Principal Findings

The results demonstrate that the CDA is present during a lateralized search task, and that it is similar in amplitude to the CDA observed in a change-detection task, but peaks slightly later. The changes in CDA amplitude during search were strongly correlated with VWM capacity, as well as with search efficiency. These results were paralleled by behavioral findings showing a strong correlation between VWM capacity and search efficiency.

Conclusions/Significance

We conclude that the activity observed during visual search was generated by the same neural resources that subserve VWM, and that this activity reflects the maintenance of previously searched distractors.     

Visual adaptation

European Biophysics Journal -