Gestalt phenomena are often so powerful that mere demonstrations can confirm their existence, but Gestalts have proven hard to define and measure. Here we outline a theory of basic Gestalts (TBG) that defines Gestalts as emergent features (EFs). The logic relies on discovering wholes that are more discriminable than are the parts from which they…

The American Academy of Pediatrics recommends vision screening of all children between 3 and 5 years of age, and states have mandated vision screening for all school children. Participants were three 4-6-year old school children with either a developmental delay or autism who scored "could not test" on the state required vision screening.…

Humans and pigeons were trained to discriminate between 2 views of actual 3-D objects or their photographs. They were tested on novel views that were either within the closest rotational distance between the training views (interpolated) or outside of that range (extrapolated). When training views were 60? apart, pigeons, but not humans,…

Several studies have indicated that children have difficulty differentiating mirror-image stimuli. In the present study adults were required to classify pairs of horseshoe stimuli as same or different. Response times were compared for stimulus pairs that varied in orientation (left-right vs up-down) and spatial plane of the pair (horizontal vs.…

Describes an in-depth, comprehensive method that enables students to understand the basic concepts of visual perception. (JRH)

This article examines how the human visual system represents the shapes of 3-dimensional (3D) objects. One long-standing hypothesis is that object shapes are represented in terms of volumetric component parts and their spatial configuration. This hypothesis is examined in 3 experiments using a whole-part matching paradigm in which participants…

Studied infant ability to extract depth information from a three-dimensional structure. Found evidence that 8-month-old infants distinguished between lines indicating edges, and lines indicating markings, and that they are able to use line junctions to perceive line drawings as depicting three-dimensional objects in the picture plane. (Author)

Visual discrimination tasks are increasingly used to explore the neurobiology of vision in rodents, but it remains unclear how the animals solve these tasks: Do they process shapes holistically, or by using low-level features such as luminance and angle acuity? In the present study we found that when discriminating triangles from squares, rats did…

Visual orientation toward a peripheral stimulus by newborns and 7-week-old infants was examined with both a central stimulus present and absent. General conclusion is that, contrary to previous assessments, the neonate appears to exercise internal control over his sampling of the stimulus array rather than being passively captured by it.…

Seventeen preschool children were administered two color-discrimination pretests, verbal and nonverbal. The five children who scored lowest were chosen to recieve the color program. Four scored elow 85 percent on the nonverbal pretest, whereas the other 12 children scored above 85 percent. On the verbal pretest, all five experimental subjects…

Studies have suggested attention-free semantic processing of natural scenes in which concurrent tasks leave category detection unimpaired (e.g., F. Li, R. VanRullen, C. Koch, & P. Perona, 2002). Could this ability reflect detection of disjunctive feature sets rather than high-level binding? Participants detected an animal target in a rapid serial…

This article describes addition of a "learn a routine" procedure to functional visual assessments of children with severe neurological and physical disabilities. The procedure capitalizes on the child's interest of the moment and provides information on the child's patterns of responses, ability to accommodate to variations of a stimulus, and…

The question of whether pupil diameter indicates information processing load during reading was investigated in three experiments involving 24 college students reading passages of varying difficulty. A TV camera and monitor, together with a video-recorder, were used to measure the diameter of the pupil under a reading condition and under three…

Specific and understandable suggestions are offered to parents of severely visually impaired children who have or may have the capacity to learn visually. Parents can assist children with even a small amount of vision to develop that vision from an early age. Vision development begins by ensuring that the child receives appropriate medical and…