Visual Scanning Task Research Articles

Selective hyperthermia and reaction time.

Two reaction time studies are reported in which subjects responded under conditions of selective hyperthermia. Wearing a helmet prototype, the cortical surface of the subject was thermally stressed to a level 1.11 degrees C over baseline as measured by a thermocouple placed against the tympanic membrane. In a simple choice RT task, both reaction time and response variability were decreased compared to performance in either a control or placebo condition. Latency in Neisser's visual scanning task was also shortened under conditions of this thermal stress localized in the cortical region. In both cases, there was no observed decrement in accuracy or level of performance. Enhanced human performance resulting from the maintenance of cortical temperature above the normal diurnal range is implied.

The use of visual and name codes in scanning and classifying colors

The effect of incongruent color words on speed of classifying ink colors was measured in visual scanning tasks and in card sorting tasks. In both cases, little or no interference effects were noted when the classification allowed focusing on a single ink color or a set of highly similar colors (adjacent hues). Substantial interference occurred when the task required grouping of three dissimilar colors (nonadjacent hues). These findings suggest that the relative efficiency of name and visual codes in making perceptual classifications is largely dependent upon the memory requirements imposed by the task.

A developmental study of visual search behavior

Children in second, fourth and sixth grades and college sophomores were compared on a visual search and scanning task under three experimental conditions. In Condition I, a single target letter was sought in a list of letters of low visual confusability. In Condition II, two target letters were sought but only one appeared in a given list. In Condition III, a single target letter was sought in a list of letters of high confusability. Search time decreased with age in all three tasks. Searching for two targets was no harder than searching for one. A highly confusable visual context increased search time at all age levels.

A developmental study of visual search behavior

Children in second, fourth and sixth grades and college sophomores were compared on a visual search and scanning task under three experimental condilions. In Condition I, a single target letter was sought in a list of letters of low visual confusability. In Condition II, two target letters were sought but only one appeared in a given list. In Condition III, a single target letter was sought in a list of letters of high confusability. Search time decreased with age in all three tasks. Searching for two targets was no harder than searching for one. A highly confusable visual context increased search time at all age levels.

A developmental study of the effects of visual and auditory interference on a visual scanning task

The effects of visual and auditory interference on a visual scanning task were compared with children from the third grade and college sophomores. A highly confusable visual context significantly reduced scanning rate for both children and adults, but a highly confusable auditory context, played over earphones, had no effect on either group. There was a significant age interaction with interfering visual context. It seems likely that theories assuming auditory encoding of visually presented graphic items have little predictive value for a scanning task.