Visual Lobe Area for Single Targets on a Competing Homogeneous Background

Abstract

The binocular visual lobe for a detection task, with a peripherally presented target embedded in a homogeneous competing background, was mapped on eight axes passing through the fixation point. The lobes were very irregular in shape and there were differences between the subjects. The eight-axis area correlated highly with area based on only the horizontal and vertical axes, but the latter area gave no indication of even gross irregularities in lobe shape. Lobe areas for two subjects were exhaustively mapped; resulting boundaries were very irregular and there were regions of insensitivity within the lobe area. It was suggested that lobe shape as well as area is important to visual search. The irregular boundary and areas of insensitivity may partly account for the difficulty experienced by some subjects in locating targets even after repeated scanning.

Get full access to this article

View all access options for this article.

References

Bellamy, L. J. , and Courtney, A. J. (1981). Development of a search task for the measurement of peripheral acuity. Ergonomics, 24, 497–509.

Bloomfield, J. R. (1975). Theoretical approaches to visual search, In J. G. Fox and C. G. Drury (Eds.), Human reliability and quality control (pp. 19–29). London: Taylor and Francis.

Brown, M. B. (1979). Mathematical approaches to modelling visual search. In J. N. Clare and M. A. Sinclair (Eds.), Search and the human observer (pp. 126–131). London: Tavlor and Francis.

Chaikin, J. D. , Corbin, H. H. , and Volkmann, J. (1962). Mapping a field of short time visual search. Science, 138, 1327–1328.

Cole, B. L. , and Jenkins, S. E. (1980). The nature and measurement of conspicuity. Proceedings of 10th Conference of Australian Road Research Board, 10(4), 99–107.

Courtney, A. J. (1978). Search time and the peripheral visual field. Unpublished M.Sc. dissertation, University of Birmingham, Birmingham, U.K.

Courtney, A. J. , and Chan, H. S. (1985). Simple measures of visual-lobe size and search performance. Ergonomics, 28, 1319–1331.

Davies, E. B. (1968). Visual search theory with particular reference to air to ground vision (Royal Aircraft Establishment Tech. Report 68055). Farnborough, Hants, U.K.: Ministry of Technology.

Engel, F. L. (1971). Visual conspicuity, directed attention and retinal locus. Vision Research, 11, 563–576.

10.

Engel, F. L. (1974). Visual conspicuity and selective background interference in eccentric vision. Vision Research, 14, 457–471.

11.

Erickson, R. A. (1964). Relation between visual search time and peripheral visual acuity. Human Factors, 6, 165–178.

12.

Gallwey, T. J. (1982). Selection tests for visual inspection on a multiple fault type task. Ergonomics, 25, 1077–1092.

13.

Ikeda, M. , and Takeuchi, T. (1975). Influence of foveal load on the functional visual field. Perception and Psychophysics, 18, 255–260.

14.

Johnston, D. M. (1965). Search performance as a function of periphcral acuity. Human Factors, 7, 528–535.

15.

Leachtenauer, J. C. (1978). Peripheral acuity and photointerpretation performance. Human Factors, 20, 537–551.

16.

Megaw, E. D. (1978). Eye movements in visual inspection tasks. Quality Assurance, 4, 121–125.

17.

Overington, I. (1979). The current status of mathematical modelling of threshold functions. In J. N. Clare and M. A. Sinclair (Eds.), Search and the human observer (pp. 114–125). London: Taylor and Francis.