Visual Pattern Perception with Varied Fixation Locus and Response Recording

Abstract

10-element binary patterns of open and blackened circles were tachistoscopically exposed such that 0–10 of the elements appeared on the left of a fixation-cross. The specific orientation relative to fixation was unknown to O before exposure. O was required to reproduce the pattern of blackened circles on a blank template after each exposure. In each of three experiments a different arrangement of the template for recording responses was used. The usual tendency for greater accuracy for elements at the left was overcome when more than half of the elements had appeared to the left of the fixation-point. The form of response recording affected the results, which were accounted for in terms of visual sensitivity, implicit motor factors, and organizational factors in the memory system of O.

Effect of event proportion on the short-term perception of linear binary patterns.

“…All specifications were the same except that the fixation cross was omitted so that only the pattern was available for organization. Camp and Harcum (1964) and Ayres (1966) have shown that the fixation cross has an imporant role in the determination of error patterns. The present study was concerned with the perception of the pattern itself.…”

Perceptibility gradients for tachistoscopic patterns: Sensitivity or saliency?

“…Some studies have obtained, without the supposed critical method for perceptual reports, distributions of errors which have the appearance of sensitivity gradients. For example, Camp and Harcum (1964) presented horizontal tachistoscopic patterns of 10 open and filled circles with fixation at unknown locations, sometimes at each of the 11 possible locations between circles or off either end of the array. These binary patterns should be less strongly connected with cognitive processes than letter groups (Harcum, 1970).…”

“…The above experiment was repeated with undergraduate students. Each 5 was given a sheet of paper describing "an experiment to determine what college student subjects expect the area of distinct vision to be in a difficult Camp & Harcum, 1964). (The different curves represent results for fixation to the left of ninth, sixth, and third element-positions from the left, respectively, and the two panels represent the first and second (last) blocks of observations.)…”

“…In Neisser's (1967) terminology, preattentive processes concentrate focal attention on the elements about fixation. Emphasis on fixation could also influence 5s to use fixation as a frame of reference for mnemonic organization (Camp & Harcum, 1964;Harcum, 1967). Thus, there are several viable alternatives to the "pure percept" interpretation.…”

“…FIG. 2.Error curves for 10-element binary patterns with element-position specified relative to fixation (data fromCamp & Harcum, 1964). (The different curves represent results for fixation to the left of ninth, sixth, and third element-positions from the left, respectively, and the two panels represent the first and second (last) blocks of observations.…”