The Influence of the Number of Alternatives on the Perceptual Recognition Threshold

Abstract

A study of the recognition thresholds for nonsense syllables previously presented in lists containing from 2 to 15 syllables is reported. The threshold is found to increase in proportion to the logarithm of the number of alternatives (i.e. the length of the list from which a given test syllable is drawn). It is therefore concluded that recognition threshold is a function of the amount of information transmitted.

Choice reaction time: An analysis of the major theoretical positions.

“…That a label-comparison process is not always involved in CRT tasks is indicated by Chase and Posner's (196S) finding that visual similarity affects CRTs but acoustic similarity does not, and by the fact that in CRT studies by Pierce and Karlin (1957) and Conrad (1962) the increases in CRT per unit increase in s were less than .5 millisecond, which agrees well with the corresponding number obtained in Fraisse and Blancheteau's (1962) perceptual recognition experiment. Surprisingly, the above two CRT studies used compatible 1:1 mappings and so varied both the number of alternative stimuli and alternative responses; yet these studies are consistent with an interpretation solely in terms of the perceptual recognition process.…”

“…However, a closer look at this evidence indicates that in some CRT tasks more than just recognition is involved in categorizing a stimulus. Thus Fraisse and Blancheteau (1962) found that recognition thresholds increase by approximately .25 millisecond when j is increased by 1, while the corresponding increase in mean CRT found by Sternberg (1964b) was approximately 40 milliseconds. Other yes-no categorization studies (Chase & Posner, 1965;Nickerson, 1966;Nickerson & Feehrer, 1964;Smith, 1967) which, like Sternberg's, varied only s, also yielded estimates of the increase in categorization time per unit increase in s of the order of 40 milliseconds.…”

“…Thus (a) . Fraisse and Blancheteau (1962) varied J in a tachistoscopic recognition study and obtained a linear relation between Iog2 5 and recognition threshold; (b) Sternberg (1964b) found virtually no difference in CRTs in a yes-no categorization task between responseterminated stimulus exposure (ca. 400 msec.)…”

Stimulus set, response set, and word identification.

“…When the task requires identifying 1 of 2 simultaneously presented words categorized either as a color (single category) or as a color or food (double category), the duration threshold is lower for 1 category than for 2 (Brown & Skinner, 1964;Postman & Bruner, 1949), but this does not occur when only 1 word is presented at a time (Freeman & Engler, 1955). Although the inverse relationship between number of alternatives and identification-duration threshold is confirmed for other stimuli and other responses (Fraisse & Blancheteau, 1962), it is known for words in only the limited case just described. Visual set and auditory set were compared using 6-letter nonsense words as stimuli (Sprague, 1959).…”

Uncertainty and Transitional Probability in the Span of Apprehension

“…Span of apprehension and memory span have repeatedly been found to be greater for digits than for letters (Cattell, 1886; Jacobs, 1887; Crossman, 1961;Mackworth, 1963). This could be an effect of ensemble size (ten as against twenty-six alternatives) as demonstrated for reaction time (Hick, 1952; Hyman, 1953) and for span of apprehension with other material (Krulee, Podell & Ronco, 1954; Fraisse & Blancheteau, 1962). However, the naming of digits and letters is highly familiar and in such tasks the effects of stimulus uncertainty may not be demonstrable (Crossman, 1953; Schmidtke, 1961; Davis, Moray & Treisman, 1961).…”