Tachistoscopic Task Research Articles

Post-cueing after erasure of the icon: is there a set effect?

Recognition accuracy in a tachistoscopic identification task typically declines as the size of the set from which the target was selected increases. To determine whether this effect is due to selective encoding from iconic store, a masking stimulus, intended to erase the icon, was presented following the stimulus. Information about the set was then presented. It was found that subjects' performance in this post-cueing situation did not differ from performance in a pre-cueing condition, where the set was presented prior to the stimulus. It was concluded that set size does not have its effect through selective encoding from iconic store. Results were discussed in terms of the fragment theory.

Tachistoscopic detection as a function of varying degrees of physical exercise.

The effect of variations in activation upon sensory sensitivity was assessed in a tachistoscopic detection task. Activation was manipulated by means of physical exercise tasks and tachistoscopic detection was measured using a forced-choice procedure. The results supported the inverted-U hypothesis.

An Improved Technique for Monitoring Fixation in Tachistoscopic Tasks

A monocular lens mounted behind a stimulus screen was used to monitor fixation in a tachistoscopic recognition task. This technique was found superior to the often used “sideview technique” and as accurate as the method involving identification of a fixation stimulus. It was found that the “telescope technique” is preferable in those studies where presentation of a fixation stimulus might interfere with recognition or report of the experimental stimulus.

A parallel between single-letter and multiple-letter recall of tachistoscopic letter displays.

Harcum (1965) has observed a close relationship between error functions for verbal serial learning and tachistoscopic pattern perception. This relationship suggests that common organizational and processing factors subsume both learning and perceptual tasks. A further parallel is here noted, between error curves arising from two different tachistoscopic tasks. Fig. 1 shows the distributions of errors from (a) a poststimulus sampling situation wherein rows of eight letters were exposed for 50 msec. and, at various delays before and after exposure, Ss were cued to report a single letter from the total display (Averbach & Sperling, 1961), and (b) an experiment conducted by the author where rows of eight letters were exposed for 100 msec. and Ss were instructed to report all letters shown. The remarkable similarity berween these curves may be taken as further support for the role of sequential trace-scanning factors, as opposed to sequential reporting factors, in determining the shape of the perceptual serial-position error curve. Contrary to the bow-shape curves reported by Harcum (1965), however, the present curves showed a dip in errors for letters near fixation. Unpublished work has shown that when lines of letters are exposed for 60 msec. or 120 msec., dips occur in the error curve; at 240 msec. a bowshape curve emerges. When lines of binary targets are exposed for 60 msec., 120 msec., or 240 msec., bow-shape error curves result. These differences may help reconcile Harcum's data with rhose reported here.

Selective Impairment of Phonetic and Non-Phonetic Transcription of Words in Japanese Aphasic Patients: Kana vs. Kanji in Visual Recognition and Writing

Two aphasic subgroups of 10 each, with and without apraxia of speech, and two nonaphasic right- and left-hemiplegic groups of six each were administered two sets of tasks: 1) three visual recognition tasks in which kanji (ideogram) and hiragana (phonogram) representations of 10 highfrequency nouns and katakana representations of 10 comparative imported nouns were used as stimuli, and 2) two writing tasks with the same nouns using kanji, hiragana and katakana transcriptions. In the visual recognition tasks, each subject was presented tachistoscopically with three sets of transcriptional stimuli, i.e., kanji, katakana, and hiragana stimuli, arranged in random order. Three subsessions were conducted with different exposure durations, 1/10 second (Task 1), 1/2 second (Task 2), and 1 second (Task 3), respectively. In the writing tasks, each patient was required to write the word for each of 20 different pictures presented (Task 4) and also to write the words to dictation (Task 5), using both kanji and hiragana (for the 10 non-imported words) or katakana only (for the 10 imported words). The results showed that 1) the performance levels of aphasics subjects in all tasks were significantly lower than those of non-aphasic subjects, 2) Group B aphasics (with apraxia of speech) made a significantly greater number of errors in kana processings than in kanji processings in the tachistoscopic tasks (Tasks 1, 2, and 3) as well as in the writing tasks (Tasks 4 and 5), while Group A aphasics (without apraxia of speech) exhibited no such clear difference. On the basis of the findings it was concluded that the selective impairment of kana processing exhibited by the Group B patients is associated not only with the overall severity but with the specific type of the aphasic syndrome of this group, i.e., “apraxia of speech” superimposed on aphasia. Hypotheses concerning the possible underlying mechanisms for this phenomenon are discussed.

EFFECTS OF HEIGHTENED DRIVE (SHOCK) ON PERFORMANCE IN A TACHISTOSCOPIC COLOR-WORD INTERFERENCE TASK.

A tachistoscopic modification of the Stroop Color-Word Interference Test was used in an attempt to demonstrate the interactive effects of shock and stimulus-competition on color identification. Results approached statistical significance.

Extension of the Repression-Sensitization Hypothesis to Success and Failure Experience

Byrne's (1961) R-S scale was administered to 244 university students. Those scoring in the 75th percentile or above were designated sensitizers; those in the 25th percentile and below, repressers. Forty Ss were selected from each of these two groups and were further sub-divided to form success and failure conditions. Ss then received a success or failure experience followed by a tachistoscopic task where eight critical words (words associated with the tests) and eight neutral words (words not associated) were presented. The following hypotheses were supported. (a) Repressers had higher thresholds than sensitizers for critical words under the failure condition. (b) There was no significant difference between repressers' and sensitizers' thresholds under the success condition. (c) Thresholds to neutral words, although following the same trend as critical words in the four groups, did not differ significantly for repressers and sensitizers under either the success or failure condition.