Central Inhibition—Some Refractory Observations

Abstract

The observation that the response t o the second of two stimuli is delayed if a response has to be made to the first has led t o the development of a theory of a central refractory state during which incoming stimuli cannot be elaborated. In the experiment reported here the two stimulus-response situations have been made as independent as possible, and under these conditions it is shown that this theory cannot be maintained in its present form. The concept that the central integrating mechanism readily becomes blocked by nay single stimulus is dismissed as nonproven and uneconomic. The present findings, however, confirm previous observations that some interference between the two situations may occur b u t indicate that this is not necessarily maximal immediately after the presentation of the first stimulus. I t is tentatively suggested that the phenomena of central inhibition can be interpreted in terms of the interaction between the excitatory and inhibitory significance of the stimuli and the internal anticipatory set. INTRODUCTIONMuch controversy in the early literature on the psychology of sldled movements centred round the discussion a s to whether attention could be divided between two skilled tasks (Woodworth 1938). Nost authorities favoured the view that such a division of attention was in fact impossible. I t was held that where simultaneity of performance was apparent this was achieved by a rapid alternation o i attention between the two tasks. Ryle, who is not addicted to dichotomies-in this case "all tasks must be either attended to or not attended to"-has pointed out that this difficulty may be largely a verbal one. He believes that the concept of heed or attention belongs to that class of dispositional statements which is both categorical

Attentional awakening: gradual modulation of temporal attention in rapid serial visual presentation

“…Nevertheless, the results obtained in this experiment provide one important suggestion related to the conditional ("a posteriori") probabilities (Trillenberg, Verleger, Wascher, Wauschkuhn, & Wessel, 2000), as we mentioned in the discussion of Experiment 1. One explanation for the usual foreperiod eVect is that reaction times depend on the a posteriori probability of an event occurring, rather than on its a priori probability (Elithorn & Lawrence, 1955). Note that despite the equal probability ("a priori probability") of the target appearance at each timing in this study, the chances of the target appearing in the next instant increased over time.…”

“…Thus, if the target did not appear at the early temporal position, it was guaranteed to occur at the other speciWc later position (cf. Elithorn & Lawrence, 1955). More speciWcally, their results (high performance in the late condition) could reXect the re-orienting, or re-focusing, process of attention to a speciWc point in time.…”

Reweighting sequential effects across different distributions of foreperiods: Segregating elementary contributions to nonspecific preparation

“…One influential account of this finding has been that nonspecific preparation develops in accordance with the conditional probability of S 2 occurrence (e.g., Elithorn & Lawrence, 1955;Jurkowski, Stepp, & Hackley, 2005; py g y y, 1161…”

For the Last Time: Temporal Sensitivity and Perceived Timing of the Final Stimulus in an Isochronous Sequence

“…If this result is interpreted as an acceleration of the last stimulus, it should be 631 considered that the difference in hazard probability would suggest greater expectation 632 and, thus, more anticipation with longer sequences (Elithorn & Lawrence, 1955;Luce, 633 1986; Näätänen, 1970;Niemi & Näätänen, 1981;). Hazard probability alone, therefore, 634…”