The Psychological Refractory Period and Vertex Evoked Potentials

1972 ◽  
Vol 24 (2) ◽  
pp. 175-192 ◽  
Author(s):  
John Boddy
Keyword(s):  
Refractory Period ◽  
Time Course ◽  
Psychological Refractory Period ◽  
Single Channel ◽  
Random Sequence ◽  
Reaction Times ◽  
Central Processor ◽  
Sensory Evoked Potential ◽  
Sensory Evoked ◽  
Simple Rt

The averaged sensory evoked potential (EP) was recorded from the scalp (vertex to mastoid) in a psychological refractory period experiment in which 12 young adults participated. Reaction times (RTs) were measured to either both or only the second of pairs of stimuli, in different trial blocks, with inter-stimulus intervals (ISIs) of 100, 200, 300 and 400 msec occurring in random sequence. EPs were recorded at each ISI. No latency changes could be found in the prominent non-specific components (P1–N1–P2) of the EP to stimulus 2 even at ISIs where the RT was substantially delayed. Thus the notions that the RT2 delay is due to occupation of a single channel central processor by S1 and that non-specific EP components reflect the time course of information processing in underlying neural tissue, do not lend each other mutual support. Furthermore, as profound amplitude refractoriness in components P1–N1 and N1–P2 persisted at ISIs where RT was as fast or faster than simple RT, there appears to be a dissociation between “psychological refractoriness” and “physiological refractoriness”. The implications of these results are discussed.

The Time Course of Preparation*

1967 ◽  
Vol 19 (3) ◽  
pp. 272-279 ◽  
Author(s):  
Paul Bertelson
Keyword(s):  
Visual Stimulus ◽  
Refractory Period ◽  
Time Course ◽  
Reaction Times ◽  
Warning Signal ◽  
High Time ◽  
Refractory Periods ◽  
Time Uncertainty ◽  
Order Of Magnitude ◽  
Choice Reaction Times

The time course of the adjustments triggered by a warning signal was studied by measuring choice reaction times (RTs) at different predictable foreperiods after such a signal. Before the warning signal, a high time uncertainty situation was created by imposing either a long constant foreperiod of 5 sec. or one varying in the range 1.5 to 5 sec. The warning signal was a click. Foreperiods ranging from 0 to 300 millisec. were used in different blocks of trials. The stimulus was the onset of one of two lamps calling for the pressing of one of two keys. A control condition, without click, was used also. RTs were found to decrease continuously when the forperiod was increased from 0 to 100-150 millisec. The click delivered simultaneously with the stimulus permitted reactions significantly faster than in the control condition. It is concluded (a) that the latency of preparation can be much shorter than the 2 to 4 sec. reported by Woodrow; (b) that the warning signal can be used as a time cue to start preparatory adjustments without starting a refractory period of the order of magnitude found in experiments with pairs of successive reactions, and thus that such refractory periods are not the inevitable cost of paying attention to a signal. There is also some suggestion that in this situation the click not only triggers preparatory adjustments, but also causes an immediate facilitation of the reaction to the visual stimulus.

The Psychological Refractory Period as a Function of Performance of a First Response

1967 ◽  
Vol 19 (4) ◽  
pp. 350-352 ◽  
Author(s):  
Marilyn C. Smith
Keyword(s):  
Refractory Period ◽  
Motor Response ◽  
Psychological Refractory Period ◽  
Single Channel ◽  
Response Selection ◽  
Expectancy Theory ◽  
Response Component ◽  
First Response ◽  
Motor Component ◽  
Channel Theory

Proponents of a “single channel” theory of the psychological refractory period have not specified whether the single channel occupies only the decision component of the response selection, only the motor or response component, or both. In this experiment, the delay in the RT to the second of two successively presented stimuli was examined as a function of whether or not an overt motor response was made to the first stimulus, keeping the decision component constant. It was found that in both conditions RT2 was delayed, suggesting that the decision component was a part of the single channel. However, RT2 was delayed by a significantly greater amount if a motor response was required, indicating that the motor component is part of the single channel as well. Implications of the results for an expectancy theory of the psychological refractory period are discussed.

Effect of Marihuana on the Psychological Refractory Period

1974 ◽  
Vol 38 (3) ◽  
pp. 959-962 ◽  
Author(s):  
Herbert Moskowitz ◽  
Richard Shea ◽  
Marcelline Burns
Keyword(s):  
Auditory Stimulus ◽  
Visual Stimulus ◽  
Refractory Period ◽  
Psychological Refractory Period ◽  
Reaction Times

Reaction times to an auditory stimulus (RT1) and a subsequent visual stimulus (RT2) were measured for 12 Ss under three levels of smoked marihuana. Marihuana impaired responses; effect was larger on RT2 than on RT1. However, delays of RT2 are longer than would be predicted in terms of the psychological refractory period.

Response Time to a First Signal as a Function of Time Relationship to a Second Signal and Mode of Presentation

1971 ◽  
Vol 32 (3) ◽  
pp. 811-816 ◽  
Author(s):  
Marcelline M. Burns ◽  
Herbert Moskowitz
Keyword(s):  
Response Time ◽  
Refractory Period ◽  
Psychological Refractory Period ◽  
Single Channel ◽  
Time Sharing ◽  
Random Presentation ◽  
Time Relationship ◽  
Processing Mechanisms ◽  
Channel Theory ◽  
Support Time

Using a random presentation of inter-stimulus intervals between stimulus 1 and stimulus 2 in a psychological refractory period paradigm, this experiment permitted comparison of data obtained earlier using a block presentation. With 10 male Ss per study, response time to stimulus 1 increased at higher inter-stimulus intervals under block presentations but not under random presentations. The results are interpreted to support time-sharing between the processing mechanisms of the two stimuli rather than a single channel theory.

Focusing of Visuospatial Attention

2001 ◽  
Vol 15 (4) ◽  
pp. 256-274 ◽  
Author(s):  
Caterina Pesce ◽  
Rainer Bösel
Keyword(s):  
Reaction Times ◽  
Visual Space ◽  
Spatial Relation ◽  
Stimulus Onset ◽  
Visuospatial Attention ◽  
Task Demands ◽  
Time Interval ◽  
Behavioral Studies ◽  
Task Conditions ◽  
Simple Rt

Abstract In the present study we explored the focusing of visuospatial attention in subjects practicing and not practicing activities with high attentional demands. Similar to the studies of Castiello and Umiltà (e. g., 1990) , our experimental procedure was a variation of Posner's (1980) basic paradigm for exploring covert orienting of visuospatial attention. In a simple RT-task, a peripheral cue of varying size was presented unilaterally or bilaterally from a central fixation point and followed by a target at different stimulus-onset-asynchronies (SOAs). The target could occur validly inside the cue or invalidly outside the cue with varying spatial relation to its boundary. Event-related brain potentials (ERPs) and reaction times (RTs) were recorded to target stimuli under the different task conditions. RT and ERP findings showed converging aspects as well as dissociations. Electrophysiological results revealed an amplitude modulation of the ERPs in the early and late Nd time interval at both anterior and posterior scalp sites, which seems to be related to the effects of peripheral informative cues as well as to the attentional expertise. Results were: (1) shorter latency effects confirm the positive-going amplitude enhancement elicited by unilateral peripheral cues and strengthen the criticism against the neutrality of spatially nonpredictive peripheral cueing of all possible target locations which is often presumed in behavioral studies. (2) Longer latency effects show that subjects with attentional expertise modulate the distribution of the attentional resources in the visual space differently than nonexperienced subjects. Skilled practice may lead to minimizing attentional costs by automatizing the use of a span of attention that is adapted to the most frequent task demands and endogenously increases the allocation of resources to cope with less usual attending conditions.

scholarly journals Individual differences effects on the psychological refractory period

SpringerPlus ◽  
2013 ◽  
Vol 2 (1) ◽  
pp. 368 ◽  
Author(s):  
Maude Laguë-Beauvais ◽  
Christine Gagnon ◽  
Nathalie Castonguay ◽  
Louis Bherer
Keyword(s):  
Individual Differences ◽  
Refractory Period ◽  
Psychological Refractory Period

Effect of Complexity of the Second Response on Reaction Time to the First Response in the Psychological Refractory Period Paradigm

1987 ◽  
Vol 64 (3_suppl) ◽  
pp. 1075-1080 ◽  
Author(s):  
Craig J. Chamberlin
Keyword(s):  
Reaction Time ◽  
Refractory Period ◽  
Psychological Refractory Period ◽  
Parallel Model ◽  
Relative Complexity ◽  
Central Processing ◽  
Psychological Refractory Period Paradigm ◽  
First Response ◽  
Grouping Effect ◽  
Flexible Model

An attempt to distinguish serial from parallel models of central processing was made by manipulating the relative complexity of R2 and observing the effect of this manipulation on RT1 in the Psychological Refractory Period paradigm. 14 subjects performed under two conditions, either a simple or complex R2. Experimental controls were used to prevent a possible grouping effect of responses. The results did not support a parallel model of central processing but did support a serial view. Implications of results, combined with previous findings, for a more flexible model of central processing were discussed.

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