The Influence of Different Doses of Caffeine on Visual Task Performance

1999 ◽  
Vol 13 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Judith Ruijter ◽  
Monicque M. Lorist ◽  
Jan Snel
Keyword(s):  
Body Weight ◽  
Information Processing ◽  
Reaction Time ◽  
Dual Task ◽  
Visual Information ◽  
Reaction Times ◽  
False Alarms ◽  
Output Stage ◽  
Improved Performance ◽  
Output Stages

Abstract In this study the influence of caffeine as an energy-increasing substance on visual information processing was examined. Subjects were presented with a dual-task consisting of two choice reaction time tasks. In addition, one of the tasks was presented at two levels of difficulty, influencing the decision-making process. Doses of 1.0, 3.0, and 7.5 mg/kg body weight caffeine and 3.0 mg/kg body weight lactose were administered (within-subjects design). The effect of caffeine was expected to be observable in terms of improved performance on measures like reaction time and type and number of errors, as well as in components of the event-related brain potential (ERP). The highest caffeine dose shortened reaction times on both the primary and the secondary task as compared to placebo. Overall there was a linear decline in reaction times on both tasks with increasing caffeine dose. As measured from ERP results, there was an increasing P3 amplitude as caffeine dose increased, indicating that the quantity of information processed was larger under caffeine. There was, however, no evidence of extra energy in terms of more hits and fewer misses or false alarms. Moreover, subjects reported no doserelated differences in amount of effort needed to perform the dual-task. It is concluded that the effect of caffeine, which is supposed to have its impact on both the input and the output stages of information processing, was evident in the output stage in the form of shortened reaction times. However, no effect of caffeine could be observed at the input stage, probably due to a data limited process.

Diffusive Feedback Influences on Hierarchical Information Processing

2012 ◽  
Vol 24 (3) ◽  
pp. 744-770 ◽  
Author(s):  
Ai Miyamoto ◽  
Jun Hasegawa ◽  
Meihong Zheng ◽  
Osamu Hoshino
Keyword(s):  
Neural Network ◽  
Information Processing ◽  
Reaction Time ◽  
Visual Information ◽  
Sensory Stimulation ◽  
Cells Of Origin ◽  
Orientation Specificity ◽  
Membrane Oscillations ◽  
Reaction Speed

In visual information processing, feedforward projection from primary to secondary visual cortex (V1-to-V2) is essential for integrating combinations of oriented bars in order to extract angular information embedded within contours that represent the shape of objects. For feedback (V2-to-V1) projection, two distinct types of pathways have been observed: clustered projection and diffused projection. The former innervates V1 domains with a preferred orientation similar to that of V2 cells of origin. In contrast, the latter innervates without such orientation specificity. V2 cells send their axons to V1 domains with both similar and dissimilar orientation preferences. It is speculated that the clustered feedback projection has a role in contour integration. The role of the diffused feedback projection, however, remains to be seen. We simulated a minimal, functional V1-V2 neural network model. The diffused feedback projection contributed to achieving ongoing-spontaneous subthreshold membrane oscillations in V1 cells, thereby reducing the reaction time of V1 cells to a pair of bars that represents specific angular information. Interestingly, the feedback influence took place even before V2 responses, which might stem largely from ongoing-spontaneous signaling from V2. We suggest that the diffusive feedback influence from V2 could act early in V1 responses and accelerate their reaction speed to sensory stimulation in order to rapidly extract angular information.

Reaction Times and Derived Information Processing Measures: Limitations of Their Practical Use in Vehicle Operator Screening

1978 ◽  
Vol 22 (1) ◽  
pp. 123-123
Author(s):  
Helmut T. Zwahlen ◽  
Michael L. Baird
Keyword(s):  
Information Processing ◽  
Reaction Time ◽  
Simple Reaction Time ◽  
Reaction Times ◽  
Point Of View ◽  
Simple Reaction ◽  
Rate Difference ◽  
Screening Measure ◽  
Time Averages ◽  
The Difference

The use of information processing rate (difference between the amount of uncertainty in a choice and simple reaction time situation, in bits, divided by the difference of the corresponding reaction time averages, in seconds) as a driver screening measure from a relevance point of view has been suggested by Fergenson (1971).

Parsing Attentional Components during a Simple Reaction Time Task Using Sleep Deprivation and Amphetamine Intervention

1992 ◽  
Vol 75 (3) ◽  
pp. 675-689 ◽  
Author(s):  
Joyce C. Cochran ◽  
David R. Thorne ◽  
David M Penetar ◽  
Paul A. Newhouse
Keyword(s):  
Information Processing ◽  
Reaction Time ◽  
Sleep Deprivation ◽  
Simple Reaction Time ◽  
Reaction Time Task ◽  
Specific Information ◽  
Temporal Uncertainty ◽  
Simple Reaction Time Task ◽  
Activation System ◽  
Output Stages

To examine the independent contributions of the attentional components of arousal and activation in performance, sleep deprivation was used as the attentional manipulation in a reaction time (RT) task. The subjects were 18 men who underwent 63 hr. of sleep deprivation during which time they periodically performed a simple auditory RT task with manipulations of temporal uncertainty and intensity. After 48 hr. sleep deprivation, subjects ingested either 20 mg d-amphetamine or placebo, then continued testing throughout Day 3. During sleep deprivation, performance was more impaired on trials associated with low temporal uncertainty (arousal) and high preparation (activation) than on trials associated with high temporal uncertainty and low preparation. Analysis indicated that sleep deprivation perturbed activation, leaving arousal relatively unimpaired and that amphetamine had a restorative effect on the sleep deprivation-impaired activation system. The stimulus of high intensity was disruptive on Day 1 but facilitative on Day 3, a result which was interpreted as an initial inhibition, then disinhibition of arousal. Results were interpreted to indicate that, in some instances, alterations in the less specific arousal and activation systems may underlie impairment or changes in the more specific information processing and motor output stages.

scholarly journals Enhanced Manual and Oral Motor Reaction Time in Young Adult Female Fragile X Premutation Carriers

2011 ◽  
Vol 17 (4) ◽  
pp. 746-750 ◽  
Author(s):  
Naomi J. Goodrich-Hunsaker ◽  
Ling M. Wong ◽  
Yingratana McLennan ◽  
Flora Tassone ◽  
Danielle Harvey ◽  
...  
Keyword(s):  
Reaction Time ◽  
Visual Information ◽  
Motor Response ◽  
Fragile X ◽  
Reaction Times ◽  
Mrna Levels ◽  
Motor Reaction ◽  
Cgg Repeat ◽  
Oral Motor ◽  
Fragile X Premutation

AbstractA previous study reported preliminary results of enhanced processing of simple visual information in the form of faster reaction times, in female fragile X premutation carriers (fXPCs). In this study, we assessed manual and oral motor reaction times in 30 female fXPCs and 20 neurotypical (NT) controls. Participants completed two versions of the reaction time task; one version required a manual motor response and the other version required an oral motor response. Results revealed that the female fXPCs displayed faster reaction times for both manual and oral motor responses relative to NT controls. Molecular measures including CGG repeat length, FMR1 mRNA levels, and age were not associated with performance in either group. Given previously reported age and CGG repeat modulated performance on a magnitude comparison task in this same group of premutation carriers, results from the current study seem to suggest that female fXPCs may have spared basic psychomotor functionality. (JINS, 2011, 17, 746–750)

Actual and Possible Body-Image Self-Schemas in Young Women with Bulimic Tendencies

2003 ◽  
Vol 96 (3_suppl) ◽  
pp. 1123-1132 ◽  
Author(s):  
Michel Girodo
Keyword(s):  
Body Image ◽  
Information Processing ◽  
Reaction Time ◽  
Young Women ◽  
Body Shape ◽  
Reaction Times ◽  
The Self ◽  
Self Concept ◽  
Image Schema ◽  
Trait Words

To examine whether information about body image is processed and cognitively organized around a self-concept, two experiments analyzed reaction time and memory for 48 young women with bulimic tendencies. Information was self-referencing to body shape vs trait words and information processing of adjectives referenced to “I dream of” and “I am afraid of” facets of self. Bulimic subjects encoded “fat” adjectives faster when these words were referenced to the present self. Reaction times were also faster to both “thin” and “fat” adjectives when these words were self-referenced to an “I dream of” and to an “I am afraid of” self, respectively. Processing of body-image information depended on which facet of self was activated rather than on the denotative meaning of the stimulus words. Memory for thin and fat adjectives was not related to preoccupation with body image or to which facet of the self was invoked. Findings suggest that an actual body-image schema and a possible body-image schema could coexist for bulimic persons. Such coexistence is necessary for a theory which posits knowledge structures might be dynamically related.

Information processing and antiretroviral therapy in HIV-1 infection

1998 ◽  
Vol 4 (4) ◽  
pp. 329-335 ◽  
Author(s):  
EILEEN M. MARTIN ◽  
DAVID L. PITRAK ◽  
KENNETH J. PURSELL ◽  
BURTON R. ANDERSEN ◽  
KATHLEEN M. MULLANE ◽  
...  
Keyword(s):  
Information Processing ◽  
Reaction Time ◽  
Antiretroviral Therapy ◽  
Reaction Times ◽  
Disease Status ◽  
Demographic Variables ◽  
Potential Utility ◽  
Untreated Individuals ◽  
Hiv Seropositive ◽  
Hiv 1

Computerized reaction time (RT) tasks are sensitive measures of subclinical HIV-related mental slowing. We previously reported that nondemented HIV-seropositive patients on antiretroviral therapy at the time of testing had faster choice RTs compared to matched untreated seropositive participants. In the present study, we evaluated the performance of 163 nondemented HIV-seropositive participants on a reaction time version of the Stroop task as a function of antiretroviral status. Persons on antiretroviral therapy at the time of testing had significantly faster reaction times than untreated individuals, although treated asymptomatic participants showed significantly less Stroop interference than treated symptomatic participants. These effects could not be attributed to differences in demographic variables, disease status, substance abuse, or psychological distress. These data indicate that central information processing is faster for patients treated with antiretroviral compounds compared to untreated patients, and suggest that reaction time tasks may have significant potential utility in clinical trials of neuroprotective compounds. (JINS, 1998, 4, 329–335.)

scholarly journals Sexual Dimorphisms in Spatial Memory, Facial Recognition, and Reaction Time

2012 ◽  
Vol 1 (1) ◽  
pp. 41-48
Author(s):  
Hannah Rose Waller ◽  
Anthony L. Lin
Keyword(s):  
Reaction Time ◽  
Spatial Memory ◽  
Visual Information ◽  
Facial Recognition ◽  
Reaction Times ◽  
The Novel ◽  
Display Duration ◽  
Female Advantage ◽  
Correct Reaction ◽  
Duration Effect

Objectives: Literature suggests that there is a female advantage in facial recognition, and a male one in spatial memory. Researchers in this study investigated whether females outperformed males on a Novel Faces and Places (NFAP) test, which uses both facial recognition and spatial memory measures. NFAP was adapted from the Novel Image Novel Location (NINL) test (Piper, Acevedo, Edwards, Curtiss, McGinnis, & Raber, 2011a). Methods: College students (N=95) completed a demographics survey and took NFAP at one of 5 different display duration conditions. Results: No significant differences were found among the sexes for total NFAP score or for novel faces or novel places identification. However, females had faster reaction times overall, and particularly when making correct judgments. Female correct reaction time was significantly faster than female incorrect reaction time and than both male correct and incorrect reaction times. Also observed was a display duration effect, where a 15 second display duration yielded the highest scores compared to 12, 9, 6, or 3 seconds. Conclusion: These findings indicate that males and females process visual information in different ways. Though no significant differences in score were found, the female advantage seen in NINL did in fact disappear on NFAP as was hypothesized.

scholarly journals The role of concern about falling on stepping performance during complex activities

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Shaira Viaje ◽  
Geert Crombez ◽  
Stephen R. Lord ◽  
Jacqueline C. T. Close ◽  
Perminder Sachdev ◽  
...  
Keyword(s):  
Reaction Time ◽  
Older People ◽  
Dual Task ◽  
Reaction Times ◽  
Cognitive Resources ◽  
Task Condition ◽  
Dual Task Condition ◽  
Visuospatial Task ◽  
General Concern

Abstract Background There is limited understanding of the underlying mechanisms explaining the role of concern about falling on fall risk in older people. Anxiety is known to interact with cognitive resources and, as people get older, they require more cognitive resources to maintain balance. This might affect an individual’s ability to perform cognitive-motor tasks concurrently. The aim of this study was to investigate the effect of a visuospatial dual-task on stepping performance in older people with and without concern about falling and the impact of repeating this task in those with high concern about falling. Methods Three-hundred-eight community-dwelling older people, aged 70 to 90 years old, participated in the study. Participants were asked to perform a Choice Stepping Reaction Time (CSRT) task in two conditions; once without any other tasks (single task condition), and once while simultaneously performing a visuospatial task (dual-task condition). Participants were asked to rate their levels of concern and confidence specifically related to each of the 25 stepping trials (before/after). We also measured general concern about falling, affect, and sensorimotor and cognitive functioning. Results Total stepping reaction times increased when participants also performed the visuospatial task. The relation between general concern about falling and stepping reaction time, was affected by sensorimotor and executive functioning. Generalised linear mixed models showed that the group with moderate to high levels of general concern about falling had slower total stepping reaction times than those with lower levels of concern about falling, especially during the dual-task condition. Individuals with greater general concern about falling showed reduced confidence levels about whether they could do the stepping tasks under both conditions. Repeatedly performing the stepping task reduced the immediate task-specific concern about falling levels and increased confidence in all participants. Conclusions These findings reveal that people with higher general concern about falling experienced more difficulties during a dual-task condition than people with lower levels of concern. Of further interest, better sensorimotor and cognitive functioning reduced this effect. Graded exposure has potential to reduce concern about falling during fear-evoking activities, especially in conjunction with therapies that improve balance, mood and cognitive function.

BLACK-WHITE DIFFERENCES IN REACTION TIMES AND INTELLIGENCE

1990 ◽  
Vol 18 (2) ◽  
pp. 299-308 ◽  
Author(s):  
Richard Lynn ◽  
Manda Holmshaw
Keyword(s):  
Information Processing ◽  
Standard Deviation ◽  
Reaction Time ◽  
South African ◽  
Reaction Times ◽  
Black Children ◽  
Processing Capacity ◽  
White Children ◽  
Black South African ◽  
Decision Times

350 black South African 9-year-old children were compared with 239 white British children on the Standard Progressive Matrices and 12 reaction time tests giving measures of decision times, movement times and variabilities in tasks of varying complexity. The black children obtained a mean IQ of approximately 65. They also had slower decision times and greater variabilities than the white children, but they had faster movement times. The magnitude of the white advantage on decision times was 0.68 of a standard deviation, about one-third of the white advantage on the Progressive Matrices. The result suggests that around one-third of the white advantage on intelligence tests may lie in faster information processing capacity.

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