ABSTRACT
The present study investigated the effect of language dominance on 40 subjects' performance on a Stroop task. In the first group were 20 Education majors using mainly the Arabic language, while in the second group of 20 students were majors in English. Each group performed two different Stroop tasks. Analysis showed that language comprehension affected the way subjects processed the information. This difference was explained in terms of cognitive processes involved and by a late selective attention process.
Subject(s)
Attention , Color Perception , Discrimination Learning , Multilingualism , Semantics , Adult , Female , Humans , Psychological Tests , Reaction Time , United Arab EmiratesABSTRACT
45 subjects performed a cued vigilance task in which location cues were presented at intervals of 150, 350, or 550 msec. before the display of the stimulus, that is, three cue-stimulus intervals. Targets preceded by valid location cues led to a normal decrement in vigilance over time, whereas targets preceded by invalid location cues produced an increment in sensitivity (d'). The results suggested that under certain conditions shifts of attention may enhance vigilance.
Subject(s)
Attention , Discrimination Learning , Inhibition, Psychological , Orientation , Pattern Recognition, Visual , Adolescent , Adult , Arousal , Cues , Female , Humans , Male , Reaction TimeABSTRACT
Factors controlling sustained visual orienting were investigated by combining the paradigms of covert orienting and vigilance. Analysis suggests a close relationship between orienting of attention and vigilance which is dependent on the event rate during the vigilance task. At a low event rate both facilitatory and inhibitory effects of orienting are found. Vigilance decrement is related to the accumulation of inhibition over time, supporting Posner, et als 1984 theory. Invalid cues reduce the decrement. At a high event rate, however, neither facilitation nor inhibition effects are reliable, and vigilance decrement is related to limitations of the allocation of attentional capacity, supporting Parasuraman's multifactorial theory. The results suggest that facilitation and inhibition caused by orienting are important opposing mechanisms in visual attention, allowing the nervous system to control the distribution of attention both over visual space and over time.
Subject(s)
Arousal , Attention , Adolescent , Adult , Eye Movements , Female , Humans , Male , Photic Stimulation , Time FactorsABSTRACT
A group of 11 hashish users were compared with 11 controls on a visual sustained attention (vigilance) task. Analysis indicated that hashish use affected subjects' sensitivity. Subjects who used hashish responded in an indiscriminate manner, making more false alarms (8.7) than controls (2.6). The importance of vigilance in the assessment of adverse effects of hashish is discussed.
Subject(s)
Attention/drug effects , Discrimination Learning/drug effects , Marijuana Smoking/psychology , Pattern Recognition, Visual/drug effects , Psychomotor Performance/drug effects , Adult , Humans , Male , Reaction Time/drug effects , Size Perception/drug effectsABSTRACT
The effect of substance abuse on visuographic functions was investigated by comparing 4 groups from an Arabian Gulf population: 63 heroin abusers, 14 alcohol abusers, 43 polydrug abusers, and 48 control subjects. The visuographic function was evaluated using Benton's Revised Visual Retention Test. Analysis of covariance yielded an over-all group effect on both number correct and errors. Assessment of significance of differences between groups showed that the polydrug-abusing group and the heroin-abusing group scored significantly lower than the nonabusing group on number correct. All 3 substance-abusing groups scored significantly higher than the non-abusing group on errors, which seems a better predictor of cognitive impairment. Classification of subjects on the basis of their scores on the Benton test showed that a significant proportion of subjects in each substance-abusing group were classified as impaired. It is concluded that the present findings were consistent with prior reports for European and American subjects.
