The impact of verbal instructions on goal-directed behaviour

It is common to use verbal instructions when performing complex tasks. To evaluate how such instructions contribute to cognitive control, mixing costs (as a measure of sustained concentration on task) were evaluated in two task-switching experiments combining the list and alternating runs paradigms. Participants responded to bivalent stimuli according to a characteristic explicitly defined by a visually presented instructional cue. The processing of the cue was conducted under four conditions across the two experiments: Silent Reading, Reading Aloud, Articulatory Suppression, and dual mode (visual and audio) presentation. The type of cue processing produced a substantial impact on the mixing costs, where its magnitude was greatest with articulatory suppression and minimal with reading aloud and dual mode presentations. Interestingly, silently reading the cue only provided medium levels of mixing cost. The experiments demonstrate that relevant verbal instructions boost sustained concentration on task goals when maintaining multiple tasks.     

Effects of incidental pictorial and verbal adjuncts on text learning

In this study, college students read and studied texts on historical figures in psychology, which were supplemented by drawings and/or brief biographies of these persons. In Experiment 1, a 2 x 2 between-groups design was conducted in which students received one adjunct with each text, both adjuncts, or neither. In Experiment 2, a single group of students received a within-subjects manipulation of the same adjunct conditions. In the between-groups comparison, students receiving biographies learned less of the target text passages, with the group receiving illustrations and biographies performing least accurately. In the within-subject conditions, texts accompanied by an illustration were better learned, with these students doing best on the text with both picture and biography. The results suggest that adjuncts may emphasize some texts, at the expense of learning from the other texts, but that too much adjunct material interferes with the learning of the target passages.     

Effects of cigarette smoking on verbal rote learning and physiological arousal

Abstract.— Verbal rote learning was studied on 12 moderate smokers. In one condition learning was interrupted twice by smoking a nicotine-containing cigarette (Virginia King, 2.1 mg nicotine) and in another condition by smoking a nicotine-free cigarette. Immediately after the first nicotine-containing cigarette there was a drop in the number of correct responses and learning was significantly less rapid under subsequent trials as compared with learning after the first nicotine-free cigarette. After the second cigarette the picture was reversed. Learning was significantly more improved in the nicotine condition than in the nicotine-free condition. Adrenalin excretion increased significantly during learning in both conditions, and heart rate increased significantly after the first nicotine-containing cigarette.