Three experiments investigated the relationship between subjective experience and attentional lapses during sustained attention. These experiments employed two measures of subjective experience to examine how differences in awareness correspond to variations in both task performance and psycho-physiological measures . This series of experiments examine these phenomena during the Sustained Attention to Response Task . The results suggest we can dissociate between two components of subjective experience during sustained attention: task unrelated thought which corresponds to an absent minded disengagement from the (...) task and a pre-occupation with one's task performance that seems to be best conceptualised as a strategic attempt to deploy attentional resources in response to a perception of environmental demands which exceed ones ability to perform the task. The implications of these findings for our understanding of how awareness is maintained on task relevant material during periods of sustained attention are discussed. (shrink)

Thought-intrusions, automatic inferences, and other unintended thought are beginning to play an important role in the study of psychiatric disease as well as normal thought processes. We examine one method for study of task-unrelated imagery and thought . TUIT likelihood was shown to be reliably measured over a wide range of vigilance tasks, to have high short-term and long-term test-retest reliability, and to be sensitive to information processing demands. Likelihood of TUITs was shown to be different as a function of (...) aging, hyperactivity, time of day, and level of depression. Thus, we now can reliably measure the influence of endogenous and exogenous influences on TUITs. In addition, TUIT measurement was proposed as a minimally interfering and natural second task for determining resource utilization in a primary task. Finally, this method was offered as a reliable approach to quantification of such mental states as obsessions and drug craving and addiction. (shrink)

Task unrelated thought (TUT) refers to thought directed away from the current situation, for example a daydream. Three experiments were conducted on healthy participants, with two broad aims. First, to contrast distributed and encapsulated views of cognition by comparing the encoding of categorical and random lists of words (Experiments One and Two). Second, to examine the consequences of experiencing TUT during study on the subsequent retrieval of information (Experiments One, Two, and Three). Experiments One and Two demonstrated lower levels of (...) TUT and higher levels of word-fragment completion whilst encoding categorical relative to random stimuli, supporting the role of a distributed resource in the maintenance of TUT. In addition the results of all three experiments suggested that experiencing TUT during study had a measurable effect on subsequent retrieval. TUT was associated with increased frequency of false alarms at retrieval (Experiment One). In the subsequent experiments TUT was associated with no advantage to retrieval based on recollection, by manipulating instructions at encoding (Experiment Two), and/or at retrieval (Experiment Three). The implications of the results of all three experiments are discussed in terms of recent accounts of memory retrieval and conscious awareness. (shrink)