This weeks readings mark a notable shift from a discussion on sustained attention and begin to delve more into the subject of mind wantering. This phenomenon is sometimes referred to as Task-unrelated images or thoughts (TUITs) or Stimulus Independent Thoughts (SITs). The take away of from this set of reading is that creating the tools and methodology to study the wandering mind is incredibly difficult. While each study poses insightful questions on the subject, the majority come across as overly ambitious. They leave the reader questioning design choices, validity of conclusions and how much progress has actually been made in this domain.
Leonard M. Giambra's study, "A Laboratory Method for Investigating Influences on Switching Attention to Task-Unrelated Imagery and Thought," published in 1995 attempts to make a very complete examination of TUITs. However, the more closely the experiments are studied the more it seems that the research is overly ambitious and somewhat removed from the conclusions of previous research. The main theory of the study iss that "when information from the external world does not demand processing or does not use all available cognitive capacity, then excess capacity can be devoted to processing information of an internal origin" (Giambra, 1). This is to say that attention and focus make certain demands on human processing. When this demand is weak and processing systems are not being fully used, the mind will attend to thoughts unrelated to the current task. Giambra further suggests that TUITs belong to two discrete categories. Uncontrolled shifts occur when a TUIT simply grabs our attention. Controlled shifts occur when we deliberately shift our attention to the TUIT.
In this article Giambra is primarily concerned with fining the best possible method of having participants report TUITs in experimental conditions. He proposes his probe-TUIT measurement method which prompts the participant at periods ranging between 15- 30 seconds about whether or not they are experiencing TUITs. This method is believed and "proved" to be ideal over the course of his experiments because it maintains consistent individual differences over different taks conditions and is very sensitive to the conditions of a concurrent task (Giambra, 4). While this may all be true, the consequences of having a participant self-report their mind wandering left me with some doubts. Thought he states that subjects didn't report more TUITs because they were being asked to be attnetiove to them, the consequences and interference involved in self reporting seems inevitable. He states that there was one occasion in which a participant explicitly stated that they had trouble actually responding to task stimuli, because they were distracted by self reporting TUITs. If this is the case for one individual it is highly likely that others have experienced this difficulty. Aside from messing with the validity of the results this possible confound has other consequences. The act of self reflection on TUIT instances while participating in a vigilance task is cognitively demanding. It is possible that the addition to the demand on the individuals central executive system. This system is extensively discussed in an article written by Teasdale et. al.
A series of experiments conducted by John Teasdale et. al. proposed an interesting perspective on SITs. In "Stimulus-independent thought depends on central executive resources,"the experimenters discuss stimulus-independent thoughts as a very natural phenomenon. Rather than viewing it as something that must be stopped they see the task that a participant is being asked to compete must prove itself more interesting and engaging than the default SIT alternative. Teasdale focuses on the Braddeley-Hitch approach to SITs by using resource interference methodology. Specifically, the experimenters believe that "the extent to which tasks [are] related to specific resources of working memory interfer[s] with spontaneous STI production reflect[s] the involvement of those resources in thought production" (Teasdale et. al., 552). Teasdale uses Braddeley and Hitch's list of three main working memory components to construct the experiments in this paper.
The first few experiments conducted attempt to evaluate the influence that the visiospatial and the phonological systems have on STI's. However this was difficult to demonstrate because the extent to which those systems could be isolated from the Central Executive was not clear. Even so, when testing the Central Executive specifically Teasdale found that "production of STI's depends on central executive resources" (Teasdale 558). One of the main questions that this work raises for me involves last weeks discussion of bidirectionality. This theory states that it is possible for an individual to lessen their attention to a stimulus in order to actively try and problem solve their work with that given stimulus in a task. Such a choice seems as thought it would involve a lot of use of the central executive system. In these instances the issues doesn't seem to be that the participant's central executive system is being arbitrarily being overwhelmed by something else, but rather that it is a conscious choice to divert attention elsewhere.
Teasdale was not the first to propose that there is a certain demand which will dreaile and individual from the task at hand. In "Study in the Stream of Consciousness: experimental Enhancement and Suppression of Spontaneous Cognitive Processes," Antrobus et. al. propose that the human cognitive system has a an "upper limit" for it's operation which is the sum of all the information it is perceiving from internal sources as well as external sources (Antrobus, 400). Specifically these two channels are:
1) External Enviornment 2) Inner Dimension
- short term memory
- elaborations of recently perceived events
- events in long term memory storage.
Unlike the vagueness of the previous study, Antrobus' paper proposes that the individual has some say, though usually subconsciously, about what information it processes more of. When the payoff for an internal source outweighs an external or vice versa, it is that channel which the cognitive system will favor. While this study had some potential issues involving unintentionally priming participants it provokes some interesting theories on the way mind wandering functions and how, if at all, individuals are aware of it.
The final article of the week makes some exciting attempts to trace participant mind wandering in a way that may lead to little self evaluation in the future. "Eye Movements During Mindless Reading", published by Reichle et. al. uses eye movements as a way to measure mindless reading in seven participants. The experimenters successfully proved that "fixations during mindless reading should be qualitatively different than fixations associated with normal reading" (Reichle, 1301).
Resources:
Antrobus, John., Singer, Jerome., Greenberg, Stanley. (1966). "Study in the Stream of Consciousness: experimental Enhancement and Suppression of Spontaneous Cognitive Processes." Perceptual and Motor Skills, 23, 399-417.
Giambra, L. (1995). "A Laboratory Method for Investigating Influences on Switching Attention to Task-Unrelated Imagery and Thought." Consciousness and Cognition 4, 1-21.
Teasdale, John D., Dritschel, Barbara H., Taylor, Melanie J. (1995). "Stimulus-independent thought depends on central executive resources." Memory and Cognition 23(5) 551-559.
Reichle, Erik D., Reinberg, Andrew E., Schooler, Jonathan W. (2010). "Eye Movements During Mindless Reading." Psychological Science, 21, 1300-1310.
