Although a large body of research shows that general cognitive ability is heritable and stable in young adults, there is recent evidence that fluid intelligence can be heightened with cognitive training. Many researchers, however, have questioned the methodology of the cognitive-training studies reporting improvements in fluid intelligence: specifically, the role of placebo effects. We designed a procedure to intentionally induce a placebo effect via overt recruitment in an effort to evaluate the role of placebo effects in fluid intelligence gains from cognitive training. Individuals who self-selected into the placebo group by responding to a suggestive flyer showed improvements after a single, 1-h session of cognitive training that equates to a 5-to 10-point increase on a standard IQ test. Controls responding to a nonsuggestive flyer showed no improvement. These findings provide an alternative explanation for effects observed in the cognitive-training literature and the brain-training industry, revealing the need to account for confounds in future research.placebo effects | cognitive training | brain training | fluid intelligence

Previous research suggests that being interrupted while reading a text does not disrupt the later recognition or recall of information from that text. This research is used as support for Ericsson and Kintsch's (1995) long-term working memory (LT-WM) theory, which posits that disruptions while reading (e.g., interruptions) do not impair subsequent text comprehension. However, to fully comprehend a text, individuals may need to do more than recognize or recall information that has been presented in the text at a later time. Reading comprehension often requires individuals to connect and synthesize information across a text (e.g., successfully identifying complex topics such as themes and tones) and not just make a familiarity-based decision (i.e., recognition). The goal for this study was to determine whether interruptions while reading disrupt reading comprehension when the questions assessing comprehension require participants to connect and synthesize information across the passage. In Experiment 1, interruptions disrupted reading comprehension. In Experiment 2, interruptions disrupted reading comprehension but not recognition of information from the text. In Experiment 3, the addition of a 15-s time-out prior to the interruption successfully removed these negative effects. These data suggest that the time it takes to process the information needed to successfully comprehend text when reading is greater than that required for recognition. Any interference (e.g., an interruption) that occurs during the comprehension process may disrupt reading comprehension. This evidence supports the need for transient activation of information in working memory for successful text comprehension and does not support LT-WM theory.

Previous research has shown that there is a time cost (i.e., a resumption lag) associated with resuming a task following an interruption and that the longer the duration of the interruption, the greater the time cost (i.e., resumption lag increases as interruption duration increases). The memory-for-goals model (Altmann & Trafton, 2002) suggests that this greater time cost is a result of increased interference caused by longer duration interruptions. Therefore, the goal for this research was to determine whether individuals who can better manage interference, i.e., individuals with higher working-memory capacity (WMC), can resume tasks more quickly following interruptions than those who cannot manage interference as well (i.e., individuals with lower WMC). A procedural interruption task with 3 different interruption durations and a measure of WMC were completed by 229 students. In line with previous research, we found a strong positive relationship between interruption duration and resumption lag. We found a strong negative effect of WMC on resumption lag (i.e., increases in WMC reduced resumption lags). Notably, WMC moderated the effect of interruption duration on resumption lag (i.e., increases in WMC attenuated the positive relationship between interruption duration and resumption lag). Specifically, individuals with high WMC experienced small increases in resumption lag as interruption duration increased, whereas individuals with low WMC experienced substantial increases in resumption lag as interruption duration increased. Our data suggest that individuals with higher WMC are less susceptible to interference caused by interruptions. (PsycINFO Database Record

Pupillometry is commonly used in research to determine how much mental effort an individual is exerting while completing tasks. Traditionally, larger pupils are associated with increased mental effort when completing more difficult tasks. However, little research has investigated how pupils change as individuals learn a new task. In theory, as one repeatedly completes a task, the task demands should reduce, reliance on working memory should decrease, and the task should become more automatic. This should translate to faster completion times and smaller peak pupil dilations. We tested this hypothesis by having participants complete multiple trials of a cognitive task that requires individuals to orient themselves in space relative to a target. We found that trial completion times and maximum pupil size significantly reduced across trials. These data suggest that measuring changes in pupil dilation may help researchers determine whether individuals have shifted from a learned procedure to an automatic processing of information when learning a new task.

This research represents a crucial first step in understanding the effect interruptions have on quality of work. Our research suggests that interruptions negatively impact quality of work during a complex, creative writing task. Since interruptions are such a prevalent part of daily life, more research needs to be conducted to determine what other tasks are negatively impacted. Moreover, the underlying mechanism(s) causing these decrements needs to be identified. Finally, strategies and systems need to be designed and put in place to help counteract the decline in quality of work caused by interruptions.