The allocation of attentional resources to a focal task can influence performance on that task, but within-person changes in allocation policy is typically understudied. This study investigates the off-task pull of emotional experiences and the competing on-task pull of goals. Emotional experience was manipulated using an ostracizing event and goals were experimenter-assigned. The results did not support the off-task pull of emotional experiences or the on-task pull of goals. Implications and directions for future research are discussed.

Executive functions are higher-order cognitive functions underlying self-regulation of behavior. That is, executive functions make it possible to resolve internal conflicts and behave according to future goals rather than acting on sudden impulses or going on automatic. Very similarly, the temperamental construct of effortful control is defined as being able to inhibit a dominant response, instead acting on a subdominant response. In children, poor executive functions and low levels of effortful control have both been associated with several negative outcomes, such as lower academic achievements and externalizing behavior problems. Although these self-regulatory functions seem to play a very important role in child development, little is still known about them during the first years of life. Furthering the knowledge of early executive functions and effortful control would likely increase the chances of early detection of risks of poor development. The present thesis aimed to investigate individual differences in executive functions and effortful control in infancy and toddlerhood, as well as the early development of, and the relation between, these two functions. The thesis further aimed to investigate the relationship between the self-regulatory functions and activity level, and the possibility of predicting toddlerhood self-regulatory functions with sustained attention in infancy. In Study I, individual differences in 10-month-olds’ rudimentary executive functions were found, and these were related to temperamental activity level. In Study II, individual differences in sustained attention in infancy were found to predict toddlerhood executive functions and effortful control. Both these self-regulatory functions improved significantly from infancy to toddlerhood although the individual stability was low. Executive functions and effortful control were related in toddlerhood but not in infancy. In Study III we replicated and extended the finding of a longitudinal relation between infant sustained attention and toddlerhood executive functions. In addition, partial support for the proposition that executive functions develop in a hierarchical fashion was found, with simple inhibition being predictive of more complex forms of working memory two years later. The results from the three studies combined contribute to a better understanding of the early development of the self-regulatory functions executive functions and effortful control.

According to the Multiprocess Theory (Einstein and McDaniel, 1990), prospective memory is supported by two separate cognitive processes: monitoring and spontaneous retrieval. Successful monitoring during prospective memory tasks requires attention to be divided between separate stimuli and the attention needs to be sustained throughout the course of the task. However, this theoretical account also allows for prospective memory in the absence of monitoring, as in cases where memory is retrieved spontaneously in response to some cue. In the course of this study, support for the Multiprocess Theory has been found. Using a dual-task paradigm, prospective memory targets were displayed during a lexical decision task where participants were required to make a word/nonword decision to letter strings. Prospective memory targets were found using both monitoring and spontaneous retrieval, although displaying the target in the focus of attention or not did not differentially induce monitoring. A small increase from 2% target presentation rates (Experiments 1 through 3) to 3% target presentation rates (Experiment 4) did produce evidence of task interference that reflects monitoring; however, increasing target presentation rates to 5% did not increase reaction times above those found with 3% target presentation rates. Focal prospective memory targets (words) had higher accuracy rates than nonfocal prospective memory targets (words starting with letter "g"). Inhibiting responses to the lexical decision task to respond to prospective memory targets encouraged priorities to shift attention to the lexical decision task and increased the speed of lexical decision responding across the extended task. No evidence was found to support the hypothesis that sustained attention is identical to, or even a significant component of, monitoring. Sustained attention was not necessary to accomplish the prospective memory action, as variables affecting vigilance were not found to influence prospective-memory performance in the extended version of the dual-task paradigm used in this experiment. In Experiment 3, draining attention resources did negatively affect lexical decision reaction times and prospective memory performance with focal targets, but not with nonfocal targets. The strength of the lexical decision task routine was manipulated by varying the number of lexical decision practice trials given before the dual-task in Experiment 5. The strength of the routine did not affect task interference for focal or nonfocal targets. Overall, monitoring did not follow the sustained-attention pattern observed in vigilance. Prospective memory can be performed utilizing both cognitive mechanisms of monitoring and spontaneous retrieval.

Search asymmetry was used to test two theories of sustained attention lapses currently debated in the literature: the boredom-mindlessness theory and the resource depletion-mental fatigue theory. Participants performed feature present and a feature absent target detection tasks using either a sustained attention to response task (high Go low No-Go) or a traditionally formatted task (high No-Go low Go) response format. In addition to performance, functional near infrared spectroscopy was employed to measure lateral cerebral oxygenation levels and self-reports of tense arousal, energetic arousal, task related and unrelated thoughts occurring during the tasks were utilised. Detections were lower and reaction times longer in the feature absent search than the feature present search regardless of response format. Detections were lower, but reaction times shorter in the sustained attention to response task than the traditionally formatted task regardless of feature search. Greater right than left frontal hemisphere activation occurred in the sustained attention to response task than the traditionally formatted task. In addition, the sustained attention to response task was more fatiguing based on self-reports than the traditionally formatted task, but there were no differences in Task-Unrelated Thoughts across task conditions. Overall, the results of this study support a resource theory explanation of sustained attention lapses, not a mindlessness-boredom theory explanation. Moreover, the results suggest the sustained attention to response task places high response inhibition, not sustained attention, demands on participants.

The goal habituation model of vigilance proposed by Ariga and Lleras (2011) posits that it is possible to attenuate the vigilance decrement (the decline in performance that occurs with time-on-task) through dis-habituation of a vigilance task’s goal. The goal in a vigilance task is to detect critical signals. Hence, a switch away from this goal should dishabituate the task goal. When a person resumes the vigilance task, the person’s performance should improve. Follow up studies to the Ariga and Lleras study have not found supporting evidence (Helton & Russell, 2011; 2012). The methods in these follow up studies differed from those of Ariga and Lleras in a number of ways. The present study attempts to replicate the original Ariga and Lleras (2011) work using methods that more closely follow the original study. The present research sought to uncover confounds in the original article through replicating the original task and manipulating variables in line with hypotheses made by attentional resource theory. Overall, the results of this research present a challenge to the goal habituation model. Rest breaks, not goal switching; lessened the magnitude of the decline in sensitivity with time on task, while task switching resulted in a temporary re-correction of increasingly conservative responding that occurred with greater time on task. We also found support for the context dependent relationship of task-unrelated thought, (TUT) and task demand. Given that the vigil was determined to impose relatively low workload, pre-task TUT was associated with average performance rather than post-task TUT. Finally, we discuss the dangers of over compliance with signal detection theory (SDT) measures. We explain that SDT sensitivity and bias measures are not independent given responding floor and ceiling effects during low demanding tasks such as the present. It is argued that this may have distorted the original conclusion arrived at by Ariga and Lleras (2011).

Momentary lapses of responsiveness frequently impair vigilance and sustained goal-directed behaviour, sometimes with serious consequences. The literature underpinning research into lapses of responsiveness has generally referred to these lapses as sustained attention lapses. Currently, this literature is divided between two competing theories. On one hand, there is the mindlessness theory and, on the other, the resource depletion theory. Mindlessness theorists propose that sustained attention lapses result from the subject disengaging from sustained tasks due to their monotony and low exogenous support for attention. Conversely, the resource depletion theorists propose that sustained attention lapses arise because demands for endogenus attentional resources outstrip supply, which leads to substantially delayed response and/or errors. In the present study, the predictions from the mindlessness and resource depletion theories were investigated by contrasting performance on attention tasks that differed in cognitive workloads. In the lesser demanding task, participants performed a simple psychomotor vigilance test (PVT). In the more demanding task, the PVT was undertaken concurrently with a continuous tracking task. The higher workload imposed by the dual task should reduce task monotony and the higher attentional requirement should increase the demand for attentional resources. If the mindlessness theory is correct the dual task should result in improved vigilance and reduce sustained attention lapses. If the resource theory is correct, the added attentional demand in the dual task should decrease vigilance and increase sustained attention lapses. However, there are other types of lapses that the literature has not always clearly separated from lapses of sustained attention. One such lapse is the microsleep. Microsleeps are brief periods of non-responsiveness (0.5–15 s) associated with overt signs of drowsiness. The two theories of vigilance impairment provide contrasting explanations in the traditional vigilance literature, but neither theory addresses lapses due to microsleep events, which remains largely ignored. Microsleeps are thought to emanate from a homeostatic drive for sleep/rest and a complex interaction between the brain’s arousal and attention systems and, therefore, depend on the type of task being undertaken to modulate propensity for microsleeps. For example, a more demanding and engaging task should counteract the homeostatic drive for sleep and rest by increasing arousal. If true, tasks that increase cognitive workloads may lead to a reduction in microsleeping propensity. We aimed to test the proposal that microsleep propensity is mediated by task by including in our study a continuous tracking task, which has previously been shown to elicit microsleeps. This task may, because of its consistency and repetitiveness, be considered a boring task. Moreover, it lacks any sudden stimulus onsets and, therefore, can be considered a less engaging task than the dual-task, which features sudden onsets. If more microsleeps were found in the tracking task compared to the dual task this would provide support for the proposition that a task-generated increase in mindlessness would increase microsleep rates. Conversely, if more microsleeps occur during the dual-task, then this suggests that factors other than mindlessness influence microsleeping. Twenty-three non-sleep deprived participants – 12 females and 11 males – with an average age of 26.3 years (range 21–40 years) and an average Epworth Sleepiness Score of 5.1 (range 0–10), completed the tasks during the early afternoon. They completed the two different tasks separately and concurrently (as a dual task), with the three conditions presented in a counterbalanced order. The PVT task was an extended 30-min version of the standard 10-min PVT used in many vigilance studies to match the duration of the continuous tracking task. In this task, the participant had to respond to a discrete randomly-presented visual stimulus. As per convention, failure to respond within 500 ms constituted an attention lapse. The 30-min continuous tracking task required the participant to use a floor-mounted joystick, to monitor and track a target randomly-moving on a computer screen. In this second task, lapses show as periods of flat tracking that, when associated with overt signs of sleepiness and at least 80 % partial eye-closure, are classified as microsleeps. The dual task was the PVT and tracking tasks being undertaken concurrently. Both sustained attention lapses and microsleep rates were affected by task differences. Using only the results from participants who had at least one sustained attention lapse in either the PVT or dual task (N = 23), it was found that a participant was more likely to experience a sustained attention lapse during the more demanding dual task then the PVT task (median 15 vs. 3; range 1–74 vs. 0–76, Wilcoxon z = 3.7, p = .001). Conversely, of those participants who had at least one microsleep in either the tracking or dual task (N = 12), they were more likely to experience a microsleep during the more monotonous tracking task than the dual task (median 0 vs. 0; range 0–18 vs. 0–1, Wilcoxon z = 2.3, p = .022). Time-on-task also had an effect. Sustained attention lapses increased with time-on-task during the PVT task and dual task (χ2 5, N 23 = 48.69, p = .001; and χ2 5, N 23 = 16.33, p = .006 respectively). Moreover, sustained attention lapses increased at a greater rate during the more cognitively demanding dual task (F5, 264 = 4.02, p = .002). Microsleeps also increased with time-on-task, but only during the tracking task and not during the dual task χ2 2, N 23 = 6.72, p = .035). The pattern of results supports the resource depletion theory over the mindlessness theory. When the cognitive workload increased, sustained attention lapses were more frequent. Conversely, the results also demonstrated that when the cognitive workload was decreased, the risk of lapsing due to microsleeps increased. Clarifying this relationship between cognitive workload and two types of lapses of responsiveness, sustained attention lapses and microsleeps, is important if we are to avoid inadvertently increasing lapses of responsiveness. Both sustained attention lapses and microsleeps can have serious real-life consequences and, therefore, any contribution towards a potent, preventative strategy is important.

The present set of experiments investigated three potential means of regulating mind-wandering and sustained attention: goals, feedback, and incentives. The experiments drew up goal-setting theory from industrial/organizational psychology, theories of vigilance and sustained attention, and recent experimental work examining mind-wandering and sustained attention. Experiment 1 investigated the role of goal-difficulty and goal-specificity. Providing a difficult goal for participants only improved sustained attention compared to a condition with no specific goal. Experiment 2 investigated the role of feedback in isolation and in combination with goals. Feedback improved sustained attention and reduced mind-wandering, but it did so regardless of whether or not the feedback was tied to a specific goal. Experiment 3 investigated how two different incentives – money and early release from the experiment – affected sustained attention and mind-wandering. The incentives had no effect on task performance, but participants in the early release condition reported being more motivated, more alert, and mind-wandered less throughout the task. I discuss the results of the experiments in light of predictions made by goal-setting theory as well as theories of vigilance and sustained attention.

Made available in DSpace on 2015-07-22T20:49:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-09-29. Added 1 bitstream(s) on 2015-08-11T03:26:29Z : No. of bitstreams: 1 Publico-370.pdf: 460541 bytes, checksum: 0bd09fcbf1ed06758089d085f2c56d6e (MD5) / Introdução: O Transtorno de déficit de atenção e hiperatividade (TDAH) é o transtorno infantil mais prevalente do mundo e se relaciona com deficiências de catecolaminas em testes físicos, bioquímicos e cognitivos; por outro lado alguns exercícios são conhecidos como potentes estimuladores de catecolaminas, tanto central quanto e perifericamente. Objetivo: Testar a hipótese das catecolaminas (CA) centrais como as responsáveis pelo aumento na velocidade de reação vistas após atividades físicas e medir o impacto que esforços físicos agudos supra limiares apresentam na atenção sustentada de 25 crianças diagnosticadas com TDAH, conforme os critérios do DSM-IV. É possível que a prática desportiva possa ser positiva no manejo dos sintomas de TDAH. Método: As crianças foram divididas entre usuárias (US) e não usuárias (NUS) de Metilfenidato (MTP), os grupos foram comparados quanto a aspectos antropométricos, cognitivos e fisiológicos assim como os efeitos crônicos da droga, sobre a cognição, imediatamente após atividades físicas intensas. Resultado: A performance cognitiva após esforços físicos não foi, de maneira relevante, modificada pelo MTP. Observamos melhoras significativas no tempo de resposta, assim como normalização da impulsividade e das medidas de vigilância por meio do CPT teste. Conclusão: Estes resultados sugerem que a melhora cognitiva usualmente vista após a prática desportiva não são CA dependentes; adicionalmente exercícios físicos podem ser de auxílio no alívio dos sintomas de TDAH. / Attention deficit hyperactivity disorder (ADHD) is related to a deficiency of central catecholamines (CA) in cognitive, biochemical, and physical tests, and pharmaceutical intervention may have no effect if it is not accompanied by changes in the environment. The objective of our study was to test the hypothesis that central CA are responsible for the increase in speed reaction seen after physical activity (PA) and to measure the impact of high intensity PA on the sustained attention of 25 children diagnosed with ADHD consistent with the Disease Statistical Mental-IV (DSM-IV) criteria. It is possible that practicing sports assists in the management of the disorder. The children were divided between users (US) and non-users (NUS) of methylphenidate (MTP), and the groups were compared to evaluate the effect of the drug on cognition after PA. Post-exercise performance on Conner’s Continuous Performance Test-II (CPT) was not affected by MTP, we observed significant improvements in response time, and we saw normalization in the impulsivity and vigilance measures. These results suggest that the improvements in cognition after physical effort are not CA dependent. Additionally, our results suggest that children’s attention deficits can be minimized through PA irrespective of treatment with MTP. Additional studies are necessary to confirm that exercise mitigates the harmful symptoms of ADHD. / TEDE

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