To investigate the effect of acute hyperglycemia on brain function in adolescents with type 1 diabetes (T1D). RESEARCH DESIGN AND METHODS Twenty participants with T1D (aged 14.64 6 1.78 years) and 20 age-matched healthy control subjects (aged 14.40 6 2.82 years) performed two functional MRI sessions. Participants with T1D performed the first scanning session under euglycemic and the second under hyperglycemic clamp (20 mmol/L [360 mg/dL]). RESULTS Lower spatial working memory (sWM) capacity during acute hyperglycemia and significant differences in activation of regions of interest during different stages of the sWM task (P 5 0.014) were observed. CONCLUSIONS Acute hyperglycemia negatively affected sWM capacity in adolescents with T1D, which is relevant for daily functioning and academic performance.

In experimental cognitive psychology, objects of inquiry are typically operationalized with psychological tasks. When interpreting results from such tasks, we focus primarily on behavioral measures such as reaction times and accuracy rather than experiences – i.e., phenomenology – associated with the task, and posit that the tasks elicit the desired cognitive phenomenon. Evaluating whether the tasks indeed elicit the desired phenomenon can be facilitated by understanding the experience during task performance. In this paper we explore the breadth of experiences that are elicited by and accompany task performance using in-depth phenomenological and qualitative methodology to gather subjective reports during the performance of a visuo-spatial change detection task. Thirty-one participants (18 females) were asked to remember either colors, orientations or positions of the presented stimuli and recall them after a short delay. Qualitative reports revealed rich experiential landscapes associated with the task-performance, suggesting a distinction between two broad classes of experience: phenomena at the front of consciousness and background feelings. The former includes cognitive strategies and aspects of metacognition, whereas the latter include more difficult-to-detect aspects of experience that comprise the overall sense of experience (e.g., bodily feelings, emotional atmosphere, mood). We focus primarily on the background feelings, since strategies of task-performance to a large extent map onto previously identified cognitive processes and discuss the methodological implications of our findings.

Sustained neural activity during the delay phase of spatial working memory tasks is compelling evidence for the neural correlate of active storage and maintenance of spatial information, however, it does not provide insight into specific mechanisms of spatial coding. This activity may reflect a range of processes, such as maintenance of a stimulus position or a prepared motor response plan. The aim of our study was to examine neural evidence for the use of different coding strategies, depending on the characteristics and demands of a spatial working memory task. Thirty-one (20 women, 23 ± 5 years) and 44 (23 women, 21 ± 2 years) participants performed a spatial working memory task while we measured their brain activity using fMRI in two separate experiments. Participants were asked to remember the position of a briefly presented target stimulus and, after a delay period, to use a joystick to indicate either the position of the remembered target or an indicated non-matching location. The task was designed so that the predictability of the response could be manipulated independently of task difficulty and memory retrieval process. We were particularly interested in contrasting conditions in which participants (i) could use prospective coding of the motor response or (ii) had to rely on retrospective sensory information. Prospective motor coding was associated with activity in somatomotor, premotor, and motor cortices and increased integration of brain activity with and within the somatomotor network. In contrast, retrospective sensory coding was associated with increased activity in parietal regions and increased functional connectivity with and within secondary visual and dorsal attentional networks. The observed differences in activation levels, dynamics of differences over trial duration, and integration of information within and between brain networks provide compelling evidence for the use of complementary spatial working memory strategies optimized to meet task demands.

<i>Objective:</i> <a>To investigate the effect of acute hyperglycemia on brain function in adolescents with type 1 diabetes.</a> <p><i><br></i></p><p><i>Research Design and Methods:</i><b> </b>Twenty participants with type 1 diabetes (T1D) (age 14.64 ±1.78 years) and 20 age-matched healthy controls (age 14.40± 2.82 years) performed two functional magnetic resonance imaging sessions. Participants with T1D performed the first scanning session under euglycemic and the second under hyperglycemic clamp (20 mmol/L (360 mg/dL)).<b> </b></p> <p><i><br></i></p><p><i>Results:</i> Lower spatial working memory (sWM) capacity during acute hyperglycemia and significant differences in activation of regions of interest during different stages of the spatial working memory task (p=0.014) were observed.<b> </b><b></b></p> <p><i><br></i></p><p><i>Conclusions</i>: Acute hyperglycemia negatively affected sWM capacity in adolescents with T1D, which is relevant for daily functioning and academic performance.</p>

Meeting everyday challenges and responding in a goal-directed manner requires both the ability to maintain the current task set in face of distractors—stable cognitive control, and the ability to flexibly generate or switch to a new task set when environmental requirements change—flexible cognitive control. While studies show that the development varies across individual component processes supporting cognitive control, little is known about changes in complex stable and flexible cognitive control across the lifespan. In the present study, we used the newly developed Cognitive Control Challenge Task (C3T) to examine the development of complex stable and flexible cognitive control across the lifespan and to gain insight into their interdependence. A total of 340 participants (229 women, age range 8–84 years) from two samples participated in the study, in which they were asked to complete the C3T along with a series of standard tests of individual components of cognitive control. The results showed that the development of both stable and flexible complex cognitive control follows the expected inverted U-curve. In contrast, the indeces of task set formation and task set switching cost increase linearly across the lifespan, suggesting that stable and flexible complex cognitive control are subserved by separable cognitive systems with different developmental trajectories. Correlations with standard cognitive tests indicate that complex cognitive control captured by the C3T engages a broad range of cognitive abilities, such as working memory and planning, and reflects global processing speed, jointly suggesting that the C3T is an effective test of complex cognitive control that has both research and diagnostic potential.