The present study examined individual differences in the development of sustained attention across toddlerhood, as well as how these individual differences related to the development of language and sleep. Toddlers (N = 314; 54% male) were assessed at 30, 36, and 42 months using multiple measures of attention, a standardized language assessment,…

Decades of research have established that "online" cognitive processes, which operate during conscious encoding and retrieval of information, contribute substantially to individual differences in memory. Furthermore, it is widely accepted that "offline" processes during sleep also contribute to memory performance. However, the question of whether…

Based on data from a 17-year longitudinal study of 1083 adolescents, from the ages of 13 to 30 years, the average development of self-reported global self-esteem was found to be high and stable during adolescence. However, there is considerable inter-individual variance in baseline and development of global self-esteem. This study used latent…

Nighttime sleep awakenings and infant and family characteristics were measured longitudinally in more than 1,200 infants when the infants were 6, 15, 24, and 36 months old. By 6 months of age, the majority of children slept through the night, awakening their mothers only about once or twice per week. However, not all children followed this…

Epileptic encephalopathy with continuous spikes and waves during slow sleep is an age-related disorder characterized by the presence of interictal epileptiform discharges during at least greater than 85% of sleep and cognitive deficits associated with this electroencephalography pattern. The pathophysiological mechanisms of continuous spikes and…

There is accumulating evidence that individual differences in stress reactivity contribute to the risk for stress-related disease. However, the assessment of stress reactivity remains challenging, and there is a relative lack of questionnaires reliably assessing this construct. We here present the Perceived Stress Reactivity Scale (PSRS), a…

The course of study of time-of-day effects on human performance has not been an easy one to chart, with many findings that seem to be in opposition. This review examines the difference between group and individual differences with regard to time-of-day effects; time-of-day effects in individuals; morningness-eveningness as an individual…