Information processing during sleep and stress-related sleep vulnerability.

AIMS: Previous studies showed enhanced attention and decreased inhibitory processes during early non-rapid eye movement sleep in primary insomnia patients, as measured by event-related potentials. The current study aims to examine information processing during sleep in non-insomniac individuals with high vulnerability (HV) to stress-related sleep disturbances. METHODS: Twenty-seven non-insomniac individuals were recruited, 14 with low vulnerability and 13 with HV. After passing a screening interview and polysomnographic recording, subjects came to the sleep laboratory for 2 nights (a baseline night and a stress-inducing night) for event-related potentials recordings. RESULTS: The HV group demonstrated shorter P2 latency during the first 5 min of stage 2 sleep and higher P900 amplitudes under the stress condition during slow-wave sleep, which indicates an increased level of inhibitory processes. In addition, they had shorter N1 latencies during slow-wave sleep that could indicate an elevated level of attention processing during deep sleep. CONCLUSIONS: Unlike patients with chronic insomnia, individuals with high sleep vulnerability to stress show a compensatory process that may prevent external stimulation from interfering with their sleep. This may be one of the factors preventing their acute sleep disturbances from becoming chronic problems.

What is the source of cultural differences? -- Examining the influence of thinking style on the attribution process.

The present research is intended to find out whether individuals with analytic or holistic thought have different attribution processes. Cross-cultural research has suggested that East Asians, who tend to have a holistic thought pattern, differ in cognitive process from Westerners, who tend to engage in analytic thought. However, studies that found cultural difference in attribution process may have non-equivalence problems that make it hard to interpret the causal relationship between thinking style and attribution process. The present research extends this by measuring participants' thinking style within a single culture in order to ensure equivalence on potentially confounding variables such as prior knowledge and cognitive capacity. Two experiments demonstrate that both types of thinkers have identical attribution processes and suggest different thinking styles might relate to different tendencies toward situational information, but not to the attribution process itself.