The ‘attentional spotlight’ can be adjusted depending on the task requirements, resulting in processing information at either the local or global level. Stroke can lead to local or global processing biases, or the inability to simultaneously attend both levels. In this study, we assessed the (1) prevalence of abnormal local and global biases following stroke, (2) differences between left- and right-sided brain damaged patients, and (3) relations between local and global interference, the ability to attend local and global levels simultaneously, and lateralized attention, search organization, search speed, visuo-construction, executive functioning, and verbal (working) memory.

Stroke patients admitted for inpatient rehabilitation completed directed (N = 192 total; N = 46 left-sided/N = 48 right-sided lesion) and divided (N = 258 total; N = 67 left-sided/N = 66 right-sided lesion) local–global processing tasks, as well as a conventional neuropsychological assessment. Processing biases and interference effects were separately computed for directed and divided tasks.

On the local–global tasks, 7.8–10.9% of patients showed an abnormal local bias and 6.3–8.3% an abnormal global bias for directed attention, and 5.4–10.1% an abnormal local bias and 6.6–15.9% an abnormal global bias for divided attention. There was no significant difference between patients with left- and right-sided brain damage. There was a moderate positive relation between local interference and search speed, and a small positive relation between global interference and neglect.

Abnormal local and global biases can occur after stroke and might relate to a range of cognitive functions. A specific bias might require a different approach in assessment, psycho-education, and treatment.

This review systematically appraised the research evidence for local versus global information processing to test the hypothesis that people with eating disorders (ED) had weak central coherence.

Searches on Medline, EMBASE, PsycINFO and ISI Web of Science databases were conducted in November 2006 and subsequently updated in September 2007. Each search was conducted in two steps: (1) neuropsychological tasks measuring central coherence and (2) words related to cognitive functioning in eating disorders. Data were summarized in a meta-analysis if the number of studies for a given test was >5.

Data were extracted from 16 studies. Meta-analyses were conducted for four tasks obtaining moderate effect sizes. The majority of studies found global processing difficulties across the ED spectrum. The results are less clear regarding local processing.

People with ED have difficulties in global processing. It is less certain as to whether they have superior local processing. Currently, there is insufficient evidence to refute the weak central coherence hypothesis.