Precise timing of sensory information from multiple sensory streams is essential for many aspects of human perception and action. Animal and human research implicates the basal ganglia and cerebellar systems in timekeeping operations, but investigations into the role of the cerebral cortex have been limited. Individuals with focal left (LHD) or right hemisphere (RHD) lesions and control subjects performed two time perception tasks (duration perception, wherein the standard tone pair interval was 300 or 600 msec) and a frequency perception task, which controlled for deficits in time-independent processes shared by both tasks. When frequency perception deficits were controlled, only patients with RHD showed time perception deficits. Time perception competency was correlated with an independent test of switching nonspatial attention in the RHD but not the LHD patients, despite attention deficits in both groups. Lesion overlays of patients with RHD and impaired timing showed that 100% of the patients with anterior damage had lesions in premotor and prefrontal cortex (Brodmann areas 6, 8, 9, and 46), and 100% with posterior damage had lesions in the inferior parietal cortex. All LHD patients with normal timing had damage in these same regions, whereas few, if any, RHD patients with normal timing had similar lesion distributions. These results implicate a right hemisphere prefrontal-inferior parietal network in timing. Time-dependent attention and working memory functions may contribute to temporal perception deficits observed after damage to this network.

The aim of this study was to examine possible neuropsychological changes in patients with advanced idiopathic Parkinson's disease treated with bilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN). Eleven patients (age = 67 +/- 8 years, years with Parkinson's disease = 15 +/- 3, verbal IQ = 114 +/- 12) were evaluated (in their best 'on state') with tests assessing processes reliant on the functional integrity of frontal striatal circuitry, prior to the procedure (n = 11), at 3-6 months (n = 11) and at 9-12 months (n =10) post-operatively. Six of these patients were older than 69 years. Despite clinical motor benefits at 3-6 months post-operative, significant declines were noted in working memory, speed of mental processing, bimanual motor speed and co-ordination, set switching, phonemic fluency, long-term consolidation of verbal material and the encoding of visuospatial material. Declines were more consistently observed in patients who were older than 69 years, leading to a mental state comparable with progressive supranuclear palsy. 'Frontal' behavioural dyscontrol without the benefit of insight was also reported by half (three of six) of the caregivers of the elderly subgroup. At 9-12 months postoperative, only learning based on multiple trials had recovered. Tasks reliant on the integrity of frontal striatal circuitry either did not recover or gradually worsened over time. Bilateral STN DBS can have a negative impact on various aspects of frontal executive functioning, especially in patients older than 69 years. Future studies will evaluate a larger group of patients and examine the possible reversibility of these effects by turning the DBS off.

Related to Bohm's holographic cosmology. Pribram has placed the anthropological aspect right in the middle of Bohm's reality-concept.

050a: QP401 050b: .D203 2003 082a: 152.4 245c: Antonio Damasio 300b: ill 300c: 24 cm 505a: Enter feelings -- Of appetites and emotions -- Feelings -- Ever since feelings -- Body, brain, and mind -- A visit to Spinoza -- Who's there?