Attention and novelty processing in stroke and Parkinson's disease

摘要: The ventral fronto-parietal network has been considered to play a crucial role in reorienting attention towards significant environmental events, while the dorsal system is thought be dominant in controlling goal-directed behaviour (Corbetta and Shulman 2002). I begin by reviewing literature which suggests this distinction may not so clear cut suggest my own scheme takes into account evidence (Singh-Curry and Husain 2009). Specifically, areas, particularly right inferior parietal lobe (IPL), appear activated tasks involving sustained attention, responding salient taskrelevant events, detecting novel stimuli switching between tasks. Accordingly, I hypothesise that IPL reconfiguring between a task-engaged state more exploratory mode of functioning, permits the identification potentially important events. The first few chapters thesis aimed test hypothesis examining attention deficits stroke patients with hemispatial neglect, syndrome frequently occurs following damage IPL. These were shown have difficulty sustaining over time, even when no spatial shifts required. This deficit was evident for lower perceptual salience. More importantly, however, these deficits found interact each other, as well as direction suggesting functions be dependent on an interrelated brain network. Consistent notion, results of lesion-symptom analysis indicated Right appears mediation all processes, including processing of novel stimuli, supporting hypothesis. The detection events also activate midbrain dopaminergic system (Bunzeck Duzel 2006), principal pathological feature Parkinson’s disease (PD) is degeneration neurons (Hornykiewicz 1998). Although PD is traditionally disorder movement, recently it recognised that there associated cognitive deficits, disorders impulse control (Weintraub 2008). At present, factors predispose some individuals with develop such problems are unclear. Accordingly, second part thesis, examined novelty risktaking behaviour order identify subgroups particularly vulnerable developing control problems. In addition with impulse (ICD), those who classified akinetic-rigid, opposed to tremor – without ICD process quickly than nonnovel perceptually unlike tremor patients. Novelty seeking was relative preservation mesolimbic ICD, increased risk-taking with preservation Mesolimbic sparing, to the akinetic-rigid motor phenotype therefore increase susceptibility impulse control PD.