Ironing out the rough spots--cognitive impairment in haemochromatosis.

A man in his late 40s, referred by his general practitioner (GP) to a psychology-led pain management programme, made a subjective and spontaneous report of cognitive impairment. He further mentioned a ten year history of erectile dysfunction, joint pain, occasional nausea and excessive fatigue. He underwent cognitive assessment. Advised to return to his GP to seek further investigation, he was ultimately subsequently diagnosed with haemochromatosis and began radical therapeutic venesection. Repeat cognitive assessment, a year later and following stabilisation of the condition, found improvement on some cognitive measures. Subjective report was of vastly improved cognitive function.

Loss of imagery phenomenology with intact visuo-spatial task performance: a case of 'blind imagination'.

The capacity for imagery, enabling us to visualise absent items and events, is a ubiquitous feature of our experience. This paper describes the case of a patient, MX, who abruptly lost the ability to generate visual images. He rated himself as experiencing almost no imagery on standard questionnaires, yet performed normally on standard tests of perception, visual imagery and visual memory. These unexpected findings were explored using functional MRI scanning (fMRI). Activation patterns while viewing famous faces were not significantly different between MX and controls, including expected activity in the fusiform gyrus. However, during attempted imagery, activation in MX's brain was significantly reduced in a network of posterior regions while activity in frontal regions was increased compared to controls. These findings are interpreted as suggesting that MX adopted a different cognitive strategy from controls when performing the imagery task. Evidence from experimental tasks thought to rely on mental imagery, such as the Brooks' matrices and mental rotation, support this interpretation. Taken together, these results indicate that successful performance in visual imagery and visual memory tasks can be dissociated from the phenomenal experience of visual imagery.