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This study sought to discover if an optimum 1 cm(2) area in the non-damaged right hemisphere (RH) was present, which could temporarily improve naming in chronic, nonfluent aphasia patients when suppressed with repetitive transcranial magnetic stimulation (rTMS). Ten minutes of slow, 1Hz rTMS was applied to suppress different RH ROIs in eight aphasia cases. Picture naming and response time (RT) were examined before, and immediately after rTMS. In aphasia patients, suppression of right pars triangularis (PTr) led to significant increase in pictures named, and significant decrease in RT. Suppression of right pars opercularis (POp), however, led to significant increase in RT, but no change in number of pictures named. Eight normals named all pictures correctly; similar to aphasia patients, RT significantly decreased following rTMS to suppress right PTr, versus right POp. Differential effects following suppression of right PTr versus right POp suggest different functional roles for these regions.

For several decades, cognitive research on personality and individual differences has focused on psychological traits other than general intelligence. Here we present data on empathizing and systemizing cognitive traits in science and humanities students. In view of existing data on autistic traits in scientists, we hypothesized that the science students would show higher systemizing than empathizing and that the humanities students would show the opposite pattern. Our findings suggest that individuals in the sciences possess a cognitive style that is more systemizing-driven than empathizing-driven, whereas individuals in humanities possess a cognitive style that is much more empathizing-driven than systemizing-driven. Both type of major and gender independently and highly significantly contribute to this effect. Within the sciences, the systemizing pattern is especially pronounced in engineering and physics. Men and women have been found previously to differ in their systemizing–empathizing cognitive style, with men being stronger in systemizing and women being stronger in empathizing. We find the same gender differences within each type of major.

Synaesthesia is characterised by idiosyncratic ectopic sensations which commonly take the form of coloured visual impressions evoked by touch or hearing. We studied six late-blind individuals who have retained synaesthetic colour perception. Four of them had been without any form of genuine colour vision for more than 10 years. All perceived colours when they heard or thought about letters, numbers, and time-related words (days of the week and months of the year). One experienced synaesthetic colours for all words. Another saw Braille characters as coloured dots when he touched them. The aberrant experiences were compelling and reliable: detailed verbal descriptions of the colours were remarkably consistent in tests more than 2 months apart. The percepts predominantly took the form of coloured patches, localised in body-centred space for five of the subjects and in head-centred space for the sixth. This implies that the neural activity underlying synaesthesia occurs after the establishment of a visual representation independent of eye (or head) position. The synaesthetic colour depended only on phonetic cues in one case, but on semantic context in others. Although synaesthesia might be due to idiosyncratic, aberrant corticocortical connectivity established during early development, it can persist for very long periods with little or no natural experience in the referred modality and therefore does not depend solely on continuing associative learning.

Many areas of the visual cortex are activated when blind people are stimulated naturally through other sensory modalities (e.g., haptically; Sadato et al., 1996). While this extraneous activation of visual areas via other senses in normal blind people might have functional value (Kauffman et al., 2002; Lessard et al., 1998), it does not lead to conscious visual experiences. On the other hand, electrical stimulation of the primary visual cortex in the blind does produce illusory visual phosphenes (Brindley and Lewin, 1968). Here we provide the first evidence that high-level visual areas not only retain their specificity for particular visual characteristics in people who have been blind for long periods, but that activation of these areas can lead to visual sensations. We used fMRI to demonstrate activity in visual cortical areas specifically related to illusory colored and spatially located visual percepts in a synesthetic man who has been completely blind for 10 years. No such differential activations were seen in late-blind or sighted non-synesthetic controls; neither were these areas activated during color-imagery in the late-blind synesthete, implying that this subject's synesthesia is truly a perceptual experience.

Transcranial magnetic stimulation (TMS) is a neuroscientific technique that induces an electric current in the brain via application of a localized magnetic field pulse. The pulse penetrates the scalp and skull non-invasively and, depending on the parameters of stimulation, facilitates or depresses the local neuronal response with effects that can be transient or long lasting. While the mechanisms by which TMS acts remain largely unknown, the behavioral effects of the stimulation are reproducible and, in some cases, are highly beneficial. This chapter reviews the technique in detail and discusses safety as the paramount ethics issue for TMS. It further examines the ethical arguments for and against neuroenhancement with TMS and how the framework for acceptable practice must differ for patient and non-patient populations.

Foreign accent syndrome (FAS) is a rare speech disorder characterized by a change in prosody and other speech variables yielding altered phonetic characteristics that are perceived as a foreign accent. Lesions associated with FAS typically involve left frontoparietal regions. However, 2 reported left-hemispheric stroke patients presenting with FAS also had hypoperfusion of the right cerebellum on 99mTc ECD SPECT imaging, presumably from diaschisis. In both cases, there was a close parallel between the normalization of the cerebellar perfusion and resolution of the clinical syndrome up to 3 years later despite continued hypoperfusion of left hemispheric structures.1,2 The authors argued that the temporal association between the clinical improvement and the right cerebellar perfusion suggested a functional role of the cerebellum in this speech disorder. We describe a unique case that provides convergent evidence for a causative role of the cerebellum in FAS. ### Case report. A right-handed English-speaking woman was 58 years of age at the time of her left frontoparietal infarct (figure, A), presenting with right upper limb paresis and aphemia. Within hours, the patient’s paresis resolved to a slight hand ataxia and her speech sounded like English spoken with an unlearned accent. Workup suggested an embolic event, and she was discharged on warfarin. The foreign accent persisted for approximately 3 years until she had a right inferior cerebellar hemorrhage (figure, B–D) from accidental excessive anticoagulation. Following this second stroke, the patient and her family noted that the foreign accent was no longer perceptible in her speech. …