Using Virtual Reality to Assess Landscape: A Comparative Study Between On-Site Survey and Virtual Reality of Aesthetic Preference and Landscape Cognition

In recent years, research on landscape perception has been generally overoptimistic about the use of virtual reality (VR); however, few have questioned the validity of VR. It is necessary to examine whether on-site stimulation can be substituted by VR. The purpose of this study was to assess the degree of agreement between on-site survey and VR for landscape perception. The sample included 11 representative landscapes from Tsuchiura city and Tsukuba city, Japan. On-site survey data was collected for 17 items related to aesthetic preference and landscape cognition. The same scenes were produced by VR and same survey data as on-site was collected. The agreement of both the overall mean of all landscapes and the ratings of all individuals in each landscape confirmed the high level of concordance of most cognitive attributes between the two stimuli. The findings support immersive VR as a reliable tool for assessing landscape cognition.

Phantom Perception of Sound and the Abnormal Cortical Inhibition System: An Electroencephalography (EEG) Study

Objectives: Despite no observable external sound present, a perceived feeling of a recurrent unpleasant sound is a main complaint in the patients with chronic tinnitus. This phantom perception of sound is considered as the auditory equivalent of phantom limb pain, and altered excitability may be involved in its underlying pathology. Tinnitus-related hyper-excitation is suppressed by inhibitory repetitive transcranial magnetic stimulation (rTMS). However, the neural mechanism underlying the treatment is not fully understood, and quantifying the suppression induced by rTMS has yet to be considered. Methods: We evaluated the effect of rTMS on the cortical inhibition status following single-site stimulation over the auditory temporal cortex (T group) or dual-site stimulation over the auditory temporal and the frontal regions (TF group). These effects were also compared with outcomes following sham stimulation (S group). Subjective response was recorded using tinnitus-related handicap index (THI), and changes in the cortical inhibition status were assessed using an auditory paired-pulse suppression index (PPSI). Results: TF group showed the greatest benefit from the treatment evidenced in the reduced PPSI and THI scores. T and S groups did not benefit much. TF group overlapped mostly with the responder group, indicating improvement in both subjective THI and objective PPSI measurements. Conclusion: Our results suggest that rTMS is a beneficial therapeutic treatment for chronic tinnitus patients and the dual-site treatment was the most effective in terms of both tinnitus complaint and quantitative indices. Thus, subjective reports and electrophysiological signatures may be complementary for the diagnosis/prognosis of tinnitus.

Paired Stimulation to Promote Lasting Augmentation of Corticospinal Circuits

After injury, electrical stimulation of the nervous system can augment plasticity of spared or latent circuits through focal modulation. Pairing stimulation of two parts of a spared circuit can target modulation more specifically to the intended circuit. We discuss 3 kinds of paired stimulation in the context of the corticospinal system, because of its importance in clinical neurorehabilitation. The first uses principles of Hebbian plasticity: by altering the stimulation timing of presynaptic neurons and their postsynaptic targets, synapse function can be modulated up or down. The second form uses synchronized presynaptic inputs onto a common synaptic target. We dub this a “convergent” mechanism, because stimuli have to converge on a common target with coordinated timing. The third form induces focal modulation by tonic excitation of one region (e.g., the spinal cord) during phasic stimulation of another (e.g., motor cortex). Additionally, endogenous neural activity may be paired with exogenous electrical stimulation. This review addresses what is known about paired stimulation of the corticospinal system of both humans and animal models, emphasizes how it qualitatively differs from single-site stimulation, and discusses the gaps in knowledge that must be addressed to maximize its use and efficacy in neurorehabilitation.

TMS in the treatment of major depressive disorder

There is a growing body of literature on animal experiments using behavioural paradigms or investigations of neurobiological mechanisms to assess the antidepressant effects of repetitive (r)TMS. This article summarizes the findings from these studies. The evidence from these studies is supportive of antidepressant effects for rTMS. This evidence has provided several plausible hypotheses for the antidepressant effects of rTMS. Several studies have suggested that rTMS may have neuroprotective effects. There are many variations in the way rTMS can be given as a clinical treatment, involving choices over treatment site, stimulation parameters and treatment course. Clinical trials to date have found rTMS to be safe when given within recommended parameter guidelines. Further research is needed to understand the role of rTMS with respect to other established antidepressant treatments.