ABSTRACT
The low-frequency repetitive transcranial magnetic stimulation (rTMS) application has been associated with changes in cognitive processes embedded during time perception tasks. Although several studies have investigated the influence of neuromodulation on time perception, the effect of the 1-Hz rTMS application on the superior parietal cortex is not clearly understood. This study analyzes the effect of the low-frequency rTMS on time estimation when applied in the parietal medial longitudinal fissure. For the proposed study, 20 subjects were randomly selected for a crossover study with two conditions (sham and 1 Hz). Our findings reveal that participant underestimate 1-s time interval and overestimate 4-s and 9-s time intervals after 1-Hz rTMS (p ≤ 0.05). We conclude that the 1-Hz rTMS in the parietal medial longitudinal fissure delays short interval and speed up long time intervals. This could be due to the effect of parietal inhibition on the attentional level and working memory functions during time estimation.
Subject(s)
Parietal Lobe/physiology , Time Perception/physiology , Transcranial Magnetic Stimulation , Adult , Cross-Over Studies , Female , Humans , Male , Young AdultABSTRACT
For many decades the parietal cortex (PC) has been considered the key area in tasks which involve the integration of different stimuli. PC is fundamental to determine spatial sense, information navigation and integration, and is involved in several aspects of the complex motor repertoire and in neurological and psychiatric disorders. In this review, we focus on seven different aspects of PC: (i) neuroanatomy of the parietal cortex; (ii) sensory motor integration processes; iii) hand movement control: reaching, grasping, and pointing; (iv) saccadic eye movements; (v) movement observation; (vi) neurological aspects: ataxia, autism and Parkinson's disease; and (vii) psychiatric aspects: schizophrenia, bipolar disorder and depression. Among these, we related the perspectives which involve the functions of the parietal cortex and mirror neurons and that seem to play a fundamental role in action prediction, planning, observation and execution. Furthermore, we focused on the relationship between posterior parietal cortex (PPC) and hand-guided movements. For this review, we conducted an academic paper search which fulfilled the objective of the study. We conclude that the PC has great participation in different motor functions and neurological/psychiatric disorders.
Subject(s)
Mental Disorders/pathology , Nervous System Diseases/pathology , Parietal Lobe/pathology , Databases, Bibliographic/statistics & numerical data , Humans , Mental Disorders/complications , Nervous System Diseases/complications , Parietal Lobe/physiologyABSTRACT
This study aimed to elucidate electrophysiological and cortical mechanisms involved when 15 healthy right-handed subjects executed an index finger flexion and extension task before and after hand immobilization, using qEEG beta band (13-30Hz) asymmetry. This beta band is involved in motor activity and sensorial factors. Our hypothesis is that an increase in beta band asymmetry in pre-frontal, motor and parietal areas will occur in post-hand immobilization, because these areas need to reorganize for new planning, preparation and voluntary motor control. We found increase in beta band asymmetry during post-treatment task. We concluded that beta band asymmetry plays an important role in the analysis of cortical changes in several brain areas when associated to motor task. Furthermore, we assume that 48h of hand immobilization change cortical functioning.