Even though retinal images of objects change their locations following each eye movement, we perceive a stable and continuous world. One possible mechanism by which the brain achieves such visual stability is to construct a craniotopic coordinate by integrating retinal and extraretinal information. There have been several proposals on how this may be done, including eye-position modulation (gain fields) of retinotopic receptive fields (RFs) and craniotopic RFs. In the present study, we investigated coordinate systems used by RFs in the lateral intraparietal (LIP) cortex and frontal eye fields (FEF) and compared the two areas. We mapped the two-dimensional RFs of neurons in detail under two eye fixations and analyzed how the RF of a given neuron changes with eye position to determine its coordinate representation. The same recording and analysis procedures were applied to the two brain areas. We found that, in both areas, RFs were distributed from retinotopic to craniotopic representations. There was no significant difference between the distributions in the LIP and FEF. Only a small fraction of neurons was fully craniotopic, whereas most neurons were between the retinotopic and craniotopic representations. The distributions were strongly biased toward the retinotopic side but with significant craniotopic shifts. These results suggest that there is only weak evidence for craniotopic RFs in the LIP and FEF, and that transformation from retinotopic to craniotopic coordinates in these areas must rely on other factors such as gain fields.
Animals ; Macaca ; Visual Fields ; Frontal Lobe/physiology* ; Eye Movements ; Brain

The aim of this study is to define the anatomical localization of corresponding brain function area during calculating. The activating modes in brain during continuous silent calculating subtraction and repeated silent reading multiplication table were compared and investigated. Fourteen volunteers of right-handedness were enrolled in this experiment. The quite different reaction models in brain area during the two models of calculation revealed that there are different processing pathways in brain during these two operating tasks. During continuous silent calculating, the function areas were found localized on the posterior portion of superior and middle gyrus of frontal lobe and the lobule of posterior parietal lobe (P < 0.01, T = 5.41), demonstrating that these function areas play an important role in the performance of calculation and working memory. During repeated silent reading multiplication table, the activating cluster was found only located in in the gyri occipital lateral(P < 0.01, T = 4.77).
Adult ; Brain ; anatomy & histology ; physiology ; Frontal Lobe ; physiology ; Humans ; Magnetic Resonance Imaging ; Male ; Memory, Short-Term ; physiology ; Occipital Lobe ; physiology ; Parietal Lobe ; physiology

OBJECTIVETo explore the working mechanism and age-related change of the conflict processing system of the frontal cortex.

METHODSFifteen normal elderly people and 15 youth were performed a modified Eriksen flanker paradigm, while event-related potential (ERPs), which include 32 systerm electroencephalography, reaction time and correct rate were recorded.

RESULTSThe elderly group showed a distinct effect of reaction time and effect of conflict in the respond level compared with the youth group. The elderly group had a longer time window of N380 and same amplitude as the youth group. Low resolution brain electromagnetic tomography (LORETA) showed the bilateral temporal lobe and the dorsolateral prefrontal cortex (especially right) were activated in the youth group, while the left temporal lobe, the left dorsolateral prefrontal cortex and left medial frontal gyrus were activated in the elderly group.

CONCLUSIONWhen conflict stimuli existed in the response level, old people showed frontal interference control hypofunction. N380 reflected the activation of the left dorsolateral prefrontal cortex and the left temporal lobe during response selection and executive control processing in older people.

Adolescent ; Aged ; Aging ; Electroencephalography ; Evoked Potentials ; Frontal Lobe ; physiology ; Humans ; Prefrontal Cortex ; physiology ; Reaction Time ; Temporal Lobe ; physiology

The present study investigated the characteristic of semantic cognition of Uyghur-Chinese bilinguals. The event-related potentials (ERP) technique was used to explore the characteristic of N400 wave and topographic map of difference-waves with "picture-word" semantic priming paradigm. There were significant semantic priming effects on two languages. The average amplitude of N400 was similar in two languages, while average amplitudes of three electrodes (F3, F4, PZ) in Chinese were negative than others. Meanwhile, the activation of topographic map of Uyghur was almost in all regions except occipital lobe, and the degree of activation of Chinese was less than Uyghur, but the activation in parietal and bilateral frontal lobes was higher. In conclusion, the present study suggests that two languages of Uyghur-Chinese bilinguals are all sensitive to semantic priming. The bilateral frontal and parietal lobes participate in language switching. Semantic cognition of two languages in Uyghur-Chinese late non-proficient bilinguals is both completed by bilateral cerebral hemispheres. We have not found obvious lateralization on two languages of Uyghur-Chinese bilinguals.
Asian Continental Ancestry Group ; China ; Cognition ; Evoked Potentials ; Frontal Lobe ; physiology ; Humans ; Language ; Parietal Lobe ; physiology ; Semantics

Active exploratory behaviors have often been associated with theta oscillations in rodents, while theta oscillations during active exploration in non-human primates are still not well understood. We recorded neural activities in the frontal eye field (FEF) and V4 simultaneously when monkeys performed a free-gaze visual search task. Saccades were strongly phase-locked to theta oscillations of V4 and FEF local field potentials, and the phase-locking was dependent on saccade direction. The spiking probability of V4 and FEF units was significantly modulated by the theta phase in addition to the time-locked modulation associated with the evoked response. V4 and FEF units showed significantly stronger responses following saccades initiated at their preferred phases. Granger causality and ridge regression analysis showed modulatory effects of theta oscillations on saccade timing. Together, our study suggests phase-locking of saccades to the theta modulation of neural activity in visual and oculomotor cortical areas, in addition to the theta phase locking caused by saccade-triggered responses.
Animals ; Frontal Lobe/physiology* ; Macaca mulatta ; Neurons/physiology* ; Saccades ; Theta Rhythm ; Visual Fields

OBJECTIVETo compare the spatiotemporal pattern of event-related potentials (ERPs) of relational memory retention between color-location binding and semantics-location binding.

METHODSThe ERPs of 19 channels were recorded from 14 healthy subjects while performing the two binding delayed-match-to-sample tasks. A paired-sample t test was used for analysis of both the behavioral performance and ERPs, and statistical parametric mapping (SPM) of the t values was applied to ERPs.

RESULTSBehavioral performances (reaction time and accuracy) in color-location binding were significant better than those of semantics-location binding. The SPM(t) of the ERPs showed significant effects in the middle frontal region and most areas of the parietal lobe (about 200 ms), the bilateral prefrontal and frontal regions (260 approximately 320 ms), and the left occipital region (500 approximately 580 ms).

CONCLUSIONRetention of semantics-location relation involves more brain regions than that of color-location relation, and the largest effect occurs in the frontal region.

Electroencephalography ; Event-Related Potentials, P300 ; physiology ; Frontal Lobe ; physiology ; Humans ; Memory ; physiology ; Retention (Psychology) ; physiology ; Task Performance and Analysis

This study sought to reveal the difference of brain functions at resting-state between subjects with sub-health and normal controls by using the functional magnetic resonance imaging (fMRI) technology. Resting-state fMRI scans were performed on 24 subjects of sub-health and on 24 healthy controls with gender, age and education matched with the sub-health persons. Compared to the healthy controls, the sub-health group showed significantly higher regional homogeneity (ReHo) in the left post-central gyrus and the right post-central gyrus. On the other hand, the sub-health group showed significantly lower ReHo in the left superior frontal gyrus, in the right anterior cingulated cortex and ventra anterior cingulate gyrus, in the left dorsolateral frontal gyrus, and in the right middle temporal gyrus. The Significant difference in ReHo suggests that the sub-health persons have abnormalities in certain brain regions. It is proved that its specific action and meaning deserves further assessment.
Brain ; physiology ; physiopathology ; Brain Mapping ; Case-Control Studies ; Cerebral Cortex ; Frontal Lobe ; Gyrus Cinguli ; Humans ; Magnetic Resonance Imaging ; Parietal Lobe

BACKGROUNDChildren with nonverbal learning disabilities (NLD) usually manifest defective attention function. This study sought to investigate the neuropsychological characteristics of selective attention, such as attention control, working memory, and attention persistence of the frontal lobe in children with NLD.

METHODSUsing the auditory detection test (ADT), Wisconsin card sorting test (WCST), and C-WISC, 27 children with NLD and 33 normal children in the control group were tested, and the results of C-WISC subtests were analyzed with factor analysis.

RESULTSCompared with the control group, the correct response rate in the auditory detection test in the NLD group was much lower (P < 0.01), and the number of incorrect responses was much higher (P < 0.01); NLD children also scored lower in WCST categories achieved (CA) and perseverative errors (PE) (P < 0.05). Factor analysis showed that perceptual organization (PO) related to visual space and freedom from distractibility (FD) relating to attention persistence in the NLD group were obviously lower than in the control group (P < 0.01).

CONCLUSIONSChildren with NLD have attention control disorder and working memory disorder mainly in the frontal lobe. We believe that the disorder is particularly prominent in the right frontal lobe.

Attention ; Child ; Frontal Lobe ; physiology ; Humans ; Learning Disorders ; psychology ; Male ; Neuropsychological Tests

OBJECTIVETo explore the influence of verbal working memory load on associative neural networks.

METHODSTwenty-one subjects were required to complete a verbal delayed matching-to-sample task under the condition of low (3 items) or high (5 items) working memory load (WML). The 19-channels event-related potentials (ERP) were analyzed with statistical parametric mapping.

RESULTSA significant difference in working memory capacity (WMC) was found between low WML and high WML groups [2.48∓0.30 vs 3.30∓0.76; t(20)=5.950, P=0.000]. Statistical parametric mapping revealed that during the encoding stage, the effects of WML appeared in succession in the right ventral attention network (rVAN), the dorsal attention network, and the language areas in the left hemisprere. During the maintenance stage, the effects WML occured in the rVAN acompanied by either DAN or left frontal-temporal regions. CONCLUSIONS;onclusions When the WML is beyond the WMC, the rVAN may participate in the prevention of interference among items and in the activation of long-term memory.

Attention ; Evoked Potentials ; Frontal Lobe ; physiology ; Humans ; Memory, Short-Term ; Spatio-Temporal Analysis

OBJECTIVETo observe the effect of acupuncture at the whole points of Hand Jueyin pericardium meridian on the amplitude of low frequency fluctuations (ALFF) of healthy people in resting state (R1) functional magnetic resonance imaging (fMRI).

METHODSTotally 16 healthy subjects received structure scan of T1 and T2. Then two fMRI scans were conducted for each participant. fMRI included the resting-state scan (R1; the scanning time was 8 min 6 s), the stimulating-acupoint scan (AP; the scanning time was 8 min 6 s). fMRI data acquisition from structure scanning and function scanning were processed with format conversion and statistical analysis.

RESULTSUnder R1 state, brain regions with activated ALFF signals included bilateral superior frontal gyrus, medial frontal gyrus, middle occipital gyrus, precuneus, superior temporal gyrus, and cingulate gyrus. Under the AP state, brain regions with activated ALFF signals were bilateral superior frontal gyrus, medial frontal gyrus, middle temporal gyrus, left fusiform gyrus, precuneus, posterior cingulate, and declivis. Compared with R1 state, obvious difference of ALFF signal areas of the brain caused by acupuncture at pericardium were: bilateral cuneus, precuneus, left posterior cingulate gyrus, right middle occipital gyrus, and right occipital lingual gyrus.

CONCLUSIONAcupuncture at the whole points of Hand Jueyin pericardium meridian could significantly change inherent activity states of the cerebral cortex, especially in bilateral superior frontal gyrus, medial frontal gyrus, and precuneus.

Acupuncture ; Acupuncture Points ; Brain ; physiology ; Brain Mapping ; Frontal Lobe ; Humans ; Magnetic Resonance Imaging ; methods ; Pericardium