Search results for "Frontal Lobe"
showing 10 items of 158 documents
Qualitative different memory impairments across frontal lobe subgroups
2006
Recall impairments in patients with lesions to the prefrontal cortex (PFC) have variously been attributed to problems with organisation at encoding, organisation at retrieval and monitoring at retrieval. Neuroimaging and recent theoretical work has associated the left lateral PFC with organisation and strategy production at encoding, and the right lateral PFC with organisation, error detection and monitoring at retrieval. However few lesion studies have been anatomically specific enough to test the direct predictions made by this work. Proactive interference, response to prompting, monitoring and organisational strategies were examined in 34 patients with frontal lobe lesions and 50 healthy…
VBM-DTI correlates of verbal intelligence: a potential link to Broca's area.
2012
Abstract Human brain lesion studies first investigated the biological roots of cognitive functions including language in the late 1800s. Neuroimaging studies have reported correlation findings with general intelligence predominantly in fronto-parietal cortical areas. However, there is still little evidence about the relationship between verbal intelligence and structural properties of the brain. We predicted that verbal performance is related to language regions of Broca's and Wernicke's areas. Verbal intelligence quotient (vIQ) was assessed in 30 healthy young subjects. T1-weighted MRI and diffusion tensor imaging data sets were acquired. Voxel-wise regression analyses were used to correla…
Modulating phonemic fluency performance in healthy subjects with transcranial magnetic stimulation over the left or right lateral frontal cortex.
2017
Abstract A growing body of evidence have suggested that non-invasive brain stimulation techniques, such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS), can improve the performance of aphasic patients in language tasks. For example, application of inhibitory rTMS or tDCs over the right frontal lobe of dysphasic patients resulted in improved naming abilities. Several studies have also reported that in healthy controls (HC) tDCS application over the left prefrontal cortex (PFC) improve performance in naming and semantic fluency tasks. The aim of this study was to investigate in HC, for the first time, the effects of inhibitory repetitive TMS (rTMS…
Dissociation of emotional processes in response to visual and olfactory stimuli following frontotemporal damage.
2005
Contemporary neuropsychological studies have stressed the widely distributed and multicomponential nature of human affective processes. Here, we examined facial electromyographic (EMG) (zygomaticus and corrugator muscle activity), autonomic (skin conductance and heart rate) and subjective measures of affective valence and arousal in patient TG, a 30 year-old man with left anterior mediotemporal and left orbitofrontal lesions resulting from a traumatic brain injury. Both TG and a normal control group were exposed to hedonically valenced visual and olfactory stimuli. In contrast with control subjects, facial EMG and electrodermal activity in TG did not differentiate among pleasant, unpleasant…
Brain slow waves preceding time-locked visuo-motor performance.
1993
According to previous findings (Konttinen and Lyytinen, 1992), the slow brain negativity preceding the trigger pull in rifle‐shooting tends to be decreased in successful shots among experienced marksmen, whereas no such pattern is found among inexperienced subjects. This effect was interpreted as resulting mainly from optimal arousal. However, another explanation is examined here. The aim of the experiment was to investigate slow electrocortical changes associated with motor regulation and visual aiming related to shooting performance. Four variations on a shooting task were used, in which the visual and motor components were contrasted. Motor activity related to gun stabilization was found…
Verbal suppression and strategy use: a role for the right lateral prefrontal cortex?
2015
Verbal initiation, suppression and strategy generation/use are cognitive processes widely held to be supported by the frontal cortex. The Hayling Test was designed to tap these cognitive processes within the same sentence completion task. There are few studies specifically investigating the neural correlates of the Hayling Test but it has been primarily used to detect frontal lobe damage. This study investigates the components of the Hayling Test in a large sample of patients with unselected focal frontal (n = 60) and posterior (n = 30) lesions. Patients and controls (n = 40) matched for education, age and sex were administered the Hayling Test as well as background cognitive tests. The sta…
Characterization of BOLD-fMRI signal during a verbal fluency paradigm in patients with intracerebral tumors affecting the frontal lobe.
2002
Previous studies have indicated that the BOLD-fMRI signal can be modified by tumor processes in close vicinity to functional brain areas. This effect has been investigated primarily for the perirolandic area but there is only a limited number of studies concerning frontal cortical regions. Therefore, the aim of the current study was to characterize BOLD-fMRI signal and activation patterns in patients with frontal brain tumors while performing a verbal fluency task. Six patients (ages 31-56 years) suffering from frontal (5 left sided and 1 right sided) intracerebral tumors were examined with fMRI while performing a verbal fluency task in a blocked paradigm design. Eight healthy volunteers se…
Perinatal cerebral insults alter auditory event-related potentials.
2011
Background: Auditory event-related potentials (AERPs) can be used as indices of neural information processing. Altered AERPs have been reported in children and young adults with frontal lobe infarction. Aim: To test the hypothesis that perinatal brain injury affects cortical auditory processing. Methods: We assessed AERPs at term. 6 and 12 months of age in preterm infants [n = 9. median gestational age (GA) 27.9, range 23.9-30.0 wk], term infants with perinatal intracerebral hemorrhage (ICH) [n = 5, GA 40.3, range 37.4-42.3 wk], and term infants with perinatal asphyxia In [n = 4. GA 39.4. range 37.9-40.3 wk]. Healthy preterm (n = 16) and term infants (n = 22) served as controls. A harmonic …
Frontoparietal cortex and cerebellum contribution to the update of actual and mental motor performance during the day
2016
AbstractActual and imagined movement speed increases from early morning until mid-afternoon. Here, we investigated the neural correlates of these daily changes. Fifteen subjects performed actual and imagined right finger opposition movement sequences at 8 am and 2 pm. Both actual and imagined movements were significantly faster at 2 pm than 8 am. In the morning, actual movements significantly activated the left primary somatosensory and motor areas, and bilaterally the cerebellum; in the afternoon activations were similar but reduced. Contrast analysis revealed greater activity in the cerebellum, the left primary sensorimotor cortex and parietal lobe in the morning than in the afternoon. Im…
The differing roles of the frontal cortex in fluency tests
2012
Fluency tasks have been widely used to tap the voluntary generation of responses. The anatomical correlates of fluency tasks and their sensitivity and specificity have been hotly debated. However, investigation of the cognitive processes involved in voluntary generation of responses and whether generation is supported by a common, general process (e.g. fluid intelligence) or specific cognitive processes underpinned by particular frontal regions has rarely been addressed. This study investigates a range of verbal and non-verbal fluency tasks in patients with unselected focal frontal ( n = 47) and posterior ( n = 20) lesions. Patients and controls ( n = 35) matched for education, age and s…