Bilateral Frontal Lobe Damage Research Articles

Forced Gazing: A Stimulus-bound Behavior.

We studied four patients with acquired brain injury who were compelled to gaze at a moving object or the face of an individual who came into their sight, especially the person's eyes. The patients continued to gaze at the object or person until it disappeared from their sight. This behavior, referred to as forced gazing, is related to visual groping (part of the instinctive grasp reaction), and, together with a similar sign of visual grasping, constitutes a spectrum of visual stimulus-bound behaviors. In addition to forced gazing, the patients exhibited a primitive reflex such as a grasp or sucking reflex. Each of the patients had lesions in the bilateral frontal lobes of the brain. We considered forced gazing to be a stimulus-bound behavior, in which patients become extremely dependent on a specific external stimulus. As gaze-related communication is considered one of the bases of an infant's social development, forced gazing may have its basis in innate human behavior that might manifest itself under specific pathological circumstances such as bilateral frontal-lobe damage.

A Patient With Psychotic Disorder Following Traumatic Brain Injury With Bilateral Frontal Lobe Damage

A Patient With Psychotic Disorder Following Traumatic Brain Injury With Bilateral Frontal Lobe Damage

A Patient With Psychotic Disorder Following Traumatic Brain Injury With Bilateral Frontal Lobe Damage

A Patient With Psychotic Disorder Following Traumatic Brain Injury With Bilateral Frontal Lobe Damage

Long-term compensatory treatment of organizational deficits in a patient with bilateral frontal lobe damage

Evans et al. (1998) described compensatory strategy use in R.P., a patient with executive dysfunction following bilateral frontal lobe damage who had difficulty acting upon her intentions. A pager was used to remind R.P. of regularly scheduled activities, along with a checklist that aimed to moderate a perseverative routine. Although successful, 10 years after the original intervention, the strategies were no longer used, and considerable everyday problems were evident. In the current study, we conducted a follow-up assessment to examine potential reasons for this deterioration. No change in neuropsychological functioning was evident. Whereas the previous study introduced the two strategies together, and examined effects upon separate goals, in the current study we reintroduced the two strategies separately, and examined effects on three common goals. In addition to prompting specific activities, we aimed to support completion of more general goals (those that could be enacted within a wider window of time). The paging intervention had a dramatic effect on all three measured behaviors, at a much more consistent level than the checklist. We suggest that, in addition to direct reminders, the pager can cue a process of goal monitoring that bridges the gap between intention and action.

Reversed negative priming following frontal lobe lesions

The present study investigated whether lesions to the prefrontal cortex would lead to impaired inhibitory control in selective attention. Patients with uni- and bilateral frontal lobe damage and age-matched control participants were compared in an identity negative priming task involving letter naming. Whereas all control groups revealed robust negative priming and distractor interference, the majority of patients showed positive instead of negative priming and not all of them were more susceptible to interference. These results suggest that frontal lobe lesions disrupt distractor inhibition and cannot be explained in terms of a retrieval deficit. However, the level of interference may not only be determined by inhibition but also by excitation of the target stimulus.

Word search in patients with Parkinson's disease

A Neisser word-search task and case-series method is employed to show that patients with Parkinson's disease (PD) are slow at word-search from lexical-semantic long-term stores. This slowing is then related to the patients' word-finding impairment in verbal fluency. The results are also compared to those of a patient with bilateral frontal lobe damage, due to Pick's disease. Neisser's word-search task is based on the premise that the time it takes to scan down a (vertical) list of words to identify a target (e.g. ‘any animal’) is a measure of the time taken to select that item in lexical semantic memory. The experimental paradigm is robust. A cognitive neuropsychology approach is necessary for this investigation, as PD double-dissociation data help to eliminate confounding factors in the data interpretation. Attentional problems, for example, are unlikely to account for the significant correlation between verbal fluency and word search stores in PD.

A pet study of monozygotic twins discordant for frontal lobe injury: neurophysiological and cognitive sequelae

Because the frontal lobes are extremely susceptible to traumatic brain insuit, closed head injury patients may serve as a useful model of frontal lobe damage. We had the opportunity to study with positron emission tomography (PET) a 28-year-old pair of male, college-educated monozygntic twins who had been involved in a motor vehicle accident, one of whom sustained a severe closed head injury. A CT scan conducted early during his 2-week coma revealed bilateral frontal lobe damage, more severe on the right side. These circumstances afforded a unique opportunity to view with PET the long-term cognitive sequelae of his frontal lobe injury and their neumphysiological concomitants against a geneticallyequated control subject. Six years after the accident, an MR! scan showed some resolution of these pathological changes but cognitive deficits remaine& At that time, we measured regional cerebral blood flow (tCBF) in both twins using the oxygen-15 water method during the Wisconsin Card Sorting Test (WCS) and during a sensorimotor control task. Data were normalized on a pixel-by-pixel basis as a percentage of the whole brain mean. To examine patterns of rCBF activation specific to higher cognitive functions, rCBF values for the sensorimotor control task were subtracted from those for the abstract reasoning task. Regions were drawn on the twins' coplanar MRi's and applied to their respective PET data. Consistent with the pattern of tCBF activation during the WCS identified in several cohorts of normal subjects in previous studies by our lab, the uninjured twin showed activation of Brodman's areas 46 and 9 in the left and right inferior frontal gyri with relative deactivation of the left hippocampus. Like his uninjm~l co-twin, the injured twin activated the left inferior frontal gyms. However, the injured twin failed to activate the right inferior frontal gyms and, instead, activated the left hippocampus, it is interesting to note that this pattern of prefrontal hypoactivity and hippocampal hyperactivity during the WCS has been shown to be associated with poor task performance in normal subjects and to be a characteristic of patients with schizophrenia. These data may help to clarify the relative contributions of the dorsolateral prefrontal cortex and the hippocampus in higher order human cognition.

Bilateral frontal lobe disease and selective delayed response deficits in humans.

The performance of patients with frontal lobe disease was compared with that of amnesic patients (with etiology of alcoholic Korsakoff's disease or surgically treated ruptured anterior communicating artery aneurysm) on tasks known to be sensitive to frontal lobe damage in nonhuman primates: delayed alternation (DA) and delayed response (DR). Alcoholic patients with no clinical memory impairment served as controls. Results showed that bilateral frontal lobe damage in humans is associated with impairment on both tasks. In addition, there was no relation between performances on DA and DR and performance on standardized tests of memory, a result strengthening the suggestion that the former tasks are not sensitive to anterograde amnesia in humans.

Bilateral frontal lobe disease and selective delayed response deficits in humans.

The performance of patients with frontal lobe disease was compared with that of amnesic patients (with etiology of alcoholic Korsakoff's disease or surgically treated ruptured anterior communicating artery aneurysm) on tasks known to be sensitive to frontal lobe damage in nonhuman primates: delayed alternation (DA) and delayed response (DR). Alcoholic patients with no clinical memory impairment served as controls. Results showed that bilateral frontal lobe damage in humans is associated with impairment on both tasks. In addition, there was no relation between performances on DA and DR and performance on standardized tests of memory, a result strengthening the suggestion that the former tasks are not sensitive to anterograde amnesia in humans.

Differential behavioral effects in frontal lobe disease

The performances of groups of patients with left, right and bilateral frontal lesions were compared on a battery consisting of two tests presumed to be related specifically to left hemisphere function, two tests presumed to be related specifically to right hemisphere function, and two tests presumed to be related specifically to bilateral frontal lobe function. Eighteen predictions, based on both theoretical considerations and the indications of previous literature, were made concerning the differences in performance to be expected among the three groups. Fifteen of the 18 predictions were confirmed by the results. It is concluded that some of the interhemispheric differences in performance which have been found in comparisons of patients with unilateral post-Rolandic lesions are also demonstrable in patients with unilateral frontal lesions and that certain task performances are particularly susceptible to the effects of bilateral frontal lobe damage.

Effects of Different Brain Lesions on Card Sorting

Sorting tasks, requiring the subject to respond selectively, first to one aspect of a situation and then to another, have traditionally been regarded as sensitive indicators of brain injury, but there has been little agreement concerning the effects of lesions in different areas of the brain on sorting behavior. Weigl,36in 1927, found that braininjured patients performed more poorly than normal control subjects on a simple Color-Form sorting task, and he described a patient with bilateral frontal-lobe damage who had particular difficulty in shifting from one sorting principle to another. Goldstein,6though rejecting any strict localization of intellectual function, also appears to stress the importance of the frontal lobes for spontaneous shifting, and this view has been further emphasized by such workers as Rylander29and Halstead.9,10Yet Teuber, Battersby, and Bender,34studying men with penetrating missile wounds of the brain, found greater deficits on