The use of symmetrical "do" and "don't" requests to interrupt ongoing activities.
(41/2225)
The results of a modified functional analysis demonstrated that aggression, displayed by a 27-year-old man, was occasioned by the use of "don't" requests to interrupt the client's ongoing and often inappropriate activities (e.g., lying on the floor, pica, inappropriate touching of others). Subsequent analyses demonstrated that aggression was lower when ongoing activities were interrupted with symmetrical "do" requests than with "don't" requests. An intervention utilizing symmetrical "do" requests (i.e., prompting an individual to engage in an incompatible behavior) to interrupt such activities resulted in reduced levels of aggression. (+info)
Reduction of frontal neocortical grey matter associated with affective aggression in patients with temporal lobe epilepsy: an objective voxel by voxel analysis of automatically segmented MRI.
(42/2225)
BACKGROUND: Interictal episodes of aggression are often reported in patients with epilepsy. Some have characteristics of what has been referred to as episodic dyscontrol or intermittent explosive disorder (IED). Although structural brain abnormalities are thought to play a part in the pathophysiology of aggression, there are few in vivo studies of structural cerebral changes in patients with epilepsy and aggression. Using quantitative MRI, subtle structural brain abnormalities can be investigated in subgroups of patients with both epilepsy and episodes of affective aggression. METHODS: After automated segmentation of cerebral grey matter from T1 weighted MRI, the objective technique of statistical parametric mapping (SPM) was applied to the analysis of 35 control subjects, 24 patients with temporal lobe epilepsy (TLE) with a history of repeated, interictal episodes of aggression, and 24 patients with TLE without episodes of aggression. Both TLE patient groups were compared with each other and with the control subjects on a voxel by voxel basis for increases and decreases of grey matter. RESULTS: The patients with TLE with aggressive episodes had a decrease of grey matter, most markedly in the left frontal lobe, compared with the control group and with patients with TLE without aggressive episodes. CONCLUSION: These findings suggest that a reduction of frontal neocortical grey matter might underly the pathophysiology of aggression in TLE. These voxel by voxel comparisons can guide further in vivo studies into aggression. (+info)
Affective aggression in patients with temporal lobe epilepsy: a quantitative MRI study of the amygdala.
(43/2225)
Recurrent episodes with interictal affective aggression are a rare but well-recognized problem in patients with temporal lobe epilepsy. They are referred to as episodic dyscontrol or, more precisely, as intermittent explosive disorder (IED). The amygdala play a crucial role in the affective evaluation of multimodal sensory input and the neurobiological mediation of aggressive behaviour. With hippocampal sclerosis, in the context of mesial temporal lobe sclerosis, being the most common cause of temporal lobe epilepsy, we hypothesized that the amygdala might be affected by the same pathogenic process in aggressive patients. We investigated 50 patients with temporal lobe epilepsy: 25 with and 25 without a history of IED. Data from clinical, electrophysiological, neuropsychological and psychometric investigations were obtained, as well as MRI scans for the quantitative assessment of possible amygdala pathology. We found no evidence of a higher prevalence of amygdala sclerosis in the aggressive patients. Hippocampal sclerosis was significantly less common in patients with temporal lobe epilepsy and IED. However, a significant subgroup of patients (20%) with temporal lobe epilepsy and aggressive behaviour had severe amygdala atrophy in the context of a history of encephalitis. Another subgroup of aggressive patients (28%) had different left temporal lesions affecting either the amygdala or periamygdaloid structures. IED was associated with left-sided or bilateral EEG and MRI abnormalities, low IQ and high scores in depression and anxiety. (+info)
Aggressive behaviour at a residential epilepsy centre.
(44/2225)
There is an extensive literature on epilepsy and violence, but no study has addressed aggression (i.e. apparently intentional violence) in a residential-care population. We performed a retrospective study at the Chalfont Centre for Epilepsy (a residential-care facility in rural Buckinghamshire) in order to determine the frequency and character of episodes of aggression. This allowed us to identify a group of aggressive subjects who were compared with age- and sex-matched control subjects drawn from the remaining residents. We found the prevalence of aggression to be 27.2% in 1 year amongst long-term residents. The overall frequency was estimated at between 121 and 207 incidents per 100 persons per year. A few incidents (0.7%) were related to an acute psychosis but they were more likely to result in significant injury. Offenders were younger than non-aggressive residents. Gender, age of onset of epilepsy, history of psychosis, mobility, abnormality on MRI scan, learning disability and seizure frequency were not associated with aggressive conduct. (+info)
Coalition formation in animals and the nature of winner and loser effects.
(45/2225)
Coalition formation has been documented in a diverse array of taxa, yet there has been little formal analysis of polyadic interactions such as coalitions. Here, we develop an optimality model which examines the role of winner and loser effects in shaping coalition formation. We demonstrate that the predicted patterns of alliances are strongly dependent on the way in which winner and loser effects change with contestant strength. When winner and loser effects decrease with the resource-holding power (RHP) of the combatants, coalitions will be favoured between the strongest members of a group, but not between the weakest. If, in contrast, winner and loser effects increase with RHP, exactly the opposite predictions emerge. All other things being equal, intervention is more likely to prove worthwhile when the beneficiary of the aid is weaker (and its opponent is stronger), because the beneficiary is then less likely to win without help. Consequently, intervention is more probable when the impact of victory on the subsequent performance of a combatant increases with that individual's strength because this selects for intervention in favour of weaker combatants. The published literature on hierarchy formation does not reveal how winner and loser effects actually change with contestant strength and we therefore hope that our model will spur others to collect such data; in this light we suggest an experiment which will help to elucidate the nature of winner and loser effects and their impact on coalition formation in animals. (+info)
Disentangling the impact of low cognitive ability and inattention on social behavior and peer relationships. Conduct Problems Prevention Re search Group.
(46/2225)
Examined the shared and unique contributions of low cognitive ability and inattention to the development of social behavior problems and peer relationships of children at the time of school entry. Kindergarten and first-grade assessments of cognitive ability, inattention and prosocial and aggressive behavior were collected for a multisite, normative sample. Sociometric assessments of peer relationships were collected at the end of first grade. Cognitive ability and inattention both contributed to the prediction of social behavior and peer relationships. Low cognitive ability was particularly predictive of prosocial skill deficits, and social behavior mediated the relation between cognitive ability and social preference. Inattention predicted both prosocial skill deficits and elevated aggressive-disruptive behavior problems. Behavior problems partially mediated the relation between inattention and social preference. Identified subgroups of children with elevated levels of inattention or low cognitive ability showed different patterns of peer problems, with low acceptance characteristic of the low cognitive ability (only) group and high dislike ratings characteristic of the inattentive and inattentive/low-ability group. Implications are discussed for the design of early intervention and prevention programs. (+info)
Behavioral effects of central administration of the novel CRF antagonist astressin in rats.
(47/2225)
Astressin, a novel corticotropin releasing factor (CRF) antagonist, has been found to be particularly potent at inhibiting the hypothalamo-pituitary-adrenal axis. The aim of the present study was to determine the effects in rats of astressin in attenuating the anxiogenic-like response produced by social stress and intracerebroventricular (ICV) CRF administration on the elevated plus-maze, and ICV CRF-induced locomotor activation in the rat. Astressin significantly reversed the anxiogenic-like response induced by both social stress and ICV rat/humanCRF (r/hCRF) on the elevated plus-maze, but failed to block the effects of r/hCRF-induced locomotor activity in a familiar environment. When these results were compared to previous studies performed with the same paradigms using other CRF antagonists, astressin showed effects similar to those of D-PheCRF(12-41) on plus-maze performance. However, contrary to alpha-helicalCRF(9-41) and D-PheCRF(12-41), astressin had no effect on CRF-induced locomotor activity. These results suggest that astressin may have a unique anti-CRF profile compared to previously tested antagonists. (+info)
Differential behavioral effects of plasma tryptophan depletion and loading in aggressive and nonaggressive men.
(48/2225)
Preliminary findings indicate that men with high trait hostility may be prone to aggression increases following plasma tryptophan (Trp) depletion. We measured laboratory aggression in men selected for presence (n = 12) or absence (n = 12) of aggressive histories. Testing occurred before and after plasma Trp depletion, Trp loading, and under a food-restricted control condition. Subjects were provoked by subtractions of money, and aggression was measured as the responses the subject made to ostensibly subtract money from the instigator of the subtractions. When subjects were highly provoked, there was a significant Trp condition x aggression history interaction effect on aggressive responding. In particular, laboratory aggression in aggressive men was elevated under Trp-depleted conditions relative to Trp-loaded conditions, whereas the opposite occurred in nonaggressive men. Moreover, plasma total Trp levels after Trp loading were significantly higher in nonaggressive men, and plasma free (but not total) Trp levels after Trp loading correlated negatively with aggressive responses in the aggressive men. These data corroborate earlier findings that aggressive men may be more prone to aggression induced by reductions in plasma Trp. (+info)