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OBJECTIVES: Defective imitation of meaningless gestures has repeatedly been demonstrated in patients with apraxia and has been interpreted as being due to a deficit of motor execution. There is, however, controversy as to whether some impairment of imitation also occurs in patients with right brain damage. The aim was to compare defective imitation in patients with left and right brain damage and to explore whether there are qualitative differences between them. METHODS: Imitation was examined in 80 patients with left brain damage (LBD) and aphasia, 40 patients with right brain damage (RBD), and 60 controls for three types of gestures:hand positions, finger configurations, and combined gestures which required a defined hand position as well as a defined configuration of the fingers. RESULTS: Regardless of whether imitation of hand positions and finger configurations were tested each on their own or together, they showed differential susceptibility to RBD and LBD. Whereas imitation of finger configurations was about equally impaired in RBD and LBD, defective imitation of hand positions occurred almost exclusively in patients with LBD, and whereas controls as well as patients with RBD committed less errors with hand positions than with finger configurations, the reverse was the case in patients with LBD. CONCLUSIONS: The pattern of results goes against a deficit of motor execution as being the cause of defective imitation in patients with LBD, as it is difficult to see why such a deficit should affect proximal movements necessary for reaching hand positions more than differential finger movements. An alternative explanation would be that in patients with LBD errors are due to defective mediation by knowledge about the human body whereas in patients with RBD they stem from faulty visuospatial analysis of the demonstrated gesture.
Eight young Lemur macaco were observed in a zoo during the first 19 weeks of life. Data were obtained on general motor development, development of independence from the mother, contributions of mothers and young to thhe maintenance of proximity, nursing, grooming, relations between twins, play, feeding, sexual dichromatism, and communication. The results are compared with similar data from other prosimians and from anthropoid primates, and some suggestions made about the evolutionary and adaptive significance of certain aspects of L. macaco development.
The effect of intruder status in territorial aggression on behavior in the elevated plus-maze, the open field and on 5-HT2 receptor-mediated behaviors was evaluated in male Long-Evans hooded rats. Intruders (350 g) were placed in the home cages of aggressive resident rats (475-600 g) and removed after 20 roll-tumble fights. On the following day, the rats were tested on the elevated plus-maze, and behavior in the open field was evaluated after injection with the 5-HT2/1C receptor agonist, DOI (1.0 mg/kg). The number of headshakes following DOI injection are thought to be an indicator of 5-HT2 receptor function. Although several other stressors were evaluated, only defeat in territorial aggression caused a significant decrement in the number of headshakes following DOI injection. To determine if ethanol (ET) could decrease the behavioral consequences of defeat, the effect of ET (1.25 g/kg) given before and immediately after aggression on behavior 24 hours later was evaluated. Although ET treatment had no effect on the control group that did not experience aggression, the ET treatment attenuated the desensitization of 5-HT2 receptor-mediated responses induced by aggression and severely exacerbated the anxiety-like effects as measured in the elevated plus-maze. These data suggest that (1) 5-HT2 receptor sensitivity decreases as a consequence of defeat, but not after several other stressors; (2) defeat in territorial aggression results in significant anxiety-like effects in the elevated plus-maze 24 hours later; and (3) these anxiety-like effects are exacerbated when ET is given before, and immediately after, the aggression.(ABSTRACT TRUNCATED AT 250 WORDS)
This experiment examined the use of attentional stimuli for reaching in hemispace by strong right-dominant adults and children. Driving the hypothesis was the notion that developmental factors associated with use of attentional information may affect the programming of reaching movements in hemispace. Although the general pattern of responses was similar for both samples, children did not use attentional cues to program reaching movements in contralateral hemispace as effectively as adults. This result suggests that motor dominance and perhaps other factors were pivotal in motor programming for children. One possible explanation for the general behavior observed underlies an attentional hemispheric bias for a tendency to use the hand that is on the same side as the stimulus.
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Interleukin-2 (IL-2), released from activated T cells, influences central neurochemical functioning, and IL-2 immunotherapy in cancer patients may provoke neuropsychiatric and cognitive disturbances. In this study, acute, systemic IL-2 did not influence Morris water-maze performance in mice. In contrast, chronic IL-2 impaired performance when the position of the escape platform varied over days but was without effect when the platform position was fixed. These effects could not be attributed to illness, because IL-1beta, which induces marked malaise, did not influence water-maze performance. Chronic IL-2 produced modest reductions in exploration and approach to a novel stimulus, effects not seen after acute treatment, but did not influence spontaneous alternation performance or behavior in an elevated plus-maze test. Thus, repeated IL-2 may influence spatial working memory without affecting habituation/ attentional processes or anxiety.
We habitually use qualitative terms to describe relationships. This paper is concerned with methods for describing, assessing and classifying these qualities objectively. Some judgements about qualities depend on which interactions occur, some concern qualities of the interactions themselves, and some depend on the way in which the different interactions within a relationship are patterned. In addition some judgements depend on diverse criteria which are not necessarily correlated with each other and need not all be satisfied. Limitations of everyday concepts of quality are discussed. Our attempts to assess qualities of the mother-infant relationship in rhesus monkeys in a quantitative fashion are described. Special attention is paid to groups of measures which appear to refer to qualities which could be described as 'maternal warmth', 'maternal rejectingness', 'maternal control', and 'meshing/dissonance' (i.e. the extent to which the goals of each partner coincide with those of the other). A type of interaction which could be called 'a game' is described. Th extent to which such assessments have predictive value is discussed.
Behavioral and clinical studies have long implicated the posterior parietal cortex of primates in spatial perception and spatially oriented behavior. However, recordings from single neurons in behaving monkeys by different laboratories have resulted in divergent views with some ascribing a largely motor and others a largely sensory role for this region. We have designed paradigms to separate the sensory and motor components of the neural activity and have found that the cells in this area respond to both sensory stimulation and motor behavior. Thus, it is likely that this area is not solely sensory or motor, but rather is involved in higher order aspects of sensory-motor integration.
The life span of the black-hooded rat has been studied in relation to two behavioural variables: (1) habituated level of responding; and (2) emotional reactivity in the open-field arena. The results indicate a relationship between the open-field measures and life span and also with growth rate measures.
Previous studies from our team have shown that a 12 month ethanol administration induced deficits in a sequential alternation task, whereas a 6 month treatment had no effects. We have already shown that the 12 month treatment induced deficits both in diencephalic and hippocampal structures, whereas the 6 month treatment damaged only the mammillary bodies. Thus, the question remained whether or not increasing selectively the diencephalic damage by lesioning the anterior thalamic nuclei would disrupt sequential alternation in 6 month ethanol-treated mice. Results indicate that alcohol-treated mice exhibiting experimental lesions into the anterior thalamus were significantly impaired in the sequential task as compared to both controls or 6 month ethanol-treated mice. In contrast, anterior thalamic lesions in normal (no alcohol treatment) subjects induced no deficits. The relative contribution of the hippocampo-mammillo-thalamic circuitry in sequential alternation is discussed.
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This study focused on some of the determinants of schematic interactional distance based on an analysis of social learning processes. It was hypothesized that closer interpersonal constructions would be associated with a more positive rather than negative self-concept, a greater rather than lesser degree of trust, and a covert positive rather than negative self-disclosure to a significant other. One hundred fifty-nine male and female undergraduate students were administered the Tennessee Self Concept Scale and Jourard's Self-Disclosure Questionnaire. Of these Ss, 82 were also given either positive or negative covert self-disclosure conditions. Interactional distances consisted of "Self" placements in relation to several key social target representations. The results supported the hypothesis regarding the relationship between self-concept and psychological distance, but only for females. There was also a tendency for more trusting females to produce closer distances than less trusting females. These results, as well as the obtained significant sex differences in distancing responses and in renditions of vertical displacements, were discussed within the context of culturally determined sex role differences.
The effects of cage density on pullet live performance and blood indices of stress were evaluated in two commercial White Leghorn strains housed at 38, 32, 26, and 20 birds per cage from Day 1 to 6 wk of age, and 19, 16, 13, and 10 birds per cage from 6 to 18 wk. Cage densities of 26 and 13 birds per cage represent a U.S. standard of 142 and 284 cm2 per bird that is often applied in commercial pullet rearing. Cage density treatments include confounding cage, feeder, and drinker spaces per bird as might be encountered in commercial practice when growing more pullets per cage. Body weight was significantly reduced at greater bird densities in both strains; however, one strain was affected as early as 6 wk of age, whereas in the other strain, body weight was not reduced significantly until 18 wk. Feed intake was increased by more than 13% in both strains at the lowest density treatment (20 birds per cage) from Day 1 to 2 wk but reduced by more than 9% by higher cage densities during the remainder of the study. Feed conversion (FC) ratio was similarly improved (i.e., reduced) when more pullets were housed per cage, and increased when fewer birds were placed per cage compared to the standard. Despite a significant reduction in feed intake and a corresponding loss of body weight, cage density treatments had no significant affect on hemagglutinin titers to sheep red blood cell antigen, percentage heterophils (H), lymphocytes (L), or the H:L ratio. However, pullet age and strain differences were observed for all blood parameters. Overall, treatments allowing more cage, feeder, and drinker spaces per bird than the U.S. commercial standard provided no body weight advantage, and allowed for greater feed intake and poorer FC at several ages.
Children and adults were escorted on their first walk across our university campus and were periodically led off the original route during the return trip. During the return, we stopped prior to intersections on and off the original route to obtain estimates of place recognition accuracy and confidence. The subjects were then asked to point to the path that led back to the start and were corrected if wrong. Accuracy of place recognition was intermediate in a way-finding task requiring reversal of an incidentally learned novel route. However, accuracy increased as subjects were farther from the original route, indicating that the presence of novel landmarks boosted the discrimination of old and new places. Eight-year-old children were less accurate than 12-year-old children and 25-year-old adults, who did not differ in accuracy. There was a similar age difference in the ability to point to the direction to return when subjects correctly recognized that they were off route. The results are used to develop a model of way finding by place recognition.
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