Search results for "Orientin"
showing 10 items of 27 documents
Electrodermal and phasic heart rate responses in the Guilty Actions Test: comparing guilty examinees to informed and uninformed innocents.
2007
The present mock-crime study concentrated on the validity of the Guilty Actions Test (GAT) and the role of the orienting response (OR) for differential autonomic responding. N=105 female subjects were assigned to one of three groups: a guilty group, members of which committed a mock-theft; an innocent-aware group, members of which witnessed the theft; and an innocent-unaware group. A GAT consisting of ten question sets was administered while measuring electrodermal and heart rate (HR) responses. For informed participants (guilty and innocent-aware), relevant items were accompanied by larger skin conductance responses and heart rate decelerations whereas irrelevant items elicited HR accelera…
An empirical test of Sokolov's entropy model of the orienting response.
1974
Several hypotheses, most of them deduced from Sokolov's entropy model of the Orienting Response (OR), were tested. The Galvanic Skin Response (GSR) served as the indicator of the OR. Printed language, analyzed with regard to the information content in bits, was used as stimulus material. Forty-eight female students served as subjects. The results indicate: (1) that the uncertainty of a situation does not determine the strength of the OR, (2) that the strength of the OR depends on the information carried by an event, and (3) that the processing of this information, as indicated by the OR, may be delayed by one or more events in a serial application. For tonic level over a series of events no…
Some Necessary Revisions of the Neuronal Model Concept of the Orienting Response
1978
Sokolov's neural trace model as well as his entropy model of the orienting response are examined. Both seem inadequate for empirical and theoretical reasons. The role of the relevance aspect of a stimulus is stressed. It is proposed to consider the information transmitted by a stimulus as in some way being weighted by the relevance of the context to which it belongs. It is furthermore proposed to restrict the neural trace concept to the physical properties of the stimulus. Major theoretical gain is achieved by viewing information content of a stimulus and its physical properties independently and by breaking the motivation determining the strength of an orienting response into a situation-s…
Structure-activity relationships of polymethoxyflavones and other flavonoids as inhibitors of non-enzymic lipid peroxidation
1990
Polymethoxylated flavones and C-glycosyl derivatives isolated from medicinal plants besides other flavonoid compounds were studied for their influence on lipid peroxidation induced by FeSO4+ cysteine in rat liver microsomes. A number of hydroxyflavones (e.g. luteolin); C-glycosyl-flavones (e.g. orientin); methoxyflavones (e.g. gardenin D) and flavonols (e.g. datiscetin), as well as the flavanol leucocyanidol and the biflavone amentoflavone behaved as inhibitors of non-enzymic lipid peroxidation. Structure-activity relationships were established and it was observed that the structural features for active polyhydroxylated compounds were different from those of polymethoxylated flavones, antip…
Multivariate analysis of the modifications induced by an environmental acoustic cue on rat exploratory behavior.
2007
The aim of the present paper is to study by means of a multivariate analysis the modifications induced by an environmental acoustic cue on the structure of rat exploratory behavior. Adult male Wistar rats were observed during the exploration of a soundproof observation box. Each rat was acoustically stimulated after 150 s from the beginning of the experimental session, lasting 300 s, and recorded through a digital videocamera. A frame by frame analysis was thereafter carried out using a professional video-recording system. Thirteen behavioral patterns were selected: immobility, immobile-sniffing, walking, rearing, climbing, chewing, paw-licking, face-grooming, body-grooming, head-turning, t…
Hippocampus responds to auditory change in rabbits
2010
Any change or novelty in the auditory environment is potentially important for survival. The cortex has been implicated in the detection of auditory change whereas the hippocampus has been associated with the detection of auditory novelty. Local field potentials (LFPs) were recorded from the CA1 area of the hippocampus in waking rabbits. In the oddball condition, a rare tone of one frequency (deviant) randomly replaced a repeated tone of another frequency (standard). In the equal-probability condition, the standard was replaced by a set of tones of nine different frequencies in order to remove the repetitive auditory background of the deviant (now labelled as control-deviant) while preservi…
Electrodermal habituation speed and visual monitoring performance.
1984
Previous research has suggested that speed of habituation of the electrodermal orienting response is related to auditory vigilance performance. The present study investigated the relationship between habituation speed, nonspecific response frequency, and detection performance in a complex visual monitoring task. Two levels of task difficulty were employed. In the visual monitoring task, correct detections declined across blocks, and fewer signals were detected in the difficult task condition. Slow habituators detected more signals than fast habituators, but NSR-frequency was not significantly related to the number of correct detections. The implications of these findings for different model…
Analisi delle modificazioni indotte dalla microgravità sulla reazione di orientamento indotta nel ratto da stimoli acustici.
2004
Experiments were performed on male Wistar rat during the 4th ESA Student Parabolioc Flight Campaign. Analysis of head turning movement has been employed to study mechanisms involved in sensorimotor integration. Results showed a significant increase both in latency and duration of the response in microgravity condition. A modified cerebellar elaboration process of peripheral proprioceptive and vestibular signals during microgravity has been hypothesized.
Behavioral and hippocampal evoked responses in an auditory oddball situation when an unconditioned stimulus is paired with deviant tones in the cat: …
1995
Event-related potentials (ERP) in the areas CA1, CA3 and dentate fascia (Df) of the hippocampal formation were recorded during an oddball situation in the cat. A rewarding electrical stimulation of the lateral hypothalamus (US) was paired with deviant tones (2500 Hz) that occurred randomly in a series of the standard tones (2000 Hz) given to the left ear. In addition to developing orienting head movements to the side of the deviant tones, an increase in the amplitude of parallel hippocampal ERPs was observed. Both the behavioral and neural responses appeared not until a 50 ms latency range. Furthermore, time-amplitude characteristics of the ERPs corresponded to time-acceleration characteris…
Secoiridoids and Xanthones fromGentianella nitida
1996
From Gentianella nitida twelve known metabolites were isolated and identified by HPLC-UV and/or by spectroscopic methods as secologanoside, amaroswerin, amarogentin (secoiridoids), isoorientin (C-glucosylflavone), mangiferin, demethylbellidifolin 8-O-glucoside, norswertianine 1-O-glucoside, swertianine 1-O-primeveroside, swertianine 8-O-glucoside, norswertianine, demethylbellidifolin, and swertianine (xanthone glycosides and aglycones). Secologanoside is reported here for the first time in Gentianaceae species ; the antioxidant mangiferin was obtained as the major compound in good yield.