Wyniki wyszukiwania - Biblioteka Nauki

1

INHIBITORY PROCESSES, LEARNING AND MEMORY IN THE MECHANISMS OF ATTENTIONAL SELECTION - THE IMPLICATIONS OF NEGATIVE PRIMING

100%

Kowalczyk M.

Psychologia-Etologia-Genetyka

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2005

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tom 11

31-63

EN

The author analyses implications of the results of research on negative priming for the theory that attributes this phenomenon to inhibitory mechanisms in selective attention. According to an early inhibitory account of negative priming, the representation of the stimulus ignored or selected against in the prime (preceding) display is actively suppressed, which entails a short-term decrease in the representation's activation level below baseline. As a result, when a response to this stimulus is required in the probe (subsequent) display, accessing the stimulus representation may be more difficult. Contrary to this account, it was found that negative priming may persist for quite a long time and that it depends on the conditions in, and on the broader context of, the probe display in which an earlier distractor appears as the target. These results are congenial with noninhibitory accounts of negative priming, which attribute the effect to a conflict or difficulty arising when on the probe trial an episodic representation of the probe target is retrieved that was established when this stimulus served as a distractor. Following the integrative proposal put forward by Tipper (2001), the author considers modifications the inhibitory account seems to require to accommodate the data indicating that both inhibition and memory processes play a role in negative priming. A basic change is a revision of the assumptions concerning the way the effects of inhibition are carried over from the prime trial to the probe trial. A modified inhibitory account assumes that this transfer involves memory coding (on the prime trial) and retrieval (on the test trial) of inhibitory processes or their effects. It is shown that this modification necessitates a revision of other assumptions of the original inhibitory account, especially those concerning the nature of the representations involved in negative priming and the very concept of inhibition. Taking into account the role learning and memory processes play in selective attention puts the mechanisms of the latter in a new theoretical perspective. The transition is from analysing attentional selection in a narrow focus of the question that concerns how the organism solves a current problem of distinguishing task-relevant stimuli from distractors, to analysing it in a broader context of the issue of how the organism in its interactions with a given environment learns to categorise stimuli as relevant or irrelevant, to represent them in the context of an activity as those that should be attended to and those that should be ignored.

2

Memory for words related to demands of a problem solved prior to encoding: An Investigation into inhibitory mechanisms of defence against distraction

100%

Kowalczyk M.

Polish Psychological Bulletin

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2006

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tom 37

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nr 3

154-171

EN

Participants solved a simple divergent problem, then performed an ostensibly unrelated speeded classification task concerning each of a series of nouns, and then free recalled the nouns. Some of the nouns in the classification task corresponded to certain demands of the problem. Recall of these nouns was analysed as a function of response-to-stimulus interval (RSI) in the classification task. Earlier studies by the author indicated that memory for such words tends to be impaired. This has been attributed to inhibitory defence against current-goal-irrelevant processing they cause in the classification task. On the assumption that the processing and the inhibitory counteraction needs time to develop between the consecutive words, impaired recall was expected at some longer and not at some shorter RSIs. Indeed, recall of problem-related words was worse in the 1550-ms RSI condition than in the 1150-ms RSI condition. Unexpectedly, however, in the 350- and 750-ms RSI conditions recall was also impaired relative to the 1150-ms RSI condition. The latter did not differ from the 1150-ms RSI control condition, in which the problem was not solved. A revised model is proposed to account for the data, which assumes that strategically controlled inhibition may block task-irrelevant processing at an earlier or at a later phase, decreasing the accessibility of the memory contents involved.

3

Inhibitory control of the Defence-Aggression reaction including its cardiovascular components

100%

Zbrozyna A. W. , Westwood D. M.

Acta Neurobiologiae Experimentalis

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1993

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tom 53

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nr 1

209-213

EN

Defence-Aggression Reaction including its cardiovascular components may be inhibited during habituation or by stimulation in the restricted area of the prefrontal cortex. During the process of habituation components of the Defence-Aggression Reaction are inhibited on the level of nucleus paragigatocellularis lateralis of the ventral lateral medulla. The prefrontal cortex probably plays an important role in developing inhibition during habituation of the Defence-Aggression Reaction.

4

Partial characterization of a lipase from gypsy moth (Lymantria dispar L.) larval midgut

100%

Mrdakovic M. , Lazarevic J. , Peric_Mataruga V. , Ilijin L. , Vlahovic M.

Folia Biologica

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2008

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tom 56

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nr 1-2

103-110

EN

Lipase activity of the gypsy moth (Lymantria dispar L.) was studied by the spectrophotometric method using crude homogenate of fifth-instar larval midgut tissues as the enzyme source and p-nitrophenyl caprylate (pNPC) as substrate. A Km value of 0.310mM and a Vmax value of 1.479U/mg prot. were obtained for this substrate. Among various p-nitrophenyl esters tested, maximum activity was obtained for p-nitrophenyl caprylate and p-nitrophenyl caprate. The enzyme was most active at alkaline pH, with maximum at pH 8.2. Decreased activity was detected after preincubation in buffers of pH below 7.0 and above 8.2. The enzyme was unstable at room temperature. The enzyme was Ca2+ independent. Its activity was inhibited by PMSF, Fe2+, Ag+ and Pb2+, while Fe3+ inhibited enzyme activity by about 40%.

5

Physiological basis of pathophysiological brain rhythms

100%

Witte O. W.

Acta Neurobiologiae Experimentalis

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2000

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tom 60

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nr 2

289-297

EN

Focal epilepsy may be induced acutely in the brain in vivo by measures which reduce inhibition or enhance excitation. Athough the various models involve different mechanisms causing the epilepsy, their epileptiform discharge patterns vary only little. Intracellular analyses in vivo and in vitro reveal that the cellular hallmark of epileptic discharge, the paroxysmal depolarization shift, is followed by a giant hyperpolarization. The latter is comprised of several, overlapping, components with different durations, including calcium dependent potassium currents and GABA dependent inhibitions. Relative reduction of one inhibitory component is compensated by other inhibitory components. In epilepsy caused by reduction of GABAergic inhibition, the absolute duration and amplitude of GABAergic inhibition may even be increased in comparison to the responses following afferent stimulation under control conditions since the excitatory drive of the paroxysmal discharges on the interneurons is strongly increased. In some interictal discharge patterns, the enhanced inhibitions within the focus determine the refractory periods of the focus. The latter is paced by neurons from the perifocal area which show a shorter inibition associated with the interictal epileptic event. The discharge pattern of the focus may switch to other patterns, either spontaneously, or as entrained by external stimulation. Such changes are caused e.g. by progressive potassium accumulations in the extracellular space with critically small intervals of the epileptic events. It is concluded that the epileptiform discharge patterns reflect intrinsic properties of the brain, and do not very well reflect the mechanism of action of the epileptogenic model. The brain is thus equipped with inherent mechanisms which favor rhythmic epileptiform discharges under certain conditions.

6

TRAIT IMPULSIVITY AND OCULOMOTOR INHIBITION

88%

Taylor A. J. G.

Studia Psychologica

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2016

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tom 58

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nr 2

134 – 144

EN

Trait impulsivity is multi-dimensional in nature. Researchers are beginning to explore how these dimensions of impulsivity relate to inhibitory control. When using behavioural tasks, some studies have found inhibitory control deficits in people with high levels of impulsivity. Comparatively, little is known about the relationship between oculomotor inhibition and trait impulsivity in healthy participants. The aim of this study was to determine the relationship between trait impulsivity and oculomotor inhibition. Using a sample of 80 participants, impulsivity was measured via two self-report questionnaires; oculomotor inhibition was measured with anti-saccades. In general there was no relationship between impulsivity and anti-saccade errors. Those with low scores on the BIS attentional scale made more anti-saccade errors than those with high scores. Neither anti-saccade nor pro-saccade latencies correlated with impulsivity. These findings suggest oculomotor inhibition is not impaired in individuals with trait impulsivity.

7

Suppressors of cytokine signaling proteins in innate and adaptive immune responses

75%

Dalpke A. , Heeg K.

Archivum Immunologiae et Therapiae Experimentalis

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2003

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tom 51

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nr 2

91-103

EN

Suppressors of cytokine signaling (SOCS) proteins have been identified as important mediators of negative regulatory circuits within cytokine receptor signaling. They are induced upon stimulation by an increasing set of cytokines as well as further immunological stimuli and are capable to inhibit Janus-kinases and signal transducer and activator of transcription signaling. Inhibition is mediated by interfering directly with signal transduction at the receptor as well as targeting of associated molecules for proteosomal degradation. Targeted gene deletion approaches have revealed the importance of SOCS mediated termination of cytokine signaling during normal cellular activation. In addition to their function as classical feedback inhibitors SOCS proteins display a broad panel of inhibitory activity thereby mediating cross-talk modulation between different stimuli. The consequences for regulation of innate and adaptive immune responses are thus obvious. Finally, there are emerging data showing involvement of SOCS proteins in various immune diseases. Modulating SOCS activity could be a promising new approach for molecular therapeutic strategies.

8

Determination of sludge methanogenic activity and metoxychlor toxity under anaerobic conditions

75%

Cimochowicz-Rybicka M. , Kurbiel J.

Biotechnologia

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1994

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nr 3

60-70

EN

In the investigations carried out on anaerobic biodegradation of pesticides, specific sludge activity and toxity of pesticides in batch tests were determined.The specific methanogenic sludge activity was deterined i.e. the amount of acetate as an amount of COD for methane production per gam of sludge VSS (voatile suspended solid) per 1 day. Using the toxity test the magnitude of inhibition caused by presence of Metaxychlor - organochlorine insecticide group of pesticides - was assessed.The laboratory model of UASB was used for sludge cultivtion ((for methanogenic activity tests).Total voume of the reactor was 6.4 l.A portion of digested sludge taken from a Myslenice municipal wastewater treatment plant was used as an inoculum.