Individuelle Lernstrategien von Totenkopfäffchen bei der Diskriminierung von visuellen Sequenzen

Zusammenfassung Durch 5 Lehrprogramme wurden Totenkopfäffchen in einer instrumentellen Verhaltenssituation darauf trainiert, Sequenzen von zwei Lichtern (weiß und blau; A und B) voneinander zu unterscheiden. In Programm 5 wurden alle 4 Permutationen der Elemente A und B, also AB, BA, AA und BB als Lichtreize verwendet. Die Beantwortung von B in AB wurde belohnt.Die Analyse der Strategien der Tiere in Programm 5 ergab verschiedene Strategien für verschiedene Tiere bei der Konfrontation mit den verschiedenen Sequenzen trotz des gleichen Vortrainings der Tiere: Zufallsbeantwortung, Beantwortung des zweiten Lichtes der Sequenzen, Beantwortung von B in 2. Position, Beantwortung nach jedem Stimulus A und jedes Stimulus A in 1. Position.Von 7 Tieren erreichten 4 die für diese Diskriminierung notwendige Strategie Beantwortung von B nach Stimulus A.3 Tiere verbliehen bis zum Schluß in der Strategie Beantwortung nach einem Stimulus A in 1. Position, die eine Vorstufe der Sequenzendiskriminierung darstellt.Durch die durchgeführte Analyse ist auch eine Beurteilung von Beantwortungsschemata möglich, die noch keine Diskriminierung von Sequenzen darstellen und damit eine Beurteilung dessen ermöglicht, was einem Versuchttier von der dargebotenen Information relevant geworden ist. Das Verhaltensmodell ist entwickelt zur Verwendung bei verschiedenen Manipulationen im Zentralnervensystem (Ausschaltungen, Psychopharmaka), bei den Effekten in den zeitlichen Parametern des Lernprozesses zu erwarten sind oder beurteilt werden sollen.

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Individual learning strategies for discrimination between visual sequences in squirrel monkeys

Summary Squirrel monkeys were trained to discriminate between the four permutations of a two-element sequence of colored lights (white and blue, A-B). Five teaching programs were developed to direct the animals' activity in an instrumental behavioral situation. In Program 5 the animals were confronted with all possible sequences in randomized order and were only rewarded if they pressed a lever in the B-part of sequence AB.Analysis of the animals' strategies revealed different strategies in different animals when exposed to program 5, although the animals had undergone the same training previously: Random responding, responding to the second part of each sequence, responding to B in the second position of a sequence, responding after each stimulus A, and responding after each stimulus A in the first position of a sequence.Four out of 7 animals reached the necessary strategy for real discrimination of sequences, namely responding to B after a stimulus A.Three animals faited to advance beyond the strategy responding after a stimulus A in the first position of a sequence, which represents the closest strategy before real discrimination of the sequences.The analysis performed makes it possible to find out which cues the animals use in the performance of the task, even if the animal has not yet reached true discrimination between sequences.The experimental model has been developed for use as a sensitive instrument for the detection or assessment of changes in the temporal parameters of the learning process in experiments where manipulations of the central nervous system (lesions, drug) make such changes likely.

     

Active hippocampus during nonconscious memories

The hippocampal formation is known for its importance in conscious, declarative memory. Here, we report neuroimaging evidence in humans for an additional role of the hippocampal formation in nonconscious memory. We maskedly presented combinations of faces and written professions such that subjects were not aware of them. Nevertheless, the masked presentations activated many of the brain regions that unmasked presentations of these stimuli did. To induce a nonconscious retrieval of the faces and face-associated occupational information, subjects were instructed to view the previously masked faces and to guess the professional category of each person--academic, artist, and workman. Guessing the professional category of previously masked versus new faces activated the left and right hippocampal formation and right perirhinal cortex as well as bilateral fusiform areas and fronto-temporal areas known to mediate the retrieval of semantic information. These activations within the semantic processing system suggest that conceptual knowledge acquired during masking was nonconsciously retrieved. Our data provide clues to an analogous role of the hippocampus in conscious and nonconscious memory.     

AMICAI: A Method Based on Risk Analysis to Integrate Responsible Research and Innovation into the Work of Research and Innovation Practitioners

Science and Engineering Ethics - The integration of ethics into the day-to-day work of research and innovation (R&I) is an important but difficult challenge. However, with the Aachen method...     

Conversing while driving: The importance of visual information for conversation modulation

Multiple studies have shown an increased accident risk due to telephoning while driving. On the other hand, driving with passengers leads to a decreased accident risk. One explanation is a conversation modulation by passengers in cars which leads to a different conversation pattern which is not so detrimental to driving as that when phoning. A driving simulator study was conducted in order to examine this conversation modulation more closely and to find out more about the factors involved in this modulation, especially about the role of visual information available to the passenger. In a within-subject design the conversational patterns of 33 drivers and passengers in different in-car settings (passenger as usual, passenger without front view or passenger without view of the driver) were compared to a hands-free cell phone and to a hands-free cell phone with additional visual information either about the driving situation or the driver. Participants were instructed to have a naturalistic small-talk with a friend. Results of the drivers’ speaking behavior showed a reduction of speaking while driving. Compared to a conversation partner on the cell phone, a passenger in the car varies his speaking rhythm by speaking more often but shorter. Further analyses showed that this effect is also found with a cell phone when providing the conversation partner additional visual information either about the driving situation or the driver. This latter finding supports the idea that conversation modulation is not triggered by being in the car but by the visual information about the driver’s state and the driving situation.     

Computers and the nature of farm management

The introduction of computer-based information systems to be used by farmers, as in many other fields, is preceded mostly by great expectations. Some persons even tend to think that eventually the computer might take over farm management. This article tries to make an assessment of the validity of such expectations. Based upon a study among Swedish farmers, it examines the nature of farmers' decision-making. The latter is based upon an adaptive rationality, as opposed to the normative models of formal rationality used by scientists. Essential to this rationality are coordination skills: the ability of farmers to arrange the many interacting factors important to the totality of a farm in a satisfactory way. What the farmer needs in this complex situation is personal communication and tacit knowledge, knowledge that cannot be reduced to facts and rules. Consequently computer-based information systems can be useful tools only in some aspects of farm management, but they will never replace farmer's decision-making. To understand the possibilities of the computer as a tool in farm management, a distinction between interpretation skills and application skills is necessary.     

Höhen- und Zeitmaße der psychogalvanischen Reaktion

Zusammenfassung Höhen- und Zeitwerte psychogalvanischer Reaktionen, die auf Grund verschieden starker und verschieden langer akustischer Reizung entstanden waren, wurden miteinander verglichen. Stärke und Dauer der Reizung fanden stets ihren Ausdruck in der Höhe der Reaktion, in einigen Fällen auch in deren Dauer. Sofern überhaupt kontrollierte Unterschiede zwischen ihnen auftraten, standen die Zeitwerte in positiver Beziehung zu den Reaktionshöhen. Es scheint demnach nicht statthaft zu sein, Höhe und Dauer der psychogalvanischen Reaktion als voneinander unabhängige Variable zu betrachten; damit fehlt eine wesentliche Voraussetzung für eine Verbindung beider Meßgrößen zu einem Flächenbzw. Integralmaß.Herr Prof. Rausch hat zu dieser Arbeit wertvolle Anregungen gegeben; die Verfasser möchten ihm auch an dieser Stelle herzlich dafür danken.Man fragt sich natürlich, ob sich bei der durchschnittlich geringen Kovariation von Ausgangswert und Zeitwerten der psychogalvanischen Reaktion die Mühe einer Transformation lohnt. In der Tat dürfte häufig der Fehler, den man begeht, wenn man auf eine Korrektur verzichtet, kaum ins Gewicht fallen. Die Höhe der Korrelation scheint jedoch auch von der Beschaffenheit der Versuchsbedingungen abzuhängen und — wie es sich vor allem in Tabelle 10 andeutet — mit der Länge der gemessenen Zeiten anzuwachsen. Je affektiver die Vpn also reagieren, desto ernsthafter wird man sich mit der Frage zu befassen haben, ob die Zeitwerte der Keaktion von der Höhe der jeweiligen Ausgangswiderstände unabhängig gemacht werden müssen.     

Höhe und Dauer der galvanischen Reaktion als einfache und multiple Vorhersagevariablen

Ohne Zusammenfassung