Effects of Long-Term Memory on Visual Attention and Access to Visual Consciousness

In dieser Dissertation zeige ich anhand einer Reihe von Beispielen, wie das Langzeitgedächtnis die perzeptuelle Verarbeitung beeinflussen kann. Anhand einer Aufgabe zur visuellen Aufmerksamkeit verdeutliche ich, inwiefern episodische Erinnerungen perzeptuelle Distrakoreffekte reduzieren können. In Experiment 1 sollten Versuchspersonen zuvor gelernte Worte entweder ins Gedächtnis zu rufen oder die Erinnerung an die Worte zu unterdrücken. Anschließend mussten sie unter Zeitdruck neue, bisher nicht präsentierte Worte semantisch einordnen, wobei die Zielworte von den zuvor abgerufenen oder unterdrückten Worten flankiert waren. Da die flankierenden Worte für die semantische Entscheidungsaufgabe irrelevant und die Versuchspersonen instruiert worden waren, diese zu ignorieren, kann von einem perzeptuellen Distraktoreffekt ausgegangen werden. Distraktoreffekte waren für zuvor unterdrückte Gedächtnisinhalte im Vergleich zur abgerufenen Gedächtnisinhalten deutlich reduziert, was nahelegt, dass episodische Gedächtnisinhalte die Wahrnehmung beeinflussen. Auf dieser Erkenntnis aufbauend zeige ich in Experiment 2, wie die suppressionsinduzierte Reduktion der Verarbeitung von Distraktorreizen durch individuelle Differenzen maskiert werden kann. Schließlich wurden den Versuchspersonen in Experiment 3 in einer „Attentional-Blink“-Aufgabe unbekannte Objekte als zweites von zwei aufeinander folgenden Zielobjekten dargeboten. Versuchspersonen konnten Objekte, die mit einer neu gelernten semantischen Information assoziiert waren, besser erkennen als Objekte, die mit minimaler Information assoziiert waren. Dieser Effekt ging mit einer Modulation der ereigniskorrelierten Potenziale 100ms nach Erscheinen des Reizes einher. Diese Ergebnisse zeigen, dass Inhalte aus dem Langzeitgedächtnis Wahrnehmungsprozesse beeinflussen können und leisten damit einen weiteren Beitrag zur Erkenntnis, dass die Wahrnehmung gegenüber höheren Kognitionen nicht unabhängig ist.Numerous studies are emerging which suggest that long-term memories can influence early perceptual processing. Notwithstanding, these finding have come under fire from critics who view perceptual processing as independent of cognition. In this dissertation I demonstrate novel instances of long-term memory effects on perceptual processing, both in the context of an attentional task where I look at the extent to which episodic memory can reduce perceptual distraction and in a conscious detection task where I assess the effect of semantic knowledge on peoples ability to consciously detect briefly presented objects. In experiment one, participants retrieved or suppressed previously memorised words. Following this task, participants made speeded semantic judgments on novel target words that were flanked by the words that had previously undergone suppression or retrieval. Because the flanking words were irrelevant to the semantic judgment and were supposed to be ignored, any influence of their presence on semantic judgment speed can be taken as a marker of perceptual distraction. Results showed that the tendency for flankers to distract from target processing was markedly reduced if those flankers had undergone suppression. In experiment two, I expanded upon this finding by showing how this suppression-induced reduction in distractor processing can be masked by individual differences. Finally, in experiment three, I presented pictures of novel objects to participants as the second of two targets in an attentional blink paradigm. Results showed that participants were able to perceive objects associated with newly acquired semantic knowledge better than objects associated with minimal knowledge, a finding that was associated with a modulation of event-related brain potentials 100 msec after stimulus onset. Taken together, these experiments contribute to the growing body of evidence showing that information from long-term memory can influence perceptual processing

Towards redistribution laser cooling of molecular gases: Production of candidate molecules SrH by laser ablation

Laser cooling by collisional redistribution of radiation has been successfully applied in the past for cooling dense atomic gases. Here we report on progress of work aiming at the demonstration of redistribution laser cooling in a molecular gas. The candidate molecule strontium monohydride is produced by laser ablation of strontium dihydride in a pressurized noble gas atmosphere. The composition of the ablation plasma plume is analyzed by measuring its emission spectrum. The dynamics of SrH molecular density following the ablation laser pulse is studied as a function of the buffer gas pressure and the laser intensity.Comment: Laser Refrigeration of Solids VI, February 2 2013, San Francisco, USA, Conference Proceeding

Was WALL-E’s Fire extinguisher adequate for his space scene?

This paper investigates Disney’s movie WALL-E and whether the fire extinguisher he uses had enough carbon dioxide, CO2, in it, to last for his entire space flight and if not, how many extinguishers he would require and the actual mass of CO2. The extinguisher used by WALL-E was estimated to contain 2 kg of CO2. The findings of the paper were that WALL-E’s extinguisher was not of adequate size and would have lasted only 16 s of the scene which lasted 105 s. For the completion he would have required 6 further extinguishers, totalling 7. With impurities of an extinguisher considered the actual mass of CO2 required was calculated to be 13.77 kg and not 14 kg

Would The Doctor and Martha Have Survived on the Moon with the Judoon?

This paper investigates a Doctor Who episode, Smith and Jones, where a hospital and its inhabitants are transported to the moon by an alien race and whether it was feasible for them to have survived for as long as they did or longer due to a limited air supply. The finding was that they had nearly 105 days of oxygen supply, a considerably longer amount of time than the half an hour of supply shown in the episode

What Does Kirks Radiation Poisoning Tell Us About The USS Enterprise?

This paper calculates the power output of Star Treks’ USS Enterprise warp core if modelled as a uranium powered fission reactor using Captain Kirk’s radiation poisoning symptoms as seen in the movie, Star Trek Into Darkness. Kirk was said to have received a dose of 30 Gy and through subsequent calculations the power output was determined to be 32 MW

What Does Kirks Radiation Poisoning Tell Us About The USS Enterprise?

This paper calculates the power output of Star Treks’ USS Enterprise warp core if modelled as a uranium powered fission reactor using Captain Kirk’s radiation poisoning symptoms as seen in the movie, Star Trek Into Darkness. Kirk was said to have received a dose of 30 Gy and through subsequent calculations the power output was determined to be 32 MW

Prediction regions for the visualization of incomplete datasets

A complication in the visualization of biomedical datasets is that they are often incomplete. A response to this is to multiply impute each missing datum prior to visualization in order to convey the uncertainty of the imputations. In our approach, the initially complete cases in a real-valued dataset are represented as points in a principal components plot and, for each initially incomplete case in the dataset, we use an associated prediction region or interval displayed on the same plot to indicate the probable location of the case. When a case has only one missing datum, a prediction interval is used in place of a region. The prediction region or interval associated with an incomplete case is determined from the dispersion of the multiple imputations of the case mapped onto the plot. We illustrate this approach with two incomplete datasets: the first is based on two multivariate normal distributions; the second on a published, simulated health survey

Bringing together bibliometrics research from different disciplines – what can we learn from each other?

Currently, there is little exchange between the different communities interested in the domain of bibliometrics. A recent conference aimed to bridge this gap. Peter Kraker, Katrin Weller, Isabella Peters and Elisabeth Lex report on the multitude of topics and viewpoints covered on the quantitative analysis of scientific research. A key theme was the strong need for more openness and transparency: transparency in research evaluation processes to avoid biases, transparency of algorithms that compute new scores and openness of useful technology