422 research outputs found
Refractory effects in picture naming as assessed in a semantic blocking paradigm
In the cyclic semantic blocking paradigm participants repeatedly name sets of objects with semantically related names (homogeneous sets) or unrelated names (heterogeneous sets). The naming latencies are typically longer in related than in unrelated sets. In we replicated this semantic blocking effect and demonstrated that the effect only arose after all objects of a set had been shown and named once. In , the objects of a set were presented simultaneously (instead of on successive trials). Evidence for semantic blocking was found in the naming latencies and in the gaze durations for the objects, which were longer in homogeneous than in heterogeneous sets. For the gaze-to-speech lag between the offset of gaze on an object and the onset of the articulation of its name, a repetition priming effect was obtained but no blocking effect. showed that the blocking effect for speech onset latencies generalized to new, previously unnamed lexical items. We propose that the blocking effect is due to refractory behaviour in the semantic system
Juvenile Fish Passage Through Culverts in Alaska: A Field Study
In the past, culvert design where fish passage was considered generally has been based on the weakest-swimming adult fish in a river system. It has also been recognized for some time that juvenile fish are very active throughout the year, moving upstream and downstream in response to a number of environmental factors. In Alaska, many natal and nonnatal streams in southcentral and southeastern Alaska support both Chinook (Oncorhynchus tschawytscha (Walbaum)) and Coho (Oncorhynchus kisutch (Walbaum)) for one to three years, respectively, before they emigrate to sea. Are we restricting desirable habitat for these juvenile salmonids with hydraulic structures such as culverts? Unfortunately we have little information on either the behavior of juveniles in the vicinity of hydraulic structures or their swimming abilities. The objective of this study was to examine the behavior of juveniles when attempting to ascend a culvert. It was hypothesized that vertical obstacles or high velocity of opposing flow may prevent juvenile fish from moving upstream. It was also hypothesized that they would determine and take the path of least resistance to optimize their chances of successfully ascending a culvert.
Four culverts were selected for intensive study regarding juvenile fish passage: Beaver and Soldotna Creeks on Kenai Peninsula and No-name and Pass Creek Tributary on Prince of Wales Island. It was postulated that fish are motivated to move upstream to obtain food if they can establish its presence. We used salmon eggs as an attractive food source both to initially capture the juveniles and then to motivate them to ascend the culvert for possible recapture. Juvenile fish were captured in a baited minnow trap and stained with a dye. They were released downstream of the culvert while the food source was placed upstream in a minnow trap. We supplemented our visual observations with underwater video cameras. We made numerous hydrologic and hydraulic measurements at each site. Although we attempted to select culverts that would prove to be quite challenging to juvenile fish passage, in three of the culverts selected, juvenile fish, of the full range of the fork length initially captured, succeeded in ascending through the culvert. For the fourth culvert, some larger juvenile fish succeeded in ascending the culvert, but not the smaller of each fish type. It was clearly established that juvenile fish were motivated to move upstream to obtain food.
In the Beaver Creek culvert, fish used the large corrugations to their advantage when ascending the culverts. The Pass Creek Tributary culvert had corrugations too small for fish to utilize. No-name Creek appeared to present not problems for juvenile fish for the water levels at the time of the visit as they small along the bottom on the centerline of the culvert. In general, observations of fish attempting to move upstream through the culvert revealed that they swam very close to the culvert wall, and in the case of high velocities (Beaver Creek and Pass Creed Tributary) they swam near the surface along the sidewall where velocities are reduced. It is obvious that the juvenile fish are attempting to minimize power output and energy expenditure by taking the path of least resistance.
Although not quantitavely proven, it appears that as long as fish make some headway in their upstream movement they are content. The rationale for this conclusion is that fish do not know what they may encounter upstream so they attempt to conserve as much power and energy as possible while still moving forward. They generally do so by seeking out the lowest velocities in the cross-section. In areas of steep velocity gradients along the wall (where the areal extent of low velocities is limited), it is clear in our videotapes that fish have problems maintaining their position and preferred orientation. It is apparent from our observations that because of their small size, juvenile fish are hindered by turbulence and that this area needs more study.List of Figures - ii
List of Tables - iv
Disclaimer - v
Abstract - vi
Acknowledgment - ix
Introduction - 1
Objectives - 2
Procedure - 3
Study Sites - 8
Selection - 8
Beaver Creek - 8
No-name Creek - 9
Soldotna Creek - 12
Pass Creek Tributary - 12
Past Studies - 14
Fish Behavior - 14
Juvenile Movement - 15
Results - 16
Beaver Creek - 16
No-name Creek - 26
Soldatna Creek - 29
Pass Creek Tributary - 39
Summary - 47
Research Needs - 49
References - 5
Early activation of object names in visual search
In a visual search experiment, participants had to decide whether or not a target object was present in a four-object search array. One of these objects could be a semantically related competitor (e.g., shirt for the target trousers) or a conceptually unrelated object with the same name as the target-for example, bat (baseball) for the target bat (animal). In the control condition, the related competitor was replaced by an unrelated object. The participants' response latencies and eye movements demonstrated that the two types of related competitors had similar effects: Competitors attracted the participants' visual attention and thereby delayed positive and negative decisions. The results imply that semantic and name information associated with the objects becomes rapidly available and affects the allocation of visual attention
Liquidity and the Dynamic Pattern of Asset Price Adjustment: A Global View
Global liquidity expansion has been very dynamic since 2001. Contrary to conventional wisdom, high money growth rates have not coincided with a concurrent rise in goods prices. At the same time, however, asset prices have increased sharply, significantly outpacing the subdued development in consumer prices. We investigate the interactions between money and goods and asset prices at the global level. Using aggregated data for major OECD countries, our VAR results support the view that different price elasticities on asset and goods markets explain the observed relative price change between asset classes and consumer goods
Exchange Rate Bands of Inaction and Play -- Hysteresis in Greek Exports to the Euro Area, the US and Turkey -- Sectoral Evidence
In this paper a non-linear model is applied, where suddenly strong spurts of exports occur when changes of the exchange rate go beyond a zone of inaction, which we call 'play' area - analogous to mechanical play. We implement an algorithm describing path-dependent play-hysteresis into a regression framework. The hysteretic impact of real exchange rates on Greek exports is estimated based on the period from 1995Q1 to 2014Q4. Looking at some of the main export partners of Greece, the euro area, Turkey and the US, and some of its most important tradeable sectors we identify significant hysteretic effects for a part of the Greek exports. We find that Greek export activity is characterized by 'bands of inaction' with respect to changes in the real exchange rate and calculate the further real depreciation needed to trigger a spurt in Greek exports. To check for robustness we (a) estimate Greek export equations for a limited sample excluding the recent financial crisis, (b) use export weight instead of deflated nominal exports as the dependent variable, (c) employ a political uncertainty variable as a determinant of the width of the area of weak reaction. Overall, we find that those specifications which take uncertainty into account display the best goodness of fit. In other words: the option value of waiting dominates the real exchange rate effect on Greek exports.Analog zu mechanischem Spiel wendet dieses Paper ein nichtlineares Modell an, in dem plötzlich starke Reaktionen der Exporte auftreten, wenn die Wechselkursveränderung eine inaktive Zone überschreitet, welche als 'play area' bezeichnet wird. Wir implementieren einen Algorithmus, der pfadabhängige Hysterese beschreibt, in einem Regressionsmodell. Der hysteretische Einfluss des realen Wechselkurses auf griechische Exporte wird für die Periode von 1995Q1 bis 2014Q4 geschätzt. Wir finden signifikante hysteretische Effekte für einen Teil der griechischen Exporte bei der Betrachtung einiger Hauptexportpartner Griechenlands, wie die Eurozone, die Türkei und die USA unter der Berücksichtigung der wichtigsten Handelssektoren. Es zeigt sich, dass griechische Exporte durch ein 'Band of Inaction' in Bezug auf Veränderungen des realen Wechselkurses charakterisiert sind, und wir berechnen die weitere Abwertung, die benötigt wird, um eine starke Exportreaktion für Griechenland auszulösen. Um auf Robustheit zu prüfen; (a) schätzen wir die Exportgleichungen für einen begrenzten Zeitraum und berücksichtigen nicht die jüngste Finanzkrise, (b) verwenden wir Mengenangaben für die Exportreihen statt nominaler Werte, (c) wird politische Unsicherheit als Determinante für die Breite der schwachen Exportreaktionen implementiert. Allgemein stellt sich heraus, dass jene Spezifikationen, die Unsicherheit berücksichtigen, die beste Güte zeigen. Anders formuliert dominiert der Optionswert abzuwarten den realen Wechselkurseffekt griechischer Exporte
Global Liquidity and House Prices: A VAR Analysis for OECD Countries
Global monetary dynamics has been particularly strong in recent years. At the same time, house prices in many OECD countries increased sharply, significantly outpacing the relatively subdued development in consumer prices. In this paper we argue that different price elasticities on asset and consumer markets help to explain the observed relative price change between assets and consumer goods. Using a VAR analysis and aggregated data for the major OECD countries, our empirical results are supportive of this relationship. Both house and consumer prices are determined by global monetary conditions; however, while global liquidity shocks lead to relatively fast responses in global house prices, significant responses of the global CPI index to money shocks occur only after long time lags. In addition, we find subsequent spillovers from asset prices to consumer prices on a global scale
The modulating effect of education on semantic interference during healthy aging
Aging has traditionally been related to impairments in name retrieval. These impairments have usually been explained by a phonological transmission deficit hypothesis or by an inhibitory deficit hypothesis. This decline can, however, be modulated by the educational level of the sample. This study analyzed the possible role of these approaches in explaining both object and face naming impairments during aging. Older adults with low and high educational level and young adults with high educational level were asked to repeatedly name objects or famous people using the semantic-blocking paradigm. We compared naming when exemplars were presented in a semantically homogeneous or in a semantically heterogeneous context. Results revealed significantly slower rates of both face and object naming in the homogeneous context (i.e., semantic interference), with a stronger effect for face naming. Interestingly, the group of older adults with a lower educational level showed an increased semantic interference effect during face naming. These findings suggest the joint work of the two mechanisms proposed to explain age-related naming difficulties, i.e., the inhibitory deficit and the transmission deficit hypothesis. Therefore, the stronger vulnerability to semantic interference in the lower educated older adult sample would possibly point to a failure in the inhibitory mechanisms in charge of interference resolution, as proposed by the inhibitory deficit hypothesis. In addition, the fact that this interference effect was mainly restricted to face naming and not to object naming would be consistent with the increased age-related difficulties during proper name retrieval, as suggested by the transmission deficit hypothesis.This research was supported by grants PSI2013-46033-P to A.M., PSI2015-65502-C2-1-P to M.T.B., PCIN-2015-165-C02-01 to D.P., PSI2017-89324-C2-1-P to DP from the Spanish Ministry of Economy and Competitiveness (http://www.mineco.gob.es/)
- …