Browsing by Subject "kognitiotiede"

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  • Lehtonen, Esko (Helsingin yliopisto, 2014)
    In the visual control of locomotion, gaze is used to sample information in an anticipatory manner. In car driving, this anticipation functions at both a short and long time distance. At the short time distance, gaze leads the locomotion with a small (1‒3 s) time headway. Many steering models have explained this behavior by interpreting that drivers track a steering point on the road to obtain visual information which is directly translated to steering actions. This gaze behaviour can be called guiding fixations, because the gaze is providing information for the online control of the steering. At the long time distance, gaze serves trajectory planning by picking up information from the road further ahead. In curves, a part of the road can be visible in highly eccentric positions relative to the typical guiding fixations direction. In these situations, the information needs of the trajectory planning can result in eccentric look-ahead fixations toward the curve. The role of these fixations in the visual control of locomotion is not well understood. In this thesis, I have developed algorithmical methods for the identification of look-ahead fixations from eye movement data collected with an instrumented vehicle on real roads. In a series of three experiments, gaze behavior in curves was studied. The effects of driving experience and cognitive load were also investigated. In general, fixation distributions do not suggest a clear division between guiding and look-ahead fixations. However, a clear tail of eccentric fixations is present in the distributions, which can be operationally defined as look-ahead fixations in curves. Look-ahead fixations target the whole visible road, but locations with a smaller eccentricity relative to the guiding fixations were more commonly fixated than those with a high eccentricity. Experienced drivers allocated more time to look-ahead fixations compared to novices. Cognitive load may negatively affect trajectory planning by interfering with look-ahead fixations. Based on the results, the role of trajectory planning in the control of steering is discussed. The results are consistent with a hierarchical model of driving behaviour, where trajectory planning supplies the intended path for the level of the online control of steering.
  • Lappi, Otto (Helsingin yliopisto, 2013)
    The thesis presents three studies on the visual control of locomotion. Each investigates the visual behaviour of human subjects driving a car. The focus is on the basic visual behaviours involved in the task of negotiating bends in a road car, at normal road speeds. The aim was to investigate the properties of visual behaviour relevant to the two predominant classes of visual steering models in the lite¬rature: tangent point models, and future path models. Study I is the first on-road study where the visual projection of the future path in the field of view is modeled explicitly, enabling a re-evaluation of the generality of the tangent point hypothesis and its methodological grounds based on simple area of interest (AOI) measures incapable of producing decisive evidence, prompting the need for complementary data. Empirically and theoretically, the future path can be considered a potential gaze target that is as equally valid as the tangent point. Study II is the first on-road study to demonstrate optokinetic nystagmus (periodic, slow eye movements) in curve-driving. Combining eye-movement data with vehicle telemetry, we were able to show that the fixations lose their pursuit-like appearance, and are stable relative to real allocentric locations. Study III used these optokinetic pursuit movements as a means to empirically contrast the tangent point and future path models. We found that 1) the gaze position was typically above the tangent point, and displays a large horizontal variation in relation to it, being spread into the far zone along the future path, 2) the optokinetic pursuit had a horizontal component in the direction opposite to the bend and 3) the magnitude of the horizontal component of the pursuit movements was approximately equal to one half of the vehicle yaw rate. All three observations are what one would predict given the hypothesis that the drivers were targeting fixed target points on the future path beyond the tangent point and tracking them with pursuit eye movements, but difficult to reconcile with a tangent point strategy. This pattern of results in the three studies is consistent with the drivers targeting points on the future path instead of, or in addition to, the tangent point. This challenges the generality of the tangent point hypothesis as an account of where we look when we steer.
  • Huhmarniemi, Saara (Helsingin yliopisto, 2012)
    This thesis investigates Finnish interrogative sentences and similar consructions from the perspective of biolinguistics and the Minimalist Program (Chomsky 1995, Chomsky 2000). Finnish interrogatives display one of the elementary properties of natural language: grammatical movement from one position to another. The movement of the question phrase in an interrogative sentence can be seen as an instance of a more general A′-movement that is typically triggered by discourse factors. The aim of this thesis is to establish an overall view to the A′-movement phenomena in Finnish that functions as a basis for future research on these topics. The focus of the investigation is on two syntactic phenomena: the syntactic edge position that is the target of A′-movement and island conditions that restrict movement to this position. In Finnish interrogative sentences, the question phrase targets the edge of a finite clause. However, the presence of an edge position can be observed in a variety of phrases in Finnish. A particular emphasis of this thesis is on phrases that undergo pied-piping, that is, movement of a larger constituent that contains the interrogative element. It is argued that the position of the wh-phrase at the edge is a necessary pre-requisite for pied-piping in Finnish wh-questions and relative clauses. With this respect, Finnish follows the existing cross-linguistic generalizations on pied-piping. Furthermore, the Finnish recursive piedpiping displays properties of successive cyclic movement via edges of pied-piped phrases, resulting to a form of snowball movement. As a result of a detailed investigation on the syntactic constructions, this thesis provides an inventory of pied-piped phrase types in Finnish and a discussion on the different mechanisms for obtaining the edge position among phrases. Among the island phenomena investigated are the adjunct island condition and constraints on subject extraction. It is proposed that Finnish obeys the adjunct island condition and the availability of subject extraction is sensitive to the presence of subject-predicate agreement, displaying a form of anti-agreement effect.
  • Leminen, Alina (Helsingin yliopisto, 2012)
    The representation of morphologically complex words in the mental lexicon and their neurocognitive processing has been a vigorously debated topic in psycholinguistics and the cognitive neuroscience of language. This thesis investigates the effect of stimulus modality on morphological processing, the spatiotemporal dynamics of the neural processing of inflected (e.g., work+ed ) and derived (e.g., work+er ) words and their interaction, using the Finnish language. Overall, the results suggest that the constituent morphemes of isolated written and spoken inflected words are accessed separately, whereas spoken derived words activate both their full form and the constituent morphemes. The processing of both spoken and written inflected words elicited larger N400 responses than monomorphemic words (Study I), whereas the responses to spoken derived words did not differ from those to monomorphemic words (Study IV). Spoken inflected words elicited a larger left-lateralized negativity and greater source strengths in the left temporal cortices than derived words (Study IV). Thus, the results suggest different cortical processing for derived and inflected words. Moreover, the neural mechanisms underlying inflection and derivation seem to be not only different, but also independent as indexed by the linear summation of the responses to derived and inflected stimuli in a combined (derivation+inflection) condition (Study III). Furthermore, the processing of meaningless, spoken derived pseudowords was more difficult than for existing derived words, indexed by a larger N400-type effect for the pseudowords. However, no differences were observed between meaningful derived pseudowords and existing derived words (Study II). The results of Study II suggest that semantic compatibility between morphemes seems to have a crucial role in a successful morphological analysis. As a methodological note, time-locking the auditory event-related potentials/fields (ERP/ERF) to the suffix onset revealed the processes related to morphological analysis more precisely (Studies II and IV), which also enables comparison of the neural processes in different modalities (Study I).
  • Palomäki, Jussi (Helsingin yliopisto, 2013)
    Poker, especially on-line poker, is a game of skill and chance that requires constant and rapid decision making under varying levels of risk and uncertainty. Poker playing skill encompasses both technical and emotional elements. In poker, it is possible to acquire enough experience and skill to win money in the long run. Yet every poker player, regardless of his/her skill, occasionally loses. Poor, out-of-control poker decision making due to negative emotions typically elicited by monetary losses is commonly known as tilting and often results in superfluous losses. The aim of this thesis was to evaluate psychological and physiological emotional processes associated with poker decision making. Studies I III were based on Internet-questionnaire data. Study I (N=60) was qualitative, and Studies II (N=354) and III (N=417) were correlative. The emphasis here was on exploring the underpinnings of the tilting phenomenon and the differences in emotion regulation abilities between experienced and inexperienced poker players. In Study IV (N=29), psychophysiological reactivity (electrodermal activity; EDA) was measured in a laboratory setting while participants played the No Limit Texas Hold'em (NLHE) poker variant on a computer. Overall, the results suggest that tilting behavior is instigated by loss-induced feelings of injustice/unfairness (moral indignation). These feelings are also associated with chasing behavior, where players attempt irrationally to regain the money that they feel is rightfully theirs. The aftermath of tilting was characterized by reports of sleeping problems and rumination over lost resources (Study I). A higher tendency to experience loss-induced negative feelings was associated with a higher reported severity of tilting (Study III). Experienced players, when compared with inexperienced ones, exhibited a more mature/impassive disposition towards losing and tilting (Studies I III), engaged in less self-rumination and more self-reflection, and made normatively better poker decisions (Study II). However, surprisingly, experienced players also reported more severe tilting (Study III). The EDA elicited while participants played poker on a computer was associated with various poker decisions (actions): Pre-decision EDA levels increased in the order of folding, calling and betting/raising. Furthermore, actions taken with strong and weak poker hands elicited higher EDA compared with actions taken with poker hands of medium/uncertain strength (Study IV). The results from Studies I III shed light on the associations between poker experience, emotion regulation abilities ( mental skills ) and tilting behavior. The results from Study IV allow for situating the game of poker within the theoretical framework of economic and neuroscientific theories of emotions and decision making by demonstrating that the EDA associated with NLHE decision making conceivably indexes the anticipated utility of the decisions.
  • Salovaara, Antti (Helsingin yliopisto, 2012)
    Vaikka vuorovaikutteiset teknologiat yleensä kehitetään ennalta mietittyihin käyttötarkoituksiin, käyttäjät usein muokkaavat niitä omiin tarpeisiinsa sopiviksi. Tätä käyttötapoja muuttavaa muokkaamisprosessia kutsutaan appropriaatioksi. Appropriaatio on sekä sosiaalinen että kognitiivinen prosessi. Sen sosiaalisia piirteistä on tutkittu mm. teknologiakäytäntöjen muuttumista ja oppimista sekä appropriaatioita levittävien avainyksilöiden toimintaa. Sitä vastoin kognitiivisia piirteitä on tutkittu vähän. Tässä väitöskirjassa kehitään teoriaa appropriaatioille, joissa yksilöt keksivät teknologioille uusia, heille aiemmin tuntemattomia käyttötarkoituksia (repurposive appropriations). Erityisesti keskitytään kiertotapoihin (workarounds): tehtävätilanteisiin, joissa käyttäjä keksii korvata aiemman kokemuksensa pohjalta tutuksi tulleen teknologian toisella teknologialla, jonka hän ei ole aiemmin mieltänyt liittyvän kyseiseen tehtävään. Tämä väitöskirja on tutkimusotteeltaan eksploratiivinen. Se pohjautuu kognitiotieteeseen, erityisesti hajautetun kognition, ongelmanratkaisun ja luovuuden tutkimukseen. Empiirisenä pohjana on kolme kenttätutkimusta langattomista multimediaviestintäjärjestelmistä (mGroup, CoMedia ja Comeks) sekä www-kysely digitaalikameroiden käytöstä. Yhteistä näille teknologioille on arkikäyttö institutionaalisen kontekstin ulkopuolella ja se, että niillä tuotetaan visuaalista sisältöä pieninä kokonaisuuksina ilman korkean tason teknistä asiantuntemusta, esim. ohjelmointitaitoa. Väitöskirja ehdottaa, että approprioidessaan yksilö muodostaa mielessään uudenlaisen kytkennän (mapping) teknologisten, sosiaalisten ja fyysisten tilannetekijöiden välille. Näin hän oppii uuden ratkaisumallin (solution schema) teknologian käyttötavasta. Väitöskirja esittää kolme kognitiivista kytkemisprosessia, joilla voidaan selittää kiertotapojen kaltaisia appropriaatioita. Kytkemisistä ensimmäinen vaihtoehtoinen prossessi perustuu osittaisten ratkaisumallien tunnistamiseen yksilön ympäristössä. Muut kaksi perustuvat analogioiden tunnistamiseen ratkaisutapojen tai ratkaisuun sopivien välineiden välillä. Väitöskirja ehdottaa, että käyttäjien aiempi teknologinen asiantuntemus edesauttaa näitä kolmea kytkemisprosessia. Tulokset tarjoavat suunnittelusuosituksia ihmisen ja tietokoneen vuorovaikutuksen kehittämiseen sekä lähtökohtia uusiin kognitiotieteellisiin tutkimuksiin.
  • Kujala, Miiamaaria (Helsingin yliopisto, 2010)
    Humans are a social species with the internal capability to process social information from other humans. To understand others behavior and to react accordingly, it is necessary to infer their internal states, emotions and aims, which are conveyed by subtle nonverbal bodily cues such as postures, gestures, and facial expressions. This thesis investigates the brain functions underlying the processing of such social information. Studies I and II of this thesis explore the neural basis of perceiving pain from another person s facial expressions by means of functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG). In Study I, observing another s facial expression of pain activated the affective pain system (previously associated with self-experienced pain) in accordance with the intensity of the observed expression. The strength of the response in anterior insula was also linked to the observer s empathic abilities. The cortical processing of facial pain expressions advanced from the visual to temporal-lobe areas at similar latencies (around 300 500 ms) to those previously shown for emotional expressions such as fear or disgust. Study III shows that perceiving a yawning face is associated with middle and posterior STS activity, and the contagiousness of a yawn correlates negatively with amygdalar activity. Study IV explored the brain correlates of interpreting social interaction between two members of the same species, in this case human and canine. Observing interaction engaged brain activity in very similar manner for both species. Moreover, the body and object sensitive brain areas of dog experts differentiated interaction from noninteraction in both humans and dogs whereas in the control subjects, similar differentiation occurred only for humans. Finally, Study V shows the engagement of the brain area associated with biological motion when exposed to the sounds produced by a single human being walking. However, more complex pattern of activation, with the walking sounds of several persons, suggests that as the social situation becomes more complex so does the brain response. Taken together, these studies demonstrate the roles of distinct cortical and subcortical brain regions in the perception and sharing of others internal states via facial and bodily gestures, and the connection of brain responses to behavioral attributes.