Browsing by discipline "Cognitive science"

Objectives and theoretical background: Traditionally, it has been considered that the relation between word and meaning is arbitrary, but this traditional view has been challenged. Sound symbolism refers to an association that links a word to its reference on perceptual or semantic level. Thus, the phonetic form of a word could serve as a cue for understanding the meaning of the word. Sound symbolic associations may have contributed to the evolution of language, as well as facilitate language and word learning. This study focuses on the association between a vowel sound and spatial distance, a phenomenon known as vowel-distance association. The goal of this study is to investigate, whether there is a sound symbolic association between vowel frontness, openness or roundness and spatial distance. Previous studies suggest that front vowels are associated with spatial proximity (close) and back vowels with spatial distance (remote). However, there is presumably only one experimental study that has confirmed such vowel-distance association, and it was conducted with English speaking participants, and vowel features were not properly controlled. This study aims to replicate the association in a new language group. With more efficient control of the basic vowel features, the study aims to clarify, whether vowel-distance association is merely based on vowel frontness or vowel openness and/or roundness as well. Methods: To investigate the role of vowel frontness, openness and roundness in vowel-distance association, this study utilized a novel behavioural setting. The experiment consisted of four blocks, and during each of these blocks, two distinct vowels were visually presented to the participant ([i] – [o], [i] – [æ], [ø] – [e] and [ø] – [o]). The participants (N = 25) were native Finnish speakers, and they were instructed to pronounce the presented vowel and simultaneously move their hand on a close or remote response button. Manual reaction times, vocal reaction times and acoustic parameters of the sound (F0, F1, F2, intensity) were recorded during the experiment. The reaction time data and the acoustic data were analysed with repeated measures ANOVA, and special attention was paid to the interaction effects of block, vowel and distance. Results and conclusions: The previously discovered vowel-distance association was only partially replicated in this study, and some of the results contradict with the idea that vowel-distance association is merely based on vowel frontness. In the first block of the study, back vowel [o] was associated with remoteness, but front vowel [i] was not associated with closeness. In the second block, open front vowel [æ] was associated with remoteness and closed front vowel [i] with closeness. In the third block, round front vowel [ø] was associated with remoteness, whereas unrounded front vowel [e] did not show any associations. In the last block, round front vowel [ø] was associated with remoteness and round back vowel [o] with closeness. Taken together, this study does not provide strong support for the vowel-distance association based on vowel frontness. Instead, the study suggests that vowel-distance association may be modulated by vowel openness and/or roundness, but further research on this topic is needed. This study also revealed a presumably novel finding that the distance of hand movement affects the intensity and fundamental frequency of vowel pronunciation.

The aim of this study is to examine the development of selective and divided attention in adolescence using functional magnetic resonance imaging (fMRI) and behavioral measures. Although the prefrontal cortex, a key area for attention and cognitive control, is thought to mature well into adulthood, few studies have examined the development of attention in adolescents and young adults. No fMRI studies have been conducted on the development of divided attention. In this study, development was examined both cross-sectionally and longitudinally to also assess the possible differences in the results they produced, as nearly all previous studies have been cross-sectional. Brain activity was measured from 103 participants aged 13–22 who were divided into three age cohorts. The youngest two cohorts were measured again after 1.5 years for the longitudinal study. While in the scanner, participants performed a sentence congruence task where they were instructed either to attend to only the speech or text stimulus or divide their attention between both modalities simultaneously. The cross-sectional results showed improvement in task performance between the youngest cohort (13– 14y.) and the older cohorts in both selective and divided attention tasks. No difference was found between the older two cohorts (16–17y. and 20–22y.) However, the longitudinal results did not indicate clear performance improvement with age in either task type. According to the longitudinal fMRI results from age 13–14 to 15–16, in the selective attention task brain activity decreased mainly in the medial prefrontal area and activity increased slightly in parietal regions. In the divided attention task, the decreased prefrontal activity was more lateral. From age 16–17 to 18– 19, increased activity in motor regions and precuneus was found in both tasks. In general, the effects were very subtle, possibly due to a short measurement interval and relatively small cohort sizes. The cross-sectional results indicated quite a different pattern of change in brain activity, concentrated on temporal areas. This difference in results emphasizes the importance of conducting longitudinal developmental studies in the future. Although the effects were not large, the longitudinal fMRI results were in line with some previous findings that prefrontal areas are recruited less with age, so that activity in more posterior task-related areas increases. The current results suggest that some fine-tuning of the attention and cognitive control-related network still occurs from adolescence to early adulthood, as the prefrontal cortex and its connections mature.

Animations are a way to visualize change and bring inanimate objects life. Today, they are all arounds us: on digital billboards, info screens in shopping malls, websites and in our mobile phones. Major technology companies, such as Apple and Google have established their own guidelines for using movement and animations in digital interfaces. Yet, there is surprisingly little formal research on the topic. The question is, what are these guidelines based on? Existing research focuses on subjective perception of time, animation principles as well as combination of animations and sound in improving comprehension. However, systematic comparison between animation types and their effects on interfaces is absent from present literature. Therefore, this study answers how animation type impacts performance and change detection rates in visual tasks. This study was conducted as an empirical experiment, for which ten participants were recruited using university’s mailing lists. The experiment was carried out using a standard computer monitor, keyboard and head-mounted eye tracking equipment. Participants performed a dual task, consisting of five blocks of equal duration. The goal of the primary task was to keep attention in one part of the screen, and in secondary task participants reacted to visual changes animated on the screen. Performance in both tasks was measured using a combination of reaction times, verbal reports and eye tracking data. Data was analyzed with ANOVA as well as linear and generalized linear regression models, depending on the type of data under scrutiny. Presence of animations greatly improved reaction times and comprehension of change. Additionally, verbal reports differed considerably between animations, as did missed responses to the primary task. In other words, certain animations were noticed and reported with greater reliability and impaired performance in a simultaneous task less than other animations. In this regard, Slide animation performed best of the ones used in this study. In addition to finding measurable differences between animation types, the results were used to contribute to interaction design by establishing general animation guidelines. These guidelines are outlined at the end of this thesis.

Tavoitteet. Sosiaalisten robottien ulkonäön vaikutuksia ihmisiin ei ole juuri tutkittu, vaikka sosiaaliset robotit yleistyvät jatkuvasti ammatillisessa, etenkin terveydenhuollon, kontekstissa. Tutkielman tavoitteena on tutkia ensin eroja ihmis- ja robottisairaanhoitajan suorittaman pakkolääkinnän moraalisessa tuomitsemisessa. Tämän jälkeen tarkastelen jatkotutkimuksella, onko sairaanhoitorobotin ulkonäöllä ja söpöydellä vaikutusta pakkolääkinnän moraaliseen tuomitsemiseen. Sairaanhoitorobotteja tarkastellaan söpöysskaalalla—söpöys valikoitui mielekkääksi muuttujaksi, koska suuri osa eri aloilla käytettävistä sosiaalisista roboteista on korostetun söpöjä. Aiempien tutkimusten perusteella viehättävä ulkonäkö ja söpöys vaikuttavat havaitsijan tekemään arviointiin ja päätöksentekoon. Tarkastelen tutkielmassa söpöyden ja ulkonäön vaikutuksia sosiaalisten robottien kontekstissa. Menetelmät. Tutkielmaan kerättiin kaksi kokeellista aineistoa, toinen pääkaupunkiseudulta ja toinen Internet-tutkimuksena. Kokeissa oli 135 ja 214 osallistujaa. Tutkimuksissa koehenkilöt lukivat tarinanpätkän, joka päättyi sairaanhoitajan suorittamaan pakkolääkintään tai potilaan tahdon noudattamiseen. Tarinan toimijan (ihmissairaanhoitaja tai robotti) päätöstä arvioitiin kysymysten avulla (kuinka loukkaava tai epäinhimillinen päätös oli, oliko päätös oikea tai tarpeellinen). Koehenkilöt arvioivat kysymyksiä porrastetulla Likert-asteikolla (“Täysin eri mieltä” – “Täysin samaa mieltä”). Ensimmäisessä tutkimuksessa tarkasteltiin ihmis- ja robottisairaanhoitajan pakkolääkintäpäätöstä neljällä satunnaistetulla koeasetelmalla. Toisessa tutkimuksessa tarkasteltiin vain sairaanhoitorobottia ja tarinanpätkään oli liitetty robotin kasvokuva, joka vaihteli skaalalla “ei söpö, keskivertosöpö, söpö”. Tarinanpätkistä ja robottien variaatioista muodostui kuusi koeasetelmaa, jotka oli satunnaistettu järjestyksen ja koehenkilöiden sijoittamisen osalta. Tulokset ja johtopäätökset. Ensimmäisen tutkimuksen perusteella havaittiin, että robotti- ja ihmissairaanhoitajiin kohdistuvat moraaliset arviot eroavat toisistaan paitsi silloin, kun sairaanhoitorobotti noudattaa potilaan omaa tahtoa. Toisen tutkimuksen perusteella suoraa ulkonäkövaikutusta moraalisiin arvioihin ei havaittu, joskin osa tuloksista oli lupaavia ja kiinnostavia lisätutkimusten kannalta.

Objective. In cognitive neuroscience empathy is defined as a set of skills and tendencies that enables us to interpret and predict the mental states and actions of others and share emotional states and the experience of others. These skills and tendencies are important for successful interaction and in most situations rely heavily on natural social cues. In addition to verbal cues, these natural cues consist of for example facial expressions, bodily gestures, and prosody of speech. Also, a shared environment that enables for example eye contact and joint attention have previously been found beneficial for empathy. However, a growing percentage of our social interaction takes place in online environments where many of these features found important during face-to-face interaction are absent. A great body of evidence exists on the decrease in empathy skills during online compared to face-to-face interaction. A fair amount of research also exists on the neural foundation underlying empathy. Research on how this decrease in empathy processes during online interaction can be observed on the neural level is however limited. One phenomenon found to occur during face-to-face interaction is the synchronization of the brain's electric activity between collaborating individuals. Associations between this neural synchrony and the quality of interaction have also been found. The purpose of this study is to investigate 1) whether inter-brain synchrony occurs during online collaboration in the absence of natural social cues and 2) whether this synchrony is associated with the empathy skills of the collaborating individuals. Methods. The subjects of the study consisted of 21 pairs, each in which the two subjects knew each other in advance and decided to participate in the study together. The subjects first completed individual empathy tests, after which their task was to play a collaborative online car game together in separate physical locations during which one of the subjects was to control the speed while the other was to control the direction of the car. During this task, the neural activity of each subject was measured with EEG. The inter-brain synchrony between the collaborating individuals was studied by investigating the associations of power in the theta, alpha, beta, and gamma frequency bands measured over the frontal, frontocentral, central, parietal, temporoparietal, and occipital regions between the two individuals. Results and Conclusions. Inter-brain synchrony specific to collaboration was found in the theta frequency band over the frontal, frontocentral, central, parietal, and temporoparietal regions; in the alpha frequency band over the frontocentral region; in the beta frequency band over the frontocentral, central, parietal, and occipital regions; and in the gamma frequency band over the frontocentral and central regions. This suggests that the synchrony in these frequency bands measured over these regions is related to computer-mediated collaboration. No significant associations were found between the inter-brain synchrony and empathy skills.

This master’s thesis studies spontaneous gaze strategies when driving on a curved path. Methods used in many previous curve driving studies have not been sufficiently precise to differentiate between possible gaze strategies drivers use during cornering (Lappi, 2013, Itkonen et al. 2015). The methods in this thesis make it possible to differentiate between different gaze strategy predictions by comparing driver’s horizontal gaze velocity and half of car’s yaw rate. Waypoint hypothesis (WP), where gaze follows targets on the future path, predicts negative linear correlation and specific -1:1 ratio between horizontal gaze velocity and half of car’s yaw rate. Tangent point hypothesis (TP) and other travel point gaze strategies predict no correlation. In addition to previous study by Itkonen et al. (2015), the yaw rate is varied for quantitative analysis of the gaze behaviour and the experiment is conducted in two different environments, simulator and real test track, for reliability and validity. Gaze and car telemetry data was collected during a slow acceleration on a circular path in similar simulated (n=15) and real environment (n=4). As predicted by the WP hypothesis, the results show a very strong linear negative correlation between car’s half yaw rate and horizontal gaze velocity in simulator (-0.91) and strong linear negative correlation in test track (-0.75) and regression analysis shows slopes close to -1:1 ratio between the variables (simulator: -0.96 and test track: -0.79). The results can be clearly observed even on individual level. This suggests that primary gaze strategy when cornering in a curve is to pursue local flow on waypoints on the future path. The slight differences in results between simulator and test track experiment are discussed. These quantitative results contribute to making more precise models of driver behaviour, that can help advance autonomous car designs and driver-vehicle interaction models. The results also help to make gaze strategies and visuomotor process theories more measurable and comparable in different environments.

The aim of this thesis is to investigate the effects of the first hit in a round of mixed martial arts competition. The theoretical background comes from theories of psychological momentum. Following these theories, if the first hit is a robust starting point for positive and/or negative psychological momentum, the effect should show in the amount of hitting following the first attack. Perspectives for both self defence and combat sports are considered. Psychological momentum as a phenomenon remains controversial. It has previously been investigated in sports contexts where the opposing player’s actions have an effect on the other player. In a mixed martial arts match that effect is more immediate due to the physical proximity of the fighters to each other. Data was gathered both by viewing Ultimate Fighting Championships matches and from the Fight Metric website, which holds records for all Ultimate Fighting Championships matches. The data consists of a total of 104 matches. A series of linear mixed models is fitted to predict the first attacker’s total strikes based on the opponent’s reaction, and a contrast analysis is used to compare the conditions based on reaction. The main result is that on the third round of the match, if the fighter who hits first is blocked, he or she will hit more during that round. The conclusion is that the fighter attacking first strikes more if his or her attack is blocked, but only on the third round. While this implies that the third round is different from the first two, the reason for that is unclear. This finding can be used to inform combat sports coaches’ strategies, and should motivate further investigations to the significance of the first attack in both self defence situations and in combat sports.

Objective: In the present study we investigated neuronal synchronization in post-traumatic stress disorder (PTSD) during real-time fMRI neurofeedback (rt-fMRI NF). We a used inter-subject covariance (ISC) -based method to discover model-free stimulus-response patterns that conventional GLM-analysis is not able to detect. So far, ISC has never been implemented in block-design nor rt-fMRI NF experiments, and only two studies have applied the method in a clinical sample. However, we hoped to find some distinct patterns that could disclose some new information regarding the psychopathology of PTSD and effects of neurofeedback. Methods: The study combined three previously conducted studies that focus on teaching participants to self-regulate anterior cingulate cortex (ACC) activity (HC=24, PTSD=9). The participants lay in the fMRI scanner whilst ACC activity was controlled with the help of a social avatar. The participants were measured three times within one week to examine the effect of neurofeedback. The analyses were completed by using ISC to detect the model-free brain activity. A 2x4 repeated ANOVA was used to investigate the group and neurofeedback effects. The ACC was chosen as a region of interest to investigate synchrony in the target region. An additional 3x4 repeated ANOVA was completed to examine the within and between-group ISC differences during the task. Results: We discovered a higher ISC in the PTSD group in respect to healthy controls, along with a linear decrease of ISC in both groups throughout the experiment. The same pattern was also detected in the ROI-analysis. The additional 3x4 ANOVA revealed a cluster in the orbitofrontal cortex showing a higher ISC within the groups, in respect to between the group ISC. Conclusions: ISC-analyses demonstrate a new type of information regarding the brain mechanisms and connections in respect to the conventional brain analyses. Our results indicate a stronger ISC in PTSD-groups and during the start of the experiment. Moreover, the results are reversed with comparison to the conventional GLM-method – demonstrating a new type of information regarding the brain synchrony. These results could further solidify the importance of the individual strategy used during the experiment. Furthermore, the additional analysis argues for disorder-specific synchrony in PTSD patients that could be meaningful in the psychopathology of PTSD. The thesis proves the feasibility of the ISC-method to discover direct stimulus-response relationship patterns that conventional GLM-analysis are not capable of revealing. Furthermore, it creates new research questions that have not previously existed and therefore it can be applied to neuroimaging.

Objectives. This study aimed to clarify the brain-level processing of face stimuli by examining event related potentials. The purpose was to examine whether it is appropriate to make conclusions about the localization of brain-level processing of face expression and identity. Additionally, the study wanted to clarify whether there are observable differences between expression processing and does the intensity of the expression affect on the brain-level differentiation of expressions. Prior studies about the perception of face stimuli have been heavily focused on the modular view of the information processing system, in which every cognitive function has its own anatomical correlates and where the modules are clearly distinguishable from each other. The opposing view to this is the network-assumption in which the confines between modules are vague. Knowledge about these cognitive processes is crucial when new rehabilitation forms are being developed for people, from whom face perception is abnormal. Methods. 17 healthy test subjects took part in the study. In total, subjects were presented with 112 face stimuli, in which face expression and identity varied systematically. Based on prior studies, the event related potentials, which are known to be present in the perception of face stimuli were especially studied: the positive or negative fluctuations that occur 100, 170 and 250 milliseconds after the presentation of face stimulus (so called P1, N170 and N250 components). The effects of expressions and identities on the event related potentials were examined with traditional one-variable analysis (comparison of averages) as well as with multiple variable methods (comparison of correlations of distributions), which better expose the changes caused by face stimuli manipulations. Results and conclusions. The average amplitude and latency of event related potentials did not differe across conditions. The complex interactions between test conditions were exposed by forming 112 x 112 dissimilarity matrices of event related potentials. General linear model, which included eight regressors, was fitted into dissimilarity matrices. Fitted models were also compiled. In those, every every regressor was weighted with beta-coefficients at the time points of P1, N170 and N250 components. Based on the results, it is possible to assume that expression processing happens in an earlier phase than identity processing. Additionally, there was a robust interaction between expression and identity, which clarified the variation in the data. These results give support to the network-assumption in the perception of faces. However, the network-assumption does not deny modularity completely.

Kovertilla tarkkaavaisuudella viitataan ihmisen kykyyn suunnata tarkkaavaisuutta ääreisnäön alueella oleviin kohteisiin ilman katseen siirtämistä. Dynaamisissa ympäristöissä kuten liikenteessä on oleellista pystyä havainnoimaan ääreisnäön alueella esiintyviä kohteita ja suunnitelemaan omaa toimintaa tämän perusteella. Silmänliiketutkimuksella on tuotettu huomattava määrä tietoa mm. autolla ajajien katsekäyttäytymistä. Tämä tutkimus on kuitenkin yksi ensimmäisistä yrityksistä tutkia kovertin tarkkaavaavaisuuden suuntautumista aktiivista ohjausta vaativan ajotehtävän aikana. Tutkimuksessa pyrittiin selvittämään kuinka aktiivinen ohjaustehtävä ja visuaalinen tienäkymä mahdollisesti vaikuttavat kovertin tarkkaavaisuuden suuntautumiseen. Aiemman silmänliiketutkimuksen perusteella tiedetään, että ajajat tekevät systemaattisesti fiksaatioita tulevalle ajolinjalle. Tarkkaavaisuuden premotorisen teorian mukaan kovertin tarkkaavaisuuden suuntaaminen kohteeseen on ollennaisesti sama prosessi kuin sakkadin suunniteleminen kohteeseen. Tämän perusteella ennustetiin, että myös koverttia tarkkaavaisuutta mahdollisesti suunnataan enemmän tulevalle ajolinjalle kuin sen ulkopuolelle. Tutkimus suoritettiin ajosimulaattorilla. Koehenkilöt (n = 26) oli ohjeistettu pitämään katseensa tiellä sijaitsevan fiksaatiympyrän sisällä, samalla kun he ohjasivat virtuaalista ajoneuvoa mutkaisella tiellä ja pyrkivät tunnistamaan perifeerisen näön alueella esitettäviä kohdeärsykkeitä. Ärsykelokaatiot oli valittu siten, että osa ärsykkeistä sijaitsi koehenkilön tulevalla ajolinjalla ja osa sen ulkopuolella. Koehenkilöt pelasivat ohjaustehtävän lisäksi myös verrokkitehtävää, jossa ohjaus oli automatisoitu ja tienäkymä oli peitetty harmaan taustan alle. Tutkimuksesta havaittiin, että ohjauksen lisäämä kuormitus tai visuaalisen ohjausympäristön vaikutus näytti heikentävän kykyä jakaa tarkkaavaisuutta ruudulla esitettyihin ärsykkeisiin. Sen sijaan ei kuitenkaan havaittu, että tarkkaavaisuutta jakaututisi enemmän tulevalle ajolinjalle.