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.

Background. Birth asphyxia is a pathological state that occurs if fetal gas exchange is disrupted for an extended period of time during delivery. Prolonged birth asphyxia causes brain damage and can even lead to death, but which in mild and moderate cases causes motor and cognitive disability. One of the brain regions often damaged is the hippocampus, which is known to play a major role in memory processing. Thus, damage to the hippocampus may in part explain the long-term cognitive consequences of birth asphyxia. In the neonatal brain hippocampal network activity is discontinuous, dominated by sharp waves and oscillatory bouts, of which the former are thought to be important for memory consolidation in the adult brain. Later in development sharp waves exhibit fast oscillations called ripples that organise hippocampal activity after learning. The aim of this thesis was to establish how sharp wave signalling in the neonatal hippocampus is affected by birth asphyxia. Methods. A rat model developed at the Laboratory of Neurobiology, University of Helsinki, was used to study birth asphyxia and a putative therapeutic strategy. Neonatal rat pups aged 5-8 days were used in the study. These animals were randomly assigned to one of four experimental groups: naive control, sham control, asphyxia, and graded restoration of normocapnia. Hippocampal network activity was measured in vivo under urethane anaesthesia using local field potential (LFP) recordings 24 hours after the asphyxic insult. Sharp waves were detected and analysed in terms of event counts, timing, size, shape and ripple properties. Results and conclusions. After asphyxia, sharp waves occurred more frequently within clusters than in isolation. In addition, sharp wave ripples were detected for the first time during early neonatal development. In asphyxiated animals, the number and magnitude of detected ripples was statistically significantly decreased. Interestingly, animals that underwent graded restoration of normocapnia after asphyxia were no different from controls, suggesting a protective effect of the treatment. The abnormal SPW development after birth asphyxia may form a mechanism contributing to the emergence of cognitive deficits.

It has been previously shown that people express disgust at moral transgressions, with both verbal reports and facial expressions. It is also known that the real or imagined presence of an audience can make people more willing to punish perceived wrongdoers and harsher in their judgments of moral violations. The aim of this thesis was to examine whether other people's emotional communication may affect one's moral judgments of speculative dilemma situations, where the killing or harming of another person is motivated by the greater good. Specifically, this thesis aimed to find out if an audience's facial expression affects judgments of moral violations that break a deontological (duty-based) moral rule but are nevertheless utilitarian, ie. the violation can be said to increase aggregate welfare. The hypothesis was that a disgust-signaling facial expression would lead to less utilitarian judgments than a neutral expression. Four data sets from experiments were collected in Finland and in the Netherlands. 117, 124, 124 and 165 people took part in the experiments Three of the experiments were conducted on a computer, and one on a paper form. An established questionnaire of 12 moral dilemma situations was used. In each dilemma, the utilitarian option was also a deontological violation.The participants indicated on a Likert scale I) how acceptable the found the utilitarian option and II) how likely they thought they themselves would act according to this option. Photographs of faces were used as the audience stimulus. Depending on the experimental condition, these faces were either neutral, or expressed disgust or anger. The order of the dilemmas, the photographs and the placing of participants in different experimental conditions was fully randomized. In the fourth experiment, the possible effect of the audience's gender on moral judgments was also examined. In each of the data sets, a main effect of participant gender was observed: males were slightly more utilitarian than females. An anger-signaling audience had no effect discernible from a neutral audience, whereas a disgust-signaling audience led to changes in utilitarian judgment. Additionally, interactions between the emotional audience manipulation and participant and audience gender were observed. Based on these results, it seems that gender and the expression of disgust may have specific roles in audience effects on moral judgment.

Bicycling is a way of transport and a sport that is considered both healthy and environmentally friendly. It is also a convenient way to get around especially for children and adolescents who cannot drive cars. However, school-aged children are an overrepresented group in bicycling-related injuries. For Finnish children, bicycling injuries are the most common traffic injuries. One possible explanation for children's higher accident liability could be their less developed hazard perception skills. This thesis is based on a study about hazard perception, where a game-like hazard perception test with videos filmed from a bicyclist's perspective was designed and tested on participants of different age and exposure to bicycling. The videos contained natural, unstaged videos from traffic, and participants were instructed to point out targets such as road users on a potential collision course and locations where road users could emerge from (e. g. house corners).The test was done using a touch screen where participants were to point out targets while the video was rolling early enough to gain points. If a target was missed or pointed out too late, the video was paused and feedback given. Performance in the hazard perception test was tested on 3 groups: one group of 49 children from the 2nd grade (age 8-9) and two adult groups: 16 adults who cycle at least 3 times a week (experienced adults) and 15 adults who cycle never or only rarely (inexperienced adults). The adults performed better than the children both in terms of answer latency and percentage of correct answers. Adults were also significantly better at pointing out view blockers as potentially hazardous targets. No significant differences were found between the experienced and inexperienced adults groups, which suggests that the test might have been too easy for the adult group. A correlation between a high percentage of correct answers and a low answer latency was found on an individual level, which suggests that the game was successful in measuring hazard perception skills.

Rapid learning or fast mapping reflects the human brain’s ability to form new memory traces to novel words during exposure without the need for a long overnight consolidation period before the word can be used in conversation. This ability to acquire new words almost instantaneously may very well reflect how well-tuned the human language systems are to the phonemes of the native language. However, the neural basis of rapid learning has been largely unknown until recent neuroimaging studies. In this study on adult learners (n = 15), I recorded brain’s event-related potentials elicited by three different types of auditory bi-syllabic stimuli (native words, native pseudowords and pseudowords with unfamiliar phonemes, all acoustically closely matched) in a passive EEG-recording session before and after subjects participated in two types of training conditions. In the attend condition, subjects listened to a flow of stimuli while pressing a button when a target stimulus appeared. In the articulation condition subjects repeated out loud the heard stimuli. An auditory memory recognition test was administered after training to allow the comparison of neural learning effects to observable change in behaviour. Larger evoked responses were expected to correlate with better performance in the recognition task. All analyses were time-locked to the onset of the second syllable (critical disambiguation point/recognition point). A two-peak waveform was observed to all stimuli after both conditions, with the earlier peak appearing circa 40 ms and the later peak circa 140 ms after second syllable onset. Unlike in similar previous studies where responses increased as a result of learning, all responses decreased in magnitude. No statistically significant differences between the conditions were observed. This may have been due to either the small sample size, test subject fatigue or suppression effects due to repetition, masking any possible learning effects. For the late peak, native pseudowords evoked significantly stronger responses than native words or non-native pseudowords. Performance in the memory recognition task was good (above chance for all stimuli in both conditions), and as such learning cannot be excluded even though statistically significant differences in the evoked responses were not found. Further research and re-exploration of the data acquired here utilising source modelling might enable to assess in more detail the effect of attentive listening vs. articulation in rapid learning.

Action video games have been found to improve many cognitive skills. Most established findings are related to faster information processing speed and improved attentional capabilities. Many of the same cognitive processes are better on elite athletes of interceptive sports compared to non-elites. This study aimed to find some preliminary evidence whether the improvements in cognitive processes gained from action video gaming might be beneficial in ball sports. This was done by comparing the performance of action video game players and nonaction-video players on an anticipation of coincidence test. Anticipation of coincidence is a laboratory test, where the task is to anticipate when a moving object arrives at a certain point and to coincide a button press with it. Performance on the task is thought to depend on information processing speed and attentional capabilities. When the speeds and possible speed changes are similar to those encountered in real ball sports, elite athletes of these sports are generally more accurate in the task compared to non-elites. Elite athletes differ from non-elites in their gaze patterns as well. For example, athletes fixate to the target quicker and their quiet eye, meaning the last fixation or tracking gaze before a motor action on a specific target lasting at least 100 ms, is longer. Thus, it was studied whether action video gamers fare better on the anticipation of coincidence task in different constant speeds and in deceleration conditions, and whether their gaze patterns are different compared to non-gamers. 10 action video game players and 9 nonaction-video game players participated in the experiment. The results show that action video game players are more accurate in the task in most constant speed conditions and in a deceleration condition with slow speeds. There was some variation in gaze patters, including that action video gamers had quiet eye more often in fast speeds. The results suggest that action video game players can program more accurate motor responses based on the speed of the target and reprogram wrong motor actions better than nonaction-video game players. In addition action video game players are better able to track fast moving targets. As these skills are important in ball sports, this possible linkage between action video games and ball sports performance should be studied further.

Objectives: GPS technology enables the visualisation of a map reader's location on a mobile map. Earlier research on the cognitive aspects of map reading identified that searching for map-environment points is an essential element for the process of determining one's location on a mobile map. Map-environment points refer to objects that are visualized on the map and are recognizable in the environment. However, because the GPS usually adds only one point to the map that has a relation to the environment, it does not provide a sufficient amount of information for self-location. The aim of the present thesis was to assess the effect of GPS on the cognitive processes involved in determining one's location on a map. Methods: The effect of GPS on self-location was studied in a field experiment. The subjects were shown a target on a mobile map, and they were asked to point in the direction of the target. In order for the map reader to be able to deduce the direction of the target, he/she has to locate himself/herself on the map. During the pointing tasks, the subjects were asked to think aloud. The data from the experiment were used to analyze the effect of the GPS on the time needed to perform the task. The subjects verbal data was used to assess the effect of the GPS on the number of landmark concepts mentioned during a task (landmark concepts are words referring to objects that can be recognized both on the map and in the environment). Results and conclusions: The results from the experiment indicate that the GPS reduces the time needed to locate oneself on a map. The analysis of the verbal data revealed that the GPS reduces the number of landmark concepts in the protocols. The findings suggest that the GPS guides the subject's search for the map-environment points and narrows the area on the map that must be searched for self-location.

Brains are capable of processing information with remarkable efficiency under constraints set by the limited supply of physical resources such as the amount of space and the availability of metabolic energy. Natural selection has optimised the structure and function of brain networks using simple design rules similar to those found in man-made electronic and information systems. This study presents findings concerning a number of general principles of brain design governing the evolution and organisation of neural information processing. The rule of minimising wiring in neuronal networks is one such principle operating on multiple levels of brain organisation. Both individual components and larger brain architectural units are seen to feature characteristics of near-optimal wiring. Miniaturisation of neuronal components conserves space but raises problems about noise in signalling. Small-world organisation of anatomical and functional networks is widely employed in the brain, contributing to high global efficiency at low cost. Metabolic costs severely constrain signal traffic in the human brain, necessitating the use of energy-efficient sparse neural representations. Extensive evidence is presented of anatomical and physiological optimisations facilitating efficient information processing in brain networks. Limitations of current experimental techniques are discussed, with a view on possible future avenues of research.

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.