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Browsing by department "Psykologiska institutionen"

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  • Nyman, Petra (2005)
    According to some models of working memory, verbal and spatial material is processed in separate systems. However, there are task environments, such as multimedia, which typically contains both verbal and spatial material. An interesting question is how these two separate systems co-operate during the use of multimedia. In this experiment, recall of words and locations was studied. Twelve participants were presented with five different conditions, of which two were verbal, two were spatial and one was a combined task. The verbal tasks were serial recall of nine words. The words were either presented in the center of the screen or in different spatial locations. The spatial task was a computerized version of the Corsi Blocks Task, in which serial recall of nine spatial locations was required. The locations were marked with a string of the letter “X”, or with a word. In the combined task participants had to recall a series of nine words and their spatial locations in the correct order. The results showed that words were recalled equally well whether presented in the center of the screen, or in different spatial locations or whether recall of their spatial locations was required. On the contrary, recall of the spatial locations was impaired if verbal material had to be recalled simultaneously. These results imply that verbal and spatial materials are processed separately and the maintenance of spatial material is more sensitive to disruption than the maintenance of verbal material. The research method and the results can be applied when navigation in web-based environments is studied. In complex web-based environments, too heavy a load on the user’s working memory may cause spatial confusion, which leads to the problem of getting lost in the web-based environment.
  • Kivisaari, Sasa (2008)
    Objective: Attention deficit hyperactivity disorder (ADHD) is a life-long condition, but because of its historical status as a self-remitting disorder of childhood, empirically validated and reliable methods for the assessment of adults are scarce. In this study, the validity and reliability of the Wender Utah Rating Scale (WURS) and the Adult Problem Questionnaire (APQ), which survey childhood and current symptoms of ADHD, respectively, were studied in a Finnish sample. Methods: The self-rating scales were administered to adults with an ADHD diagnosis (n = 38), healthy control participants (n = 41), and adults diagnosed with dyslexia (n = 37). Items of the self-rating scales were subjected to factor analyses, after which the reliability and discriminatory power of the subscales, derived from the factors, were examined. The effects of group and gender on the subscales of both rating scales were studied. Additionally, the effect of age on the subscales of the WURS was investigated. Finally, the diagnostic accuracy of the total scores was studied. Results: On the basis of the factor analyses, a four-factor structure for the WURS and five-factor structure for the APQ had the best fit to the data. All of the subscales of the APQ and three of the WURS achieved sufficient reliability. The ADHD group had the highest scores on all of the subscales of the APQ, whereas two of the subscales of the WURS did not statistically differ between the ADHD and the Dyslexia group. None of the subscales of the WURS or the APQ was associated with the participant's gender. However, one subscale of the WURS describing dysthymia was positively correlated with the participant's age. With the WURS, the probability of a correct positive classification was .59 in the current sample and .21 when the relatively low prevalence of adult ADHD was taken into account. The probabilities of correct positive classifications with the APQ were .71 and .23, respectively. Conclusions: The WURS and the APQ can provide accurate and reliable information of childhood and adult ADHD symptoms, given some important constraints. Classifications made on the basis of the total scores are reliable predictors of ADHD diagnosis only in populations with a high proportion of ADHD and a low proportion of other similar disorders. The subscale scores can provide detailed information of an individual's symptoms if the characteristics and limitations of each domain are taken into account. Improvements are suggested for two subscales of the WURS.
  • Kyröläinen, Satu (2001)
    The study of social phenomena in the World Wide Web has been rather fragmentary, and there is no coherent, research-based theory about sense of community in Web environment. Sense of community means part of one's self-concept that has to do with perceiving oneself belonging to, and feeling affinity to a certain social grouping. The present study aimed to find evidence for sense of community in Web environment, and specifically find out what the most critical psychological factors of sense of community would be. Based on known characteristics of real life communities and sense of community, and few occasional studies of Web-communities, it was hypothesized that the following factors would be the most critical ones and that they could be grouped as prerequisites, facilitators and consequences of sense of community: awareness and social presence (prerequisites), criteria for membership and borders, common purpose, social interaction and reciprocity, norms and conformity, common history (facilitators), trust and accountability (consequences). In addition to critical factors, the present study aimed to find out if this kind of grouping would be valid. Furthermore, the effect of Web-community members' background variables to sense of community was of interest. In order to answer the questions, an online-questionnaire was created and tested. It included propositions that reflect factors that precede, facilitate and follow the sense of community in Web environment. A factor analysis was calculated to find out the critical factors and analyses of variance were calculated to see if the grouping to prerequisites, facilitators and consequences was right and how the background variables would affect the sense of community in Web environment. The results indicated that the psychological structure of sense of community in Web environment could not be presented with critical variables grouped as prerequisites, facilitators and consequences. Most factors did facilitate the sense of community, but based on this data it could not be argued that some of the factors chronologically precedesense of community and some follow it. Instead, the factor analysis revealed that the most critical factors in sense of community in Web environment are 1) reciprocal involvement, 2) basic trust for others, 3) similarity and common purpose of members, and 4) shared history of members. The most influencing background variables were the member's own participation activity (indicated with reading and writing messages) and the phase in membership lifecycle (from visitor to leader). The more the member participated and the further in membership life cycle he was, the more he felt sense of community. There are many descriptions of sense of community, but the present study was one of the first to actually measure the phenomenon in Web environment, and that gained well documented, valid results based on large data, proving that sense of community in Web environment is possible, and clarifying its psychological structure, thus enhancing the understanding of sense of community in Web environment.
  • Vuoksimaa, Eero (2004)
    Studies concerning cognitive sex differences have indicated that, on average, females outperform males in some verbal abilities, whereas males outperform females in some visual-spatial abilities. Prenatal hormones play important role in sexual differentiation. Presence of androgens is believed to cause male brain differentiation. According to animal studies prenatal exposure to testosterone in females can result in masculinized behaviour or physiological traits. Human studies of possible masculinization of females from opposite-sex twin pairs are controversial. Some studies have indicated that female members of opposite-sex twins may be masculinized in some traits, while other studies show no evidence of masculinization. Hence the aim of the present study is to investigate sex differences and possible masculinization of cognitive functions in young adult twins. Subjects (N=336) were recruited from the ongoing longitudinal FinnTwin16 study of Finnish twins born in 1974-1979. Results indicate female superiority in verbal and executive functions and male superiority in visual and working memory functions. Further, in female members of opposite-sex twin pairs the visual abilities were enhanced to the male level. However, they still outperformed males in verbal and executive functions. In male members of opposite-sex twin pairs there were no signs of better performance in functions that favored females. Nor there were evidence of reduced performance in functions that favored males. This study suggests that there occurs masculinization of cognitive functions in females who have a male co-twin. In contrast, males with female co-twins are not feminized in their cognitive functions. These results indicate some benefits of twinship in female members of opposite-sex twin pairs in cognitive abilities. Whether the masculinization is a result of organizational effects of prenatal testosterone or postnatal environmental influences could not be resolved. Future research, with control over environmental influences, is needed to determine the origin of masculinization of cognitive abilities.
  • Toikkanen, Tarmo (2005)
    As computer technology evolves, both the need for knowledge workers and the pressure to increase the effectiveness of teaching with the help of ICT increase. Teaching of the skills needed by the knowledge workers requires new pedagogy, where instead facts and obedience the focus is on skills, independence and learning to learn. The use of ICT in education brings its own challenges to learning situations. Social constructivist computer supported collaborative learning (CSCL) is becoming a major challenger for the traditional teacher-centered learning. One of these methodologies is Progressive Inquiry, which is developed in Finland. Since the social constructive theory emphasizes the relations between learners more than the individuals' actions, research in this field must also take into account the interactions that occur in learning situations. While traditional psychological and pedagogical methods are not applicable, an old method of social sciences, SNA or social network analysis is designed specifically for the analysis of groups of people. Applications of SNA in psychology and collaborative learning are however few and preliminary, and no reliable evidence on the applicability nor useful results exist. The purpose of this study is to find out if SNA can be applied to this field of research. In this study SNA was used to analyze the learning situations of 23 classes in comprehensive and secondary schools that used Progressive inquiry. The results show that SNA can be applied to the study of CSCL, since the analysis produced preliminary measurements that were related to the quality of the course. The results are also in concordance with social constructivist theory: a course's usefulness increases as the several students write high quality messages and participate widely in different conversations.
  • Kangas, Ari (2005)
    Research reveals that more than every fourth Finn experiences work-related exhaustion to some degree. Stress and exhaustion have psychological and physical expressions. The main physical factor in stress is the overloading of the autonomic nervous system, which can be measured for instance by variations of heart rate. Studies show that the work field, management and authority of the work, skill developmental possibilities, and social support inhibit stress overload. The practising of self-relaxation techniques possible inhibits working stress and exhaustion. In this study of preventive rehabilitation, the focus was on the effects of the training of "applied relaxation" on psychological and physiological variables of stress and empowerment of resources. Participants (n=73) were basically healthy and capable of working, 25-40 of age, workers from the field of mental work. They practised "applied relaxation" under group conduction for seven weeks. The aim was to learn to relax easily even in everyday occasions. The subjects were tested thirdly. After the first measurement, they were grouped into two groups, of which the first group started the relaxation training. The second group began practising half a year after the second measurement. The third measurement was done one year after the beginning of the study. It was hypothesised that the training of "applied relaxation" would significantly reduce stress on both psychological and physiological variables and that these variables would correlate positively. Results revealed that the training of 'applied relaxation' reduced psychological stress symptoms rather modestly. The changes were more significant in women, who experienced a slight increase in self-directivity. Physical changes were slight decreases of the sympathetic activation. The correlations of psychological and physiological variables were modest. Some changes were reduced after the active training. There was a positive interrelation between experienced work-related demands of efficiency, insufficient social support and exhaustion. There was a tendency to significance between skill developmental possibilities and psychological stress symptoms. Further implications of the results were discussed.
  • Relander, Kristiina (2006)
    Semantic processing can be studied with semantic priming. Target words that are preceded by semantically related prime words are recognized faster and more accurately than targets preceded by unrelated prime words. Semantic priming also affects the magnitude of the N400 event-related potential. The response is smaller to a target word when it is preceded by a related than an unrelated prime word. The effect is called the N400 effect. It is not yet clear, however, how attention modulates semantic priming and the N400 effect. This study investigated how the direction of attention affects the semantic processing of speech. The N400 effect was studied in experimental conditions in which the subjects attention was directed 1) away from the speech stimuli, 2) to phonological features of the speech stimuli, and 3) to semantic features of the speech stimuli. The first aim of the study was to investigate whether the N400 effect for spoken words is dependent on attention to the auditory information. The second aim was to study the differences in the N400 effect when attention is directed to the semantic or other features of speech stimuli. The results showed an N400 effect even when attention was directed away from the speech stimuli. The N400 effect was, however, stronger in conditions during which the speech stimuli were attended. The magnitude of the behavioral semantic priming and the N400 effect did not differ between the conditions during which attention was directed to the semantic or phonological features of the words. The findings indicate that the semantic processing of spoken words is not dependent on attention to auditory information. Furthermore, the results suggest that whether or not semantic processing is relevant for the task performance does not affect the semantic processing of attended spoken words.
  • Oja, Lea (2005)
    Abnormal involuntary attention may lead to enhanced distractibility and has been proposed to be an underlying factor for cognitive problems in attention deficit hyperactivity disorder (ADHD). In the present experiment, involuntary attention switching of 6–11-year-old ADHD and healthy children performing an auditory discrimination task was compared. Deterioration of task performance and event-related brain potentials (ERP) to distracting sounds associated with attention switching, were considered as measures of distractibility. During the experiment the children performed an auditory discrimination task in which they were instructed to differentiate two animal sounds from each other. In the task-related sounds presented from loudspeakers in front of the child there were occasional task-irrelevant changes in the sound location. In addition, novel sounds completely unrelated to the task were presented from behind. The hypothesis of the present study was that the ADHD children would get more distracted than the control children as a consequence of the deviance in the direction of the task-related sound and after an occurrence of a task-irrelevant novel sound. The performance of the ADHD group was highly variable. The task-irrelevant novel sounds prolonged the reaction times, decreased the accuracy, and increased the number of omitted responses in the ADHD group more than in the control group. In addition, abnormalities in the ERPs suggest that the ADHD group was more distracted than the control group by the deviances in the task-related sounds and by the novel sounds and that the ADHD group processes the sounds partly in different brain regions than the control group. To understand these regional and functional abnormalities in more detail, additional research is required.
  • Puskala, Aapo (2002)
    Tutkimuksen tarkoituksena on selvittää, millaisia tiedonhakustrategioita tiedonhakijatkäyttävät etsiessään tietoa Internetistä. Käyttäjät luokitellaan kolmeen ryhmään tiedonhakustrategiansa mukaan. Haku-suuntautuneet käyttäjät käyttävät enimmäkseen hakukoneita, niin koko Internetin kattavia kuin sivustojen sisäisiäkin. Linkkisuuntautuneet taas joko tietävät tai arvaavat kohdesivuston osoitteen tai käyttävät laajoja hierarkkisia hakemistoja tiedon löytämiseen. He navigoivat mielummin sivustollakin linkkejä käyttäen eivätkä yleensä käytä hakutoimintoa. Eriytyneet käyttäjät eivät säännönmukaisesti suosi kumpaakaan tapaa, vaan valitsevat strategian tehtävän mukaan. Tietoa kerättiin kahdella tavalla: WWW-sivulla olleella kyselylomakkeella ja tiedonhakutestillä, jossa käyttäjille annettiin suoritettavaksi erilaisia tiedonhakutehtäviä. Tiedonhakutehtävät lajiteltiin kolmeen ryhmään sen mukaan, mitä strategiaa ne suosivat: hakustrategiaa suosivat, linkkistrategiaa suosivat ja neutraalit tehtävät. Tutkimusongelmana oli selvittää, kuinka tehtävän tyyppi ja ATK- ja Internet-kokemus vaikuttavat tiedonhakustrategian valintaan. Kävi ilmi, ettei käyttäjien suuntautuneisuus tiettyyn strategiaan vaikuta tiedonhakustrategian valintaan, vaan ainoastaan tehtävän tyyppi oli merkitsevä tekijä. Aikaisemman tutkimustiedon valossa kokeenet suosivat haku-suuntautunutta strategiaa. Tässä tutkimuksessa havaittiin, että kokemus lisäsi molempien strategioiden käyttöä yhtäläisesti, mutta tämä ilmiö oli havaittavissa ainoastaan kysely-lomakkeen pohjalta, ei testeissä. Molempien tiedonhakustrategioiden käyttö lisääntyy kokemuksen myötä, mutta suhteelliset osuudet pysyvät samoina. Syyksi sille, että kokeneet eivät suosineet hakustrategiaa, esitetään sitä, että tehtävät olivat liian helppoja, jolloin kokemus ei pääse auttamaan. Oleellisia eroja suoritusajoissa tai hakustrategian vaihdon tiheydessä ei havaittu suhteessa kokemukseen, ainoastaan suhteessa tehtävän tyyppiin.Tämäkin selitettiin toisentyyppisten tehtävien helppoudella. Tutkimuksessa pohditaan lisäksi asiantuntijuuden syntyä tiedonhakukontekstissa sekä esitetään metatietohypoteesi, jonka mukaan tiedonhakustrategian valintaan vaikuttaa tärkeänä tekijänä käyttäjän metatieto hakupalveluista. Metatietoon kuuluu tieto siitä, mitä hakukoneita on saatavilla, mitä tietoa verkosta kannattaa hakea, millä yrityksillä ja yhteisöillä on sisältörikkaat sivut jne, ja minkä tyyppistä tietoa yleensä on saatavilla. Kaikenkaikkiaan strategian valintaan esitetään taustalle kolmen tason tiedon vaikutusta: 1) oma asiantuntemus haettavasta alasta, 2) metatieto Internetin tiedonhakupalveluista sekä 3) tekninen tieto siitä, kuinka hakukoneet toimivat.
  • Hulsi, Antti (1998)
    Näköjärjestelmän monikerrosmalleja voidaan soveltaa yksinkertaisiin ärsykkeen kallistuskulman erottelutehtäviin. Kuitenkin myös testiärsykkeen ympäristössä olevat ärsykkeet vaikuttavat testiärsykkeen havaitsemiseen. Ne voivat esimerkiksi aiheuttaa testiärsykkeen havaitun kallistuskulman siirtymisen, tilt-illuusion. Sijainniltaan erillään olevien psykofyysisten mekanismien välisiä vuorovaikutuksia ei tunneta hyvin. Tutkimuksessa mitattiin sekä pelkän testiärsykkeen että kallistetuilla ärsykkeillä ympäröidyn testiärsykkeen kallistuskulman erottelua. Koehenkilöiden kallistuksen erottelukyky heikkeni, kun testiärsykkeen pituuden ja leveyden suhdetta eli sivusuhdetta pienennettiin. Kallistetut ympäröivät ärsykkeet aiheuttivat tilt-illuusion, jonka voimakkuus riippui ympäröivien ärsykkeiden kallistuskulmasta. Testiärsykkeen sivusuhteen pienentäminen voimisti tilt-illuusiota. Ympäröivien ärsykkeiden kontrastin polariteetti ei vaikuttanut tilt-illuusion voimakkuuteen. Tuloksia mallinnettiin vektorisummamallilla. Mallissa ärsykkeen kallistuskulman edustus perustuu perustason suodattimien vasteita summaavaan mekanismiin. Malli ennustaa pelkän testiärsykkeen kallistuskulman erottelukyvyn heikkenemisen testiärsykkeen sivusuhdetta pienennettäessä. Mallissa epälineaarinen normalisaatio vaimentaa perustason suodattimien vasteita. Paikalliseen normalisaatioon vaikuttavat testiärsykkeen kohdalla olevien suodattimien vasteet. Kallistuskulmavalikoivaan, alueelliseen normalisaatioon vaikuttavat ympäristön suodattimien vasteet. Alueellisen normalisaation takia malli ennustaa ympäröivien ärsykkeiden kallistuskulman vaikutuksen tilt-illuusion voimakkuuteen. Testiärsykkeen sivusuhdetta muutettaessa muuttuu testiärsykkeen pinta-alakin. Vektorisummamallilla ja normalisaatiolla ei voitu mallintaa tilt-illuusion voimakkuuden suurenemista testiärsykkeen sivusuhdetta pienennettäessä.