Behavioural responses to anthropogenic disturbances

When a habitat undergoes change, the first response of an individual is often behavioural adjustment. This immediate response can determine whether the population will survive or not, as behavioural flexibility gives time for genetic changes to arise later on. Habitat changes that alter reproductive behaviours can have long-lasting effects on populations. If the selective regime has changed under the new conditions, mate choice cues may no longer reliably reflect an individual s quality. Thus, animals have to be able to adjust their reproductive behaviours to the local conditions. The aim of my thesis was to discuss if and how animals are able to respond to rapid anthropogenic environmental change, and to study the mechanisms of the responses and the evolutionary consequences. The main focus was on the effects of human-induced eutrophication on the reproductive behaviour of fishes. Eutrophication is the result of increased nutrient input and can cause dense underwater vegetation and algal blooms. I used fishes from two very different ecosystems as model species, the Baltic Sea threespine stickleback (Gasterosteus aculeatus) and the desert goby (Chlamydogobius eremius), an endemic species of the Lake Eyre region in Central Australia. I investigated the effects of increased habitat complexity on courtship behaviour and the possibility of local differentiation in courtship and nest building behaviour depending on the level eutrophication in the habitat of origin. Furthermore, I observed the effect of turbidity on stickleback nest building behaviour. The results show that threespine stickleback males, which were born in areas that have been eutrophied for decades, court females at a higher intensity than males from clear water areas. Similarly, male desert gobies increased their courtship effort in dense vegetation. Intense courtship could be an adjustment to reduced visibility and lowered predation risk in the densely vegetated sites. However, there were no clear differences in nest building between males from clear and eutrophied areas under standardized conditions. This was expected as Baltic Sea sticklebacks prefer to nest under vegetation cover and are fairly rigid in adjusting their nest characteristics. Nest building was affected by increased turbidity: males built smaller nests with a larger nest entrance in turbid water. The large variation in the magnitude of phytoplankton blooms may require a rapid adjustment of the optimal nest structure to the current conditions. This thesis highlights the complex interactions that are set- off by human-induced changes in habitats and are followed by the immediate behavioural responses. It also encourages more research to tease apart the phenotypic and genetic components of the observed behavioural differences.

On the moderators of trait avoidance motivation in predicting cognitive biases and adjustment

The present research focused on motivational and personality traits measuring individual differences in the experience of negative affect, in reactivity to negative events, and in the tendency to avoid threats. In this thesis, such traits (i.e., neuroticism and dispositional avoidance motivation) are jointly referred to as trait avoidance motivation. The seven studies presented here examined the moderators of such traits in predicting risk judgments, negatively biased processing, and adjustment. Given that trait avoidance motivation encompasses reactivity to negative events and tendency to avoid threats, it can be considered surprising that this trait does not seem to be related to risk judgments and that it seems to be inconsistently related to negatively biased information processing. Previous work thus suggests that some variable(s) moderate these relations. Furthermore, recent research has suggested that despite the close connection between trait avoidance motivation and (mal)adjustment, measures of cognitive performance may moderate this connection. However, it is unclear whether this moderation is due to different response processes between individuals with different cognitive tendencies or abilities, or to the genuinely buffering effect of high cognitive ability against the negative consequences of high trait avoidance motivation. Studies 1-3 showed that there is a modest direct relation between trait avoidance motivation and risk judgments, but studies 2-3 demonstrated that state motivation moderates this relation. In particular, individuals in an avoidance state made high risk judgments regardless of their level of trait avoidance motivation. This result explained the disparity between the theoretical conceptualization of avoidance motivation and the results of previous studies suggesting that the relation between trait avoidance motivation and risk judgments is weak or nonexistent. Studies 5-6 examined threat identification tendency as a moderator for the relationship between trait avoidance motivation and negatively biased processing. However, no evidence for such moderation was found. Furthermore, in line with previous work, the results of studies 5-6 suggested that trait avoidance motivation is inconsistently related to negatively biased processing, implying that theories concerning traits and information processing may need refining. Study 7 examined cognitive ability as a moderator for the relation between trait avoidance motivation and adjustment, and demonstrated that cognitive ability moderates the relation between trait avoidance motivation and indicators of both self-reported and objectively measured adjustment. Thus, the results of Study 7 supported the buffer explanation for the moderating influence of cognitive performance. To summarize, the results showed that it is possible to find factors that consistently moderate the relations between traits and important outcomes (e.g. adjustment). Identifying such factors and studying their interplay with traits is one of the most important goals of current personality research. The present thesis contributed to this line of work in relation to trait avoidance motivation.

Roles of forced nicotine exposure and Comt gene disruption in the development of addiction-related behavioural and neurochemical changes in mice

Activation of midbrain dopamine systems is thought to be critically involved in the addictive properties of abused substances. Drugs of abuse increase dopamine release in the nucleus accumbens and dorsal striatum, which are the target areas of mesolimbic and nigrostriatal dopamine pathways, respectively. Dopamine release in the nucleus accumbens is thought to mediate the attribution of incentive salience to rewards, and dorsal striatal dopamine release is involved in habit formation. In addition, changes in the function of prefrontal cortex (PFC), the target area of mesocortical dopamine pathway, may skew information processing and memory formation such that the addict pays an abnormal amount of attention to drug-related cues. In this study, we wanted to explore how long-term forced oral nicotine exposure or the lack of catechol-O-methyltransferase (COMT), one of the dopamine metabolizing enzymes, would affect the functioning of these pathways. We also wanted to find out how the forced nicotine exposure or the lack of COMT would affect the consumption of nicotine, alcohol, or cocaine. First, we studied the effect of forced chronic nicotine exposure on the sensitivity of dopamine D2-like autoreceptors in microdialysis and locomotor activity experiments. We found that the sensitivity of these receptors was unchanged after forced oral nicotine exposure, although an increase in the sensitivity was observed in mice treated with intermittent nicotine injections twice daily for 10 days. Thus, the effect of nicotine treatment on dopamine autoreceptor sensitivity depends on the route, frequency, and time course of drug administration. Second, we investigated whether the forced oral nicotine exposure would affect the reinforcing properties of nicotine injections. The chronic nicotine exposure did not significantly affect the development of conditioned place preference to nicotine. In the intravenous self-administration paradigm, however, the nicotine-exposed animals self-administered nicotine at a lower unit dose than the control animals, indicating that their sensitivity to the reinforcing effects of nicotine was enhanced. Next, we wanted to study whether the Comt gene knock-out animals would be a suitable model to study alcohol and cocaine consumption or addiction. Although previous work had shown male Comt knock-out mice to be less sensitive to the locomotor-activating effects of cocaine, the present study found that the lack of COMT did not affect the consumption of cocaine solutions or the development of cocaine-induced place preference. However, the present work did find that male Comt knock-out mice, but not female knock-out mice, consumed ethanol more avidly than their wild-type littermates. This finding suggests that COMT may be one of the factors, albeit not a primary one, contributing to the risk of alcoholism. Last, we explored the effect of COMT deficiency on dorsal striatal, accumbal, and prefrontal cortical dopamine metabolism under no-net-flux conditions and under levodopa load in freely-moving mice. The lack of COMT did not affect the extracellular dopamine concentrations under baseline conditions in any of the brain areas studied. In the prefrontal cortex, the dopamine levels remained high for a prolonged time after levodopa treatment in male, but not female, Comt knock-out mice. COMT deficiency induced accumulation of 3,4-dihydroxyphenylacetic acid, which increased further under levodopa load. Homovanillic acid was not detectable in Comt knock-out animals either under baseline conditions or after levodopa treatment. Taken together, the present results show that although forced chronic oral nicotine exposure affects the reinforcing properties of self-administered nicotine, it is not an addiction model itself. COMT seems to play a minor role in dopamine metabolism and in the development of addiction under baseline conditions, indicating that dopamine function in the brain is well-protected from perturbation. However, the role of COMT becomes more important when the dopaminergic system is challenged, such as by pharmacological manipulation.

Cortical processing of musical pitch as reflected by behavioural and electrophysiological evidence

In a musical context, the pitch of sounds is encoded according to domain-general principles not confined to music or even to audition overall but common to other perceptual and cognitive processes (such as multiple pattern encoding and feature integration), and to domain-specific and culture-specific properties related to a particular musical system only (such as the pitch steps of the Western tonal system). The studies included in this thesis shed light on the processing stages during which pitch encoding occurs on the basis of both domain-general and music-specific properties, and elucidate the putative brain mechanisms underlying pitch-related music perception. Study I showed, in subjects without formal musical education, that the pitch and timbre of multiple sounds are integrated as unified object representations in sensory memory before attentional intervention. Similarly, multiple pattern pitches are simultaneously maintained in non-musicians' sensory memory (Study II). These findings demonstrate the degree of sophistication of pitch processing at the sensory memory stage, requiring neither attention nor any special expertise of the subjects. Furthermore, music- and culture-specific properties, such as the pitch steps of the equal-tempered musical scale, are automatically discriminated in sensory memory even by subjects without formal musical education (Studies III and IV). The cognitive processing of pitch according to culture-specific musical-scale schemata hence occurs as early as at the sensory-memory stage of pitch analysis. Exposure and cortical plasticity seem to be involved in musical pitch encoding. For instance, after only one hour of laboratory training, the neural representations of pitch in the auditory cortex are altered (Study V). However, faulty brain mechanisms for attentive processing of fine-grained pitch steps lead to inborn deficits in music perception and recognition such as those encountered in congenital amusia (Study VI). These findings suggest that predispositions for exact pitch-step discrimination together with long-term exposure to music govern the acquisition of the automatized schematic knowledge of the music of a particular culture that even non-musicians possess.

Impulsivity, health-related behaviour and disease : A prospective study

In clinical settings impulsivity refers to a symptom of psychiatric disorder, but nonclinically oriented research treats impulsivity as a personality and temperament dimension. This prospective study examined whether impulsivity predicts adverse health-related behaviour and increased risk of health problems in a large, nonclinical sample of 5433 subjects working in 12 Finnish hospitals. The data were collected using two questionnaire surveys at a 2-year interval. After controlling for alcohol use at baseline, higher impulsivity predicted increased alcohol consumption at follow-up in both genders (p < .01) and was associated with increased likelihood of becoming a heavy drinker or taking up smoking (p < .05). Impulsivity also predicted an increased number of cigarettes smoked per day in the follow-up among women (p < .001), but not among men, although adjustment for the number of cigarettes smoked at baseline attenuated these associations (p = .08 for women). In men, higher impulsivity was associated with shorter sleep duration and waking up several times per night independent of baseline characteristics (p < .01), whereas in women, higher impulsivity predicted difficulty in falling asleep and waking up feeling tired after the usual amount of sleep (p < .05). In women, these associations became nonsignificant after adjustment for pre-existing somatic and psychiatric diseases. Finally, higher impulsivity was associated with an increased 2-year incidence of physician-diagnosed peptic ulcer disease (adjusted odds ratio (OR) = 2.42, 95% confidence interval (CI) = 1.21 - 4.82) and onset of depression (OR = 1.95, 95% CI = 1.28 - 2.97) after adjustment for a variety of baseline covariates. In conclusion, this study shows that in a nonclinical population, impulsivity appears to be a risk factor for various unhealthy behaviour and health problems.

Finnish Homicides and Mental Disorders: An investigation of offense and offender characteristics

Although the majority of people with mental illness are not violent, scientific studies over the last decades show that certain psychiatric disorders increase the risk of violent behavior, including homicide. This thesis examined crime scene behaviors and offender background characteristics among mentally ill Finnish homicide offenders. Previously, homicide crime scene behaviors have been investigated in relation to offender demographic characteristics, whereas this study compares the behaviors of offenders with various mental illnesses. The study design was a retrospective chart review of the forensic psychiatric statements of Finnish homicide offenders. The work consists of four substudies. The aims of the study were as follows: To describe differences in the childhood and family backgrounds as well as in the adolescent and adult adjustment of Finnish homicide offenders belonging to different diagnostic categories (schizophrenia, personality disorder, alcoholism, drug addiction or no diagnosis). Further, the study examined associations between the crime scene behaviors and mental status of these offenders. Also, the distinguishing characteristics between two groups of offenders with schizophrenia were examined: early starters, who present antisocial behavior before the onset of schizophrenia, and late starters, who first offend after the onset of mental disorder. Finally, it was investigated how the use of excessive violence is associated with clinical and circumstantial variables as well as offender background characteristics among homicide offenders with schizophrenia. The main findings of the study can be summarized as follows. First, offenders with personality disorder or drug addiction had experienced multiple difficulties in their early environments: both family and individual problems were typical. Offenders with schizophrenia were relatively well-adjusted in childhood compared to the other groups. However, in adolescence and adulthood, social isolation, withdrawal and other difficulties attributable to these offenders illness became evident. In several aspects, offenders with alcohol dependency resembled offenders with no diagnosis in that these offenders had less problematic backgrounds compared to other groups. Second, the results showed that crime scene behaviors, victim gender and the victim-offender relationship differ between the groups. In particular, offenders with a diagnosis of schizophrenia or drug addiction have some unique features in their crime scene behaviors and choice of victims. Offenders with schizophrenia were more likely to kill a blood relative, to use a sharp weapon and to injure the victim s face. Drug addiction was associated with stealing from the victim and trying to cover up the body. Third, the results suggest that the offense characteristics of early- and late-start offenders with schizophrenia differ only modestly. However, several significant differences between the groups were found in characteristics of offenders: early starters had experienced a multitude of problems in their childhood surroundings and also later in life. Fourth, violent acts where the offender did not commit the offense alone or had previous homicidal history were predictive of excessive violence among offenders with schizophrenia. Positive psychotic symptoms did not predict the use of excessive violence. Nearly one third of the cases in the sample involved multiple and severe violence, including features such as sadism, mutilation, sexual components or extreme stabbing. In sum, mentally disordered homicide offenders are heterogeneous in their offense characteristics as well as their background characteristics. Empirically based information on how the offender s mental state is associated with specific crime scene behaviors can be utilized within the police force in developing methods of prioritizing suspects in unsolved homicide cases. Also, these results emphasise the importance of early interventions for problem families and children at risk of antisocial behavior. They may also contribute to the development of effective treatment for violent offenders.

Essays on Misplanning Wealth and Health: A Behavioural Approach

The dissertation consists of three essays on misplanning wealth and health accumulation. The conventional economics assumes that individual's intertemporal preferences are exponential (exponential preferences, EP). Recent findings in behavioural economics have shown that, actually, people do discount near future relatively heavier than distant future. This implies hyperbolic intertemporal preferences (HP). Essays I and II concentrate especially on the effects of a delayed completion of tasks, a feature of behaviour that HP enables. Essay III uses current Finnish data to analyse the evolvement of the quality adjusted life years (QALYs) and inconsistencies in measuring that. Essay I studies the existence effects of a lucrative retirement savings program (SP) on the retirement savings of different individual types having HP. If the individual does not know that he will have HP also in the future, i.e. he is the naïve, for certain conditions, he delays the enrolment on SP until he abandons it. Very interesting finding is that the naïve retires then poorer in the presence than in the absence of SP. For the same conditions, the individual who knows that he will have HP also in the future, i.e. he is the sophisticated, gains from the existence of SP, and retires with greater retirement savings in the presence than in the absence of SP. Finally, capabilities to learn from past behaviour and about intertemporal preferences improve possibilities to gain from the existence but an adequate time to learn must be then guaranteed. Essay II studies delayed doctor's visits, theirs effects on the costs of a public health care system and government's attempts to control patient behaviour and fund the system. The controlling devices are a consultation fee and a deductible for that. The deductible is effective only for a patient whose diagnosis reveals a disease that would not get cured without the doctor's visit. The naives delay their visits the longest while EP-patients are the quickest visitors. To control the naives, the government should implement a low fee and a high deductible, while for the sophisticates the opposite is true. Finally, if all the types exist in an economy then using an incorrect conventional assumption that all individuals have EP leads to worse situation and requires higher tax rates than assuming incorrectly but unconventionally that only the naives exists. Essay III studies the development of QALYs in Finland 1995/96-2004. The essay concentrates on developing a consistent measure, i.e. independent of discounting, for measuring the age and gender specific QALY-changes and their incidences. For the given time interval, use of a relative change out of an attainable change seems to be almost intact to discounting and reveals that the greatest gains are for older age groups.

Evaluation of methods and applications for behavioural profiling of transgenic mice

During the last 10-15 years interest in mouse behavioural analysis has evolved considerably. The driving force is development in molecular biological techniques that allow manipulation of the mouse genome by changing the expression of genes. Therefore, with some limitations it is possible to study how genes participate in regulation of physiological functions and to create models explaining genetic contribution to various pathological conditions. The first aim of our study was to establish a framework for behavioural phenotyping of genetically modified mice. We established comprehensive battery of tests for the initial screening of mutant mice. These included tests for exploratory and locomotor activity, emotional behaviour, sensory functions, and cognitive performance. Our interest was in the behavioural patterns of common background strains used for genetic manipulations in mice. Additionally we studied the behavioural effect of sex differences, test history, and individual housing. Our findings highlight the importance of careful consideration of genetic background for analysis of mutant mice. It was evident that some backgrounds may mask or modify the behavioural phenotype of mutants and thereby lead to false positive or negative findings. Moreover, there is no universal strain that is equally suitable for all tests, and using different backgrounds allows one to address possible phenotype modifying factors. We discovered that previous experience affected performance in several tasks. The most sensitive traits were the exploratory and emotional behaviour, as well as motor and nociceptive functions. Therefore, it may be essential to repeat some of the tests in naïve animals for assuring the phenotype. Social isolation for a long time period had strong effects on exploratory behaviour, but also on learning and memory. All experiments revealed significant interactions between strain and environmental factors (test history or housing condition) indicating genotype-dependent effects of environmental manipulations. Several mutant line analyses utilize this information. For example, we studied mice overexpressing as well as those lacking extracellular matrix protein heparin-binding growth-associated molecule (HB-GAM), and mice lacking N-syndecan (a receptor for HB-GAM). All mutant mice appeared to be fertile and healthy, without any apparent neurological or sensory defects. The lack of HB-GAM and N-syndecan, however, significantly reduced the learning capacity of the mice. On the other hand, overexpression of HB-GAM resulted in facilitated learning. Moreover, HB-GAM knockout mice displayed higher anxiety-like behaviour, whereas anxiety was reduced in HB-GAM overexpressing mice. Changes in hippocampal plasticity accompanied the behavioural phenotypes. We conclude that HB-GAM and N-syndecan are involved in the modulation of synaptic plasticity in hippocampus and play a role in regulation of anxiety- and learning-related behaviour.

Behavioural, population, and genetic processes affecting metapopulation dynamics of the Glanville fritillary butterfly

In my thesis I have been studying the effects of population fragmentation and extinction-recolonization dynamics on genetic and evolutionary processes in the Glanville fritillary butterfly (Melitaea cinxia). By conducting crosses within and among newly-colonized populations and using several fitness measures, I found a strong decrease in fitness following colonization by a few related individuals, and a strong negative relationship between parental relatedness and offspring fitness. Thereafter, I was interested in determining the number and relatedness of individuals colonizing new populations, which I did using a set of microsatellites I had previously developed for this species. Additionally, I am interested in the evolution of key life-history traits. By following the lifetime reproductive success of males emerging at different times in a semi-natural setup, I demonstrated that protandry is adaptive in males, and I was able to rule out, for M. cinxia, alternative incidental hypotheses evoked to explain the evolution of protandry in insects. Finally, in work I did together with Prof. Hanna Kokko, I am proposing bet-hedging as a new mechanism that could explain the evolution of polyandry in M. cinxia.

Behavioural and physiological responses to predators of captive-bred Arctic charr: significance of genetics, learning and ontogeny

Predation forms one of the main selective forces in nature and in a vast number of prey species the behavioural responses form the main way to avoid predation. World wide numerous captive breeding programs are used to produce fish and other animal species for conservational reintroductions. However, rearing animals in the absence of predators in captivity has been shown to weaken their predator avoidance skills and lead to behavioural divergence between wild and captive-bred populations. In my thesis I studied the effects of predator odour exposures on antipredator behavioural and physiological responses of captive reared Saimaa Arctic charr. This charr population is the most endangered fish population in Finland and a sample of the remaining population has been taken to captive breeding and used for an extensive reintroduction program. Lowered responsiveness to predators is probably one of the major reasons for the poor survival probability of the charr after release into the wild. The main aims of my thesis were to explore the reasons for behavioural phenotypic variation in this charr population and whether naïve charr young could be trained to recognise their natural predators. The predator species in my thesis were burbot (Lota lota) and pikeperch (Sander lucioperca). In my thesis I showed that the captive-bred charr responded to chemical cues from burbot and pikeperch, but the magnitude of responses was linked to the predator species. The burbot odour increased the spatial odour avoidance of the charr young. On the other hand, in the pikeperch treatment charr reduced their relative swimming activity and tended to show more freezing behaviour relative to the burbot treatment. It seems evident that these different responses are related to the different hunting tactics of predator species. Furthermore, I detected wide between-family differences in antipredator responsiveness (i.e. inherited variation in antipredator behaviours) in this captive stock. Detected differences were greater in the response towards burbot than towards pikeperch. These results, in addition to predator-specific antipredator responses, suggest that there is a clear inherited component in antipredator responsiveness in Saimaa charr population and that the detected inherited differences could explain a part of the behavioural phenotypic variation in this population. In my thesis I also found out that both social learning and direct exposure to live predators enhance the antipredator responsiveness of charr young. In addition, I obtained indications that predator odour exposures (i.e. life-skills training) in alevin and fry stages can fine-tune the innate antipredator responsiveness of charr. Thus, all these methods have the potential to enhance the innate antipredator responsiveness of naïve charr young, possibly also improving the post-release survival of these trained individuals in the wild. However, the next logical phase would be to carry out large scale survival studies in the wild to test this hypothesis. Finally, the results of my thesis emphasize that possible long-term life-skills training methods should take into account not only the behavioural but also the physiological effects of training.

Just say no? The influence of personal goals, beliefs, psychosocial adjustment, and parental relationships in drug use by adolescents

The study in its entirety focused on factors related to adolescents decisions concerning drug use. The term drug use is taken here to include the use of tobacco products, alcohol, narcotics, and other addictive substances. First, the reasons given for drug use (attributions) were investigated. Secondly, the influence of personal goals, the beliefs involved in decision making, psychosocial adjustment including body image and involvement with peers, and parental relationships on drug use were studied. Two cohorts participated in the study. In 1984, a questionnaire on reasons for drug use was administered to a sample of adolescents aged 14-16 (N=396). A further questionnaire was administered to another sample of adolescents aged 14-16 (N=488) in 1999. The results for both cohorts were analyzed in Articles I and II. In Articles III and IV further analysis was carried out on the second cohort (N=488). The research report presented here provides a synthesis of all four articles, together with material from a further analysis. In a comparison of the two cohorts it was found that the attributions for drug use had changed considerably over the intervening fifteen-year period. In relation to alcohol and narcotics use an increase was found in reasons involving inner subjective experiences, with mention of the good feeling and fun resulting from alcohol and narcotics use. In addition, the goals of alcohol consumption were increasingly perceived as drinking to get drunk, and for its own sake. The attributions for the adolescents own smoking behavior were quite different from the attributions for smoking by others. The attributions were only weakly influenced by the participants gender or by their smoking habits, either in 1984 or 1999. In relation to participants own smoking, the later questionnaire elicited more mention of inner subjective experiences involving "good feeling. In relation to the perceived reasons for other people s smoking, it elicited more responses connected with the notion of "belonging. In the second sample, the results indicated that the levels of body satisfaction among adolescent girls are lower than those among adolescent boys. Overall, dissatisfaction with one's physical appearance seemed to relate to drug use. Girls were also found to engage in more discussions than boys; this applied to (i) discussion with peers (concerning both intimate and general matters), and (ii) discussion with parents (concerning general matters). However, more than a quarter of the boys (out of the entire population) reported only low intimacy with both parents and peers. If both drinking and smoking were considered, it seemed that girls in particular who reported drinking and smoking also reported high intimacy with parents and peers. Boys who reported drinking and smoking reported only medium intimacy with parents and peers. In addition, having an intimate relationship with one's peers was associated with a greater tendency to drink purely in order to get drunk. Overall, the results seemed to suggest that drug use is connected with a close relationship with peers and (surprisingly) with a close relationship with parents. Nevertheless, there were also indications that to some extent peer relationships can also protect adolescents from smoking and alcohol use. The results, which underline the complexity of adolescent drug use, are taken up in the Discussion section. It may be that body image and/or other identity factors play a more prominent role in all drug use than has previously been acknowledged. It does appear that in the course of planning support campaigns for adolescents at risk of drug use, we should focus more closely on individuals and their inner world. More research on this field is clearly needed, and therefore some ideas for future research are also presented.