Search results for "behavioral"
showing 10 items of 3011 documents
Differential Response of Ant Colonies to Intruders: Attack Strategies Correlate With Potential Threat
2011
Animals are often threatened by predators, parasites, or competitors, and attacks against these enemies are a common response, which can help to remove the danger. The costs of defense are complex and involve the risk of injury, the loss of energy ⁄time, and the erroneous identification of a friend as a foe. Our goal was to study the specificity of defense strategies. We analyzed the aggressive responses of ant colonies by confronting them with workers of an unfamiliar congeneric species, a non-nestmate conspecific, a co-occurring congeneric competitor species, and a social parasite—a slave-making ant. As expected, the latter species, which can inflict dramatic fitness losses to the colony,…
The effect of scents on the territorial and aggressive behaviour of laboratory rats
1992
The majority of works found in the literature mention odours as an important factor in the development of social lines and the unleashing of aggressive behaviour, but very few authors have studied more deeply the role that these odours play, how they influence behaviour and what importance the variations of these marks of identity may have. In the present work we analyse social relations presented by laboratory rats (Rattus norvegicus, Wistar breed) in seminatural conditions, with special reference to behaviours of dominance, territorialism and aggressiveness, and the importance that these marks of odour play on these behaviours. For this purpose, different individuals (from the established…
EFFECTS OF TEACHER-STUDENT RELATIONSHIPS ON PEER HARASSMENT: A MULTILEVEL STUDY
2015
Peer harassment is a major social problem affecting children and adolescents internationally. Much research has focused on student-to-student harassment from either an individual or a multilevel perspective. There is a paucity of multilevel research on students’ relationships with the classroom teacher. The purpose of this study was to use a socioecological perspective to examine the relationships between individual student-level characteristics, problematic teacher–student relationships, and student-reported peer harassment. A total of 1,864 children (50.7% female) aged 8 to 13 years (M = 9.82, SD = 1.24), nested in 27 schools (58.2% public) in Spain, participated in the study. Ninety-four…
A combined electrophysiological and morphological examination of episodic memory decline in amnestic mild cognitive impairment.
2013
Early stages of Alzheimer’s disease (AD) are characterized by neuropathological changes within the medial temporal lobe cortex (MTLC), which lead to characteristic impairments in episodic memory, i.e., amnestic mild cognitive impairment (aMCI). Here, we tested the neural correlates of this memory impairment using event-related potentials (ERPs) and voxel-based morphometry. Twenty-four participants were instructed to encode lists of words and were tested in a yes/no recognition memory task. The dual-process model of recognition memory dissociates between acontextual familiarity and recollection of contextual details. The early frontal ERP old/new-effect, which is thought to represent a neura…
Acute psychosocial stress effects on memory performance: Relevance of age and sex.
2018
In recent decades, there has been a growing interest in investigating the effects of chronic and acute stress on cognitive processes, especially memory performance. However, research focusing on acute stress effects has reported contradictory findings, probably due to the many factors that can moderate this relationship. In addition to factors related to the individual, such as sex and age, other factors, such as the type of memory assessed, can play a critical role in the direction of these effects. This review summarizes the main findings of our research group and others about the effects of acute psychosocial stress on memory performance in young and older people of both sexes, taking in…
Up-Regulation of leucocytes Genes Implicated in Telomere Dysfunction and Cellular Senescence Correlates with Depression and Anxiety Severity Scores
2012
BACKGROUND: Major depressive disorder (MDD) is frequently associated with chronic medical illness responsible of increased disability and mortality. Inflammation and oxidative stress are considered to be the major mediators of the allostatic load, and has been shown to correlate with telomere erosion in the leucocytes of MDD patients, leading to the model of accelerated aging. However, the significance of telomere length as an exclusive biomarker of aging has been questioned on both methodological and biological grounds. Furthermore, telomeres significantly shorten only in patients with long lasting MDD. Sensitive and dynamic functional biomarkers of aging would be clinically useful to eval…
Caring for People With Dementia Under COVID-19 Restrictions: A Pilot Study on Family Caregivers
2021
IntroductionThe present pilot study examined to what extent the COVID-19 lockdown affected the behavioral and psychological symptoms of dementia (BPSD) in people with dementia and worsened their family caregivers’ distress. The associations between changes in the BPSD of relatives with dementia (RwD) and in their caregivers’ distress, and sense of social and emotional loneliness, and resilience were also investigated.Materials and MethodsThirty-five caregivers of RwD attending formal healthcare services before the COVID-19 lockdown volunteered for the study, and were interviewed by phone during the lockdown. Caregivers completed the NeuroPsychiatric Inventory (NPI) to assess their care reci…
THE OSCILLATORY MECHANISMS ASSOCIATED WITH SYNTACTIC BINDING IN HEALTHY AGEING
2020
Older adults frequently display differential patterns of brain activity compared to young adults in the same task, alongside widespread neuroanatomical changes. Differing functional activity patterns in older adults are commonly interpreted as being compensatory (e.g., Cabeza, Locantore & McIntosh, 2002). We examined the oscillatory activity in the EEG during syntactic binding in young and older adults, as well as the relationship between oscillatory activity and behavioural performance on a syntactic judgement task within the older adults. 19 young and 41 older adults listened to two-word sentences that differentially load onto morpho-syntactic binding: correct syntactic binding (m…
Contribution of genetic and environmental factors to individual differences in maximal walking speed with and without second task in older women
2005
Background. Among older people, distraction while walking may increase the risk of falls. Factors underlying individual differences in dual tasking are not fully understood. Our aim was to study the effect of a second task on maximal walking speed and to examine whether individual differences in walking speed measured with and without a second task are accounted for by genetic and environmental influences shared across tasks or specific to each task. Methods. The data were collected from the 101 monozygotic and 116 dizygotic twin pairs aged 63–76 years recruited from the Finnish Twin Cohort. Maximal walking speed (MWS) over 10 m was measured on a laboratory corridor and timed with photocell…
Cortical responses of infants with and without a genetic risk for dyslexia
1999
We studied auditory event-related potentials (ERP) in newborns and 6-month-old infants, about half of whom had a familial risk for dyslexia. Syllables varying in vowel duration were presented in an oddball paradigm, in which ERPs to deviating stimuli are assumed to reflect automatic change detection in the brain. The ERPs of newborns had slow positive deflections typical of their age, but significant stimulus and group effects were found only by the age of 6 months. In both groups, the responses to the deviant /ka/ were more positive than those to the standard /kaa/ stimuli, contrary to the findings of adult ERPs to duration changes. The results also suggested differences in brain activatio…