Peter Pajkossy

• PhD
• Budapest University of Technology and Economics

In a recognition memory task, correct “old” responses to previously studied target items (hits) trigger larger pupil dilation (PD) than correct “new” responses to previously not presented foil items (correct rejections). This pupil old/new effect reflects the specific processes involved in recognition decisions, with dilation being larger when deci...

The locus coeruleus-noradrenergic (LC-NA) system plays a crucial role in optimizing performance in different information processing domains, and its dysfunction plays an important role in age-related pathological cognitive decline. In our study, we investigated whether age-related differences are a function of the extent to which a particular task...

Introduction The aim of this study was to identify low-risk traits of schizophrenia among healthy undergraduate student volunteers, and the investigation of these traits with regards to their specificity in contrast to individuals with a latent disposition towards bipolar disorder. Self-agency, as a phenomenon closely related to psychomotor functio...

One main cornerstone of adaptive behavior is belief updating, whereby new and unexpected observations lead to the updating of learned associations between events, behaviors and outcomes. This process necessitates the detection of changed environmental contingencies which in turn leads to uncertainty about the environmental regularities. Change and...

We automatically segment the continuous stream of our experiences into events with discrete boundaries, and these events serve then as building blocks for later episodic memories. How our brain creates these discrete event representations remains elusive. Here we investigated the role of noradrenergic (NA) transmission, heavily linked to change-det...

Contextual features are integral to episodic memories; yet, we know little about context effects on pattern separation, a hippocampal function promoting orthogonalization of overlapping memory representations. Recent studies suggested that various extrahippocampal brain regions support pattern separation; however, the specific role of the parahippo...

The measurement of pupil size changes is a promising method to investigate the neural correlates of information processing. Whereas a long line of research demonstrates that pupil responses are sensitive to specific characteristics of information processing (e.g. mental effort, attentional allocation, surprise), an emerging line of research investi...

Background: Inflammatory bowel diseases (IBDs) are chronic conditions that negatively affect the patient’s quality of life. With the spread of the biopsychosocial model, the role of mental health in the activity and course of inflammatory bowel disease is becoming more and more recognized. Our study aimed to assess the prevalence of anxiety and dep...

Background and purpose: The decline of episodic memory is one of the earliest cognitive markers of mild cognitive impairment and various types of dementia. Until today, however, there is no standardized Hun­garian episodic memory test that takes into account the characteristics of the Hungarian language. The study presents the structure and stand...

Beside its well-known link to mental effort, pupil dilation (PD) can be also informative regarding the cognitive and neurobiological background of episodic memory. It has been shown, for example, that the magnitude of PD during retrieval signals the strength of a memory trace. Importantly, however, this link might be mediated by the specific memory...

During decision making, we are continuously faced with two sources of uncertainty regarding the links between stimuli, our actions, and outcomes. On the one hand, our expectations are often probabilistic, that is, stimuli or actions yield the expected outcome only with a certain probability (expected uncertainty). On the other hand, expectations mi...

Context-dependent episodic memory is typically investigated using tasks in which retrieval occurs either in the reinstated context of encoding or in a completely new context. A fundamental question of episodic memory models is the level of detail in episodic memory representations containing contextual information about the encoded event. The prese...

Introduction This study was carried out to map psychosis spectrum disorder risk factors. Objectives Our goal was to find what kind of instrumental methods may help to detect latent liabilities for schizophrenia and bipolar affective disorder Methods Using online questionnaires n=710 students were screened. Groups were formed based on the inclusio...

Introduction Our series of studies in the spectrum of psychosis (schizophrenia, bipolar affective disorder, schizoaffective disorder) is based on the concept of the RDoC system. Objectives In this study, we were interested in knowing whether cross-diagnostic disturbances in cognitive functions can be found in the spectrum and whether they predict...

A környezeti válság napjaink kiemelkedő kérdésköreként, s alapvetően emberi tevékenység következményeként a társadalom minden szintjén tanulmányozandó. Jelen kutatás az egyéni vizuális figyelmi mintázatokat, illetve az esetleges figyelmi torzítás megjelenését helyezte a középpontba, környezeti problémákat megjelenítő képekkel kapcsolatban, háboríta...

Context-dependent episodic memory is typically investigated using tasks in which retrieval occurs either in the reinstated context of encoding or in a completely new context. A fundamental question for episodic memory models is how detailed those episodic memory representations are that contain contextual information about the encoded event. The pr...

One of the greatest commonplaces in memory research is that context improves recall and enhances or leaves recognition intact. Here we present results which draw attention to the fact that the reappearance of irrelevant and unattended background contexts of encoding significantly impairs memory discrimination functions. This manuscript presents the...

A major task of episodic memory is to create unique, distinguishable representations of highly overlapping perceptual inputs. Several studies on this basic function have shown that it is based on the intact functioning of certain subregions of the hippocampus and is among the most sensitive behavioral indicators of mild cognitive impairment (MCI) a...

Pupillometry have recently added valuable insights about the cognitive and possible neurobiological processes underlying episodic memory. Most of the studies, however, investigated recognition memory, which only partially relies on cue-driven recollection, the hallmark feature of episodic memory. Here we measured pupil size during a paired associat...

Retrieval practice is an effective long-term learning strategy. Items practiced through repeated retrieval are resistant to interference, stress, and secondary load, which attributes also characterize automatization in skill learning. In two experiments, we investigated whether retrieval practice is associated with decrease in processing load, whic...

Dopamine (DA) and noradrenaline (NA) are important neurotransmitters, which are suggested to play a vital role in modulating the neural circuitry involved in the executive control of cognition. One way to investigate the functions of these neurotransmitter systems is to assess physiological indices of DA and NA transmission. Here we examined how va...

Recent findings suggest that acute stress can improve the execution of delayed intentions (prospective memory, PM). However, it is unclear whether this improvement can be explained by altered executive control processes or by altered associative memory functioning. To investigate this issue, we used physical-psychosocial stressors to induce acute s...

A constant task for every living organism is to decide whether to exploit rewards associated with current behavior or to explore the environment for more rewarding options. Current empirical evidence indicates that exploitation is related to phasic whereas exploration is related to tonic firing mode of noradrenergic neurons in the locus coeruleus....

Although the improvement of motor symptoms in Parkinson's disease (PD) after Deep Brain Stimulation (DBS) of the subthalamic nucleus (STN) is well documented, there are open questions regarding its impact on cognitive functions. The aim of the present study was to assess the effect of bilateral DBS of the STN on executive functions in PD patients u...

Worrying is a key concept in describing the complex relationship between anxiety and cognitive control. On the one hand, cognitive control processes might underlie the specific tendency to engage in worrying (i.e. trait worry), conceptualized as a future-oriented mental problem-solving activity. On the other hand, the general tendency to experience...

There is a growing amount of evidence about the deficit of executive system in OCD, which is strongly related to the fronto-basal loop dysfunctions of the disorder (e.g. Chamberlain et al., 2005; Olley et al., 2007). In addition to the executive deficit, several studies found impaired visual and spatial memory performance in this disorder. In an ea...

Prospective memory is the ability to formulate and carry out actions at the appropriate time or in the appropriate context. This study aimed to identify the effect of hypnosis on prospective memory performance and to analyze the involvement of executive control processes in intention realization in a hypnotically altered state of consciousness. In...

Depressive symptoms are often found to be associated with the number of imagined positive and negative future episodes. Whereas most previous studies investigated the number of imagined events within a limited time period, our study focused on the phenomenal nature of future episodes and their relationships to depressive symptoms, as measured by th...

The Hungarian version of the Penn State Worry Questionnaire (PSWQ) was validated in two studies, using five different samples. Study 1 tested the factor structure and internal consistency of the PSWQ in two undergraduate student samples, comparing the psychometric properties of the paper-pencil and the online versions of the scale. Study 2 assessed...

Nightmare disorder is a prevalent parasomnia characterized by vivid and highly unpleasant dream experiences during night time sleep. The neural background of disturbed dreaming was proposed to be associated with impaired prefrontal and fronto-limbic functioning during REM sleep. We hypothesized that the impaired prefrontal and fronto-limbic functio...

Intentional forgetting refers to the surprising phenomenon that we can forget previously successfully encoded memories if we are instructed to do so. Here, we show that participants cannot only intentionally forget episodic memories but they can also mirror the "forgetting performance" of an observed model. In four experiments a participant observe...

The impact of state/trait anxiety and worry on decision-making was investigated applying a computerized gambling task (Iowa Gambling Task). Besides, using two measures of knowledge about the task-contingencies, we examined the role of declarative knowledge in successful performance on the task and we tested whether the amount of declarative knowled...

The link between cannabis use and psychosis has been studied intensively and debated hotly for decades. The authors review the research that has been done on the topic, including the studies which produced evidence of a relationship between the two phenomena, and give a detailed analysis of the hypotheses about the nature of the link (the direction...

This study examined the applicability of broader thematic categories for coding personal strivings, and tested the relationship between both dimensions and contents of personal goals and life satisfaction. We also applied the psychosocial theory of Erikson (1963) to evaluate personal goals. These issues were explored on a Hungarian youth sample of...