Browsing by Subject "attention"

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  • Mäntylä, Teemu; Nummenmaa, Lauri; Rikandi, Eva; Lindgren, Maija; Kieseppä, Tuula; Hari, Riitta; Suvisaari, Jaana; Raij, Tuukka T. (2018)
    BACKGROUND: Functional magnetic resonance imaging studies of psychotic disorders have reported both hypoactivity and hyperactivity in numerous brain regions. In line with the dysconnection hypothesis, these regions include cortical integrative hub regions. However, most earlier studies focused on a single cognitive function at a time, assessed by delivering artificial stimuli to patients with chronic psychosis. Thus, it remains unresolved whether these findings are present already in early psychosis and whether they translate to real-life-like conditions that require multisensory processing and integration. METHODS: Scenes from the movie Alice in Wonderland (2010) were shown to 51 patients with first-episode psychosis (16 women) and 32 community-based control subjects (17 women) during 3T functional magnetic resonance imaging. We compared intersubject correlation, a measure of similarity of brain signal time courses in each voxel, between the groups. We also quantified the hubness as the number of connections each region has. RESULTS: Intersubject correlation was significantly lower in patients with first-episode psychosis than in control subjects in the medial and lateral prefrontal, cingulate, precuneal, and parietotemporal regions, including the default mode network. Regional magnitude of between-group difference in intersubject correlation was associated with the hubness. CONCLUSIONS: Our findings provide novel evidence for the dysconnection hypothesis by showing that during complex real-life-like stimulation, the most prominent functional alterations in psychotic disorders relate to integrative brain functions. Presence of such abnormalities in first-episode psychosis rules out long-term effects of illness or medication. These methods can be used in further studies to map widespread hub alterations in a single functional magnetic resonance imaging session and link them to potential downstream and upstream pathways.
  • Karadeniz, Sami (Helsingin yliopisto, 2019)
    Aims of the present study: Attention-deficit/hyperactivity disorder (ADHD), beginning in childhood and often continuing into adulthood, is a neurodevelopmental condition that impairs an individual’s functioning in everyday life. The disorder is characterized by impairments in attention regulation or impulse control, or both. Many of the symptoms are related to disturbances in attention, the ability to select behaviorally relevant stimuli and to filter out irrelevant information among the overwhelming amount of sensory data. Neural mechanisms of attention have been linked to oscillations in electophysiological brain activity at alpha frequencies (8–13 Hz), but information on alpha oscillations in adult ADHD has remained scarce. The aim of the present study was to examine differences in attention and distractibility related alpha oscillations between adult ADHD patients and neurotypical controls. Methods: Participants were instructed to attend moving spherical objects and to report color changes in the objects. Number of attended objects varied from one (in right or left visual hemifield) to two (one in both hemifields). In addition to the attended objects, participants were at times presented with distractors which they were instructed to ignore. Brain activity during task performance was measured with magnetoencephalography (MEG). Results and discussion: Behavioral performance was similar between the groups. However, alpha oscillations related to distractor processing differed in a statistically significant manner between ADHD patients and controls. Main differences were related to inter-hemispheric interactions, suggesting that attentional deficits in ADHD might be related to abnormalities between inter-hemispheric communication.
  • Juurmaa, Kristiina (Helsingfors universitet, 2017)
    Introduction: Attention-deficit hyperactivity disorder (ADHD) is among the most common childhood psychiatric disorders and is marked by persistent, age-inappropriate levels of inattention, hyperactivity and/or impulsivity. The present study examines cortical oscillations in adults diagnosed with ADHD/ADD during administration of T.O.V.A. (Test of Variables of Attention). T.O.V.A. is a continuous performance test (CPT) that measures the ability to sustain attention for a prolonged period of time. The motivation for the study is to contribute to the diagnostic picture of ADHD through the novel combination of T.O.V.A. with an EEG measurement. Parieto-occipital alpha and frontomedial theta are examined in particular as they have been linked to sustained attention as measured in CPTs. Methods: 53 adults diagnosed with ADHD/ADD and 18 healthy controls were recruited. Concomitant T.O.V.A. and EEG was measured. Oscillatory power in theta and alpha bands was compared between groups and between different behavioural conditions. Results & Conclusions: T.O.V.A. performance of healthy controls was more likely to be within normal limits as compared to ADHD/ADD diagnosed adults, and vice versa. There were moderate significant differences in commission errors, RT variability and d’ (response sensitivity) between groups. The control group tended to manifest higher theta synchronisation during correct inhibition trials. Given differences in behavioural performance, this result might be related to a higher sensitivity to task demands in the control group. However, there were no between-groups differences in frontomedial theta power and parietal or frontal alpha power. Further research should compare groups formed on the basis of not only diagnostic status but also of behavioural performance.
  • Savisaari, Olli (Helsingin yliopisto, 2020)
    Animations are a way to visualize change and bring inanimate objects life. Today, they are all arounds us: on digital billboards, info screens in shopping malls, websites and in our mobile phones. Major technology companies, such as Apple and Google have established their own guidelines for using movement and animations in digital interfaces. Yet, there is surprisingly little formal research on the topic. The question is, what are these guidelines based on? Existing research focuses on subjective perception of time, animation principles as well as combination of animations and sound in improving comprehension. However, systematic comparison between animation types and their effects on interfaces is absent from present literature. Therefore, this study answers how animation type impacts performance and change detection rates in visual tasks. This study was conducted as an empirical experiment, for which ten participants were recruited using university’s mailing lists. The experiment was carried out using a standard computer monitor, keyboard and head-mounted eye tracking equipment. Participants performed a dual task, consisting of five blocks of equal duration. The goal of the primary task was to keep attention in one part of the screen, and in secondary task participants reacted to visual changes animated on the screen. Performance in both tasks was measured using a combination of reaction times, verbal reports and eye tracking data. Data was analyzed with ANOVA as well as linear and generalized linear regression models, depending on the type of data under scrutiny. Presence of animations greatly improved reaction times and comprehension of change. Additionally, verbal reports differed considerably between animations, as did missed responses to the primary task. In other words, certain animations were noticed and reported with greater reliability and impaired performance in a simultaneous task less than other animations. In this regard, Slide animation performed best of the ones used in this study. In addition to finding measurable differences between animation types, the results were used to contribute to interaction design by establishing general animation guidelines. These guidelines are outlined at the end of this thesis.
  • Mikkola, Katri (Helsingfors universitet, 2016)
    Attention-deficit/hyperactivity disorder (ADHD) is a pervasive neurodevelopmental disorder of executive functions, which affects the social, occupational, educational, and personal life of the individuals concerned. The main characteristics of this disorder are age inappropriate inattention, impulsivity and hyperactivity. The research on adult ADHD is still scarce, especially concerning the neural networks of attention. Childhood ADHD has been associated with impairment in two of the attentional network subsystems alerting and executive control, leaving the third subsystem, orienting of attention, intact. Research on adult ADHD and the subsystems of attentional network is contradicting. The aim of this study was to investigate neural activation of these attentional networks during highly demanding attentional tasks in adults with ADHD. The first hypothesis was that the ADHD group have decreased activity in the frontoparietal network during orienting of attention in contrast to the control group. The second hypothesis was that the ADHD group have decreased activity in the dorsolateral prefrontal cortex, anterior cingulate gyrus, and precuneus during divided attention in contrast to the control group. Both the ADHD group and the control group included 16 participants, aged 25 – 56 across all participants, whose brain activation was measured with functional magnetic resonance imaging during the attentional tasks. The tasks included divided and selective attention. Both conditions included task-irrelevant novel distractors. The results supported both hypotheses. The ADHD group had decreased brain activity in the frontoparietal network during top-down controlled and bottom-up triggered attention. Decreased activation in the dorsolateral prefrontal cortex, anterior cingulate gyrus and precuneus was observed during divided attention in the ADHD group. Furthermore, the default-mode network was hyperactivated in the ADHD group. Activation of this network has been related to increasing task demands and failure of maintaining an alert state. Thus, adult ADHD seems to associate with abnormally functioning attention networks. Moreover, the results indicated that in addition to dysfunctional alerting and executive control, adults with ADHD have also impaired orienting of attention. These dysfunctional attentional networks may have a connection with the inattentive symptoms of adult ADHD.
  • EFSA Panel Dietetic Prod Nutr All (2018)
    Following an application from Unilever NV, submitted for authorisation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of Ireland, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to black tea and improvement of attention. The scope of the application was proposed to fall under a health claim based on newly developed scientific evidence. The food proposed by the applicant as the subject of the health claim is black tea. The Panel considers that black tea characterised by its content of tea solids, caffeine and L-theanine, which is the subject of the health claim, is sufficiently characterised in relation to the claimed effect. The claimed effect proposed by the applicant is 'improves attention'. The Panel considers that improvement of attention is a beneficial physiological effect. Three human intervention studies provided by the applicant show an effect of black tea on attention under the conditions of used proposed by the applicant. The applicant proposed that the claimed effect depends on the concerted action of two substances, caffeine and L-theanine, both of which are present in black tea. The Panel considers that the effect of black tea on attention observed in the three human intervention studies provided by the applicant can be explained by its caffeine content. The Panel concludes that a cause and effect relationship has been established between the consumption of black tea and improvement of attention. The Panel considers that the effect of black tea on attention can be explained by its caffeine content. The following wording reflects the scientific evidence: 'Owing to its caffeine content, black tea improves attention'. In order to obtain the claimed effect, 2-3 servings of black tea providing at least 75 mg of caffeine in total should be consumed within 90 min. (C) 2018 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.
  • Kauppinen, Hannele (Svenska handelshögskolan, 2005)
    Economics and Society
    Colour is an essential aspect of our daily life, and still, it is a neglected issue within marketing research. The main reason for studying colours is to understand the impact of colours on consumer behaviour, and thus, colours should be studied when it comes to branding, advertising, packages, interiors, and the clothes of the employees, for example. This was an exploratory study about the impact of colours on packages. The focus was on low-involvement purchasing, where the consumer puts limited effort into the decision-making. The basis was a scenario in which the consumer faces an unpredictable problem needing immediate action. The consumer may be in hurry, which indicate time pressure. The consumer may lack brand preferences, or the preferred brand may be out of stock. The issue is that the choice is to be made at the point of purchase. Further, the purchasing involves product classes where the core products behind the brands are indistinguishable from each other. Three research questions were posed. Two questions were answered by conjoint analysis, i.e. if colours have an impact on decision-making and if a possible impact is related to the product class. 16 hypothetical packages were designed in two product classes within the healthcare, i.e. painkillers and medicine against sore throats. The last research question aimed at detecting how an analysis could be carried out in order to understand the impact of colours. This question was answered by conducting interviews that were analysed by applying laddering method and a semiotics approach. The study found that colours do indeed have an impact on consumer behaviour, this being related to the context, such as product class. The role of colours on packages was found to be threefold: attention, aesthetics, and communication. The study focused on colours as a means of communication, and it proposes that colours convey product, brand, and product class meanings, these meanings having an impact on consumers’ decision-making at the point of purchase. In addition, the study demonstrates how design elements such as colours can be understood by regarding them as non-verbal signs. The study also presents an empirical design, involving quantitative and qualitative techniques that can be used to gain in depth understanding of the impact of design elements on consumer behaviour. Hannele Kauppinen is associated with CERS, the Centre for Relationship Marketing and Service Management of the Swedish School of Economics and Business Administration
  • Yli-Jyrä, Anssi (Linköping University Electronic Press, 2019)
    NEALT Proceedings Series
    Deep neural networks (DNN) and linguistic rules are currently the opposite ends in the scale for NLP technologies. Until recently, it has not been known how to combine these technologies most effectively. Therefore, the technologies have been the object of almost disjoint research communities. In this presentation, I first recall that both Constraint Grammar (CG) and vanilla RNNs have finite-state properties. Then I relate CG to Google’s Transformer architecture (with two kinds of attention) and argue that there are significant similarities between these two seemingly unrelated architectures.
  • Torppa, Ritva; Faulkner, Andrew; Kujala, Teija; Huotilainen, Minna; Lipsanen, Jari (2018)
    THE PERCEPTION OF SPEECH IN NOISE IS challenging for children with cochlear implants (CIs). Singing and musical instrument playing have been associated with improved auditory skills in normal-hearing (NH) children. Therefore, we assessed how children with CIs who sing informally develop in the perception of speech in noise compared to those who do not. We also sought evidence of links of speech perception in noise with MMN and P3a brain responses to musical sounds and studied effects of age and changes over a 14-17 month time period in the speech-in-noise performance of children with CIs. Compared to the NH group, the entire CI group was less tolerant of noise in speech perception, but both groups improved similarly. The CI singing group showed better speech-in-noise perception than the CI non-singing group. The perception of speech in noise in children with CIs was associated with the amplitude of MMN to a change of sound from piano to cymbal, and in the CI singing group only, with earlier P3a for changes in timbre. While our results cannot address causality, they suggest that singing and musical instrument playing may have a potential to enhance the perception of speech in noise in children with CIs.
  • Alsius, Agnes; Möttönen, Riikka; Sams, Mikko E.; Soto-Faraco, Salvador; Tiippana, Kaisa (2014)
  • Cowley, Benjamin; Lukander, Kristian (2016)
    Background: Recognition of objects and their context relies heavily on the integrated functioning of global and local visual processing. In a realistic setting such as work, this processing becomes a sustained activity, implying a consequent interaction with executive functions. Motivation: There have been many studies of either global-local attention or executive functions; however it is relatively novel to combine these processes to study a more ecological form of attention. We aim to explore the phenomenon of global-local processing during a task requiring sustained attention and working memory. Methods: We develop and test a novel protocol for global-local dissociation, with task structure including phases of divided ("rule search") and selective ("rule found") attention, based on the Wisconsin Card Sorting Task (WCST). We test it in a laboratory study with 25 participants, and report on behavior measures (physiological data was also gathered, but not reported here). We develop novel stimuli with more naturalistic levels of information and noise, based primarily on face photographs, with consequently more ecological validity. Results: We report behavioral results indicating that sustained difficulty when participants test their hypotheses impacts matching-task performance, and diminishes the global precedence effect. Results also show a dissociation between subjectively experienced difficulty and objective dimension of performance, and establish the internal validity of the protocol. Contribution: We contribute an advance in the state of the art for testing global local attention processes in concert with complex cognition. With three results we establish a connection between global local dissociation and aspects of complex cognition. Our protocol also improves ecological validity and opens options for testing additional interactions in future work.
  • Tammi, Tuisku (Helsingin yliopisto, 2019)
    Objectives. This thesis aims to explore temporal changes in task-related physiological arousal and their connection to performance in repeated trials of a steering task. Moderate physiological arousal is believed to direct attention towards task-relevant stimuli, leading to performance improvements, while too high or low arousal is detrimental (the Yerkes-Dodson law). However, this approach does not explicitly account for changes in arousal over time. In this study, temporal changes in task-related sympathetic arousal are modelled as habituation, which has traditionally been used to describe changes in orienting responses to repeated presentations of non-target stimuli. Habituation during task performance is interpreted in terms of predictability and significance, aiming to describe changes in attentional processing during learning in an evolutionarily plausible manner. Furthermore, connections between performance and individual differences in habituation rate and spontaneous (task-unrelated) sympathetic activity are examined. Finally, habituation is compared to deviations from predicted performance. Methods. Participants (N = 9) played a total of 40 trials of a high-speed steering task in eight sessions over a period of 2-3 weeks. Electrodermal activity during baseline and task performance was recorded in five sessions. Change in task-related skin conductance response (SCR) frequency over trials 1-5 within sessions was used to determine individual rates of habituation whereas SCR frequency during baseline indicated individual spontaneous activity. Trial-level difference scores were used to explore habituation and deviations from predicted performance (a power-law learning curve) within participants. Results and conclusions. Task-related arousal was found to decrease with repeated trials for all participants in nearly all sessions, indicating that a habituation model was successful in capturing changes in arousal in a task situation. Furthermore, sustained task-related arousal (slow habituation) was connected to better performance both between and within participants. High spontaneous activity, on the other hand, was associated with performance decrements. Taken together, these results suggest that temporal changes in task-related arousal during learning are related to the processing of task-relevant cues and may reflect motivational states that direct selective attention, while high spontaneous activity is related to performance decrements, perhaps due to interference from task-unrelated stress.
  • Linnavalli, Tanja; Ojala, Juha; Haveri, Laura; Putkinen, Vesa; Kostilainen, Kaisamari; Seppänen, Sirke; Tervaniemi, Mari (2020)
    CONSONANCE AND DISSONANCE ARE BASIC phenomena in the perception of chords that can be discriminated very early in sensory processing. Musical expertise has been shown to facilitate neural processing of various musical stimuli, but it is unclear whether this applies to detecting consonance and dissonance. Our study aimed to determine if sensitivity to increasing levels of dissonance differs between musicians and nonmusicians, using a combination of neural (electroencephalographic mismatch negativity, MMN) and behavioral measurements (conscious discrimination). Furthermore, we wanted to see if focusing attention to the sounds modulated the neural processing. We used chords comprised of either highly consonant or highly dissonant intervals and further manipulated the degree of dissonance to create two levels of dissonant chords. Both groups discriminated dissonant chords from consonant ones neurally and behaviorally. The magnitude of the MMN differed only marginally between the more dissonant and the less dissonant chords. The musicians outperformed the nonmusicians in the behavioral task. As the dissonant chords elicited MMN responses for both groups, sensory dissonance seems to be discriminated in an early sensory level, irrespective of musical expertise, and the facilitating effects of musicianship for this discrimination may arise in later stages of auditory processing, appearing only in the behavioral auditory task.
  • Criscuolo, Antonio; Bonetti, Leonardo; Särkämö, Teppo; Kliuchko, Marina; Brattico, Elvira (2019)
    Converging evidence has demonstrated that musical training is associated with improved perceptual and cognitive skills, including executive functions and general intelligence, particularly in childhood. In contrast, in adults the relationship between cognitive performance and musicianship is less clear and seems to be modulated by a number of background factors, such as personality and socio-economic status. Aiming to shed new light on this topic, we administered the Wechsler Adult Intelligence Scale III (WAIS-III), the Wechsler Memory Scale III (WMS-III), and the Stroop Test to 101 Finnish healthy adults grouped according to their musical expertise (non-musicians, amateurs, and musicians). After being matched for socio-economic status, personality traits and other demographic variables, adult musicians exhibited higher cognitive performance than non-musicians in all the mentioned measures. Moreover, linear regression models showed significant positive relationships between executive functions (working memory and attention) and the duration of musical practice, even after controlling for intelligence and background variables, such as personality traits. Hence, our study offers further support for the association between cognitive abilities and musical training, even in adulthood.
  • Alho, Kimmo; Zarnowiec, Katarzyna; Gorina-Careta, Natalia; Escera, Carles (2019)
    In electroencephalography (EEG) measurements, processing of periodic sounds in the ascending auditory pathway generates the frequency-following response (FFR) phase-locked to the fundamental frequency (F0) and its harmonics of a sound. We measured FFRs to the steady-state (vowel) part of syllables /ba/ and /aw/ occurring in binaural rapid streams of speech sounds as frequently repeating standard syllables or as infrequent (p = 0.2) deviant syllables among standard /wa/ syllables. Our aim was to study whether concurrent active phonological processing affects early processing of irrelevant speech sounds reflected by FFRs to these sounds. To this end, during syllable delivery, our healthy adult participants performed tasks involving written letters delivered on a computer screen in a rapid stream. The stream consisted of vowel letters written in red, infrequently occurring consonant letters written in the same color, and infrequently occurring vowel letters written in blue. In the phonological task, the participants were instructed to press a response key to the consonant letters differing phonologically but not in color from the frequently occurring red vowels, whereas in the non-phonological task, they were instructed to respond to the vowel letters written in blue differing only in color from the frequently occurring red vowels. We observed that the phonological task enhanced responses to deviant /ba/ syllables but not responses to deviant /aw/ syllables. This suggests that active phonological task performance may enhance processing of such small changes in irrelevant speech sounds as the 30-ms difference in the initial formant-transition time between the otherwise identical syllables /ba/ and /wa/ used in the present study.
  • Hakkinen, Suvi; Ovaska, Noora; Rinne, Teemu (2015)
    The relationship between stimulus-dependent and task-dependent activations in human auditory cortex (AC) during pitch and location processing is not well understood. In the present functional magnetic resonance imaging study, we investigated the processing of task-irrelevant and task-relevant pitch and location during discrimination, n-back, and visual tasks. We tested three hypotheses: (1) According to prevailing auditory models, stimulus-dependent processing of pitch and location should be associated with enhanced activations in distinct areas of the anterior and posterior superior temporal gyrus (STG), respectively. (2) Based on our previous studies, task-dependent activation patterns during discrimination and n-back tasks should be similar when these tasks are performed on sounds varying in pitch or location. (3) Previous studies in humans and animals suggest that pitch and location tasks should enhance activations especially in those areas that also show activation enhancements associated with stimulus-dependent pitch and location processing, respectively. Consistent with our hypotheses, we found stimulus dependent sensitivity to pitch and location in anterolateral STG and anterior planum temporale (PT), respectively, in line with the view that these features are processed in separate parallel pathways. Further, task-dependent activations during discrimination and n-back tasks were associated with enhanced activations in anterior/posterior STG and posterior STG/inferior parietal lobule (IPL) irrespective of stimulus features. However, direct comparisons between pitch and location tasks performed on identical sounds revealed no significant activation differences. These results suggest that activations during pitch and location tasks are not strongly affected by enhanced stimulus dependent activations to pitch or location. We also found that activations in PT were strongly modulated by task requirements and that areas in the inferior parietal lobule (IPL) showed task-dependent activation modulations, but no systematic activations to pitch or location. Based on these results, we argue that activations during pitch and location tasks cannot be explained by enhanced stimulus specific processing alone, but rather that activations in human AC depend in a complex manner on the requirements of the task at hand.
  • Cowley, Benjamin Ultan; Juurmaa, Kristiina; Palomaki, Jussi (2022)
    Attention-deficit/hyperactivity disorder (ADHD) in adults is understudied, especially regarding neural mechanisms such as oscillatory control of attention sampling. We report an electroencephalography (EEG) study of such cortical mechanisms, in ADHD-diagnosed adults during administration of Test of Variables of Attention (TOVA), a gold-standard continuous performance test for ADHD that measures the ability to sustain attention and inhibit impulsivity. We recorded 53 adults (28 female, 25 male, aged 18-60), and 18 matched healthy controls, using 128-channel EEG. We analyzed sensor-space features established as neural correlates of attention: timing-sensitivity and phase-synchrony of response activations, and event-related (de)synchronization (ERS/D) of alpha and theta frequency band activity; in frontal and parietal scalp regions. TOVA test performance significantly distinguished ADHD adults from neurotypical controls, in commission errors, response time variability (RTV) and d' (response sensitivity). The ADHD group showed significantly weaker target-locked and responselocked amplitudes, that were strongly right-lateralized at the N2 wave, and weaker phase synchrony (longer reset poststimulus). They also manifested significantly less parietal prestimulus 8-Hz theta ERS, less frontal and parietal poststimulus 4-Hz theta ERS, and more frontal and parietal prestimulus alpha ERS during correct trials. These differences may reflect excessive modulation of endogenous activity by strong entrainment to stimulus (alpha), combined with deficient modulation by neural entrainment to task (theta), which in TOVA involves monitoring stimulus spatial location (not predicted occurrence onset which is regular and task-irrelevant). Building on the hypotheses of theta coding for relational structure and rhythmic attention sampling, our results suggest that ADHD adults have impaired attention sampling in relational categorization tasks.
  • Rouhinen, Santeri; Siebenhühner, Felix; Palva, J. Matias; Palva, Satu (2020)
    The capacity of visual attention determines how many visual objects may be perceived at any moment. This capacity can be investigated with multiple object tracking (MOT) tasks, which have shown that it varies greatly between individuals. The neuronal mechanisms underlying capacity limits have remained poorly understood. Phase synchronization of cortical oscillations coordinates neuronal communication within the fronto-parietal attention network and between the visual regions during endogenous visual attention. We tested a hypothesis that attentional capacity is predicted by the strength of pretarget synchronization within attention-related cortical regions. We recorded cortical activity with magneto- and electroencephalography (M/EEG) while measuring attentional capacity with MOT tasks and identified large-scale synchronized networks from source-reconstructed M/EEG data. Individual attentional capacity was correlated with load-dependent strengthening of theta (3-8 Hz), alpha (8-10 Hz), and gamma-band (30-120 Hz) synchronization that connected the visual cortex with posterior parietal and prefrontal cortices. Individual memory capacity was also preceded by crossfrequency phase-phase and phase-amplitude coupling of alpha oscillation phase with beta and gamma oscillations. Our results show that good attentional capacity is preceded by efficient dynamic functional coupling and decoupling within brain regions and across frequencies, which may enable efficient communication and routing of information between sensory and attentional systems.
  • Rinne, Teemu; Koistinen, Sonja; Salonen, Oili; Alho, Kimmo (2009)
    "The functional organization of auditory cortex (AC) is still poorly understood. Previous studies suggest segregation of auditory processing streams for spatial and nonspatial information located in the posterior and anterior AC, respectively (Rauschecker and Tian, 2000; Arnott et al., 2004; Lomber and Malhotra, 2008). Furthermore, previous studies have shown that active listening tasks strongly modulate AC activations (Petkov et al., 2004; Fritz et al., 2005; Polley et al., 2006). However, the task dependence of AC activations has not been systematically investigated. In the present study, we applied high-resolution functional magnetic resonance imaging of the AC and adjacent areas to compare activations during pitch discrimination and n-back pitch memory tasks that were varied parametrically in difficulty. We found that anterior AC activations were increased during discrimination but not during memory tasks, while activations in the inferior parietal lobule posterior to the AC were enhanced during memory tasks but not during discrimination. We also found that wide areas of the anterior AC and anterior insula were strongly deactivated during the pitch memory tasks. While these results are consistent with the proposition that the anterior and posterior AC belong to functionally separate auditory processing streams, our results show that this division is present also between tasks using spatially invariant sounds. Together, our results indicate that activations of human AC are strongly dependent on the characteristics of the behavioral task."