Project DyAdd : Nonlinguistic theories of dyslexia predict intelligence

Two themes have puzzled the research on developmental and learning disorders for decades. First, some of the risk and protective factors behind developmental challenges are suggested to be shared and some to be specific for a given condition. Second, language-based learning difficulties like dyslexia are suggested to result from or correlate with also nonlinguistic aspects of information processing. In the current study, we investigated how adults with developmental dyslexia and ADHD as well as healthy controls cluster across various dimensions designed to tap the prominent nonlinguistic theories of dyslexia. Participants were 18–55-year-old adults with dyslexia (n = 36), ADHD (n = 22), and…

Project DyAdd: Non-linguistic Theories of Dyslexia Predict Intelligence

Two themes have puzzled the research on developmental and learning disorders for decades. First, some of the risk and protective factors behind developmental challenges are suggested to be shared and some are suggested to be specific for a given condition. Second, language-based learning difficulties like dyslexia are suggested to result from or correlate with non-linguistic aspects of information processing as well. In the current study, we investigated how adults with developmental dyslexia or ADHD as well as healthy controls cluster across various dimensions designed to tap the prominent non-linguistic theories of dyslexia. Participants were 18–55-year-old adults with dyslexia (n = 36), …

The effect of writing modality on recollection in children and adolescents

We set out to assess the extent to which writing modality affects recollection in children and adolescents. We examined 10- to 11-year-old children’s (N = 63) and 16-year-old adolescents’ (N = 43) handwriting, keyboarding with a laptop computer and keyboarding with a touchscreen tablet computer or mobile phone in a within-subjects experimental design. Participants were instructed to write down stories dictated to them in the three writing modalities. Recollection of the stories was assessed using free recall of details in the stories. The results indicate that the writing modality affects recollection, handwriting leading to better recollection. However, currently, digital writing tools are…

Activity in the rabbit somatosensory cortex reflects the active procedural memory trace of a classically conditioned eyeblink response.

Behavioral responses and neural responses in the somatosensory cortex were recorded in nine rabbits during the unpaired and paired treatments of classical eyeblink conditioning with a tone conditioned stimulus (CS) and an airpuff unconditioned stimulus. During the unpaired treatment, neither the behavioral nor neural responses to the CS were observed. During the paired treatment, behavioral conditioned response (CR), accompanied by neural activity, was developed. In well-trained animals occasional failures to elicit the CR were accompanied by an absence of neural responses. Nevertheless, the CS modified the behavioral unconditioned response in paired trials, implying that the CR-failures co…

Hippocampal theta-band activity and trace eyeblink conditioning in rabbits.

The authors examined the relationship between hippocampal theta activity and trace eyeblink conditioning. Hippocampal electrophysiological local field potentials were recorded before, during, and after conditioning or explicitly unpaired training sessions in adult male New Zealand White rabbits. As expected, a high relative power of theta activity (theta ratio) in the hippocampus predicted faster acquisition of the conditioned response during trace conditioning but, contrary to previous results obtained using the delay paradigm, only in the initial stage of learning. The presentation of the conditioned stimulus overall elicited an increase in the hippocampal theta ratio. The theta ratio dec…

Interpositus nucleus inactivation reduces unconditioned response amplitude after paired but not explicitly unpaired treatment in rabbit eyeblink conditioning.

The amplitude of unconditioned responses (URs) in unconditioned stimulus (US) alone presentations were measured in six rabbits during explicitly unpaired and classical conditioning treatments. After both phases of the experiment, the interpositus nucleus (IPN) was reversibly inactivated by a cold probe. URs after unpaired treatment were unaffected by inactivation but after acquisition of a robust level of conditioned responses (CRs), URs in US-alone test trials were reduced in amplitude compared with URs immediately before and after inactivation. The results suggest that the IPN has a role in CR-related reflex modification.

Hippocampal theta (3-8 Hz) activity during classical eyeblink conditioning in rabbits

In 1978, Berry and Thompson showed that the amount of theta (3–8 Hz) activity in the spontaneous hippocampal EEG predicted learning rate in subsequent eyeblink conditioning in rabbits. More recently, the absence of theta activity during the training trial has been shown to have a detrimental effect on learning rate. Here, we aimed to further explore the relationship between theta activity and classical eyeblink conditioning by determining how the relative power of hippocampal theta activity [theta/(theta + delta) ratio] changes during both unpaired control and paired training phases. We found that animals with a higher hippocampal theta ratio immediately before conditioning learned faster a…

Hippocampal theta activity is selectively associated with contingency detection but not discrimination in rabbit discrimination-reversal eyeblink conditioning

The relative power of the hippocampal theta-band (∼6 Hz) activity (theta ratio) is thought to reflect a distinct neural state and has been shown to affect learning rate in classical eyeblink conditioning in rabbits. We sought to determine if the theta ratio is mostly related to the detection of the contingency between the stimuli used in conditioning or also to the learning of more complex inhibitory associations when a highly demanding delay discrimination-reversal eyeblink conditioning paradigm is used. A high hippocampal theta ratio was not only associated with a fast increase in conditioned responding in general but also correlated with slow emergence of discriminative responding due to…

Anodal tDCS over the left prefrontal cortex does not cause clinically significant changes in circulating metabolites

Background: Transcranial direct current stimulation (tDCS), a putative treatment for depression, has been proposed to affect peripheral metabolism. Metabolic products from brain tissue may also cross the blood–brain barrier, reflecting the conditions in the brain. However, there are no previous data regarding the effect of tDCS on circulating metabolites.\ud Objective: To determine whether five daily sessions of tDCS modulate peripheral metabolites in healthy adult men.\ud Methods: This double-blind, randomized controlled trial involved 79 healthy males (aged 20–40 years) divided into two groups, one receiving tDCS (2 mA) and the other sham stimulated. The anode was placed over the left dor…

Progression of adverse effects over consecutive sessions of transcranial direct current stimulation

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Selective breeding for endurance running capacity affects cognitive but not motor learning in rats

The ability to utilize oxygen has been shown to affect a wide variety of physiological factors often considered beneficial for survival. As the ability to learn can be seen as one of the core factors of survival in mammals, we studied whether selective breeding for endurance running, an indication of aerobic capacity, also has an effect on learning. Rats selectively bred over 23 generations for their ability to perform forced treadmill running were trained in an appetitively motivated discrimination-reversal classical conditioning task, an alternating T-maze task followed by a rule change (from a shift-win to stay-win rule) and motor learning task. In the discrimination-reversal and T-maze …

Inactivation of the interpositus nucleus blocks the conditioned response acquired by a somatosensory conditioned stimulus in rabbit eyeblink conditioning.

1. Earlier studies suggest that the memory trace for the conditioned eyeblink reflex is formed and maintained in the interpositus nucleus (IPN) in the deep cerebellar nuclei when either an auditory or visual stimulus is used as a conditioned stimulus (CS). 2. In the present study, the eyeblink reflex of the rabbit was conditioned to a somatosensory CS (an airpuff onto the back). 3. In well-trained animals, the IPN was reversibly inactivated by local cooling and the existence of the learned responses to the CS was then tested. 4. The reversible IPN inactivation blocked the memory trace the somatosensory CS. The finding further supports the view that IPN-mediated memory trace formation is not…

Disrupting neural activity related to awake-state sharp wave-ripple complexes prevents hippocampal learning

Oscillations in hippocampal local-field potentials (LFPs) reflect the crucial involvement of the hippocampus in memory trace formation: theta (4–8 Hz) oscillations and ripples (~200 Hz) occurring during sharp waves are thought to mediate encoding and consolidation, respectively. During sharp wave-ripple complexes (SPW-Rs), hippocampal cell firing closely follows the pattern that took place during the initial experience, most likely reflecting replay of that event. Disrupting hippocampal ripples using electrical stimulation either during training in awake animals or during sleep after training retards spatial learning. Here, adult rabbits were trained in trace eyeblink conditioning, a hippoc…

Processing of melodic contours in urethane-anaesthetized rats

The human brain can automatically detect changes even in repeated melodic contours of spectrally varying sounds. However, it is unclear whether this ability is specific to humans. We recorded event-related potentials (ERPs) in urethane-anaesthetized Wistar rats presented with rare pairs of tones ('deviants') interspersed with frequently repeated ones ('standards'). The frequency of the tones varied nonsystematically across their pairs so that deviants stood out from standards only in the melodic ordering (ascending or descending) of the tones of a pair. We found that the absolute amplitude of the ERP was significantly higher to deviants than standards between 106 and 136 ms from the onset o…

Cooling of the cerebellar interpositus nucleus abolishes somatosensory cortical learning-related activity in eyeblink conditioned rabbits.

Nictitating membrane movement and multiple-unit activity in the somatosensory cortex were recorded from rabbits during paired (N = 6) and unpaired (N = 5) presentations of a tone conditioned stimulus (CS) and an airpuff unconditioned stimulus (US). A behavioural conditioned response (CR) to the CS and an accompanying neural response in the somatosensory cortex developed only in the paired group. Inactivation of the cerebellar interpositus nucleus abolished both the acquired CR and the accompanying neural response. However, the CS facilitated both behavioural and neural responses to the US during the inactivation. Thus, the absence of the CR could not be accounted for by the general inabilit…

Measuring psychosocial stress with heart rate variability-based methods in different health and age groups

Abstract Objective. Autonomic nervous system function and thereby bodily stress and recovery reactions may be assessed by wearable devices measuring heart rate (HR) and its variability (HRV). So far, the validity of HRV-based stress assessments has been mainly studied in healthy populations. In this study, we determined how psychosocial stress affects physiological and psychological stress responses in both young (18–30 years) and middle-aged (45–64 years) healthy individuals as well as in patients with arterial hypertension and/or either prior evidence of prediabetes or type 2 diabetes. We also studied how an HRV-based stress index (Relax-Stress Intensity, RSI) relates to perceived stress …

Effects of Hippocampal State-Contingent Trial Presentation on Hippocampus-Dependent Nonspatial Classical Conditioning and Extinction

Hippocampal local field potentials are characterized by two mutually exclusive states: one characterized by regular θ oscillations (∼4–8 Hz) and the other by irregular sharp-wave ripples. Presenting stimuli during dominant θ oscillations leads to expedited learning, suggesting that θ indexes a state in which encoding is most effective. However, ripple-contingent training also expedites learning, suggesting that any discrete brain state, much like the external context, can affect learning. We trained adult rabbits in trace eyeblink conditioning, a hippocampus-dependent nonspatial task, followed by extinction. Trials were delivered either in the presence or absence of θ or regardless of hippo…

Ajokyvyn arviointi MoCA-menetelmällä Alzheimerin taudin varhaisvaiheessa

Vertaisarvioitu Lähtökohdat Tutkimme Montreal Cognitive Assessment (MoCA) -menetelmän soveltuvuutta varhaista Alzheimerin tautia sairastavien potilaiden ajokyvyn arviointiin. Selvitimme myös menetelmän herkkyyttä tunnistaa kognitiomuutoksia. Menetelmät Tutkimus sisälsi haastattelun, kognitiivisen arvioinnin (MoCA), ajon simulaattorilla ja oman ajamisen arvioinnin. Siihen osallistui 7 potilasta ja 17 tervettä ikätoveria. Tulokset Potilaat suoriutuivat verrokkeja heikommin MoCA-testissä ja simulaattoriajossa. Arvio omasta suoriutumisesta ajossa oli heillä merkitsevästi parempi kuin verrokeilla. Potilaat saivat testipisteitä keskimäärin 18,6 ja verrokit 27,4. Simulaattoriajossa potilaat tekivä…

Affective modulation of conditioned eyeblinks

Affective states are known to modulate reflexive actions. Aversive states potentiate defensive reflexes while appetitive states diminish them. The present study examined whether the same holds for associatively learned defensive eyeblinks to mild, initially neutral auditory stimuli. First, delay eyeblink conditioning was applied to human participants while they viewed emotionally neutral images. Next, the conditioned eyeblink responses (CRs) of the participants were tested during the viewing of unpleasant, neutral, or pleasant images. The most vigorous CRs were found during the unpleasant images, although they did not differ between neutral and pleasant images. The results add to the motiva…

Effect of transcranial direct current stimulation on semantic discrimination eyeblink conditioning

Abstract Background Transcranial direct current stimulation (tDCS) is a neuromodulation method that has been used to modulate learning. We tested whether anodal tDCS targeted at the left DLPFC could enhance learning in a semantic variant of discrimination eyeblink conditioning, i.e., whether the stimulation would have a specific effect on the discrimination ability, rate of acquisition, amplitude of the conditioned response (CR), or all of these. Methods Immediately prior to the eyeblink conditioning, the participants received either active stimulation of 1 mA for 10 min or sham stimulation. The anode was placed over F3 and the cathode over the right supraorbital area. The conditioned stimu…

Transcranial direct current stimulation: Adverse effects and the efficacy of a commonly utilised sham protocol

IntroductionTranscranial direct current stimulation (tDCS) is a promising neuromodulation method that has, for example, been used to treat depression. Nevertheless, the adverse effects of tDCS and the validity of the current standard tDCS sham protocols have received limited attention.ObjectivesTo evaluate the extent and types of tDCS adverse effects and to assess the reliability of sham stimulation as a control procedure for tDCS in a double-blind setting.AimsTo compare adverse effects between tDCS and sham stimulation groups, and to determine how well the participants and the experimenter are able to distinguish tDCS from sham stimulation.MethodsA sample of healthy volunteers received a 2…

Learning by heart : cardiac cycle reveals an effective time window for learning

Cardiac cycle phase is known to modulate processing of simple sensory information. This effect of the heartbeat on brain function is likely exerted via baroreceptors, the neurons sensitive for changes in blood pressure. From baroreceptors, the signal is conveyed all the way to the forebrain and the medial prefrontal cortex. In the two experiments reported, we examined whether learning, as a more complex form of cognition, can be modulated by the cardiac cycle phase. Human participants ( experiment 1) and rabbits ( experiment 2) were trained in trace eyeblink conditioning while neural activity was recorded. The conditioned stimulus was presented contingently with either the systolic or dias…

Hippocampal theta activity is selectively associated with contingency detection but not discrimination in rabbit discrimination-reversal eyeblink conditioning

The relative power of the hippocampal theta-band ( approximately 6 Hz) activity (theta ratio) is thought to reflect a distinct neural state and has been shown to affect learning rate in classical eyeblink conditioning in rabbits. We sought to determine if the theta ratio is mostly related to the detection of the contingency between the stimuli used in conditioning or also to the learning of more complex inhibitory associations when a highly demanding delay discrimination-reversal eyeblink conditioning paradigm is used. A high hippocampal theta ratio was not only associated with a fast increase in conditioned responding in general but also correlated with slow emergence of discriminative res…

Fyysinen aktiivisuus pitää yllä aivojenkin terveyttä ja toimintakykyä läpi elämän

Fyysisesti aktiivisilla ikääntyneillä ihmisillä on pienempi riski sairastua muistisairauksiin, kuten Alzheimerin tautiin, ja liikuntaa on ehdotettu jopa muistisairauksien hoidoksi. Positiivinen yhteys aerobisen kunnon ja aivojen rakenteellisen kunnon välillä näkyy vielä yli 80-vuotiailla. Liikunnan vaikutuksia aivojen terveyteen ja oppimisen edellytyksiin tutkitaan nyt monitieteellisesti ja -menetelmällisesti. nonPeerReviewed

Hippocampo-cerebellar theta band phase synchrony in rabbits.

Hippocampal functioning, in the form of theta band oscillation, has been shown to modulate and predict cerebellar learning of which rabbit eyeblink conditioning is perhaps the most well-known example. The contribution of hippocampal neural activity to cerebellar learning is only possible if there is a functional connection between the two structures. Here, in the context of trace eyeblink conditioning, we show (1) that, in addition to the hippocampus, prominent theta oscillation also occurs in the cerebellum, and (2) that cerebellar theta oscillation is synchronized with that in the hippocampus. Further, the degree of phase synchrony (PS) increased both as a response to the conditioning sti…

Specific and nonspecific associations in eyeblink conditioning in rabbits

Inside the Thompson laboratory during the “cerebellar years” and the continuing cerebellar story

This paper is based on the talk by one of the authors (DL) given at the symposium for the retirement of RF Thompson (RF Thompson: A bridge between 20th and 21st century neuroscience). We first make some informal observations of the historical times and research conditions in the Thompson laboratory when the cerebellum was found to play a critical role in eye lid classical conditioning, the "cerebellar years". These conditions influenced our collaborative international program on the phenomenon known as "transfer of training" or "savings". Our research shows that the appearance of "savings" is an artifact of the order of testing, and depends upon the functioning of the contralateral interpos…

Effects of emotional picture viewing on voluntary eye blinks

Eyeblinks, whether reflexive or voluntary, play an important role in protecting our vision. When viewing pictures, reflexive eyeblinks are known to be modulated by the emotional state induced thereby. More specifically, the hedonic valence (unpleasantness-pleasantness) induced by the picture has been shown to have a linear relationship with the amplitude of a startle blink elicited during picture viewing. This effect has been attributed to congruence between an ongoing state and task demands: an unpleasant emotional state is assumed to bias our attention towards potentially harmful stimuli, such as startle tones. However, recent research suggests that the valence-specific modulation may not…

Hippocampal theta phase-contingent memory retrieval in delay and trace eyeblink conditioning

Hippocampal theta oscillations (3-12Hz) play a prominent role in learning. It has been suggested that encoding and retrieval of memories are supported by different phases of the theta cycle. Our previous study on trace eyeblink conditioning in rabbits suggests that the timing of the conditioned stimulus (CS) in relation to theta phase affects encoding but not retrieval of the memory trace. Here, we directly tested the effects of hippocampal theta phase on memory retrieval in two experiments conducted on adult female New Zealand White rabbits. In Experiment 1, animals were trained in trace eyeblink conditioning followed by extinction, and memory retrieval was tested by presenting the CS at t…

Event-related potentials reveal rapid registration of features of infrequent changes during change blindness.

Abstract Background Change blindness refers to a failure to detect changes between consecutively presented images separated by, for example, a brief blank screen. As an explanation of change blindness, it has been suggested that our representations of the environment are sparse outside focal attention and even that changed features may not be represented at all. In order to find electrophysiological evidence of neural representations of changed features during change blindness, we recorded event-related potentials (ERPs) in adults in an oddball variant of the change blindness flicker paradigm. Methods ERPs were recorded when subjects performed a change detection task in which the modified i…

Aging and strength training influence knee extensor intermuscular coherence during low- and high-force isometric contractions

Aging is associated with reduced maximum force production and force steadiness during low-force tasks, but both can be improved by training. Intermuscular coherence measures coupling between two peripheral surface electromyography (EMG) signals in the frequency domain. It is thought to represent the presence of common input to alpha-motoneurons, but the functional meaning of intermuscular coherence, particularly regarding aging and training, remain unclear. This study investigated knee extensor intermuscular coherence in previously sedentary young (18–30 years) and older (67–73 years) subjects before and after a 14-week strength training intervention. YOUNG and OLDER groups performed maximu…

Explicit behavioral detection of visual changes develops without their implicit neurophysiological detectability

Change blindness is a failure of reporting major changes across consecutive images if separated, e.g., by a brief blank interval. Successful change detection across interrupts requires focal attention to the changes. However, findings of implicit detection of visual changes during change blindness have raised the question of whether the implicit mode is necessary for development of the explicit mode. To this end, we recorded the visual mismatch negativity (vMMN) of the event-related potentials (ERPs) of the brain, an index of implicit pre-attentive visual change detection, in adult humans performing an oddball-variant of change blindness flicker task. Images of 500 ms in duration were prese…

Constituents of Music and Visual-Art Related Pleasure - A Critical Integrative Literature Review.

The present literature review investigated how pleasure induced by music and visualart has been conceptually understood in empirical research over the past 20 years. After an initial selection of abstracts from seven databases (keywords: pleasure, reward, enjoyment, and hedonic), twenty music and eleven visual-art papers were systematically compared. The following questions were addressed: (1) What is the role of the keyword in the research question? (2) Is pleasure considered a result of variation in the perceiver’s internal or external attributes? (3) What are the most commonly employed methods and main variables in empirical settings? Based on these questions, our critical integrative an…

Can you put your finger on it? : The effects of writing modality on Finnish students’ recollection

Digitalisation has changed and broadened the ways people write. In higher education, typing is a common practice both for note-taking and for completing written assignments, relegating pen and pape...

Genotype determining aerobic exercise capacity associates with behavioral plasticity in middle-aged rats

Good aerobic fitness associates positively with cognitive performance and brain health and conversely, low aerobic fitness predisposes to neurodegenerative diseases. To study how genotype together with exercise, started at older age, affects brain and behavior, we utilized rats that differ in inherited aerobic fitness. Rats bred for Low Capacity for Running (LCR) are shown to display less synaptic plasticity and more inflammation in the hippocampus and perform worse than rats bred for a High Capacity for Running (HCR) in tasks requiring flexible cognition. Here we used middle-aged (∼ 16 months) HCR and LCR rats to study how genotype and sex associate with anxiety and neural information filt…

Modulation of impulsive behaviours using transcranial random noise stimulation

Rats with elevated genetic risk for metabolic syndrome exhibit cognitive deficiencies when young

Metabolic syndrome (MetS) is a known risk factor for cognitive decline. Using polygenic rat models selectively bred for high and low intrinsic exercise capacity and simultaneously modelling as low and high innate risk factor for MetS respectively, we have previously shown that adult animals with lower exercise capacity/higher MetS risk perform poorly in tasks requiring flexible cognition. However, it is not known whether these deficits in cognition are present already at young age. Also, it is unclear whether the high risk genome is related also to lower-level cognition, such as sensory gating measured as prepulse inhibition. In this study, young and adult (5-8 weeks and ∼9 months) rats sel…

Breathe out and learn: Expiration-contingent stimulus presentation facilitates associative learning in trace eyeblink conditioning.

Rhythmic variation in heart rate and respiratory pattern are coupled in a way that optimizes the level of oxygen in the blood stream of the lungs and the body as well as saves energy in pulmonary gas exchange. It has been suggested that the cardiac cycle and respiratory pattern are coupled to neural oscillations of the brain. Yet, studies on how this rhythmic coupling is related to behavior are scarce. There is some evidence that, for example, the phase of respiration affects memory retrieval and the electrophysiological oscillatory state of the limbic system. It is also known that the phase of the cardiac cycle and hippocampal electrophysiological oscillations alone affect learning. Here, …

Hippocampal theta phase-contingent memory retrieval in delay and trace eyeblink conditioning

Hippocampal theta oscillations (3–12 Hz) play a prominent role in learning. It has been suggested that encoding and retrieval of memories are supported by different phases of the theta cycle. Our previous study on trace eyeblink conditioning in rabbits suggests that the timing of the conditioned stimulus (CS) in relation to theta phase affects encoding but not retrieval of the memory trace. Here, we directly tested the effects of hippocampal theta phase on memory retrieval in two experiments conducted on adult female New Zealand White rabbits. In Experiment 1, animals were trained in trace eyeblink conditioning followed by extinction, and memory retrieval was tested by presenting the CS at …

Rats bred for low intrinsic aerobic exercise capacity link obesity with brain inflammation and reduced structural plasticity of the hippocampus.

Abstract BACKGROUND Increasing evidence shows obesity and poor metabolic health are associated with cognitive deficits, but the mechanistic connections have yet to be resolved. We studied rats selectively bred for low and high intrinsic aerobic capacity in order to test the association between low physical fitness, a genetic predisposition for obesity, and brain health. We hypothesized that low-capacity runner (LCR) rats with concurrently greater levels of adiposity would have increased hippocampal inflammation and reduced plasticity compared to the more physically fit high-capacity runner (HCR) rats. METHODS We examined markers for inflammation and brain plasticity in the hippocampi of LCR…

Effects of rewarding electrical stimulation of lateral hypothalamus on classical conditioning of the nictitating membrane response.

1. Adult New Zealand albino rabbits were prepared with chronic hypothalamic stimulating electrodes and hippocampal recording electrodes. 2. Rabbits were restrained and classically conditioned by a tone CS and an airpuff US either followed or preceded by a hypothalamic stimulation (HS). Control rabbits were conditioned without the HS. 3. It was found that HS following the CS facilitated both behavioral and hippocampal responses, while HS preceding the CS inhibited them. 4. Enhanced hippocampal learning-related unit firing to the CS may represent an early indication of conditioning before the behavioral activity produces any observable change.

Breathe out and learn : Expiration-contingent stimulus presentation facilitates associative learning in trace eyeblink conditioning

Rhythmic variation in heart rate and respiratory pattern are coupled in a way that optimizes the level of oxygen in the blood stream of the lungs and the body as well as saves energy in pulmonary gas exchange. It has been suggested that the cardiac cycle and respiratory pattern are coupled to neural oscillations of the brain. Yet, studies on how this rhythmic coupling is related to behavior are scarce. There is some evidence that, for example, the phase of respiration affects memory retrieval and the electrophysiological oscillatory state of the limbic system. It is also known that the phase of the cardiac cycle and hippocampal electrophysiological oscillations alone affect learning. Here, …

The Effect of Memory in Inducing Pleasant Emotions with Musical and Pictorial Stimuli

Music is known to evoke emotions through a range of mechanisms, but empirical investigation into the mechanisms underlying different emotions is sparse. This study investigated how affective experiences to music and pictures vary when induced by personal memories or mere stimulus features. Prior to the experiment, participants were asked to select eight types of stimuli according to distinct criteria concerning the emotion induction mechanism and valence. In the experiment, participants (N = 30) evaluated their affective experiences with the self-chosen material. EEG was recorded throughout the session. The results showed certain interaction effects of mechanism (memory vs. stimulus feature…

Hippocampal ripple-contingent training accelerates trace eyeblink conditioning and retards extinction in rabbits.

There are at least two distinct oscillatory states of the hippocampus that are related to distinct behavioral patterns. Theta (4–12 Hz) oscillation has been suggested to indicate selective attention during which the animal concentrates on some features of the environment while suppressing reactivity to others. In contrast, sharp-wave ripples (∼200 Hz) can be seen in a state in which the hippocampus is at its most responsive to any kind of afferent stimulation. In addition, external stimulation tends to evoke and reset theta oscillation, the phase of which has been shown to modulate synaptic plasticity in the hippocampus. Theoretically, training on a hippocampus-dependent learning task conti…

Physical Activity, Fitness, Glucose Homeostasis, and Brain Morphology in Twins

The main aim of the present study (FITFATTWIN) was to investigate how physical activity level is associated with body composition, glucose homeostasis, and brain morphology in young adult male monozygotic twin pairs discordant for physical activity.From a population-based twin cohort, we systematically selected 10 young adult male monozygotic twin pairs (age range, 32-36 yr) discordant for leisure time physical activity during the past 3 yr. On the basis of interviews, we calculated a mean sum index for leisure time and commuting activity during the past 3 yr (3-yr LTMET index expressed as MET-hours per day). We conducted extensive measurements on body composition (including fat percentage …

Phase matters: responding to and learning about peripheral stimuli depends on hippocampal θ phase at stimulus onset.

Hippocampal θ (3–12 Hz) oscillations are implicated in learning and memory, but their functional role remains unclear. We studied the effect of the phase of local θ oscillation on hippocampal responses to a neutral conditioned stimulus (CS) and subsequent learning of classical trace eyeblink conditioning in adult rabbits. High-amplitude, regular hippocampal θ-band responses (that predict good learning) were elicited by the CS when it was timed to commence at the fissure θ trough (Trough group). Regardless, learning in this group was not enhanced compared with a yoked control group, possibly due to a ceiling effect. However, when the CS was consistently presented to the peak of θ (Peak group…

The human brain processes visual changes that are not cued by attended auditory stimulation.

Event-related potentials (ERPs) to visual stimuli were recorded from the scalp of eight adult humans performing a task in which they counted vowels from a heard story. In the oddball condition, a repeated (standard) light bar of 50 ms in duration was rarely (P = 0.1) replaced by a (deviant) one differing in orientation from the standard. In the control condition, standards were simply omitted from the series and only (alone-) deviants retained. In both conditions, visual stimuli were asynchronous with auditory-task-relevant stimuli. ERPs to deviants significantly differed in amplitude from those to standards in the midline electrodes centrally, parietally and occipitally at 160-200 ms from …

Diffuse and discrete associations in aversive classical conditioning

The aim of the present study was to assess the role of the cerebellar interpositus nucleus (IPN) in different types of associations during classical eyeblink conditioning in rabbits.

Effects of Hippocampal State-Contingent Trial Presentation on Hippocampus-Dependent Nonspatial Classical Conditioning and Extinction

Hippocampal local field potentials are characterized by two mutually exclusive states: one characterized by regular θ oscillations (∼4–8 Hz) and the other by irregular sharp-wave ripples. Presenting stimuli during dominant θ oscillations leads to expedited learning, suggesting that θ indexes a state in which encoding is most effective. However, ripple-contingent training also expedites learning, suggesting that any discrete brain state, much like the external context, can affect learning. We trained adult rabbits in trace eyeblink conditioning, a hippocampus-dependent nonspatial task, followed by extinction. Trials were delivered either in the presence or absence of θ or regardless of hippo…

Hippocampus responds to auditory change in rabbits

Any change or novelty in the auditory environment is potentially important for survival. The cortex has been implicated in the detection of auditory change whereas the hippocampus has been associated with the detection of auditory novelty. Local field potentials (LFPs) were recorded from the CA1 area of the hippocampus in waking rabbits. In the oddball condition, a rare tone of one frequency (deviant) randomly replaced a repeated tone of another frequency (standard). In the equal-probability condition, the standard was replaced by a set of tones of nine different frequencies in order to remove the repetitive auditory background of the deviant (now labelled as control-deviant) while preservi…

Phase-locked hippocampal theta-band responses are related to discriminative eyeblink conditioned responding

Hippocampal electrophysiological oscillatory activity is undoubtedly related to learning and memory. The relative power of spontaneously occurring hippocampal theta (∼4-8 Hz) oscillations predicts how fast and how well an animal will learn: more theta predicts faster acquisition of the conditioned response in eyeblink conditioning in both rats and rabbits. Here, our aim was to study how hippocampal theta-band responses to conditioned stimuli elicited during very-long delay discrimination eyeblink conditioning relate to the accompanying conditioned behavior. We trained adult male New Zealand White rabbits using 1500-ms auditory stimuli as conditioned stimuli and a 100-ms airpuff as an uncond…

Cardiorespiratory Fitness Estimation Based on Heart Rate and Body Acceleration in Adults With Cardiovascular Risk Factors : Validation Study

Publisher Copyright: © Antti-Pekka E Rissanen, Mirva Rottensteiner, Urho M Kujala, Jari L O Kurkela, Jan Wikgren, Jari A Laukkanen. Originally published in JMIR Cardio (https://cardio.jmir.org), 25.10.2022. This is an open-access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in JMIR Cardio, is properly cited. The complete bibliographic information, a link to the original publication on https://cardio.jmir.org, as well as this copyright and license information must be included. Background: C…

Explicit behavioral detection of visual changes develops without their implicit neurophysiological detectability

Change blindness is a failure of reporting major changes across consecutive images if separated, e.g., by a brief blank interval. Successful change detection across interrupts requires focal attention to the changes. However, findings of implicit detection of visual changes during change blindness have raised the question of whether the implicit mode is necessary for development of the explicit mode. To this end, we recorded the visual mismatch negativity (vMMN) of the event-related potentials (ERPs) of the brain, an index of implicit pre-attentive visual change detection, in adult humans performing an oddball-variant of change blindness flicker task. Images of 500 ms in duration were prese…

Event-related potentials reveal rapid registration of features of infrequent changes during change blindness

Background. Change blindness refers to a failure to detect changes between consecutively presented images separated by, for example, a brief blank screen. As an explanation of change blindness, it has been suggested that our representations of the environment are sparse outside focal attention and even that changed features may not be represented at all. In order to find electrophysiological evidence of neural representations of changed features during change blindness, we recorded event-related potentials (ERPs) in adults in an oddball variant of the change blindness flicker paradigm. Methods. ERPs were recorded when subjects performed a change detection task in which the modified images w…