Habituation Effects Research Articles

Beneficial Effects of Electrostimulation Contingencies on Sustained Attention and Electrocortical Activity

Chinese acupuncture therapy has been practiced for more than 3000 years. According to neuroimaging studies, electroacupuncture has been demonstrated to be effective via control of the frequency parameter of stimulation, based on the theory of frequency modulation of brain function. To investigate the following: (1) possible sustained effects of acustimulation in improving perceptual sensitivity in attention by comparing before, during, and 5 min following stimulation; (2) relations between commission errors and the motor inhibition event-related potential (ERP) component measured with independent component analysis (ICA); (3) whether habituation would be demonstrated in the sham control group and would be militated by acustimulation in the experimental groups. Twenty-seven subjects were divided into three groups (n = 9). d-Prime (d') derived from signal detection theory was used as an index of perceptual sensitivity in the visual continuous performance attention test. Increased d' was found during both alternating frequency (AE) and low frequency (LE) stimulation, but with no change in the sham control group (SE). However, only following AE was there a sustained poststimulation effect. Spatial filtration-based independent components (ICs) in the AE group revealed significantly decreased amplitudes of the motor inhibition ICs both during and poststimulation. There was a significant habituation effect from task repetition in the sham group with decreased amplitudes of ICs as follows: the visual comparison component difference between go (correct response) and nogo cues (correct withheld response), the P400 action monitoring and the working memory component in the nogo condition, and the passive auditory component on control trials. The results showed associations between acustimulation and improved perceptual sensitivity with sustained improvements following AE, but not LE stimulation. Improvements in commission errors in the AE group were related to the motor inhibition IC. The activational effects of acustimulation apparently attenuated the across-task habituation that characterized the control group.

The Effects of Habituation and Gaze Stability Exercises in the Treatment of Unilateral Vestibular Hypofunction: A Preliminary Results

The efficacy of both habituation and adaptation exercise interventions in the treatment of unilateral vestibular hypofunction has been demonstrated by previous studies. The purpose of this article is to describe the preliminary results of an ongoing study that compares the effects of these 2 different exercise approaches on outcomes related to vestibular function. Seven participants with unilateral vestibular hypofunction completed a 6-week exercise intervention after random assignment to either habituation exercises or gaze stability (GS) adaptation exercises. The following measures were performed pre- and posttreatment: Dizziness Handicap Inventory to measure the symptom impact, motion sensitivity quotient (MSQ) to assess sensitivity to head movements, and the dynamic visual acuity (DVA) test as a measure of GS during head movements. After the 6-week intervention, there was an overall improvement in the Dizziness Handicap Inventory, the MSQ score, and both the active and passive DVA. The habituation and GS intervention group participants each demonstrated similar improvements in both the MSQ score and the active and passive DVA measures. The improvement in the MSQ score for the GS group and the improvement in the DVA measures for the habituation group were unexpected findings. Head movement, which is required by both exercise interventions, rather than the specific type of exercise may be the critical factor underlying the observed improvements in motion sensitivity and DVA.

Sexual Behaviour of Hair Rams (Ovis aries) Subjected to Frequent Collection and Free from Habituation to the Female

Andrade, O., Vázquez, R. and Orihuela, A. 2010. Sexual behaviour of hair rams (Ovis aries) subjected to frequent collection and free from habituation to the female. J. Appl. Anim. Res., 37: 121–124. An experiment was designed to measure the relationship between repeated collection, semen characteristics and reaction time (RT) as an estimator of libido while isolating the effect of habituation to the female. Fourteen rams were equally and randomly assigned to two treatments. In TO (control) an ejaculation of each ram was collected daily with an artificial vagina (AV) for 10 consecutive days. In T1, semen was collected from the rams as in T0, but starting 60 min after this collection, electroejaculation was applied three times, with a 60 min interval to reduce epidydimal sperm reserves avoiding habituation to a female stimulus. No difference (P>0.05) was found in average RT and average sperm concentration between groups, while average semen volume was larger (P<0.01) in TO (0.82±0.04 ml) than in the T1 (0.64±0.04 ml). The slope for RT in the regression analysis was not different (P>0.05) from 0 in T0 and T1. However, a statistically significant (P<0.05) linear relationship was observed in ejaculate volumes and sperm concentration in the T1 as the experiment progressed. It was concluded that under no habituation to the female, rams RT was not affected by repeated collection, whereas, ejaculate volumes and sperm concentration declined proportionally as semen collection increased.

Time Scales of Auditory Habituation in the Amygdala and Cerebral Cortex

Habituation is a fundamental form of learning manifested by a decrement of neuronal responses to repeated sensory stimulation. In addition, habituation is also known to occur on the behavioral level, manifested by reduced emotional reactions to repeatedly presented affective stimuli. It is, however, not clear which brain areas show a decline in activity during repeated sensory stimulation on the same time scale as reduced valence and arousal experience and whether these areas can be delineated from other brain areas with habituation effects on faster or slower time scales. These questions were addressed using functional magnetic resonance imaging acquired during repeated stimulation with piano melodies. The magnitude of functional responses in the laterobasal amygdala and in related cortical areas and that of valence and arousal ratings, given after each music presentation, declined in parallel over the experiment. In contrast to this long-term habituation (43 min), short-term decreases occurring within seconds were found in the primary auditory cortex. Sustained responses that remained throughout the whole investigated time period were detected in the ventrolateral prefrontal cortex extending to the dorsal part of the anterior insular cortex. These findings identify an amygdalocortical network that forms the potential basis of affective habituation in humans.

Attenuation of maternal psychophysiological stress responses and the maternal cortisol awakening response over the course of human pregnancy

The effects of maternal stress during pregnancy may depend, in part, on the timing in gestation of the occurrence of stress. The aim of the present study was to examine the effect of stage of gestation on maternal psychophysiological responses to stress using a standardized laboratory paradigm and on the cortisol response to awakening (CAR). A longitudinal design was employed to quantify maternal psychophysiological stress reactivity [changes in heart rate (HR), blood pressure, salivary cortisol, and psychological distress in response to the trier social stress test (TSST)] and the CAR at approximately 17 and 31 weeks gestation in a sample of 148 women. To account for the possible effects of habituation when being exposed to the same stress protocol twice, a non-pregnant comparison group (CG, N = 36) also underwent these assessments at two time points, with a comparable time interval between the assessments. In both groups, the TSST elicited significant changes in maternal HR, mean arterial pressure, and psychological distress levels but not a significant increase in cortisol levels. Among the pregnant women (pregnant group(PG)), the stressor-induced increases in HR, blood pressure, and psychological distress were significantly lower at the second (31 weeks gestation) compared to the first (17 weeks gestation) assessment of pregnancy (all p < 0.01). The maternal CAR was also significantly attenuated in later compared to earlier gestation (p = 0.003). In the CG, there were no significant differences in psychophysiological stress responses and in the CAR across the two assessments. Among pregnant women there is a progressive attenuation of psychophysiological stress responses with advancing gestation. This attenuation is unlikely to be attributable to habituation. Individual differences in the degree of attenuation of stress responses over gestation may represent a novel marker of stress susceptibility in human pregnancy.

Presence of mammalian predators decreases tolerance to human disturbance in a breeding shorebird

Nonlethal disturbance can impose fitness costs, particularly during sensitive life history stages such as reproduction. Prey animals are thus expected to assess the costs and benefits of expressing antipredator behavior in different circumstances and to respond optimally according to the perceived risk of predation. One prediction of this hypothesis is that the response to nonlethal disturbance should be elevated when the risk of predation is high, although few studies have tested this prediction with respect to the distribution of actual predators in nature. We used landscape-level variation in the distribution of large mammalian predators (feral cats) to investigate antipredator behavior in a small breeding shorebird, the Two-banded Plover Charadrius falklandicus .W e used 8 sites in the Falkland Islands and Argentina and measured the flushing distances of incubating Two-banded Plovers in response to a controlled human approach to the nest. We found that flushing distances were increased at sites where mammalian predators were present and decreased where exposure to humans was high. These effects were additive, and we interpret them as the effects of generalization and habituation, respectively. Key words: antipredator behavior, feral cats, human disturbance, introduced predators, natural experiment, nest predation, predation risk, shorebird. [Behav Ecol]

Philip Samuel Weston Wilkins

<h3>Abstract</h3> Most olfactometers used to study human olfaction have stimulus durations of more than 1 second and often lasting minutes(Dravnieks 1975; Leland <i>et al</i>. 2001; Schmidt and Cain 2010). During...

Olfactory bulb habituation to odor stimuli.

Habituation is a simple form of memory, yet its neurobiological mechanisms are only beginning to be understood in mammals. In the olfactory system, the neural correlates of habituation at a fast experimental timescale involving very short intertrial intervals (tens of seconds) have been shown to depend on synaptic adaptation in olfactory cortex. In contrast, behavioral habituation to odorants on a longer timescale with intertrial intervals of several minutes depends on processes in the olfactory bulb, as demonstrated by pharmacological studies. We here show that behavioral habituation to odorants on this longer timescale has a neuronal activity correlate in the olfactory bulb. Spiking responses of mitral cells in the rat olfactory bulb adapt to, and recover from, repeated odorant stimulation with 5-min intertrial intervals with a time course similar to that of behavioral habituation. Moreover, both the behavioral and neuronal effects of odor habituation require functioning N-methyl-d-aspartic acid receptors in the olfactory bulb.

Escape tactics and effects of perch height and habituation on flight initiation distance in two Jamaican anoles (Squamata: Polychrotidae)

Escape by Anolis lizards is influenced by microhabitats and fight initiation distance increases with predation risk. Differences in microhabitat use among ecomorphs affect escape behavior, but only two studies have reported ecomorphological differences in flight initiation distance among Greater Antillean species. I studied effects of predation risk and microhabitats on escape behavior by conducting field experiments using two species of anoles, Anolis lineatopus and A. grahami, on the campus of the University of the West Indies at Mona, Jamaica. Because ecomorphological variation of anoles has evolved independently within each island of the Greater Antilles, but relationships between ecomorphs and escape behaviors are poorly known, I characterized microhabitat use and escape tactics, and determined relationships between flight initiation distance and two risk factors, habituation to human presence and perch height, in Anolis lineatopus, a trunk-ground anole and A. grahami, a trunk-crown anole. Sample sizes for A. lineatopus and A. grahami were 214 and 93, for microhabitat use and escape destinations, 74 and 34 for human presence and 125 and 34 for perch height. The two species occurred in similar microhabitats and exhibited similar escape tactics, but exhibited key differences expected for their ecomorphs. Both species were sighted frequently on the ground and on trees, but A. lineatopus were more frequently on ground and were perched lower than A. grahami. Both species escaped from ground to trees and when on trees hid on far sides and escaped without changing climbing direction with equal frequency. The frequency of fleeing upward was greater for A. grahami than A. lineatopus. Both species exhibited habituation by having shorter flight initiation distances in areas with more frequent exposure to people. In both species flight initiation distance increased as perch height decreased because, lizards had to climb farther to be out of reach when perched lower. The relationship between flight initiation distance and perch height may apply to other anole ecomorphs that flee upward when low perched on trees.

Exploring cortical attentional system by using fMRI during a Continuous Perfomance Test.

Functional magnetic resonance imaging (fMRI) was performed in eight healthy subjects to identify the localization, magnitude, and volume extent of activation in brain regions that are involved in blood oxygen level-dependent (BOLD) response during the performance of Conners' Continuous Performance Test (CPT). An extensive brain network was activated during the task including frontal, temporal, and occipital cortical areas and left cerebellum. The more activated cluster in terms of volume extent and magnitude was located in the right anterior cingulate cortex (ACC). Analyzing the dynamic trend of the activation in the identified areas during the entire duration of the sustained attention test, we found a progressive decreasing of BOLD response probably due to a habituation effect without any deterioration of the performances. The observed brain network is consistent with existing models of visual object processing and attentional control and may serve as a basis for fMRI studies in clinical populations with neuropsychological deficits in Conners' CPT performance.

Habituation, Dishabituation, and Recovery Effects in Visual Warnings

Decrement of visual attention to repeatedly exposed warning labels and signs has been discussed in the warning literature without much empirical research support. The present research examined whether habituation, dishabituation, and recovery of habituation occur to visually presented warnings. Participants (N=72) were presented to a long sequence of repeated visual warnings (40 warnings presented 8 times = 320 initial trials) in a particular format (ANSI or OSHA type formats), followed by 5 warnings manipulated either in the same or different format. Five more warnings in same format as in the initial trials were presented to end the sequence. Measured were participants' ratings of perceived alertness to each warning. Findings showed a decrease in ratings from beginning to end of the initial 320 trials, indicative of habituation. Dishabituation was observed with higher ratings when the warning format changed. Evidence of habituation recovery of lowered ratings was observed upon return to the previously habituated (initial trials) format after a set of different formatted warnings. Implications for formalized standards and guidelines, which recommend an unchanging, relatively constant format, are discussed.

Habituation, Dishabituation, and Recovery Effects in Visual Warnings

Decrement of visual attention to repeatedly exposed warning labels and signs has been discussed in the warning literature without much empirical research support. The present research examined whether habituation, dishabituation, and recovery of habituation occur to visually presented warnings. Participants (N=72) were presented to a long sequence of repeated visual warnings (40 warnings presented 8 times = 320 initial trials) in a particular format (ANSI or OSHA type formats), followed by 5 warnings manipulated either in the same or different format. Five more warnings in same format as in the initial trials were presented to end the sequence. Measured were participants' ratings of perceived alertness to each warning. Findings showed a decrease in ratings from beginning to end of the initial 320 trials, indicative of habituation. Dishabituation was observed with higher ratings when the warning format changed. Evidence of habituation recovery of lowered ratings was observed upon return to the previously habituated (initial trials) format after a set of different formatted warnings. Implications for formalized standards and guidelines, which recommend an unchanging, relatively constant format, are discussed.

Electrophysiological correlates of reduced pain perception after theta-burst stimulation

In an earlier study, we reported the antinociceptive effects of a special repetitive transcranial magnetic stimulation paradigm: continuous theta-burst stimulation (cTBS), when applied to human motor cortex. Here, we investigated whether the reduced subjective pain perception of 10 healthy individuals could be measured by changes in laser-evoked potentials, a reflection of pain related activations in the operculoinsular and midcingulate cortex. To minimize the effect of habituation during repeated laser stimulation, a bioadaptive design was used. However, both pain ratings and laser-evoked potential amplitudes were reduced after real and sham cTBS. When compared with sham stimulation, cTBS resulted in a significantly greater diminution of pain ratings and N2-P2 amplitudes on the hand contralateral to the site of motor cortex stimulation.

Higher order color mechanisms: A critical review

A large number of studies, using a wide variety of experimental techniques, have investigated the “higher-order” color mechanisms proposed by Krauskopf and colleagues in 1986. Results reviewed here come from studies of chromatic discrimination at threshold, habituation, classification images, spatial alignment and orientation effects, and noise masking. The bulk of the evidence has been taken to support the existence of multiple, linear color mechanisms in addition to (or after) the three putative low-level cardinal mechanisms. But there remain disconcerting inconsistencies in the results of noise masking experiments, and the results of chromatic discrimination experiments clearly show that there are a very limited number of labeled-line mechanisms near threshold. No consensus on higher order mechanisms has been reached even after more than 20 years of study.

Three-way matrix analysis, the MUSIC algorithm and the coupled dipole model

The inverse problem of multi-channel MEG/EEG data is considered as a parameter estimation problem. The stability of the solution of the inverse problem, which decreases with the number of included dipoles, can be improved by either adding constraints to the model parameters, or by adding more data of related data sets. The latter approach was taken by Bijma et al. [Bijma F, de Munck JC, Böcker KBE, Huizenga HM, Heethaar RM. The coupled dipole model: an integrated model for multiple MEG/EEG data sets. NeuroImage 2004;23(3):890–904; Bijma F, de Munck JC, Huizenga HM, Heethaar RM, Nehorai A. Simultaneous estimation and testing in multiple MEG data sets. IEEE Trans SP 2005;53(9):3449–60] by introducing coupling matrices that link dipole parameters and source time functions of different data sets.Here, the theoretical foundations of the coupled dipole model are explored and the MUSIC algorithm is generalised to the analysis of multiple related data sets. Similar to the MUSIC algorithm, the number of sources and the number of constraints are derived from the data by considering the minimum possible residual error as a function of the number of sources and constraints. However, contrary to the MUSIC algorithm, where the minimum residual error can be obtained from an SVD analysis of a two-way data matrix, here we deal with multiple data sets and therefore three-way matrix analysis is used.From a simulation study it appears that the number of sources and constraints can be clearly determined from a generalised SVD analysis. The generalisation of the MUSIC algorithm to three-way data gives reasonable estimates of the dipole parameters. These results can be used in the simultaneous analysis of MEG/EEG data of multiple subjects, multiples data sets of the same subject or models where subsequent trials of data show habituation effects.

In defence of thought stopping

Thought stopping (TS) has a long and established history as an effective mental control technique among the cognitive behavioural therapies (CBT). Recent claims have arisen, particularly from acceptance and mindfulness-based authors, that thought suppression – and therefore TS – is counterproductive. These claims take the syllogistic form: TS is a form of thought suppression. All thought suppression is counterproductive. Therefore TS is counterproductive. This paper examines the evidence for and against each of these propositions, covering the literature related to anxiety, depression, exposure therapy, and the special case of obsessive–compulsive disorder. It is concluded that TS is a very particular form of thought suppression. Undifferentiated thought suppression has mixed and mild effects on psychopathological mental states, but TS can be highly effective if it is applied judiciously within a CBT model. It can enhance a person's coping repertoire. And this effect appears to be stronger than any possible concurrent dilution of habituation effects in exposure therapy.

Aversive phototaxic suppression: evaluation of a short‐term memory assay in Drosophila melanogaster

Drosophila melanogaster is increasingly being used to model human conditions that are associated with cognitive deficits including fragile-X syndrome, Alzheimer's disease, Parkinson's disease, sleep loss, etc. With few exceptions, cognitive abilities that are known to be modified in these conditions in humans have not been evaluated in fly models. One reason is the absence of a simple, inexpensive and reliable behavioral assay that can be used by laboratories that are not expert in learning and memory. Aversive phototaxic suppression (APS) is a simple assay in which flies learn to avoid light that is paired with an aversive stimulus (quinine/humidity). However, questions remain about whether the change in the fly's behavior reflects learning an association between light and quinine/humidity or whether the change in behavior is because of nonassociative effects of habituation and/or sensitization. We evaluated potential effects of sensitization and habituation on behavior in the T-maze and conducted a series of yoked control experiments to further exclude nonassociative effects and determine whether this task evaluates operant learning. Together these experiments indicate that a fly must associate the light with quinine/humidity to successfully complete the task. Next, we show that five classic memory mutants are deficient in this assay. Finally, we evaluate performance in a fly model of neurodegenerative disorders associated with the accumulation of Tau. These data indicate that APS is a simple and effective assay that can be used to evaluate fly models of human conditions associated with cognitive deficits.

Strategies for longitudinal neuroimaging studies of overt language production

Longitudinal fMRI studies of language production are of interest for evaluating recovery from post-stroke aphasia, but numerous methodological issues remain unresolved, particularly regarding strategies for evaluating single subjects at multiple timepoints. To address these issues, we studied overt picture naming in eleven healthy subjects, scanned four times each at one-month intervals. To evaluate the natural variability present across repeated sessions, repeated scans were directly contrasted in a unified statistical framework on a per-voxel basis. The effect of stimulus familiarity was evaluated using explicitly overtrained pictures, novel pictures, and untrained pictures that were repeated across sessions. For untrained pictures, we found that activation declined across multiple sessions, equally for both novel and repeated stimuli. Thus, no repetition priming for individual stimuli at one-month intervals was found, but rather a general effect of task habituation was present. Using a set of overtrained pictures identical in each session, no decline was found, but activation was minimized and produced less consistent patterns across participants, as measured by intra-class correlation coefficients. Subtraction of a baseline task, in which subjects produced a stereotyped utterance to scrambled pictures, resulted in specific activations in the left inferior frontal gyrus and other language areas for untrained items, while overlearned stimuli relative to pseudo pictures activated only the fusiform gyrus and supplementary motor area. These findings indicate that longitudinal fMRI is an effective means of detecting changes in neural activation magnitude over time, as long as the effect of task habituation is taken into account.

Male but not female Wistar rats show increased anxiety-like behaviour in response to bright light in the defensive withdrawal test

The defensive withdrawal test (DWT) is used to model anxiety-like behaviour in rats. The aim of this study was to investigate whether an aversive stimulus, bright light, affects the behaviour in this test. Additionally, the effect of habituation to the apparatus was studied. Both male and female Wistar rats were used to study whether sex differences exist in the DWT, as reported for other tests of anxiety. On day 1 half of the rats were tested under low light and half under bright light. Two to seven days after trial one the same rats were repeatedly tested under the same light condition for five consecutive days. The male rats showed a higher degree of anxiety-like behaviour when tested under bright light than under low light. In contrast, the behaviour of the female rats was not affected by changes in illumination. Male rats also exhibited elevated anxiety-like behaviour compared to female rats under bright light, whereas under low light conditions no sex difference was seen. Males in low light habituated much faster than males tested under bright light, whereas in females there was little difference in habituation between low and bright light. In summary, we found that bright light is aversive for male but not female Wistar rats in the DWT. Whether this is due to sex differences in light sensitivity or if females respond with a different behavioural strategy in response to bright light, which could not be detected in the DWT, remains to be elucidated.

Modulation of alpha oscillations in insular cortex reflects the threat of painful stimuli

Pain is a sensory and emotional experience that involves numerous brain areas. Among these areas the insular cortex has been shown to be involved in the expectation and processing of pain. Alpha power modulation has been associated with the experience of pain. The aim of this study was to test the hypothesis that the threat of a painful stimulus affects alpha rhythm oscillation in the insular cortex and to find the time intervals during which the insular cortex is most active. We used a beamforming method in the frequency domain to estimate alpha power associated with source activity during psychologically different conditions, namely a sequence of nonpainful somatosensory stimuli (non-threatening condition) and a sequence of nonpainful stimuli randomly intermixed with painful stimuli (threatening condition). The results revealed that the anterior insula alone was involved during the threat of painful stimuli. Conversely, the posterior insula – as well as other brain areas such as SII – was involved in the processing of somatosensory stimuli regardless their painfulness. Additionally, the involvement of the anterior insula should not be accounted for by fear, arousal, habituation effect or by the occurrence of randomly interleaved different stimuli, but it is likely to be related mainly to expectancy mechanisms enhancing activity of specific neuronal populations.