Habituation Patterns Research Articles

Patterns of Anxious Arousal During a Speech Task Between Nonanxious Controls and Individuals With Social Anxiety Disorder Pre- and Posttreatment

Although research indicates that anxious arousal in response to feared stimuli is related to treatment outcome (Heimberg et al., 1990), less is known about the patterns of anxious arousal. We identified patterns of anxious arousal in individuals with social anxiety disorder (SAD) at pre- (n= 61) and posttreatment (n= 40; 12-session CBGT, Heimberg & Becker, 2002), and in non-anxious controls (NACs; n= 31) using an assessment speech task administered at pretreatment (SAD) or the pretreatment equivalent (NACs), as well as at posttreatment (SAD only). We identified nine patterns of anxious arousal across groups that we further clustered into three groups: fear habituation, fear plateau, and fear increase. Chi-square and adjusted standardized residual analyses revealed that individuals in the pretreatment SAD group displayed the fear habituation patterns significantly more than chance and the fear plateau patterns significantly less than chance. In contrast, NACs displayed the fear plateau patterns significantly more than chance and the fear habituation patterns significantly less than chance. At posttreatment, treatment non-responders displayed fear habituation patterns significantly more than chance, whereas treatment responders displayed the fear habituation patterns significantly less than chance. Findings indicate that fear habituation during an anxiety-provoking assessment task is not necessary for treatment response.

Program Mushafahah (Bersalaman) Sebagai Upaya Character Building Pada Siswa Sekolah Dasar Islam Swasta Pekanbaru

The study was administered at Private Islamic elementary school Pekanbaruwhich aimed to obtain objective data, factual, accurate and systematic regarding implementation Program as an attempt to shake the character building students of private Islamic elementary school Pekanbaru. Character is life mustika what distinguishes man from other creatures. Given the urgent and fundamen character, then the educational institution has a responsibility to incorporate them to the students in the school environment in general and in the process of learning, especially in order to form human character with various policies set out in the program within the school and the learning process. This study is a qualitative research case study type with a naturalistic approach in which researchers describe the study and case studies related to implementation Program as an attempt to shake the character building students of private Islamic elementary school Pekanbaru by direct observation, interview and documentation as data collection techniques. As for the informant is the head master, deputy superintendent of curriculum, deputy head of the student, the teacher and studens in grade five. The results of study showed that implementation Program as an attempt to shake went well with the pattern of habituation and modeling, but there is no planned evaluation and follow-up of the school.
 
 Keywords: Shake Hands, Character Building, Students

Exploring the heterogeneity of neural social indices for genetically distinct etiologies of autism

BackgroundAutism spectrum disorder (ASD) is a genetically and phenotypically heterogeneous disorder. Promising initiatives utilizing interdisciplinary characterization of ASD suggest phenotypic subtypes related to specific likely gene-disrupting mutations (LGDMs). However, the role of functionally associated LGDMs in the neural social phenotype is unknown.MethodsIn this study of 26 children with ASD (n = 13 with an LGDM) and 13 control children, we characterized patterns of mu attenuation and habituation as children watched videos containing social and nonsocial motions during electroencephalography acquisition.ResultsDiagnostic comparisons were consistent with prior work suggesting aberrant mu attenuation in ASD within the upper mu band (10–12 Hz), but typical patterns within the lower mu band (8–10 Hz). Preliminary exploration indicated distinct social sensitization patterns (i.e., increasing mu attenuation for social motion) for children with an LGDM that is primarily expressed during embryonic development. In contrast, children with an LGDM primarily expressed post-embryonic development exhibited stable typical patterns of lower mu attenuation. Neural social indices were associated with social responsiveness, but not cognition.ConclusionsThese findings suggest unique neurophysiological profiles for certain genetic etiologies of ASD, further clarifying possible genetic functional subtypes of ASD and providing insight into mechanisms for targeted treatment approaches.

Altered visual repetition suppression in Fragile X Syndrome: New evidence from ERPs and oscillatory activity

Fragile X Syndrome (FXS) is a neurodevelopmental genetic disorder associated with cognitive and behavioural deficits. In particular, neuronal habituation processes have been shown to be altered in FXS patients. Yet, while such deficits have been primarily explored using auditory stimuli, less is known in the visual modality. Here, we investigated the putative alteration of repetition suppression using faces in FXS patients compared to controls that had the same age distribution. Electroencephalographic (EEG) signals were acquired while participants were presented with 18 different faces, each repeated ten times successively. The repetition suppression effect was probed by comparing the brain responses to the first and second presentation, based on task-evoked event-related potentials (ERP) as well as on task-induced oscillatory activity. We found different patterns of habituation for controls and patients both in ERP and oscillatory power. While the N170 was not affected by face repetition in controls, it was altered in FXS patients. Conversely, while a repetition suppression effect was observed in the theta band (4–8Hz) over frontal and parieto-occipital areas in controls, it was not seen in FXS patients. These results provide the first evidence for diminished ERP and oscillatory habituation effects in response to face repetitions in FXS. These findings extend previous observations of impairments in learning mechanisms and may be linked to deficits in the maturation processes of synapses caused by the mutation. The present study contributes to bridging the gap between animal models of synaptic plasticity dysfunctions and human research in FXS.

Behavioral Inhibition and Behavioral Activation are Related to Habituation of Nociceptive Flexion Reflex, but Not Pain Ratings.

Using repeated NFR stimulation, this study showed that most participants exhibited NFR habituation and pain sensitization; however, a substantial subgroup showed an opposite pattern of pain habituation (25.0%) and NFR sensitization (31.4%). Further, NFR habituation was moderated by individual differences in behavioral activation and behavioral inhibition.

Amygdala and dlPFC abnormalities, with aberrant connectivity and habituation in response to emotional stimuli in females with BPD

BackgroundLittle is known about the frontolimbic abnormalities thought to underlie borderline personality disorder (BPD). We endeavoured to study regional responses, as well as their connectivity and habituation during emotion processing. Methods14 BPD patients and 14 normal female controls (NC) controlled for menstrual phase underwent emotion-induction during an fMRI task using standardised images in a block design. We then performed psychophysiological interaction (PPI) analysis to investigate functional connectivity. ResultsBPD patients reported more disgust in questionnaires compared to controls. Relative to NC, they showed reduced left amygdala and increased dorsolateral prefrontal cortex (dlPFC) activation to all emotions collapsed versus neutral. Habituation of ventral striatal activity to repeated emotional stimuli was observed in controls but not in BPD. Finally, in the context of disgust (but not other emotions) versus neutral, BPD patients displayed enhanced left amygdala coupling with the dlPFC and ventral striatum. LimitationsStrict inclusion criteria reduced the sample size. ConclusionsIn summary, BPD showed abnormal patterns of activation, habituation and connectivity in regions linked to emotion regulation. Amygdala deactivation may be mediated by abnormal top-down regulatory control from the dorsolateral prefrontal cortex. Aberrant emotion processing may play a unique role in the pathophysiology of BPD.

Amygdala habituation to emotional faces in adolescents with internalizing disorders, adolescents with childhood sexual abuse related PTSD and healthy adolescents

Adolescents with internalizing disorders and adolescents with childhood sexual abuse related post-traumatic stress disorder (CSA-related PTSD) show a large overlap in symptomatology. In addition, brain research indicated hyper-responsiveness and sustained activation instead of habituation of amygdala activation to emotional faces in both groups. Little is known, however, about whether the same patterns of amygdala habituation are present in these two groups. The current study examined habituation patterns of amygdala activity to emotional faces (fearful, happy and neutral) in adolescents with a DSM-IV depressive and/or anxiety disorder (N=25), adolescents with CSA-related PTSD (N=19) and healthy controls (N=26). Behaviourally, the adolescents from the internalizing and CSA-related PTSD group reported more anxiety to fearful and neutral faces than adolescents from the control group and adolescents from the CSA-related PTSD group reacted slower compared to the internalizing group. At the whole brain level, there was a significant interaction between time and group within the left amygdala. Follow-up ROI analysis showed elevated initial activity in the amygdala and rapid habituation in the CSA-related PTSD group compared to the internalizing group. These findings suggest that habituation patterns of amygdala activation provide additional information on problems with emotional face processing. Furthermore, the results suggest there are differences in the underlying neurobiological mechanisms related to emotional face processing for adolescents with internalizing disorders and adolescents with CSA-related PTSD. Possibly CSA-related PTSD is characterized by a stronger primary emotional response driven by the amygdala.

ID 424 – Laser evoked potentials habituation and central sensitization symptoms in childhood migraine

Objectives Few studies dealt with central sensitization symptoms and pain processing in childhood migraine. Our aims were to examine pain sensitivity and evoked responses by CO2 laser stimuli (LEPs) including habituation in migraine children compared to controls, and to correlate LEPs features to signs of central sensitization Methods Thirty five 8–15 years aged migraine without aura patients were evaluated during the inter-critical phase and compared to 17 controls. LEPs were analyzed and main features correlated with clinical symptoms including allodynia and pericranial tenderness. Results Laser pain threshold was lower in migraine children and the N2P2 vertex complex amplitude was increased. Furthermore LEPs vertex waves habituation showed a clearly tendency toward progressive amplitude enhancement in migraine. Acute allodynia and inter-critical pericranial tenderness correlated with trigeminal LEPs features and in particular abnormal habituation pattern. Discussion Abnormalities of pain processing and symptoms of central sensitization seem to characterize migraine children. Conclusions Reduced habituation and progressive amplification of cortical responses under laser stimuli, indicate an overactive nociceptive system at the onset of migraine, which may subtend allodynia and pericranial tenderness. Key message Future trials may aid to early individuation of clinical phenotypes with tendency to chronic form development, worthy of a timely therapeutic approach.

Persistent Postural-Perceptual Dizziness: A Matter of Higher, Central Dysfunction?

ObjectivePersistent postural-perceptual dizziness (PPPD) is the most common vestibular disorder in the age group between 30 and 50 years. It is considered to be based on a multisensory maladjustment involving alterations of sensory response pattern including vestibular, visual and motion stimuli. Previous data supported a link between vestibular and pain mechanism. The aim of the study was to investigate whether other sensory inputs such as pain stimuli might be altered in terms of a more widespread central perception dysfunction in this disorder.MethodsNociceptive blink reflex was measured in 27 patients with PPPD and compared with 27 healthy, age and gender matched controls. The habituation of the R2 component of the blink reflex was evaluated as the percentage area-under-the curve (AUC) decrease in ten consecutive blocks of five averaged rectified responses. Additionally, clinical characteristics were evaluated.ResultsIn patients with PPPD a lack of habituation was observed compared to healthy controls. Relative AUC decreased between the first and the tenth block by 19.48% in PPPD patients and by 31.63% (p = 0.035) in healthy controls. There was no correlation between clinical data (course of disease, comorbid depression, medication, trigger factors) or electrophysiological data (perception threshold, pain threshold, stimulus intensity) and habituation pattern. No trigeminal sensitization in terms of facilitation of absolute values could be detected.ConclusionOur study results supports the hypothesis of the multisensory dimension of impaired sensory processing in patients with PPPD extends beyond vestibular/visual motion stimuli and reflexive postural/oculomotor control mechanisms to other sensory inputs such as pain perception in terms of a more generalized disturbed habituation pattern.

P042. Mechanism of action and clinical evidence of botulinum toxin in chronic migraine.

Considerable evidence exists supporting the notion that botulinum toxin type A (BoNT/A) can exert a direct analgesic effect in addition to its myorelaxant effect. It is likely that the benefict of using BoNT/A as prophylactic treatment for chronic migraine is due to its ability to inhibit overactivity of motor neurons and hyperexcitability of sensory neurons, by involving the suppression of peripheral and central sensitization. In this study we aimed to evaluate the effects of BoNT/A on amplitude, latency and habituation of laser evoked potentials (LEPs) in patients with chronic migraine. We recruited 20 patients with a diagnosis of chronic migraine treated with type A botulinum toxin every 3 months. LEPs were recorded in basal, two hours and ten days after both BoNT/A and placebo injection. Headache frequency, allodynia and total tenderness score (TTS) were evaluated at basal condition and after one-year of treatment. We found N2 and P2 latency increased 10 days after toxin injection, while LEPs amplitude was not modified. Compared to placebo injection, the habituation of N2/P2 LEPs component obtained by stimulating supraorbital zone was significantly increased after BoNT/A infiltration. After ten days, habituation pattern in migraine patients was similar to that of normal subjects. In the one-year follow-up we observed a significant migraine frequency and allodynia improvement, but no effect on total tenderness score. Furthermore the habituation change correlated with the clinical effectiveness. Study results suggest a toxin modulating action on nociceptive afferents in patients with chronic migraine. The N2 and P2 latency increase obtained from hand laser stimulation suggests a possible systemic pain inhibiting effect. Although the botulinum toxin did not show an inhibitory effect on trigeminal nociceptive system, it seems to improve the reduced habituation pattern which promotes the central sensitization. The therapeutic effect of BoTN/A seemed to be related to the effect on trigeminal habituation obtained after 10 days from the first infiltration, which could be considered as a potential neurophysiological pattern to predict the non-responders. Results of this study confirm that the effect of botulinum toxin on chronic migraine may be related to a modulation and normalization of central sensitization mechanisms. The lack of effects on pericranial muscle tension precludes to suppose a modulating effect on trigeminal nociception by the inhibition of the neuromuscular synapse. Written informed consent to publish was obtained from the patient(s).

Laser evoked potentials and central sensitization in migraine.

Migraine is a disabling disorder of neuro-vascular origin. An abnormal neuronal excitability, largely based on genetic nature, is a predisposing factor to attack onset. A reduced habituation to multimodal repetitive non nociceptive stimuli was observed in migraine. The pattern of reduced habituation to nociceptive stimuli may favor the increase of pain and the phenomena of central sensitization. Central sensitization is a phenomenon of pain processing, which may predispose to chronic pain. Allodynia occurring during migraine attack and persistent pericranial tenderness in migraine are symptoms of central sensitization[1, 2]. CO2 laser evoked potentials (LEPs) have been used in migraine research, proving very useful in demonstrating functional abnormalities of the central nociceptive system which might be linked to the pathophysiological mechanisms of this disease. Abnormalities of pain processing seem to characterize children with migraine. Reduced habituation and progressive amplification of cortical responses under laser stimuli indicate an overactive nociceptive system just at the onset of migraine, which may subtend symptoms of central sensitization as allodynia and pericranial tenderness. An abnormal pattern of habituation of the trigeminal nociceptive system is an endophenotypic marker of migraine[3], suggesting that the nociceptive system is prone to sensitization even before clinical appearance[4]. These aspects may guide therapeutic approach: in a recent work in which we explored the efficacy of botulinum toxin in the treatment of chronic migraine, we found a correlation of the clinical effect with an improvement of the LEPs habituation deficit. The modes of action of pharmacological or nonpharmacological interventions, such as neuromodulation methods, should therefore be reconsidered in terms of their ability to normalize the complex abnormalities of brain hyperresponsivity and the central sensitization phenomena.

Laser-evoked potential habituation and central sensitization symptoms in childhood migraine.

Few studies have addressed central sensitization symptoms and pain processing in childhood migraine. Our aims were to examine pain sensitivity and responses, including habituation, evoked by CO2 laser stimuli (laser-evoked potentials (LEPs)) in a cohort of children with migraine compared to non-migraine controls and to determine the correlation between LEP features and signs of central sensitization. Thirty-five patients 8-15 years of age with migraines without aura were evaluated during the inter-critical phase and were compared to 17 controls. LEPs were analyzed, and their main features were correlated with clinical symptoms including allodynia and pericranial tenderness. The laser-evoked pain threshold was lower and the N2P2 vertex complex amplitude was higher in children with migraines. Furthermore, habituation of vertex waves of LEPs clearly showed a tendency toward progressive amplitude enhancement in the migraine group. Acute allodynia and inter-critical pericranial tenderness correlated with trigeminal LEP features, particularly with the abnormal habituation pattern. Abnormalities of pain processing and symptoms of central sensitization appear to be characteristics of children with migraine. Reduced habituation and progressive amplification of cortical responses to laser stimuli indicate an overactive nociceptive system at the onset of migraine, and this hyperactivity may subtend allodynia and pericranial tenderness. Future prospective trials may aid in the early identification of clinical phenotypes that display a tendency to develop into the chronic form of migraine, warranting a timely therapeutic approach.

Emotional Activation and Habituation During Imaginal Exposure for PTSD Among Women With Borderline Personality Disorder.

The current study examined patterns and outcomes of emotional activation and habituation during imaginal exposure for posttraumatic stress disorder (PTSD). Participants were 16 women with borderline personality disorder (BPD), PTSD, and recent suicidal and/or self-injurious behavior who received imaginal exposure for PTSD concurrently with dialectical behavior therapy. The intensity of global distress and 6 specific emotions were assessed before and after imaginal exposure trials. Results indicated that significant within-session habituation (WSH) occurred for global distress (Hedge's g effect size = -2.52) and fear (g = -0.80), whereas significant between-session habituation (BSH) occurred for global distress (g = -2.18), fear (g = -1.89), guilt (g = -1.14), shame (g = -0.74), and disgust (g = -0.41). BSH significantly predicted PTSD diagnostic status at posttreatment, whereas activation and WSH were unrelated to outcome. Clients who remitted from PTSD showed significantly more BSH in global distress than nonremitters (η(2) = .39). In addition, remitters reported reductions in sadness and anger across trials, whereas sadness and anger increased for those who did not remit (η(2) = .54 and .40, respectively). Overall, BPD clients exhibited patterns of activation and habituation during imaginal exposure comparable to other client populations, and there was no evidence of persistent emotional engagement or habituation problems.

A social–ecological systems approach to non-native species: Habituation and its effect on management of coqui frogs in Hawaii

Non-native species introductions have the ability to affect both ecological and social systems, thus to address those outcomes both ecological and social influences on an invasion need to be understood. We use a social–ecological systems approach to investigate connections between human and ecological factors that affect efforts to control the non-native coqui frog (Eleutherodactylus coqui) on the island of Hawaii. The coqui frog is recognized as a ‘pest’ and ‘injurious wildlife’ by the Hawaii Department of Agriculture. Because the coqui occurs on many small private properties across the island, it is necessary to enlist private citizens in control efforts. Control efforts can include direct chemical control of the coqui as well as landscape manipulations that reduce habitat quality for the frog. On 85 private properties in 12 communities across the island, we measured the relationship between coqui abundance, residents’ attitudes toward the coqui, their reported participation in control activities, and environmental variables that affect habitat quality for the frog. Residents’ attitudes correlated with coqui frog abundance, but in an unexpected direction: People with more frogs on their property and those who owned that property tended to have less negative attitudes toward the coqui. In addition, negative attitudes toward the coqui were not significantly related to participation in control activities. Coqui abundance was related to a habitat variable, canopy cover, which can be manipulated by residents to reduce habitat quality and discourage coqui occupancy. Tolerance for this non-native species is likely to hinder attempts to engage residents in control efforts as the species’ range on the island continues to expand. If this pattern of habituation is manifested with other non-native species considered to have potentially negative effects on the ecological or social environment, it would be important to recognize as early as possible because managers may be most effective at engaging citizens in control efforts before habituation becomes widespread.

Sheltering behavior and locomotor activity in 11 genetically diverse common inbred mouse strains using home-cage monitoring.

Functional genetic analyses in mice rely on efficient and in-depth characterization of the behavioral spectrum. Automated home-cage observation can provide a systematic and efficient screening method to detect unexplored, novel behavioral phenotypes. Here, we analyzed high-throughput automated home-cage data using existing and novel concepts, to detect a plethora of genetic differences in spontaneous behavior in a panel of commonly used inbred strains (129S1/SvImJ, A/J, C3H/HeJ, C57BL/6J, BALB/cJ, DBA/2J, NOD/LtJ, FVB/NJ, WSB/EiJ, PWK/PhJ and CAST/EiJ). Continuous video-tracking observations of sheltering behavior and locomotor activity were segmented into distinguishable behavioral elements, and studied at different time scales, yielding a set of 115 behavioral parameters of which 105 showed highly significant strain differences. This set of 115 parameters was highly dimensional; principal component analysis identified 26 orthogonal components with eigenvalues above one. Especially novel parameters of sheltering behavior and parameters describing aspects of motion of the mouse in the home-cage showed high genetic effect sizes. Multi-day habituation curves and patterns of behavior surrounding dark/light phase transitions showed striking strain differences, albeit with lower genetic effect sizes. This spontaneous home-cage behavior study demonstrates high dimensionality, with a strong genetic contribution to specific sets of behavioral measures. Importantly, spontaneous home-cage behavior analysis detects genetic effects that cannot be studied in conventional behavioral tests, showing that the inclusion of a few days of undisturbed, labor extensive home-cage assessment may greatly aid gene function analyses and drug target discovery.

123. Response and habituation of pro- and anti-inflammatory gene expression to repeated psychosocial stress

Rationale: Acute stress is accompanied by an inflammatory response and some individuals show sensitization to repeated stress. Increased peripheral inflammation is a risk factor for many age-related illnesses, highlighting the need to understand factors controlling inflammation. No studies have examined changes in pro- and anti-inflammatory gene expression in response to repeated acute stress in humans. Methods: We recruited n = 31 healthy individuals and examined gene expression of IL-6, IL-1beta, RelA and IkappaB before, 30 and 120 min after exposure to the Trier Social Stress Test (TSST) on two days. We assessed the inflammatory response by measuring plasma IL-6, and cortisol as the major anti-inflammatory stress hormone. Results: Stress exposure induced inflammatory and cortisol responses (IL-6: F = 49.3, p F = 13.7, p ∗ time interaction F = 4.2, p = 0.011) but IL-6 responses did not (n.s.). IL-6 and IL-1beta gene expression increased on Day 1, but not on Day 2 (day ∗ time interaction: IL-6: F = 106, p = 0.001; IL-1beta: F = 7.9, p = 0.006). RelA expression increased on both days (time effect F = 5.0, p = 0.013). IkB expression increased then decreased below baseline on Day 1, and decreased post-TSST on Day 2 (day ∗ time interaction: F (2,54) = 5.4, p = 0.08). There was no relationship between IL-1Beta, IkB, and RelA with plasma IL-6 or cortisol, or between cortisol and plasma IL-6. Conclusions: Taken together, results show a response pattern of pro- and anti-inflammatory gene expression characterized by differential stress responses and habituation patterns that are in disjunction with patterns of cortisol and plasma IL-6 responses to repeated stress. This indicates that increases in plasma concentrations of inflammatory cytokines are unlikely to originate solely from de novo transcription within PBMCs, but that alternative or additional sources of plasma inflammatory cytokines need to be explored.

Personality, Anxiety, and Individual Variation in Psychophysiological Habituation and Sensitization to Painful Stimuli

Habituation and sensitization are two fundamental consequences in response to repeated painful stimulation. However, individual differences as to who systematically habituate versus sensitize are currently not well understood. Investigating changes in response modulation (habituation and sensitization) in laboratory subjects undergoing pain testing, we evaluated the hypotheses: 1) significant individual differences exist in patterns of habituation and sensitization, and 2) variations in response modulation are systematically associated with subjects’ characteristic personality styles. We explored personality and state predictors of individual differences in response modulation consisting of habituation and sensitization in pain-free, healthy subjects. We recruited 81 healthy subjects who underwent 36 trials of painful stimulations to their fingertips. Subjective pain reports and psychophysiological responses - evoked potential (EP) and skin conductance response (SCR) - served as measurement indicators for habituation and sensitization, and to evaluate how these different measures manifested in the group averages as well as in correlations across individuals. Results showed that although subjective pain report tended to indicate sensitization on average, both EP and SCR showed habituation. However, further analyses revealed that there was a positive convergence among the three channels across different subjects, suggesting that individuals tend to have consistent response styles in responding to repeated pain stimulations. Our analyses allowed us to make inferences about the relative proportions of individuals in the population who systematically habituate versus sensitize. Variations in the habituation-sensitization continuum are highly robust and systematic, and preexisting individual characteristics (personality and current psychological states such as state anxiety) in part accounted for these patterns.

Patterns of habituation and clinical fluctuations in migraine

Habituation deficit, suggesting a deregulation of cortical excitability, represents a typical hallmark of interictal stages of migraine. We previously demonstrated that several neurophysiological markers of altered cortical excitability are significantly correlated to spontaneous clinical fluctuations of migraine. We therefore aimed at verifying whether clinical fluctuations are correlated to specific patterns of somatosensory evoked potential (SEP) habituation. We analyzed habituation after median nerve stimulation of both high-frequency oscillations (HFOs) and N20 SEP in 25 migraine patients and 18 healthy volunteers. Subjects underwent six consecutive series of 500 stimuli. Migraine patients as a whole showed a significant habituation deficit of the N20 response. Moreover, spontaneously worsening patients show a clear potentiation of this wave in the last block of stimuli, whereas in spontaneously improving patients the N20 amplitude remained stable. Presynaptic HFOs were smaller in worsening patients and larger in improving ones, but they did not undergo habituation in patients as well as in healthy subjects. Potentiation of the N20 response in spontaneously worsening migraineurs confirms that the reduction of the thalamocortical drive plays a major role in migraine pathogenesis. Moreover, the stable pattern we observed in spontaneously improving patients suggests that compensatory mechanisms can also play an important role. The normal response to repeated stimuli of HFOs in migraineurs might indicate that, although its initial amount depends on clinical conditions, high-frequency thalamocortical drive remains stable during the stimulation and probably reflects the activity of a buffer mechanism.

Anxiety type modulates immediate versus delayed engagement of attention‐related brain regions

Background Habituation of the fear response, critical for the treatment of anxiety, is inconsistently observed during exposure to threatening stimuli. One potential explanation for this inconsistency is differential attentional engagement with negatively valenced stimuli as a function of anxiety type. Methods The present study tested this hypothesis by examining patterns of neural habituation associated with anxious arousal, characterized by panic symptoms and immediate engagement with negatively valenced stimuli, versus anxious apprehension, characterized by engagement in worry to distract from negatively valenced stimuli. Results As predicted, the two anxiety types evidenced distinct patterns of attentional engagement. Anxious arousal was associated with immediate activation in attention-related brain regions that habituated over time, whereas anxious apprehension was associated with delayed activation in attention-related brain regions that occurred only after habituation in a worry-related brain region. Conclusions Results further elucidate mechanisms involved in attention to negatively valenced stimuli and indicate that anxiety is a heterogeneous construct with regard to attention to such stimuli.

Habituation of Sexual Responses in Men and Women: A Test of the Preparation Hypothesis of Women's Genital Responses

Laboratory studies have revealed two well-replicated sex differences in sexual arousal patterns: category specificity and sexual concordance. Men's genital responses are dependent on specific sexual cues and are concordant with subjective reports of arousal. Women's genital responses are much less dependent on specific sexual cues and are much less concordant with their subjective reports. The preparation hypothesis provides a functional explanation for these sex differences and posits that women's genital responses are not tied to sexual preferences but rather occur automatically in the presence of any sexual cue to protect the genital tissues from injuries incurred through sexual activity. This hypothesis leads to the expectation that women's genital responses may not habituate as quickly or as completely as men's. To determine whether there is a sex difference in the habituation of genital responses and to further test the preparation hypothesis of women's genital responses. Twenty men and 20 women had their genital responses measured while they were exposed to nine consecutive presentations of the same erotic film clip (habituation), followed by two presentations of different erotic film clips (novelty), and followed by two presentations of the original erotic film clip (dishabituation). Genital responses were measured continuously using penile strain gauges (assessing penile circumference) and vaginal probes (assessing vaginal pulse amplitude). Participants reported subjective sexual arousal, perceived genital arousal, and attention after each film clip presentation. Men and women displayed very similar patterns of genital responses, consistent with habituation and novelty effects. Effects of habituation and novelty were eliminated once subjective reports of attention were covaried. Contrary to the prediction from the preparation hypothesis of women's genital responses, men's and women's responses showed similar patterns of habituation upon repeated exposure. Future research should attempt to maintain participants' attention in order to further test the preparation hypothesis.