Habituation of P3a and P3b brain potentials in men engaged in extreme sports

Effects of sensation seeking on habituation to novelty: An EEG study

Sensation seeking is characterized by a strong need for novelty and has been associated with various risk-taking behaviors. Using the extreme between-group design, the current study investigated the electrophysiological mechanisms underlying habituation to novelty processing in sensation seeking. Twenty high sensation seekers (HSS) and 20 low sensation seekers (LSS) performed an auditory oddball task while their EEG was recorded. The results revealed that both the novelty P3 and midfrontal theta power decreased from the first to the second half for LSS but not for HSS. Additionally, this reduced vigilance was predicted by the experience-seeking subcomponent of sensation seeking. Together, our findings are supportive of an abnormal habituation to novel events in the sensation-seeking trait.

Long-Term Effects of Sports Concussions: Bridging the Neurocognitive Repercussions of the Injury with the Newest Neuroimaging Data

Little is known of the long-term effects of sports-related concussion. Within the scientific literature, conclusions vary substantially where some work suggests there are no long-term consequences at all and other studies show rampant neurodegeneration thought to be caused by sometimes even a single concussive blow to the head. There is growing evidence that supports multiple long-term outcomes, showing both subclinical and clinically relevant changes in the brains of athletes, young and old alike. This article reviews the pathohistology of cerebral concussions and examines the extant literature with a focus on electrophysiological and neuroimaging findings. Neurobehavioral and neurocognitive changes are also reviewed, particularly as they are related to chronic traumatic encephalopathy. Lacunae within the literature are explored, and future research directions are proposed.

A comparison of genetic variants between proficient low- and high-risk sport participants

Athletes participating in high-risk sports consistently report higher scores on sensation-seeking measures than do low-risk athletes or non-athletic controls. To determine whether genetic variants commonly associated with sensation seeking were over-represented in such athletes, proficient practitioners of high-risk (n = 141) and low-risk sports (n = 132) were compared for scores on sensation seeking and then genotyped at 33 polymorphic loci in 14 candidate genes. As expected, athletes participating in high-risk sports score higher on sensation seeking than did low-risk sport athletes (P < .01). Genotypes were associated with high-risk sport participation for two genes (stathmin, (P = .004) and brain-derived neurotrophic factor (P = .03)) as well as when demographically matched subsets of the sport cohorts were compared (P < .05); however, in all cases, associations did not survive correction for multiple testing.

Sexual desire, not hypersexuality, is related to neurophysiological responses elicited by sexual images

BACKGROUND

Modulation of sexual desires is, in some cases, necessary to avoid inappropriate or illegal sexual behavior (downregulation of sexual desire) or to engage with a romantic partner (upregulation of sexual desire). Some have suggested that those who have difficulty downregulating their sexual desires be diagnosed as having a sexual 'addiction'. This diagnosis is thought to be associated with sexual urges that feel out of control, high-frequency sexual behavior, consequences due to those behaviors, and poor ability to reduce those behaviors. However, such symptoms also may be better understood as a non-pathological variation of high sexual desire. Hypersexuals are thought to be relatively sexual reward sensitized, but also to have high exposure to visual sexual stimuli. Thus, the direction of neural responsivity to sexual stimuli expected was unclear. If these individuals exhibit habituation, their P300 amplitude to sexual stimuli should be diminished; if they merely have high sexual desire, their P300 amplitude to sexual stimuli should be increased. Neural responsivity to sexual stimuli in a sample of hypersexuals could differentiate these two competing explanations of symptoms.

METHODS

Fifty-two (13 female) individuals who self-identified as having problems regulating their viewing of visual sexual stimuli viewed emotional (pleasant sexual, pleasant-non-sexual, neutral, and unpleasant) photographs while electroencephalography was collected.

RESULTS

Larger P300 amplitude differences to pleasant sexual stimuli, relative to neutral stimuli, was negatively related to measures of sexual desire, but not related to measures of hypersexuality.

CONCLUSION

Implications for understanding hypersexuality as high desire, rather than disordered, are discussed.

Psychometric Properties of the Romanian Version of the Zuckerman-Kuhlman Personality Questionnaire

This research investigated the psychometric properties and the convergent and divergent validity of the Romanian version of the Zuckerman-Kuhlman Personality Questionnaire (ZKPQ) at the factor-level. The ZKPQ assesses the five basic factors of Zuckerman’s alternative five-factor model (AFFM). Study 1 (n = 449) assessed the psychometric properties of the Romanian version of the ZKPQ and verified its factorial structure. The factors reliability ranged from .69 to .88, and gender differences were similar to those found in the Spanish, French, and Chinese samples. Exploratory factor analysis supported the replicability of the original five-factor structure, and correlations between the scales showed that the five basic factors of the AFFM are relatively independent. Study 2 (n = 238) verified the convergent and divergent validity of the Romanian version of the ZKPQ, by testing its links with DECAS, a personality inventory based on the five-factor model, developed and well-validated on the Romanian population. The results showed good convergent and divergent validity, with all identified correlations supporting the correspondence between the two personality models. Overall, the present findings showed that the Romanian version of the ZKPQ is a valid tool for assessing personality traits according to the AFFM.

Association between locomotor response to novelty and light reinforcement: sensory reinforcement as a rodent model of sensation seeking

BACKGROUND

The human personality trait of sensation seeking (SS) indicates an attraction to novel sensations and experiences, and is associated with greater likelihood of drug abuse. In rodents, locomotor activity in a novel environment (Loco) has been found to predict drug self-administration (SA), and has been hypothesized to be a translational model of human SS. Previously, we reported (Gancarz et al., 2011) that high responder (HR) animals responded more than low responder (LR) animals to produce a response contingent light onset. The primary goal of this paper was a detailed analysis of the association between Loco and light contingent responding in a large sample of rats (n = 93).

METHODS

Male rats were pre-exposed to dark operant test chambers for ten 30 min sessions and baseline levels of responding (snout poking) were determined. The pre-exposure phase was followed by 6 sessions during which active responding produced a visual sensory reinforcer (VSR; 5 s light onset) according to a variable interval 1 min schedule of reinforcement. After completion of the VSR phase, Loco was tested.

RESULTS

The activating effects (total responding) of light were associated with Loco, but the response guiding effects (proportion of active responding) of the light were not. In addition, HR rats habituated more slowly in both the VSR and Loco tests than LR rats.

CONCLUSIONS

These data indicate that VSR measures aspects of the rodent’s response to novel sensations and experiences that are not detected by Loco. These data provide some evidence for the use of light reinforcement as an animal model of SS.

Brain responses to repeated visual experience among low and high sensation seekers: role of boredom susceptibility

To better understand individual differences in sensation seeking and its components, including boredom susceptibility and experience seeking, we examined brain responses of high and low sensation seekers during repeated visual experience. Individuals scoring in the top and bottom quartiles from a college-aged population on the Brief Sensation-Seeking Scale (BSSS) participated in an event-related potentials (ERPs) experiment. Line drawings of common objects were randomly intermixed and presented 1-3 times. Sixty-four channel ERP responses were recorded while participants classified items as "man-made" or "not man-made" in a repetition priming task. The two groups showed different ERP responses at frontal electrode sites after seeing a visual stimulus for 400-800 ms. The frontal late positive components (LPC) showed different habituation of ERP responses to new and studied repeated objects between high and low sensation seekers. Source localization analysis (LORETA) indicated that during visual stimulus adaptation the ventral pre-frontal cortex showed lack of frontal involvement among high sensation seekers. Furthermore, frontal LPC latencies during repeated visual exposure correlated with boredom susceptibility and experience seeking subscales. The distinct profiles of brain responses to repeated visual experience in high and low sensation seekers provide evidence that individual differences in neural adaptation can be linked to personality dimensions.