“Queasy does it”: False alcohol beliefs and memories may lead to diminished alcohol preferences

Studies have shown that false memories can be implanted via innocuous suggestions, and that these memories can play a role in shaping people's subsequent attitudes and preferences. The current study explored whether participants (N = 147) who received a false suggestion that they had become ill drinking a particular type of alcohol would increase their confidence that the event had occurred, and whether their new-found belief would subsequently affect their alcohol preferences. Results indicated that participants who received a suggestion that they had gotten sick drinking rum or vodka before the age of 16 reported increased confidence that the suggested experience had occurred. Moreover, participants who received a false alcohol suggestion also showed a strong trend to report diminished preference for the specified type of alcohol after the false suggestion. Implantation of a false memory related to one's past drinking experiences may influence current drink preferences and could be an important avenue for further exploration in the development of alcohol interventions.     

Neurophysiological marker of inhibition distinguishes language groups on a non-linguistic executive function test

Successful interaction with the environment depends on flexible behaviors which require shifting attention, inhibiting primed responses, ignoring distracting information, and withholding motor responses. These abilities, termed executive function (EF), are believed to be mediated by inhibitory processes in the frontal lobes. Superior performance on EF tests (i.e., faster reaction times (RT), and fewer errors) has been shown in bilinguals compared to monolingual speakers. However, findings are inconsistent, and no study has directly linked this bilingual advantage to frontal lobe inhibitory processes. To clarify this uncertainty, we concomitantly tested neural inhibitory processes and behavioral responses on an EF test in bilinguals and monolinguals. Specifically, we compared English monolinguals (N = 15) to Spanish/English bilinguals (N = 13) on event-related brain potentials (ERP) during a non-linguistic, auditory Go/NoGo task, a task linked to non-motor, cognitive inhibition in monolinguals. Participants responded with a button press on trials in which target tone-pairs (Go trials) were presented and withheld their responses on non-target trials (NoGo trials). Results revealed significantly greater inhibition (i.e., greater mean N2 amplitude) in bilinguals compared to monolinguals during NoGo trials even though both groups performed the task equally well (i.e., withheld a motor response). On Go trials where participants pressed a response button, neither ERPs nor RT distinguished the groups. Additionally, scores on a second language proficiency test (i.e., English in our bilingual group) were positively correlated with N2 amplitude. These findings are the first to directly link this bilingual advantage to a neural correlate of inhibition and to reveal that inhibition in bilinguals is moderated by second language proficiency. Results are discussed in the context of plasticity, and we propose that evaluating bilinguals at varying levels of second-language proficiency may serve as a model of human neuroplasticity.     

Neuromagnetic correlates of intra- and extra-dimensional set-shifting

Set-shifting is essential to cognitive flexibility and relies on frontal lobe function. Previous studies have mostly focused on feedback processes following shifting rather than set-shifting itself. We designed an MEG paradigm without feedback to directly investigate the neural correlates of set-shifting. Adults (n = 16) matched one of two coloured images with a third stimulus, the target, by either the colour or shape dimension of the target. Half of the shift trials involved colour-to-colour or shape-to-shape (intra-dimensional: ID) shifting and the other half involved colour-to-shape or shape-to-colour (extra-dimensional: ED) shifting. MEG was continuously recorded on a 151 channel CTF system. We used beamforming to analyze responses to the first (shift) and the third (repeat) trials in each set. These trials were contrasted separately for ID and ED sets. Shift versus repeat trials showed larger MEG activations for intra-dimensional shifting in the right inferior frontal gyrus (BA 47), left medial frontal gyrus (BA 10) and right superior frontal gyrus (BA 9) as early as 100 ms, and in left middle frontal gyrus (BA 11) between 250–500 ms. Activations related to extra-dimensional shifting were detected in left inferior frontal gyrus (BA 44), left middle frontal gyrus (BA 11), and right middle frontal gyrus (BA 46) between 100 ms and 350 ms, followed by superior frontal gyrus (BA 8/BA 10) between 250–500 ms. Intra-dimensional and extra-dimensional shifting also activated bilateral and right parietal areas, respectively. This study establishes the location and timing of frontal and parietal activations during an intra-dimensional versus extra-dimensional shifting task.     

Effects of an acute bout of localized resistance exercise on cognitive performance in middle-aged adults: A randomized controlled trial study

ObjectivesTo examine the effect of an acute bout of resistance exercise on cognitive performance in healthy middle-aged adults.DesignA randomized controlled trial design.MethodsForty-one adults (M_age = 49.10 years, SD = 8.73) were randomly assigned to either resistance exercise or a control condition. The resistance exercise condition consisted of 2 sets of 10 repetitions for 6 exercises, and the control condition involved reading about resistance exercise for a time period approximating the duration of the exercise condition. The Stroop Test and the Trail Making Test (TMT) were completed at baseline and immediately following performance of the treatment.ResultsResults indicated that resistance exercise significantly benefits speed of processing (Stroop Word and Stroop Color), and that there is a trend towards resistance exercise benefiting performance on an executive function task (Stroop Color–Word) that requires shifting of the habitual response. However, the results for the TMT were not significant which demonstrates that acute resistance exercise has a limited effect on inhibition.ConclusionThe present findings extend the literature by indicating that an acute bout of resistance exercise has a positive impact on automatic cognitive processes and on particular types of executive function in middle-aged adults.     

Acute effects of alcohol on memory: Impact of emotional context and serial position

Although the amnestic effects of alcohol in humans are well known, its effects on emotional memory are unclear. In this study, using a randomized double-blind placebo-controlled design, we examine narrative emotional episodic memory in healthy human female volunteers (n = 32) who received either a single dose of alcohol (0.6 g/kg), or a placebo and then viewed neutral story elements presented in either a neutral or emotional context. Memory was tested for gist and detail of the neutral elements 3 days later in a surprise recognition test. Since alcohol modulates GABAergic neurotransmission and may exert its effects on emotion through the limbic system, we predicted that acute alcohol treatment would reduce the expected emotional memory-advantage for gist, leaving detail memory relatively unaffected. Furthermore, given previous findings showing that ‘primacy’ memory is enhanced by physiological arousal, we predicted that reduced arousal produced by alcohol would have the opposite effect and impair primacy memory relative to the middle or ‘recency’ sections of the narrative. Emotional arousal was expected to oppose this effect, so impaired primacy memory following alcohol was only expected in the neutral version of the narrative. Although there was a main effect of story phase (though not of story version), contrary to expectations, alcohol impaired primacy memory for emotionally encoded neutral material. The results suggest that under certain circumstances emotional context or physiological arousal make memories labile and susceptible to disruption through pharmacological manipulation during encoding.     

Sense of body ownership in patients affected by functional motor symptoms (conversion disorder)

Background and aimPatients with functional neurological symptoms are commonly seen in neurological practice. Nevertheless their aetiopathology remains unclear. We have recently shown that patients affected by functional motor symptoms (FMS) present lower interoceptive awareness and higher alexithymia levels than healthy controls. Nevertheless sense of body ownership has never been studied in FMS patients.The aim of the present study was to systematically investigate the sense of body ownership, with the rubber hand illusion (RHI) paradigm, in patients with FMS and healthy controls.Materials and methodsWe included in the study 16 patients with FMS and 18 healthy controls (HC). Patients and HC were asked to complete the Toronto Alexithymia Scale (TAS-20) and the self-consciousness scale (self-objectification questionnaire). All participants underwent the RHI paradigm: illusionary experience was measured by self-report and by proprioceptive alteration.ResultsA Mann–Whitney U test performed revealed that FMS (median = 2.11) participants embodied the rubber hand to the same extent than HC participants (median = 2.0, Z = −0.86, p > 0.05, r = −0.15). The same test revealed no significant difference in the Proprioceptive Drift experience between FMS (median = 0.0) and HC participants (median = −0.5, Z = −0.96, p > 0.05, r = −0.16).ConclusionsOur study revealed that sense of body ownership is not impaired in patients affected by FMS. This, together with the results from our previous experiment (studying the interoceptive awareness), supports the hypothesis that interoceptive awareness and sense of body ownership may be dissociated in patients with FMS.     

Effects of distraction and experience on situation awareness and simulated driving

This study examined the impact of cell phone conversation on situation awareness and performance of novice and experienced drivers. Driving performance and situation awareness among novice drivers ages 14–16 (n = 25) and experienced drivers ages 21–52 (n = 26) were assessed using a driving simulator. Performance was measured by the number of driving infractions committed: speeding, collisions, pedestrians struck, stop signs missed, and centerline and road edge crossings. Situation awareness was assessed through a query method and through participants’ performance on a direction-following task. Cognitive distractions were induced through simulated hands-free cell phone conversations. The results indicated that novice drivers committed more driving infractions and were less situationally aware than their experienced counterparts. However, the two groups suffered similar decrements in performance during the cell phone condition. This study provides evidence of the detrimental effects of cell phone use for both novice and experienced drivers. These findings have implications for supporting driving legislation that limits the use of cell phones (including hands-free) in motor vehicles, regardless of the driver’s experience level.     

Are errors detected before they occur? Early error sensations revealed by metacognitive judgments on the timing of error awareness

Errors in choice tasks are not only detected fast and reliably, participants often report that they knew that an error occurred already before a response was produced. These early error sensations stand in contrast with evidence suggesting that the earliest neural correlates of error awareness emerge around 300 ms after erroneous responses. The present study aimed to investigate whether anecdotal evidence for early error sensations can be corroborated in a controlled study in which participants provide metacognitive judgments on the subjective timing of error awareness. In Experiment 1, participants had to report whether they became aware of their errors before or after the response. In Experiment 2, we measured confidence in these metacognitive judgments. Our data show that participants report early error sensations with high confidence in the majority of error trials across paradigms and experiments. These results provide first evidence for early error sensations, informing theories of error awareness.     

Testing the involvement of the prefrontal cortex in lucid dreaming: A tDCS study

Recent studies suggest that lucid dreaming (awareness of dreaming while dreaming) might be associated with increased brain activity over frontal regions during rapid eye movement (REM) sleep. By applying transcranial direct current stimulation (tDCS), we aimed to manipulate the activation of the dorsolateral prefrontal cortex (DLPFC) during REM sleep to increase dream lucidity. Nineteen participants spent three consecutive nights in a sleep laboratory. On the second and third nights they randomly received either 1 mA tDCS for 10 min or sham stimulation during each REM period starting with the second one. According to the participants’ self-ratings, tDCS over the DLPFC during REM sleep increased lucidity in dreams. The effects, however, were not strong and found only in frequent lucid dreamers. While this indicates some preliminary support for the involvement of the DLPFC in lucid dreaming, further research, controlling for indirect effects of stimulation and including other brain regions, is needed.     

Alterations in stride-to-stride variability during walking in individuals with chronic ankle instability

The aim of this study was to evaluate stride-to-stride variability of the lower extremity during walking in individuals with and without chronic ankle instability (CAI) using a nonlinear analysis. Twenty-five participants with self-reported CAI and 27 healthy control participants volunteered for this study. Participants walked on a motor-driven treadmill for 3 min at their selected speed. Lower extremity kinematics in the sagittal and frontal planes were recorded using a passive retroreflective marker motion capture system. The temporal structure of walking variability was analyzed with sample entropy (SampEn). The CAI group produced lower SampEn values in frontal-plane ankle kinematics compared to the control group (P = .04). No significant group differences were observed for SampEn values of other kinematics (P > .05). Participants with CAI demonstrated less stride-to-stride variability of the frontal plane ankle kinematics compared to healthy controls. Decreased variability of walking patterns demonstrated by participants with CAI indicates that the presence of CAI may be associated with a less adaptable sensorimotor system to environmental changes. The altered sensorimotor function associated with CAI may be targets for clinical interventions, and it is critical to explore how interventions protocols affect sensorimotor system function.     

Impaired retention is responsible for temporal order memory deficits in mild cognitive impairment

Temporal order memory, or remembering the order of events, is critical for everyday functioning and is difficult for patients with mild cognitive impairment (MCI). It is currently unclear whether these patients have difficulty acquiring and/or retaining such information and whether deficits in these patients are in excess of “normal” age-related declines. Therefore, the current study examined age and disease-related changes in temporal order memory as well as whether memory load played a role in such changes. Young controls (n = 25), older controls (n = 34), and MCI patients (n = 32) completed an experimental task that required the reconstruction of sequences that were 3, 4, or 5 items in length both immediately after presentation (i.e., immediate recall) and again after a 10-min delay (i.e., delayed recall). During the immediate recall phase, there was an effect of age largely due to reduced performance at the two longest span lengths. Older controls and MCI patients only differed during the five span (controls > MCI). During the delayed recall, however, there were significant effects of both age and MCI regardless of span length. In MCI patients, immediate recall was significantly correlated with measures of executive functioning, whereas delayed recall performance was only related to other memory tests. These findings suggest that MCI patients experience initial temporal order memory deficits at the point when information begins to exceed working memory capacity and become dependent on medial temporal lobe functioning. Longer-term deficits are due to an inability to retain information, consistent with the characteristic medial temporal lobe dysfunction in MCI.     

Acceptance and Commitment Therapy for Problematic Internet Pornography Use: A Randomized Trial

Problematic Internet pornography use is the inability to control the use of pornography, the experience of negative cognitions or emotions regarding pornography use, and the resulting negative effects on quality of life or general functioning. This study compared a 12-session individual protocol of acceptance and commitment therapy (ACT) for problematic Internet pornography use to a waitlist control condition with 28 adult males, all but 1 of whom were members of the Church of Jesus Christ of Latter-day Saints. Measures of self-reported pornography viewing, standardized measures of compulsive sexual behavior and related cognitions, and quality of life occurred at pretreatment, posttreatment, and 3-month follow-up. Results demonstrate significant between-condition reductions in pornography viewing compared to the waitlist condition (93% reduction ACT vs. 21% waitlist). When combining all participants (N = 26), a 92% reduction was seen at posttreatment and an 86% reduction at 3-month follow-up. Complete cessation was seen in 54% of participants at posttreatment and at least a 70% reduction was seen in 93% of participants. At the 3-month follow-up assessment, 35% of participants showed complete cessation, with 74% of participants showing at least 70% reduction in viewing. Treatment suggestions and future directions are discussed.     

Functioning of peripheral Ia pathways in leg muscles of newly walking toddlers

Monosynaptic and polysynaptic spinal level reflexes in the leg muscles of infants show significant dispersion across muscles, high variability, and no change in response patterns over the first 10 months. Here we tested the hypothesized relation between early walking experience and the tuning of these responses in three primary gait muscles of participants in four subgroups: cruisers (n = 7) and toddlers with one (n = 5), two (n = 5), or three (n = 5) months of walking experience. Reflex responses in multiple Ia pathways – tendon reflex (T-reflex), vibration-induced inhibition of the T-reflex (VIM-T-reflex), and tonic vibration-induced reflex (VIR), were elicited by mechanical stimuli applied to the distal tendons of the quadriceps, gastrocnemius-soleus, and tibialis anterior of both legs. Walking skill was assessed via a GAITRite mat. Generally, walking experience seemed to be related to slowly emerging improvements and, depending on muscle tested and pathway, progress was quite varied. Amplitude and latency of reflex responses were more clearly impacted by age or leg length while the ratio or distribution pattern of reflex response among antagonist pairs of muscles was impacted by walking experience and skill. As walking experience increased, the ratio of reflex responses tended to increase for the stimulated and decrease for the antagonist reflex loops with distribution of the pattern shifting gradually toward a single type of reflex response in all tested muscles. The very slow tuning of these reflexes may underlie the many missteps and falls reported to occur during early walking and suggest that subsequent studies should continue to follow the developmental trajectory through the first year of walking experience.     

Improving general intelligence with a nutrient-based pharmacological intervention

Cognitive enhancing substances such as amphetamine and modafinil have become popular in recent years to improve acute cognitive performance particularly in environments in which enhanced cognition or intelligence is required. Nutraceutical nootropics, which are natural substances that have the ability to bring about acute or chronic changes in cognition have also been gaining popularity in a range of settings and applications including the workplace, driving and in the amelioration of age related cognitive decline. Huperzine A, Vinpocetine, Acetyl-l-carnitine, Rhodiola Rosea and Alpha-lipoic Acid are popular nutritional supplements that have shown promising benefits in improving a range of biological (e.g., blood flow, anti-inflammatory, anti-oxidant, and direct neurotransmitter effects) and cognitive processes from in vitro, animal and human clinical research. We report here the first human randomized clinical trial for cognition in which we administer a combination of Huperzine A, Vinpocetine, Acetyl-l-carnitine, R. Rosea and Alpha-lipoic acid (called Ceretrophin) vs placebo. Sixty participants (40 females and 20 males, with a mean age of 45.4 years, SD = 12.6) completed either the odd or even items from the Raven Advanced Progressive Matrices (APM) at baseline and the opposite odd or even items at week 4 after consuming either the combination nootropic or placebo. A significant study visit (time) × treatment condition interaction was found: F (1, 57) = 7.279, p = 0.009, partial η² = .113, with paired samples t-tests revealing a significant improvement in mean APM score from baseline to retest (week 4) (t(34) = ? 4.045, p < .001) for the Ceretrophin? group. Improvements in APM scores could be attributed to the active intervention over the placebo, indicating that the treatment improved general intelligence. Implications for improving our understanding of the biological basis of intelligence and pharmacologically improving human cognition are discussed.     

Distinguishing intentions from desires: Contributions of the frontal and parietal lobes

The ability to represent desires and intentions as two distinct mental states was investigated in patients with parietal (N = 8) and frontal (N = 6) lesions and in age-matched controls (N = 7). A task was used where the satisfaction of the desire and the fulfilment of the intention did not co-vary and were manipulated in a 2 × 2 set. In two experiments we show that lesions to the frontal lobe may impair the ability to deal with desires when their outcome is not congruent with that of the intention, and that parietal damage – especially if it encompasses the left temporo-parietal junction – may cause severe difficulties in the processing of both desires and intentions. The implications of the results for the neuropsychological and the developmental literature are discussed.     

The influence of age,anxiety and concern about falling on postural sway when standing at an elevated level

Psychological processes may influence balance and contribute to the risk of falls in older people. While a self-reported fear of falling is associated with increased postural sway, inducing fear using an elevated platform can lead to reduced sway, suggesting different underlying mechanisms whereby fear may influence balance control. This study examined changes in postural sway, muscle activity and physiological measures of arousal while standing on a 65 cm elevated platform, compared to floor level, in young and older adults. The older adults were classified as fall concerned or not fall concerned based on the Falls Efficacy Scale-International and anxious or not anxious based on the Goldberg Anxiety Scale. Fall concern did not affect the physiological and sway response to the elevated platform. In response to the postural threat, the anxious participants increased their sway frequency (p = 0.001) but did not reduce sway range (p = 0.674). Conversely, non-anxious participants showed an adaptive tightening of balance control, effectively reducing sway range in the elevated condition (p < 0.001). Generalised anxiety in older adults appears to differentially affect postural control strategies under threatening conditions.     

Self-unawareness of levodopa induced dyskinesias in patients with Parkinson’s disease

The study analyzes the presence of dyskinesias-reduced-self-awareness in forty-eight patients suffering from Parkinson’s disease (PD). As the association with executive dysfunction is a matter of debate and we hypothesize it plays an important role in dyskinesias self-unawareness, we analyzed the role of dopaminergic treatment on the medial-prefrontal-ventral-striatal circuitry using a neurocognitive approach. Special attention was given to metacognitive abilities related to action-monitoring that represent a novel explanation of the phenomenon.PD patients were assessed using different rating scales that we devised to measure movement awareness disorders. In order to ascertain whether each variable measured at a cognitive-clinical level contributes to predicting the scores of the movement-disorder-awareness-scales, we conducted multiple logistic regression models using the latter as binary dependent variables. We used the Wisconsin Card Sorting Test-metacognitive-version to assess the executive functions of the prefrontal-ventral-striatal circuitry.Data showed that a reduction of self-awareness using the Dyskinesia rating scale was associated with global monitoring (p = .04), monitoring resolution (p = .04) and control sensitivity (p = .04). Patients failed to perceive their performance, distinguish between correct and incorrect sorts, be confident in their choice and consequently decide to gamble during the task.We did not find any association with executive functions using the hypo-bradykinesia rating scale.Our findings indicate that when the comparator mechanism for monitoring attentive performance is compromised at a prefrontal striatal level, patients lose the ability to recognize their motor disturbances that do not achieve conscious awareness.     

The role of executive function,personality and attitudes to risks in explaining self-reported driving behaviour in adolescent and adult male drivers

Young drivers show high levels of risky driving and are over-represented in motor vehicle crash statistics world-wide. As well as personality and attitudinal factors, high rates of risk taking during adolescence may be due to poorly developed executive functions, a result of the slow maturation of the pre-frontal cortex of the brain. This study was undertaken to investigate the roles of executive function, personality, attitudes to risk in relation to self-reported driving behaviour. Adolescent (n = 46, age 16–18 years) and adult (n = 32, 25 years and over) male drivers completed a battery of neuropsychological tests to assess general cognitive ability and executive function, and questionnaires to assess driving history, personality, attitudes to physical and psychological risk as well as questionnaires of self-reported driving behaviour (Driver risk taking and Driver Attitude Questionnaire, DAQ). The adolescent drivers showed poorer executive function, higher levels of impulsivity and risk-taking, lower levels of agreeableness and conscientiousness compared to adult drivers. Regression analyses revealed that attitudes to risk, agreeableness and working memory made unique significant contributions in explaining self-reported driving behaviour. Interestingly though, better working memory was associated with higher levels of self-reported risky driving and more accepting attitudes to risky driving. Together the findings suggest that some aspects of executive function, personality, and attitudes to risk may help to explain self-reported driving behaviour. Whether these findings are relevant to female drivers and apply to on-road driving behaviour should be the focus of future studies.     

The relationship between mental toughness and affect intensity

Mentally tough athletes are conceptualized as being able to function effectively in stressful situations and recent research has found small to moderate correlations between mental toughness and coping. Despite this no research has thus far examined the possibility that mentally tough athletes experience less intense emotions. This paper tested the relationship between mental toughness and affect intensity to determine whether mentally tough athletes generally experienced more or less intense emotions. A sample of 112 sport performers (55 men and 57 women) aged between 18 and 51 years (M = 29.3, s = 10.3) acted as participants, and ranged from recreational to national level in a variety of sports. Mental toughness and affect intensity were found to be unrelated. This is an important finding because it suggests participants with high or low levels of mental toughness do not characteristically experience more or less intense emotions. Thus there is no evidence to suggest the ability of mentally tough athletes to remain relatively unaffected by pressure or adversity is due to lower levels of affect intensity. More research is required to understand how mentally tough athletes (in comparison to less tough athletes) maintain control and high levels of performance in stressful circumstances.     

An fMRI study of the social competition in healthy subjects

Social interaction requires the ability to infer another person’s mental state (Theory of Mind, ToM) and also executive functions. This fMRI study aimed to identify the cerebral correlates activated by ToM during a specific social interaction, the human–human competition. In this framework, we tested a conflict resolution task (Stroop) adapted to a virtual situation of competition. The participants were instructed to play in order to win either against a human-like competitor (human–human competition) or against a non-human competitor (human–machine competition). Only the human–human competition requires ToM as this type of competition is performed under social interaction. We identified first the classical network of executive regions activated by Stroop. Secondly, we identified the social (human–human) competition regions, represented by the bilateral superior and inferior frontal gyri, the anterior cingulate, the insula, the superior and anterior temporal, the hippocampus, the fusiform gyrus, the cuneus and the precuneus. Finally, we identified the executive regions that were modulated by the human–human competition, i.e., the executive control regions additionally activated when mentalizing in the context of social competition. They constituted a network predominant to the right and composed of the superior and middle frontal, anterior cingulate, insula and fusiform gyrus. We suggest that our experimental paradigm may be useful in exploration of the cerebral correlates of social adjustments in several situations such as psychiatric disorders presenting executive and social dysfunctions.