Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 28
Filter
1.
Behav Res Ther ; 162: 104267, 2023 03.
Article in English | MEDLINE | ID: mdl-36780810

ABSTRACT

Child labourers are more likely to have experienced physical victimisation, which may increase risk for anxiety/depression, by shaping threat biases in information-processing. To target threat biases and vulnerability for anxiety/depression, we evaluated whether Cognitive Bias Modification (CBM) training could be feasibly and acceptably delivered to rescued youth labourers. Seventy-six physically abused rescued labourers aged 14-17 (40 from Nepal, 36 from India) in out-of-home care institutions received either multi-session computerised CBM or control training. Training targeted attention away from threat to positive cues and the endorsement of benign over threat interpretations. Feasibility and acceptability data were gathered along with pre and post intervention measures of attention and interpretation bias and emotional and behavioural symptoms. In terms of feasibility, uptake (proportion of those who completed the pre-intervention assessment from those who consented) and retention (proportion of those who completed the post-intervention assessment from those who completed the pre-intervention assessment) were above 75% in both countries. Average acceptability ratings were mostly 'moderate' on most indices for both countries, and none of the participants reported experiencing serious adverse events or reactions in response to or during the trial. Secondarily, CBM participants showed increased attention to positive and decreased attention to threatening stimuli, as well as increased endorsement of benign interpretation and decreased endorsement in negative interpretations of ambiguous social situations. Symptom changes were less clear. Delivering CBM to former child labourers in out-of-home care institutions has interventive potential. ClinicalTrials.gov Identifier: NCT03625206, Date of registration: August 10, 2018.


Subject(s)
Cognitive Behavioral Therapy , Physical Abuse , Adolescent , Humans , Child , Cognitive Training , Feasibility Studies , Bias
2.
Pers Individ Dif ; 204: 112060, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36588787

ABSTRACT

Dark Triad traits (psychopathy, narcissism) are associated with nonadherence to COVID-19 prevention measures such as social distancing and wearing face masks, although the psychological mechanisms underpinning this relationship remain unclear. In contrast, high threat-sensitivity may motivate compliance, and maybe seen in relation to vulnerable dark traits (secondary psychopathy, vulnerable narcissism and borderline personality disorder). The relationship between vulnerable dark traits and COVID-19 prevention behaviour has not been examined. During April 2021, participants (n = 263) completed an online psychometric study assessing engagement with COVID-19 prevention behaviour, traditional DT traits (primary psychopathy; grandiose narcissism) and vulnerable DT traits. Potential indirect effects were fear of COVID-19, perceived coronavirus severity, belief in COVID-19 conspiracy theories and altruism. Model of path analysis identified predictors of engagement in disease prevention behaviour. Primary psychopathy, grandiose narcissism, secondary psychopathy and BPD were associated with less COVID-19 prevention behaviour, with an indirect effect of reduced coronavirus severity. Grandiose narcissism and BPD were also motivated by COVID-19 conspiracy theories, and increased prevention behaviour when fear of COVID-19 was higher. No direct or indirect effects were observed for vulnerable narcissism. The current study is the first to elucidate psychological mechanisms linking vulnerable dark traits with COVID-19 prevention behaviour.

3.
J Community Appl Soc Psychol ; 32(3): 521-535, 2022.
Article in English | MEDLINE | ID: mdl-34230792

ABSTRACT

Communities are vital sources of support during crisis, providing collective contexts for shared identity and solidarity that predict supportive, prosocial responses. The COVID-19 pandemic has presented a global health crisis capable of exerting a heavy toll on the mental health of community members while inducing unwelcome levels of social disconnection. Simultaneously, lockdown restrictions have forced vulnerable community members to depend upon the support of fellow residents. Fortunately, voluntary helping can be beneficial to the well-being of the helper as well as the recipient, offering beneficial collective solutions. Using insights from social identity approaches to volunteering and disaster responses, this study explored whether the opportunity to engage in helping fellow community members may be both unifying and beneficial for those engaging in coordinated community helping. Survey data collected in the UK during June 2020 showed that coordinated community helping predicted the psychological bonding of community members by building a sense of community identification and unity during the pandemic, which predicted increased well-being and reduced depression and anxiety. Implications for the promotion and support of voluntary helping initiatives in the context of longer-term responses to the COVID-19 pandemic are provided. Please refer to the Supplementary Material section to find this article's Community and Social Impact Statement.

4.
Psychiatry Res Neuroimaging ; 314: 111323, 2021 08 30.
Article in English | MEDLINE | ID: mdl-34198012

ABSTRACT

Aberrations in stress-linked hypothalamic-pituitary-adrenal axis function have been independently associated with schizophrenia, antisocial behaviour and childhood maltreatment. In this study, we examined pituitary volume (PV) in relation to childhood maltreatment (physical abuse, sexual abuse, neglect) in men (i) with schizophrenia and a history of serious violence (n = 13), (ii) with schizophrenia but without a history of serious violence (n = 15), (iii) with antisocial personality disorder (ASPD) and a history of serious violence (n = 13), and (iv) healthy participants without a history of violence (n = 15). All participants underwent whole-brain magnetic resonance imaging. Experiences of childhood maltreatment were rated based on interviews (for all), and case history and clinical/forensic records (for patients only). There was a trend for smaller PV, on average, in schizophrenia patients (regardless of a history of violence), compared to the healthy group and the ASPD group; other group differences in PV were non-significant. Sexual abuse ratings correlated negatively with PVs in ASPD participants, but no significant association between childhood maltreatment and PV was found in schizophrenia participants. Our findings are consistent with previous evidence of smaller-than-normal PV in chronic schizophrenia patients, and suggest that illness-related influences may mask the possible sexual abuse-smaller PV association, seen here in ASPD, in this population.


Subject(s)
Child Abuse , Schizophrenia , Child , Humans , Hypothalamo-Hypophyseal System , Male , Pituitary-Adrenal System , Schizophrenia/diagnostic imaging , Violence
5.
Addict Behav ; 107: 106429, 2020 08.
Article in English | MEDLINE | ID: mdl-32283445

ABSTRACT

Neurophysiological studies of Gaming Disorder (GD) and internet addiction (IA) are providing important insight into neurocognitive mechanisms underpinning these disorders, which will enable more accurate diagnostic classification. Electroencephalography (EEG) has been widely used to investigate addictive behaviours, and offers advantages of accessibility, low cost, and excellent temporal resolution. The present systematic review evaluates resting-state EEG studies in GD and IA. Papers (n = 7293) were identified in the PsychARTICLES, PsychINFO, Scopus, and Pubmed databases. Following inclusion/exclusion criteria, ten studies remained for evaluation. Results suggest individuals with GD have raised delta and theta activity and reduced beta activity, with coherence analysis suggesting altered brain activity in the mid-to-high frequency range. IA individuals demonstrate raised gamma activity and reduced beta and delta activity. Results suggest that the altered brain activity found in GD/IA may represent distinct underlying neurophysiological markers or traits, lending further support to their unique constructs. Results are also discussed in relation to relevant psychometric measurements and similar (higher frequency) activity found in substance addiction. Future research should focus on replicating the findings in a wider variety of cultural contexts to support the neurophysiological basis of classifying GD and IA.


Subject(s)
Behavior, Addictive , Disruptive, Impulse Control, and Conduct Disorders , Video Games , Behavior, Addictive/diagnosis , Electroencephalography , Humans , Internet , Internet Addiction Disorder
6.
Sci Rep ; 9(1): 6367, 2019 04 23.
Article in English | MEDLINE | ID: mdl-31015534

ABSTRACT

There has been substantial interest in Mindfulness Training (MT) to understand how it can benefit healthy individuals as well as people with a broad range of health conditions. Research has begun to delineate associated changes in brain function. However, whether measures of brain function can be used to identify individuals who are more likely to respond to MT remains unclear. The present study applies a recently developed brain-inspired Spiking Neural Network (SNN) model to electroencephalography (EEG) data to provide novel insight into: i) brain function in depression; ii) the effect of MT on depressed and non-depressed individuals; and iii) neurobiological characteristics of depressed individuals who respond to mindfulness. Resting state EEG was recorded from before and after a 6 week MT programme in 18 participants. Based on self-report, 3 groups were formed: non-depressed (ND), depressed before but not after MT (responsive, D+) and depressed both before and after MT (unresponsive, D-). The proposed SNN, which utilises a standard brain-template, was used to model EEG data and assess connectivity, as indicated by activation levels across scalp regions (frontal, frontocentral, temporal, centroparietal and occipitoparietal), at baseline and follow-up. Results suggest an increase in activation following MT that was site-specific as a function of the group. Greater initial activation levels were seen in ND compared to depressed groups, and this difference was maintained at frontal and occipitoparietal regions following MT. At baseline, D+ had great activation than D-. Following MT, frontocentral and temporal activation reached ND levels in D+ but remained low in D-. Findings support the SNN approach in distinguishing brain states associated with depression and responsiveness to MT. The results also demonstrated that the SNN approach can be used to predict the effect of mindfulness on an individual basis before it is even applied.


Subject(s)
Brain/physiology , Mindfulness , Neural Networks, Computer , Adult , Analysis of Variance , Electroencephalography , Female , Humans , Male
7.
Neuropsychologia ; 121: 79-87, 2018 12.
Article in English | MEDLINE | ID: mdl-30412713

ABSTRACT

Light-flicker Ganzfeld (LFG) induces a lower to upper-alpha frequency shift. However, it is unclear how this neurophysiological response might relate to LFG-induced pseudo-hallucinatory phenomena. It is also unknown whether emotional states (e.g., fear) or traits associated with risk for psychosis (e.g., proneness to perceptual anomalies, ability to produce vivid mental imagery) affect such neurophysiological and/or perceptual responses to LFG. The present study investigated alpha sub-bands during LFG across several flicker frequencies, in relation to individual differences in propensity for Ganzfeld-induced imagery (GI), positive schizotypy and trait mental imagery, and in relation to manipulations of affective state. Given previously reported sex differences in risk for psychosis and response to Ganzfeld, the effect of sex on GI was also studied. Forty-six healthy adults (16 men) completed psychometric measures of trait mental imagery and positive schizotypy before undergoing three LFG (20 min each) conditions. In each condition, participants wore white-out goggles and listened to either mood-inducing soundscapes (fear, serenity) or pink noise (control) through headphones. Greatest propensity for GI arose between 13.1 and 16.0 Hz flicker, with a peak at 16.0 Hz flicker. Occipital lower-alpha was reduced for lower flicker frequencies (13.1-16.0 Hz) and was inversely associated with GI. Upper-alpha power was not significantly related to GI or to other measures. Fear-induction was associated with reduction in alpha power, but did not significantly affect GI. Men reported more GI than women. Findings support a role for cortical destabilisation, as reflected in reduced lower-alpha, in perceptual anomalies; and, by extension, LFG as an experimental model of liability for psychosis.


Subject(s)
Alpha Rhythm/physiology , Brain/physiopathology , Hallucinations/physiopathology , Personality/physiology , Schizotypal Personality Disorder/physiopathology , Visual Perception/physiology , Adolescent , Adult , Affect/physiology , Fear/physiology , Female , Hallucinations/etiology , Hallucinations/psychology , Humans , Imagination/physiology , Male , Middle Aged , Photic Stimulation/methods , Sex Characteristics , Young Adult
8.
J Technol Behav Sci ; 3(3): 141-149, 2018.
Article in English | MEDLINE | ID: mdl-30238057

ABSTRACT

Contemporary technological advances have led to a significant increase in using mobile technologies. Recent research has pointed to potential problems as a consequence of mobile overuse, including addiction, financial problems, dangerous use (i.e. whilst driving) and prohibited use (i.e. use in forbidden areas). The aim of this study is to extend previous findings regarding the predictive power of psychopathological symptoms (depression, anxiety and stress), mobile phone use (i.e. calls, SMS, time spent on the phone, as well as the engagement in specific smartphone activities) across Generations X and Y on problematic mobile phone use in a sample of 273 adults. Findings revealed prohibited use and dependence were predicted by calls/day, time on the phone and using social media. Only for dependent mobile phone use (rather than prohibited), stress appeared as significant. Using social media and anxiety significantly predicted belonging to Generation Y, with calls per day predicted belonging to Generation X. This finding suggests Generation Y are more likely to use asynchronous social media-based communication, whereas Generation X engage more in synchronous communication. The findings have implications for prevention and awareness-raising efforts of possibly problematic mobile phone use for educators, parents and individuals, particularly including dependence and prohibited use.

9.
Psychopharmacology (Berl) ; 232(3): 519-28, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25038870

ABSTRACT

RATIONALE: An acute challenge with delta-9-tetrahydrocannabinol (THC) can induce psychotic symptoms including delusions. High electroencephalography (EEG) frequencies, above 20 Hz, have previously been implicated in psychosis and schizophrenia. OBJECTIVES: The objective of this study is to determine the effect of intravenous THC compared to placebo on high-frequency EEG. METHODS: A double-blind cross-over study design was used. In the resting state, the high-beta to low-gamma magnitude (21-45 Hz) was investigated (n = 13 pairs + 4 THC only). Also, the event-related synchronisation (ERS) of motor-associated high gamma was studied using a self-paced button press task (n = 15). RESULTS: In the resting state, there was a significant condition × frequency interaction (p = 0.00017), consisting of a shift towards higher frequencies under THC conditions (reduced high beta [21-27 Hz] and increased low gamma [27-45 Hz]). There was also a condition × frequency × location interaction (p = 0.006), such that the reduction in 21-27-Hz magnitude tended to be more prominent in anterior regions, whilst posterior areas tended to show greater 27-45-Hz increases. This effect was correlated with positive symptoms, as assessed on the Positive and Negative Syndrome Scale (PANSS) (r = 0.429, p = 0.042). In the motor task, there was a main effect of THC to increase 65-130-Hz ERS (p = 0.035) over contra-lateral sensorimotor areas, which was driven by increased magnitude in the higher, 85-130-Hz band (p = 0.02) and not the 65-85-Hz band. CONCLUSIONS: The THC-induced shift to faster gamma oscillations may represent an over-activation of the cortex, possibly related to saliency misattribution in the delusional state.


Subject(s)
Brain Waves/drug effects , Cannabinoid Receptor Agonists/pharmacology , Cerebral Cortex/drug effects , Dronabinol/pharmacology , Adult , Cross-Over Studies , Double-Blind Method , Female , Humans , Male , Young Adult
10.
Psychiatr Danub ; 26(1): 27-33, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24608149

ABSTRACT

BACKGROUND: Depressive symptoms in schizophrenia are common, more so in women, but associated neurobiological mechanisms are poorly understood. The current study investigated sex differences in the relationship between depression and brain function, as measured using event-related potentials (ERPs), in people with schizophrenia. SUBJECTS AND METHODS: Fourteen men and 14 women with schizophrenia, matched on age of illness onset and illness duration, were assessed for depression using the Calgary Depression Scale. ERP amplitudes were measured during an auditory oddball task in response to target (P3b, anterior N100) and novel (P3a, posterior N100) stimuli. RESULTS: Depression was significantly positively associated with early perceptual processing in response to novels in men (parietal N100 amplitude), and with a later processing stage (parietal P3b) in women. No association was found for anterior P3a. CONCLUSIONS: Results suggest that temporally distinct pathophysiological mechanisms are involved in depression in men compared to women, at least in the context of schizophrenia.

11.
Laterality ; 19(3): 340-53, 2014.
Article in English | MEDLINE | ID: mdl-23988195

ABSTRACT

Despite several recent important developments in understanding numerical processing of both isolated numbers and numbers in the context of arithmetic equations, the relative impact of congruency on high-level compared to low-level processing remains unclear. The current study investigated hemispheric differences in the processing of arithmetic material, as a function of semantic and perceptual congruency, using a delayed answer verification task and divided visual field paradigm. A total of 37 participants (22 females and 15 males, mean age 30.06, SD 9.78) were presented unilaterally or bilaterally with equation results that were either correct or incorrect and had a consistent or inconsistent numerical notation. Statistical analyses showed no visual field differences in a notation consistency task, whereas when judgements had to be made on mathematical accuracy there was a right visual field advantage for incorrect equations that were notation consistent. These results reveal a clear differential processing of arithmetic information by the two cerebral hemispheres with a special emphasis on erroneous calculations. Faced with incorrect results and with a consistent numerical notation, the left hemisphere outperforms its right counterpart in making mathematical accuracy decisions.


Subject(s)
Functional Laterality , Judgment , Mathematics , Visual Fields , Adult , Female , Humans , Male , Middle Aged , Reaction Time , Young Adult
12.
Article in English | MEDLINE | ID: mdl-23838273

ABSTRACT

OBJECTIVE: The excitement cluster (excitement, hostility, uncooperativeness and impulsivity) may contribute to the risk of violent behaviour, treatment non-adherence, likelihood of discharge and substance use in psychosis. Evidence suggests involvement of frontal executive mechanisms that may show sex differences in their association with symptom severity. The current study tests the association between excitement and the frontal N200 and P300 components of the auditory event-related potential in schizophrenia as a function of sex. METHOD: Fourteen men and 14 women with schizophrenia (mean illness duration=20years) completed a novelty oddball and clinical interview. RESULTS: Men showed higher midline N200 and lower novelty P300 amplitude than women. They had more pronounced differences between midline and lateral N200 amplitude, and did not show the same Novel>Target effect for right frontal P300 as did women. Right frontal N200 amplitude to target stimuli was positively associated with excitement in women and inversely associated with excitement in men. Novelty P300 amplitude was inversely associated with excitement, particularly in women and over the right hemisphere. CONCLUSION: Results suggest that mechanisms underpinning frontal N200 and P300 subcomponents are differentially involved in excitement depending on sex. Understanding these individual differences may have implications for developing personalised treatment.


Subject(s)
Acoustic Stimulation/methods , Evoked Potentials, Auditory/physiology , Psychomotor Performance/physiology , Schizophrenia/diagnosis , Schizophrenia/physiopathology , Schizophrenic Psychology , Adult , Female , Humans , Male , Middle Aged
13.
Article in English | MEDLINE | ID: mdl-23566869

ABSTRACT

Atypical fatty acid metabolism has been reported in attention deficit hyperactivity disorder (ADHD), however, its relationship with temperament in this population is unclear. The current study investigated the association between blood levels of fatty acids implicated in brain structure and function (omega-3, omega-6, omega-9) and personality traits of stability (neuroticism, conscientiousness and agreeableness) and plasticity (extraversion and openness). Twenty right-handed adolescent boys with ADHD completed a self-report NEO-FFI personality questionnaire, and had fatty acid content assessed from red blood using gas chromatography. Pearson's correlations showed no significant associations between omega-3 levels and personality. After correction for multiple comparisons, Adrenic Acid (C22:4n6) was inversely associated with stability. Oleic acid (C18:1n9) was positively associated with plasticity. Results are in line with a role of fatty acids in brain function. They suggest that those fatty acids that are involved in myelination (Adrenic, Oleic) have the strongest associations with temperament in adolescents with ADHD.


Subject(s)
Attention Deficit Disorder with Hyperactivity/blood , Erucic Acids/blood , Fatty Acids, Omega-3/blood , Fatty Acids, Omega-6/blood , Oleic Acid/blood , Temperament , Adolescent , Attention Deficit Disorder with Hyperactivity/physiopathology , Attention Deficit Disorder with Hyperactivity/psychology , Brain/metabolism , Child , Extraversion, Psychological , Facial Expression , Fatty Acids, Unsaturated , Humans , Male , Surveys and Questionnaires
14.
Int J Psychophysiol ; 87(2): 205-14, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23376596

ABSTRACT

Neuroplastic changes that take place in the brain after sustaining a spinal cord injury have generally been studied encompassing various post-injury time periods, sometimes ranging from just a few days to many years. Although research on the low-end of this time spectrum has established that neuroplastic changes can be detected shortly after trauma, electroencephalographic changes that take place in long-term injuries are still poorly defined. To investigate this, the present study recorded the movement-related brain potentials from 9 long suffering spinal cord injury patients (post-injury range 6-24years, mean 14.63; age range 27-44years, mean 36.78) while they were attempting to move their paralysed toes. Their data were compared with the data of similar age and same sex spinal intact participants; 10 of whom only prepared for action and 10 others who actually executed the movement. The results showed that the amplitudes of the readiness potential and motor potential were lower in the spinal cord injury group than in the movement control group. The topographic distribution of the motor potential was also more similar between the spinal cord injury group and the no-movement control group, whereas that of the readiness potential was more similar between the spinal cord injury group and the movement control group. These findings suggest that both motor preparatory processes and motor execution processes are affected by neuroplastic changes that take place in the brain of long suffering spinal cord injury patients.


Subject(s)
Evoked Potentials/physiology , Movement/physiology , Neuronal Plasticity/physiology , Spinal Cord Injuries/physiopathology , Adult , Analysis of Variance , Contingent Negative Variation/physiology , Electrodes , Electroencephalography , Evoked Potentials, Motor/physiology , Female , Humans , Male , Middle Aged , Software , Young Adult
15.
Neuropsychopharmacology ; 36(4): 827-36, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21150914

ABSTRACT

The main ingredient in cannabis, Δ(9)-tetrahydrocannabinol (THC), can elicit acute psychotic reactions in healthy individuals and precipitate relapse in schizophrenic patients. However, the neural mechanism of this is unknown. We tested the hypothesis that THC psychopathology is related to changes in electroencephalography (EEG) power or inter-regional coherence. In a within-subjects design, participants (n=16) were given intravenous THC (1.25 mg) or placebo under double-blind conditions, during EEG recordings. Using fast-Fourier transform, EEG data were analyzed for power and coherence in the delta (1-3.5 Hz), theta (3.5-7 Hz), alpha (8-13 Hz), beta (14-25 Hz), low-gamma (30-40 Hz), and high-gamma (60-70 Hz) bands during engagement in the n-back test of working memory (WM). Compared with placebo, THC evoked positive and negative psychotic symptoms, as measured by the positive and negative syndrome scale (p<0.001) and slowed WM performance (p<0.05). Under THC, theta power was specifically reduced, (p<0.001) regardless of WM load; however, the reduction showed no relationship with psychotic symptoms or WM impairment. Coherence between bi-frontal electrodes in the theta band was also reduced by THC (p<0.05) and these reductions correlated with the change-in positive psychotic symptoms (rho=0.79, p<0.001). Bi-frontal specificity was suggested by the absence of a relationship between psychotic symptoms and fronto-parietal coherence. The results reveal that the pro-psychotic effects of THC might be related to impaired network dynamics with impaired communication between the right and left frontal lobes.


Subject(s)
Dronabinol/toxicity , Frontal Lobe/drug effects , Psychoses, Substance-Induced/physiopathology , Psychoses, Substance-Induced/psychology , Theta Rhythm/drug effects , Adult , Cross-Over Studies , Double-Blind Method , Dronabinol/blood , Electroencephalography/drug effects , Electroencephalography/methods , Female , Frontal Lobe/physiology , Humans , Male , Middle Aged , Nerve Net/drug effects , Nerve Net/metabolism , Psychoses, Substance-Induced/blood , Theta Rhythm/physiology , Young Adult
16.
Psychiatry Res ; 183(2): 174-6, 2010 Aug 30.
Article in English | MEDLINE | ID: mdl-20620033

ABSTRACT

Thalamic neurochemical abnormalities may underlie psychotic symptoms and auditory event-related potential (ERP) abnormalities in schizophrenia. We investigated this hypothesis in subjects at risk of psychosis using magnetic resonance spectroscopy and electroencephalography (EEG). Reduced thalamic glutamate plus glutamine and N-acetyl aspartate levels were associated with abnormal frontal ERPs, supporting a thalamic basis for filtering impairments.


Subject(s)
Evoked Potentials, Auditory/physiology , Neurochemistry , Schizophrenia/pathology , Thalamus/metabolism , Acoustic Stimulation/methods , Adult , Aspartic Acid/analogs & derivatives , Aspartic Acid/metabolism , Electroencephalography , Female , Frontal Lobe/physiopathology , Glutamic Acid/metabolism , Glutamine/metabolism , Humans , Linear Models , Magnetic Resonance Spectroscopy/methods , Male , Protons , Radionuclide Imaging , Schizophrenia/diagnostic imaging , Schizophrenia/physiopathology , Young Adult
17.
Cortex ; 44(10): 1342-52, 2008.
Article in English | MEDLINE | ID: mdl-18625497

ABSTRACT

Separate dimensions of schizotypy have been differentially associated with electrophysiological measures of brain function, and further shown to be modified by sex/gender. We investigated event-related potential (ERP) correlates of two subdimensions of positive schizotypy, paranormal ideation (PI) and unusual experiences (UEs). Seventy-two individuals with no psychiatric diagnosis (men=36) completed self-report measures of UE and PI and performed an auditory oddball task. Average scores for N100, N200 and P300 amplitudes were calculated for left and right anterior, central and posterior electrode sites. Multiple linear regression was used to examine the relationships between the measures of schizotypy and ERPs across the entire sample, as well as separately according to sex. PI was inversely associated with P300 amplitude at left-central sites across the entire sample, and at right-anterior electrodes in women only. Right-anterior P300 and right-posterior N100 amplitudes were negatively associated with UE in women only. Across the entire sample, UE was negatively associated with left-central N100 amplitude, and positively associated with left-anterior N200 amplitude. These results provide support from electrophysiological measures for the fractionation of the positive dimension of schizotypy into subdimensions of PI and UE, and lend indirect support to dimensional or quasidimensional conceptions of psychosis. More specifically, they suggest that PI may be associated with alteration in contextual updating processes, and that UE may reflect altered sensory/early-attention (N100) mechanisms. The sex differences observed are consistent with those previously observed in individuals with schizophrenia.


Subject(s)
Brain/physiology , Delusions/psychology , Parapsychology , Adult , Aged , Analysis of Variance , Event-Related Potentials, P300 , Evoked Potentials , Female , Humans , Male , Middle Aged , Schizophrenic Psychology , Sex Characteristics , Young Adult
18.
Behav Sci Law ; 26(1): 51-64, 2008.
Article in English | MEDLINE | ID: mdl-18327832

ABSTRACT

In this study, response inhibition and associated neural activation during a motor inhibition paradigm were investigated in (i) men with antisocial personality disorder (APD) with a history of violence (n = 14), (ii) men with schizophrenia with a history of violence (n = 12), (iii) men with schizophrenia without a history of violence (n = 12), and (iv) healthy control subjects (n = 14) using functional magnetic resonance imaging (fMRI). At the behavioural level, individuals with schizophrenia showed impaired performance across all conditions, whereas an increased error rate was seen in the APD group only during the conditions requiring inhibition. At the neural level, both violent groups showed reduced thalamic activity, compared with controls, in association with modulation of inhibition by task demands. In addition, the violent schizophrenia group, compared with controls, showed reduced activity in the caudate nucleus during the condition requiring inhibition. It is concluded that violence may not be specifically associated with impaired voluntary inhibition in schizophrenia but this is likely in APD. Reduced thalamic function, perhaps due to its known association with sensorimotor disturbances, is implicated in violent behaviour across both disorders. In addition, caudate dysfunction may contribute, given its role in timing and temporal processing as well as suppression of motor actions, to deficient inhibition and violent behaviour in schizophrenia.


Subject(s)
Antisocial Personality Disorder/psychology , Inhibition, Psychological , Schizophrenic Psychology , Violence/psychology , Adolescent , Adult , Analysis of Variance , Antisocial Personality Disorder/diagnostic imaging , Antisocial Personality Disorder/physiopathology , Case-Control Studies , Caudate Nucleus/physiopathology , Humans , Magnetic Resonance Imaging , Male , Mental Disorders , Middle Aged , Neurons , Psychiatric Status Rating Scales , Radiography , Schizophrenia/diagnostic imaging , Schizophrenia/physiopathology , User-Computer Interface
19.
Schizophr Res ; 98(1-3): 265-77, 2008 Jan.
Article in English | MEDLINE | ID: mdl-18022352

ABSTRACT

BACKGROUND: P300 amplitude reduction is reliably seen in schizophrenia. Inconsistent reports of isolated frontal and/or parietal deficits in unaffected family members may be clarified using a task that places greater load on frontal function. METHOD: Go and No-Go versions of the auditory oddball task were performed by eighteen schizophrenia patients, age-matched unaffected siblings and healthy controls matched closely to unaffected siblings on age, sex, education, socioeconomic-status, handedness and ethnicity. Groups were compared on P300 and N100 amplitude and latency. Spearman correlations were used to test the relationship between ERP amplitudes and neuropsychological measures of executive function and memory. The relationship between schizotypy--as measured using the structured interview--and ERPs was explored in a combined group of siblings and controls. RESULTS: Independent of task, patients had lower P300 than controls and reduced parietal amplitude compared to siblings. Siblings had enhanced frontocentral N100 compared to controls. No-Go P300 amplitude and N100 latency was associated with executive function measures. There were significant intraclass correlations between patients and siblings for No-Go P300 amplitude, particularly at the central midline electrode. Frontocentral N100 and P300 amplitude were positively correlated with anxiety-related aspects of schizotypy. CONCLUSION: Enhanced N100 is present in unaffected siblings. Parietal P300 is intact in unaffected siblings, but reduced in patients. The No-Go-oddball is more sensitive than the Go-oddball to executive function deficits in patients and as an index of heritability.


Subject(s)
Cerebral Cortex/physiopathology , Evoked Potentials/physiology , Frontal Lobe/physiopathology , Neuropsychological Tests/statistics & numerical data , Schizophrenia/genetics , Schizophrenia/physiopathology , Schizophrenic Psychology , Siblings/psychology , Adult , Brain Mapping , Cluster Analysis , Electroencephalography/statistics & numerical data , Event-Related Potentials, P300/genetics , Event-Related Potentials, P300/physiology , Evoked Potentials/genetics , Evoked Potentials, Auditory/genetics , Evoked Potentials, Auditory/physiology , Female , Functional Laterality/physiology , Genetic Predisposition to Disease/genetics , Humans , Image Processing, Computer-Assisted , Male , Parietal Lobe/physiopathology , Psychiatric Status Rating Scales/statistics & numerical data , Reaction Time/genetics , Reaction Time/physiology , Schizophrenia/diagnosis
20.
Int J Neurosci ; 117(9): 1341-60, 2007 Sep.
Article in English | MEDLINE | ID: mdl-17654096

ABSTRACT

The present study employs standardized data acquired from the Brain Resource International Database to study the relationship between mobile phone usage, personality, and brain function (n = 300). Based on the frequency and duration of mobile phone usage, three groups were formed. The findings suggest a subtle slowing of brain activity related to mobile phone use that is not explained by differences in personality. These changes are still within normal physiological ranges. Better executive function in mobile phone users may reflect more focused attention, possibly associated with a cognitive training effect (i.e., frequently making phone calls in distracting places), rather than a direct effect of mobile phone use on cognition.


Subject(s)
Cell Phone , Electroencephalography/radiation effects , Electromagnetic Fields/adverse effects , Personality/radiation effects , Problem Solving/radiation effects , Adolescent , Adult , Analysis of Variance , Eye Movements , Female , Humans , Male , Neuropsychological Tests , Personality Inventory , Surveys and Questionnaires
SELECTION OF CITATIONS
SEARCH DETAIL
...