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1.
BMC Med Educ ; 23(1): 883, 2023 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-37978372

RESUMO

BACKGROUND: Clinical neuroscience training programmes are becoming increasingly competitive to enter. UK university neuroscience societies act as a local environment for students to develop their career interests and provide portfolio building opportunities through hosting events such as annual conferences. Recently there has been a transition to more of these events being held online yet the impact of this, if any, remains unclear. This prospective study aimed to identify the impact of student-led neuroscience conferences on delegates and examine attitudes towards an online delivery approach. METHODS: Multi-centre prospective survey study using pre-conference, post-conference, and 6-month post-conference online questionnaires distributed at 6 virtual student-led neuroscience conferences in 2021. The questionnaires had five-domains: demographics, career aspirations, academic skillsets, an educational manipulation check (EMC) and mode of delivery preference. RESULTS: Nine hundred twenty-four surveys were completed across 559 conference attendances. 79.9% of delegates were medical students. Interest in a neuroscience career (p < 0.001), preparedness to undertake research (p < 0.001) and presentation (p < 0.001), as well as EMC scores (p < 0.001) increased immediately post conference. Most participants at 6 months post-attendance had completed an academic project (71.9%) or presentation (50.9%), although 88.8% were lost to follow up. Online format was preferred (65%) with reasons including elimination of travel and access to home facilities whilst lack of face-to-face interaction and engagement were recognised limitations. CONCLUSION: UK student-led online neuroscience conferences play a role in developing knowledge and may facilitate career interest, academic skillset and longer term portfolio building. A hybrid virtual and in-person experience would offer an ideal solution to future conferencing, providing options promoting engagement and interactivity whilst advocating sustainability, accessibility and widening participation.


Assuntos
Estudantes de Medicina , Humanos , Estudos Prospectivos , Atitude , Inquéritos e Questionários , Reino Unido
2.
Eur J Sport Sci ; 23(7): 1094-1101, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35912815

RESUMO

This study assessed the influence of environmental factors, air travel, and epoch estimation method on locomotor demands of international men's rugby sevens match-play. Eighteen men's rugby sevens players wore 10 Hz Global Positioning Systems (STATsport) during 52 international matches over nine global tournaments (418 observations). Whole-match average speed was recorded, whilst average speed and relative high-speed distance (>5.0 m·s-1) were quantified using FIXED and ROLL methods over 60-420 s epochs (60 s increments) to establish worst-case scenario demands. Linear mixed models compared FIXED versus ROLL estimation methods and assessed whether temperature, humidity, travel duration, number of time-zones crossed, and travel direction were associated with locomotor responses. Temperature and humidity were positively associated with overall and worst-case scenario average speed (effect estimates; b: 0.18-0.54), whilst worst-case scenario high-speed distance at 300 s was also related to temperature (b: 0.19). Easterly air travel compromised overall and 180 and 300 s worst-case scenario average speed (b: -8.31 to-7.39), alongside high-speed distance over 300 s (b: -4.54). For worst-case scenario average speed and high-speed distance, FIXED underestimated ROLL at all epoch lengths (∼9.9-18.4%, p≤0.001). This study indicated that international rugby sevens match-play locomotor responses were greater as air temperature increased but reduced following eastward air travel. Underestimation of demands in FIXED vs ROLL over 60-420 s epochs was confirmed. Such climatic and travel influences warrant the adoption of strategies targeted at maximising performance and safety according to the tournament conditions. Knowing the most demanding periods of match-play facilitates training specificity.HighlightsSelected locomotor responses were reduced following eastward air travel, potentially suggesting interventions to mitigate these effects are warranted.Match-play running responses were greater as air temperature increased. Strategies targeted at optimising body temperature in both warm and cool conditions warrant consideration to promote performance and maintain player safety.Fixed epochs underestimated worst-case scenario average speed (9.9-11.7%) and high-speed distance (11.4-18.4%). Rolling averages may thus be more appropriate for detecting the most intense periods, while duration-specific data provide training targets.


Assuntos
Desempenho Atlético , Futebol Americano , Corrida , Masculino , Humanos , Futebol Americano/fisiologia , Rugby , Desempenho Atlético/fisiologia , Viagem , Corrida/fisiologia , Sistemas de Informação Geográfica
3.
PLoS One ; 10(3): e0119500, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25798822

RESUMO

Several studies have investigated the neural basis of effortful emotion regulation (ER) but the neural basis of automatic ER has been less comprehensively explored. The present study investigated the neural basis of automatic ER supported by 'implementation intentions'. 40 healthy participants underwent fMRI while viewing emotion-eliciting images and used either a previously-taught effortful ER strategy, in the form of a goal intention (e.g., try to take a detached perspective), or a more automatic ER strategy, in the form of an implementation intention (e.g., "If I see something disgusting, then I will think these are just pixels on the screen!"), to regulate their emotional response. Whereas goal intention ER strategies were associated with activation of brain areas previously reported to be involved in effortful ER (including dorsolateral prefrontal cortex), ER strategies based on an implementation intention strategy were associated with activation of right inferior frontal gyrus and ventro-parietal cortex, which may reflect the attentional control processes automatically captured by the cue for action contained within the implementation intention. Goal intentions were also associated with less effective modulation of left amygdala, supporting the increased efficacy of ER under implementation intention instructions, which showed coupling of orbitofrontal cortex and amygdala. The findings support previous behavioural studies in suggesting that forming an implementation intention enables people to enact goal-directed responses with less effort and more efficiency.


Assuntos
Atenção/fisiologia , Encéfalo/fisiologia , Emoções/fisiologia , Resposta Galvânica da Pele , Intenção , Imageamento por Ressonância Magnética/métodos , Adolescente , Adulto , Feminino , Voluntários Saudáveis , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Neuroimagem , Reconhecimento Visual de Modelos , Adulto Jovem
4.
Cogn Emot ; 29(2): 319-31, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-24678930

RESUMO

Emotion regulation (ER) is vital to everyday functioning. However, the effortful nature of many forms of ER may lead to regulation being inefficient and potentially ineffective. The present research examined whether structured practice could increase the efficiency of ER. During three training sessions, comprising a total of 150 training trials, participants were presented with negatively valenced images and asked either to "attend" (control condition) or "reappraise" (ER condition). A further group of participants did not participate in training but only completed follow-up measures. Practice increased the efficiency of ER as indexed by decreased time required to regulate emotions and increased heart rate variability (HRV). Furthermore, participants in the ER condition spontaneously regulated their negative emotions two weeks later and reported being more habitual in their use of ER. These findings indicate that structured practice can facilitate the automatic control of negative emotions and that these effects persist beyond training.


Assuntos
Inteligência Emocional , Aprendizagem , Adolescente , Adulto , Inteligência Emocional/fisiologia , Emoções , Feminino , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa , Adulto Jovem
5.
Neuropsychologia ; 67: 159-74, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25527112

RESUMO

Self-deception and impression-management comprise two types of deceptive, but generally socially acceptable behaviours, which are common in everyday life as well as being present in a number of psychiatric disorders. We sought to establish and dissociate the 'normal' brain substrates of self-deception and impression-management. Twenty healthy participants underwent fMRI scanning at 3T whilst completing the 'Balanced Inventory of Desirable Responding' test under two conditions: 'fake good', giving the most desirable impression possible and 'fake bad' giving an undesirable impression. Impression-management scores were more malleable to manipulation via 'faking' than self-deception scores. Response times to self-deception questions and 'fake bad' instructions were significantly longer than to impression-management questions and 'fake good' instructions respectively. Self-deception and impression-management manipulation and 'faking bad' were associated with activation of medial prefrontal cortex (mPFC) and left ventrolateral prefrontal cortex (vlPFC). Impression-management manipulation was additionally associated with activation of left dorsolateral prefrontal cortex and left posterior middle temporal gyrus. 'Faking bad' was additionally associated with activation of right vlPFC, left temporo-parietal junction and right cerebellum. There were no supra-threshold activations associated with 'faking good'. Our neuroimaging data suggest that manipulating self-deception and impression-management and more specifically 'faking bad' engages a common network comprising mPFC and left vlPFC. Shorter response times and lack of dissociable neural activations suggests that 'faking good', particularly when it comes to impression-management, may be our most practiced 'default' mode.


Assuntos
Encéfalo/fisiologia , Enganação , Percepção Social , Adulto , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Córtex Pré-Frontal/fisiologia , Adulto Jovem
6.
Front Hum Neurosci ; 8: 688, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25309380

RESUMO

The neural basis of progress monitoring has received relatively little attention compared to other sub-processes that are involved in goal directed behavior such as motor control and response inhibition. Studies of error-monitoring have identified the dorsal anterior cingulate cortex (dACC) as a structure that is sensitive to conflict detection, and triggers corrective action. However, monitoring goal progress involves monitoring correct as well as erroneous events over a period of time. In the present research, 20 healthy participants underwent functional magnetic resonance imagining (fMRI) while playing a game that involved monitoring progress toward either a numerical or a visuo-spatial target. The findings confirmed the role of the dACC in detecting situations in which the current state may conflict with the desired state, but also revealed activations in the frontal and parietal regions, pointing to the involvement of processes such as attention and working memory (WM) in monitoring progress over time. In addition, activation of the cuneus was associated with monitoring progress toward a specific target presented in the visual modality. This is the first time that activation in this region has been linked to higher-order processing of goal-relevant information, rather than low-level anticipation of visual stimuli. Taken together, these findings identify the neural substrates involved in monitoring progress over time, and how these extend beyond activations observed in conflict and error monitoring.

7.
Front Hum Neurosci ; 8: 376, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24936178

RESUMO

Studies investigating the neurophysiological basis of intrapersonal emotion regulation (control of one's own emotional experience) report that the frontal cortex exerts a modulatory effect on limbic structures such as the amygdala and insula. However, no imaging study to date has examined the neurophysiological processes involved in interpersonal emotion regulation, where the goal is explicitly to regulate another person's emotion. Twenty healthy participants (10 males) underwent fMRI while regulating their own or another person's emotions. Intrapersonal and interpersonal emotion regulation tasks recruited an overlapping network of brain regions including bilateral lateral frontal cortex, pre-supplementary motor area, and left temporo-parietal junction. Activations unique to the interpersonal condition suggest that both affective (emotional simulation) and cognitive (mentalizing) aspects of empathy may be involved in the process of interpersonal emotion regulation. These findings provide an initial insight into the neural correlates of regulating another person's emotions and may be relevant to understanding mental health issues that involve problems with social interaction.

8.
Physiol Meas ; 34(3): N9-N14, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23400029

RESUMO

Gravitational forces may lead to local changes in subarachnoid cerebrospinal fluid (CSF) layer thickness, which has important implications for neurophysiological modulation and recording techniques. This study examines the effect of gravitational pull associated with different head positions on the distribution of subarachnoid CSF using structural magnetic resonance imaging. Images of seven subjects in three different positions (supine, left lateral and prone) were statistically compared. Results suggest that subarachnoid CSF volume decreases on the side of the head closest to the ground, due to downward brain movement with gravity. These findings warrant future research into currently unexplored gravitation-induced changes in regional subarachnoid CSF thickness.


Assuntos
Líquido Cefalorraquidiano/metabolismo , Cabeça/fisiologia , Imageamento por Ressonância Magnética , Movimento/fisiologia , Fenômenos Fisiológicos do Sistema Nervoso , Espaço Subaracnóideo/metabolismo , Adulto , Feminino , Humanos , Masculino
9.
Bipolar Disord ; 14(2): 135-45, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22420589

RESUMO

OBJECTIVE: Several neuroimaging studies have reported structural brain differences in bipolar disorder using automated methods. While these studies have several advantages over those using region of interest techniques, no study has yet estimated a summary effect size or tested for between-study heterogeneity. We sought to address this issue using meta-analytic techniques applied for the first time in bipolar disorder at the level of the individual voxel. METHODS: A systematic review identified 16 voxel-based morphometry (VBM) studies comparing individuals with bipolar disorder with unaffected controls, of which eight were included in the meta-analysis. In order to take account of heterogeneity, summary effect sizes were computed using a random-effects model with appropriate correction for multiple testing. RESULTS: Compared with controls, subjects with bipolar disorder had reduced grey matter in a single cluster encompassing the right ventral prefrontal cortex, insula, temporal cortex, and claustrum. Study heterogeneity was widespread throughout the brain; though the significant cluster of grey matter reduction remained once these extraneous voxels had been removed. We found no evidence of publication bias (Eggers p = 0.63). CONCLUSIONS: Bipolar disorder is consistently associated with reductions in right prefrontal and temporal lobe grey matter. Reductions elsewhere may be obscured by clinical and methodological heterogeneity.


Assuntos
Transtorno Bipolar/patologia , Encéfalo/patologia , Mapeamento Encefálico , Bases de Dados Bibliográficas/estatística & dados numéricos , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino
10.
Front Hum Neurosci ; 6: 349, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23335893

RESUMO

Subjective assessment of emotional valence is typically associated with both brain activity and autonomic arousal. Accurately assessing emotional salience is particularly important when perceiving threat. We sought to characterize the neural correlates of the interaction between behavioral and autonomic responses to potentially threatening visual and auditory stimuli. Twenty-five healthy male subjects underwent fMRI scanning whilst skin conductance responses (SCR) were recorded. One hundred and eighty pictures, sentences, and sounds were assessed as "harmless" or "threatening." Individuals' stimulus-locked, phasic SCRs and trial-by-trial behavioral assessments were entered as regressors into a flexible factorial design to establish their separate autonomic and behavioral neural correlates, and convolved to examine psycho-autonomic interaction (PAI) effects. Across all stimuli, "threatening," compared with "harmless" behavioral assessments were associated with mainly frontal and precuneus activation with specific within-modality activations including bilateral parahippocampal gyri (pictures), bilateral anterior cingulate cortex (ACC) and frontal pole (sentences), and right Heschl's gyrus and bilateral temporal gyri (sounds). Across stimulus modalities SCRs were associated with activation of parieto-occipito-thalamic regions, an activation pattern which was largely replicated within-modality. In contrast, PAI analyses revealed modality-specific activations including right fusiform/parahippocampal gyrus (pictures), right insula (sentences), and mid-cingulate gyrus (sounds). Phasic SCR activity was positively correlated with an individual's propensity to assess stimuli as "threatening." SCRs may modulate cognitive assessments on a "harmless-threatening" dimension, thereby modulating affective tone and hence behavior.

11.
Neuroimage ; 57(4): 1552-60, 2011 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-21664277

RESUMO

The perception and judgement of social hierarchies forms an integral part of social cognition. Hierarchical judgements can be either self-referential or allocentric (pertaining to two or more external agents). In psychiatric conditions such as dissocial personality disorder and schizophrenia, the impact of hierarchies may be problematic. We sought to elucidate the brain regions involved in judging allocentric social hierarchies. Twenty-two healthy male subjects underwent three fMRI scans. During scanning, subjects answered questions concerning visually-presented target pairs of human individual's relative superiority within a specific social hierarchy or their perceived degree of social alliance (i.e., whether they were "friends or enemies"). Subjects also made judgements relating to target pairs' age, gender and fame to control for confounding factors and performed a baseline numerical task. Response times increased in line with hypothesized ascending executive load. Both social hierarchy and social alliance judgements activated left ventrolateral prefrontal cortex (VLPFC), left dorsal inferior frontal gyrus (IFG) and bilateral fusiform gyri. In addition, social alliance judgements activated right dorsal IFG and medial prefrontal cortex. When compared directly with social alliance, social hierarchy judgements activated left orbitofrontal cortex. Detecting the presence of social hierarchies and judging other's relative standing within them implicates the cognitive executive, in particular the VLPFC. Our finding informs accounts of 'normal' social cognition but our method also provides a means of probing the dissocial brain in personality disorder and schizophrenia where executive function may be dysfunctional.


Assuntos
Mapeamento Encefálico , Julgamento/fisiologia , Percepção/fisiologia , Córtex Pré-Frontal/fisiologia , Percepção Social , Feminino , Hierarquia Social , Humanos , Interpretação de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Tempo de Reação , Adulto Jovem
12.
Neuroimage ; 57(3): 1154-61, 2011 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-21571075

RESUMO

Investigating auditory hallucinations that occur in health may help elucidate brain mechanisms which lead to the pathological experience of auditory hallucinations in neuropsychiatric disorders such as schizophrenia. In this study, we investigated healthy individuals who reported auditory hallucinations whilst falling asleep (hypnagogic hallucinations; HG) and waking up (hypnopompic hallucinations; HP). In an initial behavioural study, we found that subjects with a history of auditory HG/HP hallucinations (n = 26) reported significantly greater subjective sensitivity to environmental sounds than non-hallucinator controls (n = 74). Then, two fMRI experiments were performed. The first examined speech-evoked brain activation in 12 subjects with a history of auditory HG/HP hallucinations and 12 non-hallucinator controls matched for age, gender and IQ. The second fMRI experiment, in the same subjects, probed how brain activation was modulated by auditory attention using a bimodal selective attention paradigm. In the first experiment, the hallucinator group demonstrated significantly greater speech-evoked activation in the left supramarginal gyrus than the control group. In the second experiment, directing attention towards the auditory (vs. visual) modality induced significantly greater activation of the anterior cingulate gyrus in the hallucinator group than in the control group. These results suggest that hallucination proneness is associated with increased sensitivity of auditory and polysensory association cortex to auditory stimulation, an effect which might arise due to enhanced attentional bias from the anterior cingulate gyrus. Our data support the overarching hypothesis that top-down modulation of auditory cortical response characteristics may be a key mechanistic step in the generation of auditory hallucinations.


Assuntos
Atenção/fisiologia , Mapeamento Encefálico , Encéfalo/fisiopatologia , Potenciais Evocados Auditivos/fisiologia , Alucinações/fisiopatologia , Estimulação Acústica , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem
13.
Int J Neurosci ; 120(5): 335-43, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20402571

RESUMO

The clock drawing (CD) task involves visual integration skills associated with parietal lobe function. Seven mild Alzheimer's Disease (AD) patients and 11 healthy elderly controls (EC) underwent functional magnetic resonance imaging (fMRI) scanning while viewing a radial motion (RM) task. This RM task in EC activated the bilateral secondary visual cortex and parietal regions, whereas AD patients activated only the right-sided secondary visual cortex. The magnitude of the fMRI signal in the left superior parietal lobe was positively correlated with performance on the CD task in AD patients. These findings suggest that complex visuospatial processing impairments reflect the underlying AD neuropathology in parietal regions.


Assuntos
Doença de Alzheimer/fisiopatologia , Doença de Alzheimer/psicologia , Desempenho Psicomotor/fisiologia , Percepção Espacial/fisiologia , Percepção Visual/fisiologia , Idoso , Estudos de Casos e Controles , Lateralidade Funcional , Humanos , Imageamento por Ressonância Magnética/métodos , Lobo Parietal/fisiopatologia , Córtex Visual/fisiopatologia
14.
Dement Geriatr Cogn Disord ; 29(2): 176-88, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20215749

RESUMO

BACKGROUND/AIMS: Visuospatial impairments are known to occur in Alzheimer's disease (AD). We hypothesised that functional magnetic resonance imaging (fMRI) response in task-related brain regions would be impaired in patients with AD during the task and that treatment with acetyl cholinesterase inhibitors would enhance activations in brain regions concerned with this visual perceptual processing. METHOD: Ten AD subjects were neuropsychologically assessed and underwent fMRI imaging whilst performing a series of visuospatial perception tasks, before and after treatment with acetyl cholinesterase inhibitors. Eleven healthy elderly comparison subjects were also scanned twice. RESULTS: Regions of increased brain activation in AD included the left precuneus, left cuneus, left supramarginal gyrus, right parieto-temporal cortex and right inferior parietal lobule. Further, increased activation in the left precuneus was found to correlate significantly with improved functioning of activities of daily living. CONCLUSIONS: We believe this to be the first fMRI study that, after controlling for the confound of repeat scanning, demonstrates altered patterns of brain activation associated with visuospatial processing following treatment in patients with AD. The treatment-related improvement of visual perception in AD may rely on enhanced attentional mechanisms, thereby possibly supporting independent living through improvement on activities of daily living.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/psicologia , Inibidores da Colinesterase/uso terapêutico , Percepção Espacial/efeitos dos fármacos , Percepção Visual/efeitos dos fármacos , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/patologia , Córtex Cerebral/patologia , Interpretação Estatística de Dados , Progressão da Doença , Feminino , Fixação Ocular , Humanos , Processamento de Imagem Assistida por Computador , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Percepção de Movimento/fisiologia , Córtex Motor/patologia , Testes Neuropsicológicos , Oxigênio/sangue , Lobo Parietal/patologia , Estimulação Luminosa , Resultado do Tratamento
15.
Am J Psychol ; 123(4): 447-53, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21291161

RESUMO

In the executive model of deception, the telling of a lie necessitates the inhibition of a veridical prepotent response (the truth), and such inhibition incurs a temporal penalty, manifest as a longer response time. If memory processes are engaged in generating such truths, then memory function should affect truthful and deceptive response times. To investigate this we examined the relationship between performance on a semantic knowledge deception task and a test of verbal memory in 40 college students. We found that verbal memory performance differentially affects the temporal parameters of truth and deception.


Assuntos
Enganação , Função Executiva , Rememoração Mental , Tempo de Reação , Aprendizagem Verbal , Adolescente , Adulto , Feminino , Humanos , Masculino , Revelação da Verdade , Adulto Jovem
16.
Open Neuroimag J ; 3: 48-53, 2009 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-19572020

RESUMO

Limited behavioural repertoire impacts quality of life in chronic schizophrenia. We have previously shown that the amount of movement exhibited by patients with schizophrenia is positively correlated with the volume of left anterior cingulate cortex and that this quantity of movement can be increased by modafinil. However, increased movement in itself may be of limited clinical significance. Hence, we sought to analyse the 'structure' of spontaneous movement in patients with schizophrenia and to examine whether the chunking of spontaneous activity has a neuroanatomical basis. 'Actiwatches' were used to record spontaneous motor activity over a 20 hour period in sixteen male patients with schizophrenia. Time-series data were analysed for the number of discrete spontaneous activities, which might indicate a degree of structure to ongoing activity. Subjects underwent a whole-brain structural MRI scan. The 'number of discrete movement epochs' correlated with volumes of regions within bilateral rostro-ventral putamen and temporal poles. These data suggest that in people with schizophrenia the volume of bilateral putamen may influence the complexity of their behaviours, as distinct from the overall amount of behaviour. The results are presented in the context of a large body of previous research examining the role of the basal ganglia in motor and cognitive pattern generation.

17.
Psychiatry Res ; 172(3): 175-9, 2009 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-19395244

RESUMO

Of the few studies that have directly investigated the neuroanatomical correlates of delusions in patients with recent-onset schizophrenia, a number have paradoxically reported a positive correlation between delusion severity and regional grey matter volume. In order to explore this relationship, 31 patients with first-episode schizophrenia (FES) underwent a clinical interview and a T1-weighted structural MRI scan. Patients' scores on the Delusions subscale of the Positive and Negative Syndrome Scale were correlated with the volume of every voxel in their grey matter images in SPM99. Patients' delusion scores were found to correlate with the volume of a cluster of voxels located in the dorso-medial frontal cortex, centred on the medial frontal gyrus. Post-hoc analysis revealed that this 'region-of-correlation' was volumetrically reduced in the FES patients relative to a group of 21 matched healthy controls. The results of this study support the hypothesis that while a certain level of structural brain atrophy is necessary for delusion formation in patients with FES, excessive structural atrophy may in fact preclude the formation of highly systematized delusions.


Assuntos
Delusões/patologia , Delusões/psicologia , Lobo Frontal/patologia , Imageamento por Ressonância Magnética , Esquizofrenia/patologia , Psicologia do Esquizofrênico , Adolescente , Adulto , Análise de Variância , Estudos de Casos e Controles , Feminino , Lateralidade Funcional , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Escalas de Graduação Psiquiátrica , Esquizofrenia/diagnóstico , Fatores de Tempo , Adulto Jovem
18.
Psychiatry Res ; 172(2): 109-16, 2009 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-19324533

RESUMO

The neural basis of visuospatial deficits in Alzheimer's disease is unclear. We wished to investigate the neural basis of visuospatial perception in patients with Alzheimer's disease compared with healthy elderly comparison subjects using functional magnetic resonance imaging (fMRI). Twelve patients with AD and thirteen elderly comparison subjects were investigated. The patients were recruited from the local clinic and comparison subjects were from spouses and community. All participants underwent fMRI whilst viewing visuospatial stimuli and structural MRI, and findings were analysed using voxel-based morphometry. The comparison group activated V5, superior parietal lobe, parieto-occipital cortex and premotor cortices. The AD group demonstrated hypoactivation in the above regions and instead showed greater activation in inferior parietal lobule and activated additional areas. There was no structural atrophy above and beyond that found globally in patients in the identified regions of BOLD activation. To our knowledge, this is the first study to explore the neuroanatomy of perception of depth and motion in Alzheimer's disease. These specific functional deficits in AD provide evidence for an underlying patho-physiological basis for the clinically important symptom of visuospatial disorientation in patients with AD.


Assuntos
Doença de Alzheimer/fisiopatologia , Encéfalo/fisiopatologia , Percepção de Profundidade/fisiologia , Percepção de Movimento/fisiologia , Percepção Visual/fisiologia , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/fisiopatologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Testes Neuropsicológicos , Orientação/fisiologia , Oxigênio/sangue , Percepção Espacial/fisiologia , Análise e Desempenho de Tarefas
19.
Neuroimage ; 40(3): 1411-8, 2008 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-18308586

RESUMO

Behavioural and functional anatomical responses exhibited by humans support the hypothesis that deception involves the prefrontal executive. Functional neuroimaging studies have demonstrated that ventrolateral prefrontal cortex (among other areas) is activated during lying, compared with telling the truth. However, despite some consistencies discernible across studies, problems remain concerning experimental validity, e.g., the expediencies of experimenter-sanctioned cued-deception (i.e., subjects being told when to lie); such 'lies' may not have comprised adequate proxies for 'real-life' deception. In this experiment, we attempted to address such confounding issues by designing an fMRI paradigm in which subjects chose when to lie (thereby minimising cue-dependency), using spoken words, concerning intimate material, which they regarded as 'embarrassing'; and where further control conditions required them to 'comply' with their examiners or to 'defy' them (by withholding pre-specified responses). The main effect of lying revealed significant activation of ventrolateral prefrontal cortices. These results replicate and extend our previous findings to those circumstances under which subjects are allowed to choose when to deceive.


Assuntos
Detecção de Mentiras/psicologia , Córtex Pré-Frontal/fisiologia , Voz/fisiologia , Adulto , Mapeamento Encefálico , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
20.
Prog Neuropsychopharmacol Biol Psychiatry ; 32(2): 531-8, 2008 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-18061326

RESUMO

OBJECTIVE: This study explored the concurrent courses of the neuroanatomical and neuropsychological changes that occurred over the first 2-3 years of illness in patients with first-episode schizophrenia (FES). METHODS: Fifty-two patients with FES underwent neuropsychological testing and a structural magnetic resonance imaging (sMRI) scan within three months of their first presentation to mental health services with psychotic symptoms (time1). Patients' cognitive performance was evaluated via an extensive neuropsychological test battery, which assessed 9 cognitive domains. Of the 52 patients at time1, 32 returned 2-3 years later (time2) for follow-up neuropsychological testing, and 20 of these also underwent follow-up sMRI. MR images were preprocessed in SPM99. Grey matter volumes of patients' whole-brain, frontal lobes and temporal lobes were calculated by convolving the preprocessed images with manually-drawn binary masks. RESULTS: Patients exhibited longitudinal improvements in full-scale IQ, performance IQ and visual memory. In contrast, concurrent reductions in grey matter were observed for the whole-brain (3% reduction) and the frontal lobe (3.65% reduction). Furthermore, the extent of patients' whole-brain and frontal-lobe grey matter changes were positively correlated with longitudinal changes in verbal learning and memory. DISCUSSION: The results of this study suggest that while the early stages of schizophrenia are associated with a mild improvement in patients' overall cognitive functioning, they are also associated with progressive grey matter atrophy.


Assuntos
Encéfalo/patologia , Testes Neuropsicológicos/estatística & dados numéricos , Esquizofrenia/diagnóstico , Psicologia do Esquizofrênico , Adolescente , Adulto , Atrofia/patologia , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/patologia , Transtornos Cognitivos/psicologia , Feminino , Seguimentos , Lobo Frontal/patologia , Humanos , Testes de Inteligência/estatística & dados numéricos , Estudos Longitudinais , Imageamento por Ressonância Magnética/estatística & dados numéricos , Masculino , Transtornos da Memória/diagnóstico , Transtornos da Memória/psicologia , Estudos Prospectivos , Esquizofrenia/patologia , Lobo Temporal/patologia , Aprendizagem Verbal/classificação
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