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1.
BMC Med ; 21(1): 445, 2023 11 16.
Artículo en Inglés | MEDLINE | ID: mdl-37974189

RESUMEN

BACKGROUND: Acquired brain injury (ABI) is linked to increased depression risk. Existing therapies for depression in ABI (e.g., cognitive behavioural therapy) have mixed efficacy. Behavioural activation (BA), an intervention that encourages engaging in positively reinforcing activities, shows promise. The primary aims were to assess feasibility, acceptability, and potential efficacy of two 8-week BA groups. METHODS: Adults (≥ 18 years) recruited from local ABI services, charities, and self-referral via social media were randomised to condition. The Activity Planning group (AP; "traditional" BA) trained participants to plan reinforcing activities over 8 weeks. The Activity Engagement group (AE; "experiential" BA) encouraged engagement in positive activities within session only. Both BA groups were compared to an 8-week Waitlist group (WL). The primary outcomes, feasibility and acceptability, were assessed via recruitment, retention, attendance, and qualitative feedback on groups. The secondary outcome, potential efficacy, was assessed via blinded assessments of self-reported activity levels, depression, and anxiety (at pre- and post-intervention and 1 month follow-up) and were compared across trial arms. Data were collected in-person and remotely due to COVID-19. RESULTS: N = 60 participants were randomised to AP (randomised n = 22; total n = 29), AE (randomised n = 22; total n = 28), or re-randomised following WL (total n = 16). Whether in-person or remote, AP and AE were rated as similarly enjoyable and helpful. In exploring efficacy, 58.33% of AP members had clinically meaningful activity level improvements, relative to 50% AE and 38.5% WL. Both AP and AE groups had depression reductions relative to WL, but only AP participants demonstrated anxiety reductions relative to AE and WL. AP participants noted benefits of learning strategies to increase activities and learning from other group members. AE participants valued social discussion and choice in selecting in-session activities. CONCLUSIONS: Both in-person and remote group BA were feasible and acceptable in ABI. Though both traditional and experiential BA may be effective, these may have different mechanisms. TRIAL REGISTRATION: Clinicaltrials.gov, NCT03874650. Protocol version 2.3, May 26 2020.


Asunto(s)
Acer , Lesiones Encefálicas , Terapia Cognitivo-Conductual , Adulto , Humanos , Lesiones Encefálicas/terapia , Terapia Cognitivo-Conductual/métodos , Estudios de Factibilidad , Satisfacción Personal , Proyectos Piloto
2.
Neuropsychol Rehabil ; 32(10): 2603-2627, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34505555

RESUMEN

Cognitive difficulties are common following stroke and can have widespread impacts on everyday functioning. Technological advances offer the possibility of individualized cognitive training for patients at home, potentially providing a low-cost, low-intensity adjunct to rehabilitation services. Using this approach, we have previously demonstrated post-training improvements in attention and everyday functioning in fronto-parietal stroke patients. Here we examine whether these benefits are observed more broadly in a community stroke sample. Eighty patients were randomized to either 4 weeks of online adaptive attention training (SAT), working memory training (WMT) or waitlist (WL). Cognitive and everyday function measures were collected before and after the intervention, and after 3 months. During training, weekly measures of patients' subjective functioning were collected. The training was well received and compliance good. No differences in our primary end-point, spatial bias, or other cognitive functions were observed. However, on patient-reported outcomes, SAT participants showed greater levels of improvement in everyday functioning than WMT or WL participants. In line with our previous work, everyday functioning improvements were greatest for patients with spatial impairments and those who received SAT training. Whether attention training can be recommended for stroke survivors depends on whether cognitive test performance or everyday functioning is considered more relevant.


Asunto(s)
Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular , Humanos , Entrenamiento Cognitivo , Cognición , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/psicología , Memoria a Corto Plazo , Atención
3.
Neuropsychol Rehabil ; 30(6): 1092-1114, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30569816

RESUMEN

Difficulties with attention are common following stroke, particularly in patients with frontal and parietal damage, and are associated with poor outcome. Home-based online cognitive training may have the potential to provide an efficient and effective way to improve attentional functions in such patients. Little work has been carried out to assess the efficacy of this approach in stroke patients, and the lack of studies with active control conditions and rigorous evaluations of cognitive functioning pre and post-training means understanding is limited as to whether and how such interventions may be effective. Here, in a feasibility pilot study, we compare the effects of 20 days of cognitive training using either novel Selective Attention Training (SAT) or commercial Working Memory Training (WMT) programme, versus a waitlist control on a range of attentional and working memory tasks. We demonstrate separable effects of each training condition, with SAT leading to improvements in spatial and non-spatial aspects of attention and WMT leading to improvements on closely related working memory tasks. In addition, both training groups reported improvements in everyday functioning, which were associated with improvements in attention, suggesting that improving attention may be of particular importance in maximising functional improvements in this patient group.


Asunto(s)
Atención , Disfunción Cognitiva , Remediación Cognitiva , Lóbulo Frontal/patología , Memoria a Corto Plazo , Evaluación de Resultado en la Atención de Salud , Lóbulo Parietal/patología , Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular , Actividades Cotidianas , Adulto , Anciano , Atención/fisiología , Disfunción Cognitiva/etiología , Disfunción Cognitiva/fisiopatología , Disfunción Cognitiva/rehabilitación , Estudios de Factibilidad , Femenino , Humanos , Masculino , Memoria a Corto Plazo/fisiología , Persona de Mediana Edad , Proyectos Piloto , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/patología , Accidente Cerebrovascular/terapia
4.
Br J Clin Psychol ; 58(1): 91-109, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30129665

RESUMEN

OBJECTIVES: Depression, which is common following acquired brain injury (ABI), has been shown to predict cognitive impairment, rehabilitation outcome, and quality of life. Whilst many studies have examined links between depression and cognitive-affective processing in the non-ABI population, their applicability to this important clinical group, where cognitive difficulties can be marked, remains unknown. Here, we investigated biases in prospective cognition, which is known to be disrupted in (non-ABI) depression yet important for well-being. DESIGN: Cross-sectional design with three groups (depressed ABI, non-depressed ABI, and non-ABI control participants). Continuous data were additionally analysed in correlation analyses. METHODS: Individuals with ABI varying in extent of self-reported depression and matched non-ABI control participants completed assessments of mood and prospective cognition (anticipating and imagining future events), alongside background tests of executive function and fluid intelligence. RESULTS: Relative to non-depressed ABI and control participants, depressed ABI individuals demonstrated a reduced positive bias in prospective cognition: whereas non-depressed ABI and control participants generated more examples of likely or possible positive versus negative future events, there was no evidence for such a positive bias in depressed ABI participants. Non-depressed ABI and control participants also reported more vivid mental imagery for positive versus negative future scenarios, whereas such a pattern was not evident in depressed ABI participants. This pattern emerged despite background impairments in fluid intelligence and executive function associated with ABI. CONCLUSIONS: These findings (1) elucidate depression-linked cognitive-affective processes following ABI, where cognitive difficulties are common, and (2) highlight psychological processes associated with depression that are common to ABI and non-ABI populations. PRACTITIONER POINTS: Clinical implications A relative negative bias in future-directed cognition is associated with depressed mood in individuals with chronic ABI. Such processes may contribute to the onset and maintenance of depression following ABI. These findings suggest it may be important to consider a role for prospective cognition in psychological interventions for depression following ABI. Limitations of the study The extent to which depressed mood following ABI is associated with biases in other cognitive domains remains unclear. Whether similar patterns would be observed in acute patients with more profound cognitive difficulties requires further investigation. Despite large effect sizes, our sample size is modest; these effects thus require replication in larger groups.


Asunto(s)
Afecto , Lesiones Encefálicas/fisiopatología , Lesiones Encefálicas/psicología , Cognición , Depresión/complicaciones , Adulto , Anciano , Sesgo , Lesiones Encefálicas/complicaciones , Estudios de Casos y Controles , Estudios Transversales , Función Ejecutiva , Femenino , Humanos , Imaginación , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Calidad de Vida , Autoinforme , Resultado del Tratamiento
5.
Brain ; 135(Pt 7): 2089-102, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22637582

RESUMEN

Although progressive supranuclear palsy is defined by its akinetic rigidity, vertical supranuclear gaze palsy and falls, cognitive impairments are an important determinant of patients' and carers' quality of life. Here, we investigate whether there is a broad deficit of modality-independent social cognition in progressive supranuclear palsy and explore the neural correlates for these. We recruited 23 patients with progressive supranuclear palsy (using clinical diagnostic criteria, nine with subsequent pathological confirmation) and 22 age- and education-matched controls. Participants performed an auditory (voice) emotion recognition test, and a visual and auditory theory of mind test. Twenty-two patients and 20 controls underwent structural magnetic resonance imaging to analyse neural correlates of social cognition deficits using voxel-based morphometry. Patients were impaired on the voice emotion recognition and theory of mind tests but not auditory and visual control conditions. Grey matter atrophy in patients correlated with both voice emotion recognition and theory of mind deficits in the right inferior frontal gyrus, a region associated with prosodic auditory emotion recognition. Theory of mind deficits also correlated with atrophy of the anterior rostral medial frontal cortex, a region associated with theory of mind in health. We conclude that patients with progressive supranuclear palsy have a multimodal deficit in social cognition. This deficit is due, in part, to progressive atrophy in a network of frontal cortical regions linked to the integration of socially relevant stimuli and interpretation of their social meaning. This impairment of social cognition is important to consider for those managing and caring for patients with progressive supranuclear palsy.


Asunto(s)
Mapeo Encefálico/psicología , Trastornos del Conocimiento/patología , Percepción Social , Parálisis Supranuclear Progresiva/patología , Parálisis Supranuclear Progresiva/psicología , Anciano , Atrofia/psicología , Mapeo Encefálico/métodos , Estudios de Casos y Controles , Trastornos del Conocimiento/complicaciones , Trastornos del Conocimiento/psicología , Emociones , Femenino , Lóbulo Frontal/patología , Humanos , Imagen por Resonancia Magnética/métodos , Imagen por Resonancia Magnética/psicología , Masculino , Fibras Nerviosas Mielínicas/patología , Fibras Nerviosas Amielínicas/patología , Pruebas Neuropsicológicas/estadística & datos numéricos , Reconocimiento en Psicología , Parálisis Supranuclear Progresiva/complicaciones , Teoría de la Mente
6.
Assessment ; : 10731911231182693, 2023 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-37357954

RESUMEN

Intolerance of uncertainty (IU) is a risk factor for poor mental health. Acquired brain injury (ABI; for example, stroke, traumatic brain injury) often brings considerable uncertainty and increased mood disorder vulnerability. The Intolerance of Uncertainty Scale-Short Form (IUS-12) is a brief, well-validated IU measure in non-ABI samples, comprising two subscales, namely, Prospective Anxiety and Inhibitory Anxiety. Here, for the first time, we investigated its reliability and validity (N = 118), and factor structure (N = 176), in ABI. Both subscales had high test-retest reliability (intraclass correlation coefficients [ICCs] of .75 and .86) and were significantly associated with mood disorder symptoms. The two-factor model was superior to a one-factor IU model fit. Some fit statistics were less than optimal (standardized root mean square residual [SRMR] = 0.06, root mean square error of approximation [RMSEA] = 0.09); hence, exploration of other factor structures in other ABI samples may be warranted. Nonetheless, the IUS-12 appears suitable in ABI.

7.
BMC Psychol ; 11(1): 207, 2023 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-37443147

RESUMEN

BACKGROUND: Acquired brain injuries (ABI) from stroke, head injury, or resected brain tumours are associated with poor emotional wellbeing and heightened risk of mood disorder. Common sequalae of ABI, such as poor attention and memory, can create barriers to the efficacy of cognitively demanding mood interventions, such as Cognitive Behavioural Therapy (CBT). Behavioural Activation (BA), where individuals plan and engage in reinforcing activities, is a promising alternative due to lower cognitive demands. However, BA was initially developed in clinical populations without ABI where the primary barriers to activity engagement were low mood and anxious avoidance. Additionally, BA can incorporate a range of techniques (e.g., mood monitoring, activity scheduling, targeting avoidance, contingency management) and psychoeducational topics (e.g., mindfulness, managing uncertainty; social/communication skills). Exploring barriers and facilitators to adopting specific BA components in ABI is an important aim. METHODS: Semi-structured interviews were conducted with purposively selected ABI survivors (N = 16) with both low and high depressive symptoms, and family members (N = 7). Questions focused on routine and enjoyable activities, and feedback on 10 different BA techniques and associated psychoeducational topics. Transcripts were analysed using an interpretive description framework. Analysis was informed by field notes, reflexivity diaries, and peer debriefing. RESULTS: The final constructed framework, Creating Sustainable Engagement, comprises a two-tier hierarchy. Higher-level themes concerned core perspectives of BA, regardless of BA component discussed. This included identifying optimal time windows for different BA components (Right Tool at the Right Time), that BA components should, at least initially, not be burdensome or fatiguing (Perceived Effort), that emotional readiness to confront activity-mood relationships should be addressed (Emotional Impact), and that planned BA activities be consistent with individual values (Relation to Values). Lower-level themes concerned specific BA components: Of these, activity scheduling, procedures targeting avoidance, managing uncertainty and social/communication skills were generally well-received, while mood monitoring, contingency management, and mindfulness had mixed feedback. CONCLUSIONS: BA is a widely scalable intervention that can be adapted for ABI. This study provides a novel framework on implementing a range of BA components in ABI and adds to the limited evidence on which components may be particularly suitable.


Asunto(s)
Lesiones Encefálicas , Terapia Cognitivo-Conductual , Humanos , Terapia Conductista , Lesiones Encefálicas/terapia , Lesiones Encefálicas/psicología , Terapia Cognitivo-Conductual/métodos , Emociones , Depresión/psicología
8.
Cereb Cortex ; 20(2): 479-85, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19542474

RESUMEN

Numerous functional neuroimaging studies have observed lateral parietal lobe activation during memory tasks: a surprise to clinicians who have traditionally associated the parietal lobe with spatial attention rather than memory. Recent neuropsychological studies examining episodic recollection after parietal lobe lesions have reported differing results. Performance was preserved in unilateral lesion patients on source memory tasks involving recollecting the context in which stimuli were encountered, and impaired in patients with bilateral parietal lesions on tasks assessing free recall of autobiographical memories. Here, we investigated a number of possible accounts for these differing results. In 3 experiments, patients with bilateral parietal lesions performed as well as controls at source recollection, confirming the previous unilateral lesion results and arguing against an explanation for those results in terms of contralesional compensation. Reducing the behavioral relevance of mnemonic information critical to the source recollection task did not affect performance of the bilateral lesion patients, indicating that the previously observed reduced autobiographical free recall might not be due to impaired bottom-up attention. The bilateral patients did, however, exhibit reduced confidence in their source recollection abilities across the 3 experiments, consistent with a suggestion that parietal lobe lesions might lead to impaired subjective experience of rich episodic recollection.


Asunto(s)
Lateralidad Funcional/fisiología , Trastornos de la Memoria/patología , Trastornos de la Memoria/fisiopatología , Memoria/fisiología , Lóbulo Parietal/anatomía & histología , Lóbulo Parietal/fisiología , Daño Encefálico Crónico/complicaciones , Daño Encefálico Crónico/patología , Daño Encefálico Crónico/fisiopatología , Mapeo Encefálico , Evaluación de la Discapacidad , Dominancia Cerebral/fisiología , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Trastornos de la Memoria/etiología , Recuerdo Mental/fisiología , Persona de Mediana Edad , Pruebas Neuropsicológicas , Desempeño Psicomotor/fisiología
9.
Pilot Feasibility Stud ; 6: 135, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32974044

RESUMEN

BACKGROUND: Acquired brain injury (ABI) affects approximately 79.3 million individuals annually and is linked with elevated rates of depression and low mood. Existing methods for treating depression in ABI have shown mixed efficacy. Behavioural activation (BA) is a potentially promising intervention. Its premise is that individuals with low mood avoid planning and engaging in activities due to low expectations of a positive outcome. Consequently, their exposure to positive reinforcement is reduced, exacerbating low mood. BA aims to break this cycle by encouraging activity planning and engagement. It is unknown whether cognitive demands of traditional BA may undermine efficacy in ABI. Here, we assess the feasibility and acceptability of two groups designed to increase activity engagement. In the activity planning group (traditional BA), the importance of meaningful and positive activity will be discussed and participants encouraged to plan/engage in activities in everyday life. The activity engagement group (experiential BA) instead focuses on engagement in positive experiences (crafts, games, discussion) within the group. The primary aims are to evaluate the feasibility and acceptability of the two groups in ABI. A secondary aim is to explore relative efficacy of the groups compared to an equivalent period of waitlist controls. METHOD: This study outlines a parallel-arm pilot feasibility trial for individuals with low mood and ABI that compares a traditional vs experiential BA group vs waitlist controls. Adults (≥ 18 years) will be recruited from local ABI services and randomised to condition. Feasibility and acceptability will be assessed via recruitment, retention, attendance and participant feedback. Groups will be compared (pre- and post-intervention and 1 month follow-up) by assessing self-reported activity engagement. Secondary outcomes include self-report measures of depression, anxiety, post-traumatic distress related to the ABI, motivation, participation and sense of control over one's life. ETHICS AND DISSEMINATION: The trial has been approved by the Health Research Authority of the NHS in the UK (East of England-Cambridge Central, REF 18/EE/0305). Results will inform future research on interventions for mood in ABI and be disseminated broadly via peer-reviewed journals, conference presentations and social media. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03874650 pre-results. Protocol version 2.1, March 5, 2019.

10.
Neuroimage ; 44(3): 1144-51, 2009 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-18996489

RESUMEN

Behavioural evidence indicates that individual differences in anxiety influence the response to facial signals of threat. Angry and fearful faces represent qualitatively different forms of threat. Fearful faces are thought to signal the presence of a significant, yet undetermined source of danger within the environment, referred to as 'ambiguous threat'. In contrast, angry faces represent a more direct form of threat, often used in face-to-face encounters to exert dominance. Given the inherent differences between anger and fear, we hypothesised that anxiety would modulate the amygdala response to angry faces to a greater extent when attended. Following previous research, we expected anxiety to show a stronger relationship with the amygdala response to unattended fearful faces. In an event-related fMRI study, we presented images of two houses and two faces (consisting of fearful, angry or neutral expressions) in horizontal and vertical pairs around a central fixation cross, with participants instructed to attend to either the face or house stimuli. The results showed that higher anxiety levels produced an increased right amygdala response to viewer directed angry facial expressions (versus neutral or fearful faces) only when attended. By contrast, increased anxiety was associated with a greater left amygdala response to fearful faces (versus neutral or angry faces) in the unattended condition, with only borderline evidence for attended fear (relative to neutral). Our findings demonstrate the striking effects of personality in a non-clinical population, and show how this can distinguish the neural coding of anger and fear faces.


Asunto(s)
Ira , Ansiedad/fisiopatología , Encéfalo/fisiopatología , Potenciales Evocados , Expresión Facial , Miedo , Imagen por Resonancia Magnética , Reconocimiento Visual de Modelos , Adulto , Femenino , Humanos , Masculino
11.
Neuropsychologia ; 47(1): 41-9, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18789956

RESUMEN

Rightward shifts in attention are a common consequence of brain injury. A growing body of evidence appears to suggest that increases in attentional load, and decreases in alertness can lead to rightward shifts in attention in healthy and patient populations. It is unclear however whether these factors affect spatial biases in attention at the level of preparatory control processes or at the level of stimulus driven expression mechanisms. Whilst such effects cannot easily be dissociated behaviourally, the robust association between changes in alpha-band activity and shifts in visual attention provides a neural marker by which the temporal dynamics of effects of attentional load on spatial processing might be examined. Here we use electroencephalography to examine the relationship between modulations in alpha-band activity and behavioural outcome on a dual task paradigm comprising a detection task (t1), closely followed by a temporal order judgment task (t2). We examine the effects of high (respond to t1 and t2) and low (t2 only) attentional load conditions on spatial bias and changes in lateralization of alpha-band activity over the course of the trial. As anticipated a rightward bias in detecting target onsets was observed in the temporal order judgment task (t2) under conditions of high attentional load. This rightward shift in attention was associated with changes in the lateralization of alpha-band activity that occurred only after the presentation of t2, suggesting that attentional load may primarily influence expression mechanisms.


Asunto(s)
Ritmo alfa , Atención/fisiología , Lateralidad Funcional/fisiología , Juicio/fisiología , Percepción Visual/fisiología , Adolescente , Adulto , Mapeo Encefálico , Electroencefalografía/métodos , Femenino , Humanos , Masculino , Estimulación Luminosa , Estadística como Asunto , Adulto Joven
12.
Emotion ; 9(1): 140-5, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19186928

RESUMEN

Temperament research has highlighted the importance of attentional control in both emotion regulation and as a predictor of psychopathology. Enhanced susceptibility to emotional distraction is a key feature of mood disturbance. Whereas many studies have examined the influence of individual differences in anxiety on the disruptive effects of emotional distractors, individual differences in attentional control have been largely neglected. Here we examine, within healthy volunteers, the relative contributions of individual differences in self-reported anxiety and attentional control to distractibility caused by emotional or neutral faces distractors occurring prior to neutral face targets during rapid serial visual presentation. Participants with good attentional control were less affected by both neutral and emotional distractors than participants with poorer attentional control. More pronounced distraction deficits were seen for emotional relative to neutral distractors in individuals with poor attentional control. In contrast state anxiety was not associated with increased emotional distraction. Our findings suggest a protective role of attentional control mechanisms in minimizing the influence of emotional distraction.


Asunto(s)
Afecto , Atención , Estimulación Luminosa , Tiempo de Reacción , Adulto , Cognición , Femenino , Humanos , Masculino , Factores de Tiempo
13.
Neuropsychologia ; 46(7): 1800-12, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18402990

RESUMEN

There has been much recent investigation into the role of parietal cortex in memory retrieval. Proposed hypotheses include attention to internal memorial representations, an episodic working memory-type buffer, and an accumulator of retrieved memorial information. The current investigation used event-related potentials (ERPs) to test the episodic buffer hypothesis, and to assess the memorial contribution of parietal cortex in younger and older adults, and in patients with circumscribed lateral parietal lesions. In a standard recognition memory paradigm, subjects studied color pictures of common objects. One-third of the test items were presented in the same viewpoint as the study phase, one-third were presented in a 90 degrees rotated viewpoint, and one-third were presented in a noncanonical viewpoint. Conflicting with the episodic buffer hypothesis, results revealed that the duration of the parietal old/new effect was longest for the canonical condition and shortest for the noncanonical condition. Results also revealed that older adults demonstrated a diminished parietal old/new effect relative to younger adults. Consistent with previous data reported by Simons et al., patients with lateral parietal lesions showed no behavioral impairment compared to controls. Behavioral and ERP data from parietal lesion patients are presented and discussed. From these results, the authors speculate that the parietal old/new effect may be the neural correlate of an individual's subjective recollective experience.


Asunto(s)
Encefalopatías/fisiopatología , Recuerdo Mental/fisiología , Lóbulo Parietal/fisiología , Reconocimiento en Psicología/fisiología , Percepción Visual/fisiología , Adulto , Factores de Edad , Encefalopatías/diagnóstico , Mapeo Encefálico , Percepción de Color/fisiología , Potenciales Evocados/fisiología , Femenino , Humanos , Juicio/fisiología , Imagen por Resonancia Magnética/estadística & datos numéricos , Masculino , Modelos Neurológicos , Lóbulo Parietal/fisiopatología , Reconocimiento Visual de Modelos/fisiología , Estimulación Luminosa/métodos , Desempeño Psicomotor/fisiología , Tiempo de Reacción/fisiología
14.
Neuropsychologia ; 46(4): 1185-91, 2008 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-17850832

RESUMEN

An intriguing puzzle in cognitive neuroscience over recent years has been the common observation of parietal lobe activation in functional neuroimaging studies during the performance of human memory tasks. These findings have surprised scientists and clinicians because they challenge decades of established thinking that the parietal lobe does not support memory function. However, direct empirical investigation of whether circumscribed parietal lobe lesions might indeed be associated with human memory impairment has been lacking. Here we confirm using functional magnetic resonance imaging that significant parietal lobe activation is observed in healthy volunteers during a task assessing recollection of the context in which events previously occurred. However, patients with parietal lobe lesions that overlap closely with the regions activated in the healthy volunteers nevertheless exhibit normal performance on the same recollection task. Thus, although the processes subserved by the human parietal lobe appear to be recruited to support memory function, they are not a necessary requirement for accurate remembering to occur.


Asunto(s)
Recuerdo Mental/fisiología , Lóbulo Parietal/fisiología , Adolescente , Adulto , Lesiones Encefálicas/patología , Femenino , Lateralidad Funcional , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , Masculino , Pruebas Neuropsicológicas , Oxígeno/sangre , Lóbulo Parietal/irrigación sanguínea , Reconocimiento Visual de Modelos/fisiología , Estimulación Luminosa/métodos
15.
Neuropsychology ; 22(4): 545-52, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18590365

RESUMEN

Research suggests that the severity of left spatial neglect can be modulated by changes in general alertness. Analogous effects in healthy volunteers now suggest that this may reflect an amplified form of a normal pattern. Recent neuropsychological studies also suggest that concurrent cognitive load may exacerbate rightward bias. In this study, for the first time, the authors examined the effect of both factors on spatial bias in healthy volunteers. Participants performed a task in which as many letters as possible needed to be reported from a briefly presented visual array under three conditions (alone, with a syllable-discrimination secondary task and with a pitch-discrimination secondary task). The results confirmed a significant rightward shift associated with time-on-task across all conditions--the first demonstration of such an effect within a fixation controlled, brief presentation task. While the secondary tasks influenced overall visual performance, there was no discernable effect on bias.


Asunto(s)
Sesgo , Cognición/fisiología , Trastornos de la Percepción/fisiopatología , Desempeño Psicomotor/fisiología , Percepción Espacial/fisiología , Percepción Visual/fisiología , Estimulación Acústica , Adulto , Femenino , Lateralidad Funcional/fisiología , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Estimulación Luminosa/métodos , Discriminación de la Altura Tonal/fisiología , Tiempo de Reacción/fisiología , Factores de Tiempo , Conducta Verbal
16.
Neuropsychologia ; 44(8): 1325-35, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16522325

RESUMEN

Lateral attentional bias is common after unilateral brain damage. It has sometimes been proposed that lateral bias is increased by concurrent cognitive demands, perhaps because of lost top-down compensation. However, an important limitation of previous studies is the sole use of right hemisphere patients. Here we employed a dual task paradigm to measure spatial bias on a visual task while manipulating demands of a concurrent auditory task. Bias was examined in patients with left or right parietal lesions and controls. In Experiment 1 the addition of either a non-spatial or spatial auditory task led to a rightward shift in visual bias. This same rightward shift occurred in controls, left parietals and right parietals. Experiment 2 examined whether the participant's response hand affected their bias. In addition, it attempted to distinguish between the hypothesis that modulatory effects are strongly dependent on lateralization of the concurrent task, and the hypothesis that dual tasks cause a general rightward shift. Response hand was found to have no effect on spatial bias. In addition, bias did not differ between left hemisphere (verbal) and right hemisphere (pitch) concurrent tasks, though the trend was for a smaller rightward shift with the verbal task. Our results show that dual tasks do not exacerbate patients' underlying deficits; instead they cause a global shift in attention to the right. This shift may resemble general rightward shifts that have previously been linked to reduced arousal.


Asunto(s)
Sesgo , Daño Encefálico Crónico/patología , Daño Encefálico Crónico/fisiopatología , Lateralidad Funcional/fisiología , Lóbulo Parietal/patología , Conducta Espacial/fisiología , Estimulación Acústica/métodos , Adulto , Anciano , Análisis de Varianza , Atención/fisiología , Mapeo Encefálico , Estudios de Casos y Controles , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Estimulación Luminosa/métodos , Desempeño Psicomotor/fisiología
17.
Front Hum Neurosci ; 7: 24, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23386824

RESUMEN

Attentional control refers to the regulatory processes that ensure that our actions are in accordance with our goals. Dual-system accounts view temperament as consisting of both individual variation in emotionality (e.g., trait anxiety) and variation in regulatory attentional mechanisms that act to modulate emotionality. Increasing evidence links trait variation in attentional control to clinical mood and anxiety disorder symptoms, independent of trait emotionality. Attentional biases to threat have been robustly linked to mood and anxiety disorders. However, the role of variation in attentional control in influencing such biases, and the neural underpinnings of trait variation in attentional control, are unknown. Here, we show that individual differences in trait attentional control, even when accounting for trait and state anxiety, are related to the magnitude of an attentional blink (AB) following threat-related targets. Moreover, we demonstrate that activity in dorso-lateral prefrontal cortex (DLPFC), is observed specifically in relation to control of attention over threatening stimuli, in line with neural theories of attentional control, such as guided activation theory. These results have key implications for neurocognitive theories of attentional bias and emotional resilience.

18.
Cereb Cortex ; 15(10): 1469-84, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-15689522

RESUMEN

A model of normal attentional function, based on the concept of competitive parallel processing, is used to compare attentional deficits following parietal and frontal lobe lesions. Measurements are obtained for visual processing speed, capacity of visual short-term memory (VSTM), spatial bias (bias to left or right hemifield) and top-down control (selective attention based on task relevance). The results show important differences, but also surprising similarities, in parietal and frontal lobe patients. For processing speed and VSTM, deficits are selectively associated with parietal lesions, in particular lesions of the temporoparietal junction. We discuss explanations based on either grey matter or white matter lesions. In striking contrast, measures of attentional weighting (spatial bias and top-down control) are predicted by simple lesion volume. We suggest that attentional weights reflect competition between broadly distributed object representations. Parietal and frontal mechanisms work together, both in weighting by location and weighting by task context.


Asunto(s)
Atención/fisiología , Lóbulo Parietal/fisiología , Corteza Prefrontal/fisiología , Estimulación Acústica , Adulto , Anciano , Percepción Auditiva/fisiología , Neoplasias Encefálicas/psicología , Infarto Cerebral/psicología , Conducta de Elección/fisiología , Discriminación en Psicología/fisiología , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Memoria a Corto Plazo/fisiología , Persona de Mediana Edad , Pruebas Neuropsicológicas , Trastornos de la Percepción/fisiopatología , Estimulación Luminosa , Tiempo de Reacción/fisiología , Reconocimiento en Psicología/fisiología , Percepción Visual/fisiología
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