Philip Jackson

Publications (40) View all

• Article: The neural network of motor imagery: an ALE meta-analysis.

  Sébastien Hétu, Mathieu Grégoire, Arnaud Saimpont, Michel-Pierre Coll, Fanny Eugène, Pierre-Emmanuel Michon, Philip L Jackson
  [show abstract] [hide abstract]
  ABSTRACT: Motor imagery (MI) or the mental simulation of action is now increasingly being studied using neuroimaging techniques such as positron emission tomography and functional magnetic resonance imaging. The booming interest in capturing the neural underpinning of MI has provided a large amount of data which until now have never been quantitatively summarized. The aim of this activation likelihood estimation (ALE) meta-analysis was to provide a map of the brain structures involved in MI. Combining the data from 75 papers revealed that MI consistently recruits a large fronto-parietal network in addition to subcortical and cerebellar regions. Although the primary motor cortex was not shown to be consistently activated, the MI network includes several regions which are known to play a role during actual motor execution. The body part involved in the movements, the modality of MI and the nature of the MI tasks used all seem to influence the consistency of activation within the general MI network. In addition to providing the first quantitative cortical map of MI, we highlight methodological issues that should be addressed in future research.
  Neuroscience & Biobehavioral Reviews 04/2013; · 8.65 Impact Factor
• Source

  Available from: Philip Jackson

  Article: Impact of social anxiety on social cognition and functioning in patients with recent-onset schizophrenia spectrum disorders.

  Amélie M Achim, Rosalie Ouellet, Marie-Audrey Lavoie, Chantal Vallières, Philip L Jackson, Marc-André Roy
  [show abstract] [hide abstract]
  ABSTRACT: Schizophrenia patients display important rates of comorbid social anxiety disorder (SAD) but few studies have directly examined how SAD affects the presentation of schizophrenia, notably social cognition deficits and functioning. To compare social cognition performance of schizophrenia patients who meet the diagnostic criteria for a comorbid SAD (SZ+) relative to patients without such comorbidity (SZ-) and to determine if the impact of social cognition performance on functioning is moderated by that comorbidity. Social cognition performance (emotion recognition, social knowledge, and mentalizing), a control non-social reasoning task, as well as clinical symptoms and functioning were assessed in 26 patients with comorbid SAD (SZ+), 29 SZ- and 84 healthy controls. Patient groups significantly differed from each other on social knowledge performance, but not in levels of symptoms or overall functioning. Relative to healthy controls, SZ+ were impaired uniquely on mentalizing, whereas SZ- showed a more encompassing social cognition deficit that included mentalizing, social knowledge and non-social reasoning impairments. Mentalizing was the best predictor of functioning across both patient groups. Importantly, non-social reasoning negatively influenced mentalizing and in turn functioning only in the SZ- group. The overall pattern of results indicates common mentalizing deficits in SZ+ and SZ-; however, these deficits appear linked to different underlying deficits and different pathways to functional impact in the two patient subgroups. This study highlights some distinctive characteristics of schizophrenia patients with comorbid SAD and signals a need for further investigations into the sources of the mentalizing and functioning impairments in SZ+ patients.
  Biological Psychiatry 04/2013; 145(1-3):75-81. · 8.28 Impact Factor
• Source

  Available from: Philip Jackson

  Article: Motor Imagery and Aging.

  Arnaud Saimpont, Francine Malouin, Béatrice Tousignant, Philip L Jackson
  [show abstract] [hide abstract]
  ABSTRACT: ABSTRACT Motor imagery (MI) is the mental simulation of an action without its actual execution. It has been successfully used through mental practice-the repetition of imagined movements-to optimize motor function either in sport or rehabilitation settings. Healthy elderly individuals facing age-related impairments in motor function could also benefit from this method of training-retraining. The authors review studies that have investigated MI in physically and mentally healthy adults aged 55 years and older. First, they provide an overview of the psychophysical data on MI in the elderly, which show no changes with aging in the ability to imagine simple-usual movements but reveal some age-related alterations in the mental simulation of difficult-unusual movements. Second, they present emerging neuroimaging and neurostimulation data revealing that the sensorimotor system is engaged during MI in older adults. Finally, the authors emphasize the potential of using mental practice as a safe and easy way to help preserving/improving motor function in the elderly and provide some recommendations for future research in this direction.
  Journal of Motor Behavior 02/2013; · 1.64 Impact Factor
• Article: Social cognition in first-degree relatives of people with schizophrenia: A meta-analysis.

  Marie-Audrey Lavoie, India Plana, Jacinthe Bédard Lacroix, Florence Godmaire-Duhaime, Philip L Jackson, Amélie M Achim
  [show abstract] [hide abstract]
  ABSTRACT: Social cognition is affected in people with schizophrenia, but whether this is the case for healthy relatives of these patients is less clear. The presence of social cognition impairments in relatives would suggest a potential genetic role of social cognition in schizophrenia. To determine whether social cognition is affected in first-degree relatives of people with schizophrenia and examine the impact of potential moderator variables, a meta-analysis of studies investigating at least one domain of social cognition (mentalizing, emotional processing, social perception, social knowledge and/or attributional style) in adult first-degree relatives of patients with schizophrenia was performed. Our inclusion criteria were satisfied by 29 studies, of which 11 evaluated mentalizing, 20 emotional processing, and two social perception. Moderate mean effect sizes were obtained for these three components. Across all studies, effect sizes were significantly correlated with IQ and age differences between groups, calling for careful group matching for future studies. Overall, the results from this meta-analysis highlight that social cognition is globally affected in first-degree relatives of people with schizophrenia, suggesting that social cognition deficits in schizophrenia may be related to a genetic vulnerability for the disorder.
  Psychiatry research. 01/2013;
• Article: The influence of body configuration on motor imagery of walking in younger and older adults.

  A Saimpont, F Malouin, B Tousignant, P L Jackson
  [show abstract] [hide abstract]
  ABSTRACT: Motor imagery (MI) refers to the mental simulation of a movement. It is used as a tool to improve motor function in several populations. In young adults, it has been repeatedly shown that MI of upper-limb movements is facilitated when one's posture is congruent with the movement to simulate. As MI training is notably used for improving locomotor-related activities in older populations, it may be questioned whether subjects' body configuration could also influence MI of walking movements and whether this influence is preserved with age. In the present study, we examined the impact of one's body position (congruent with walking: standing/incongruent with walking: sitting) on the duration of walking simulation over two distances (3m/6m), in 26 young (21 females, 5 males; mean: 23.2 ± 2.4 years) and 26 elderly (18 females, 8 males; mean: 72.7 ± 5.5 years) healthy subjects. It was found that, in both age groups, walking simulation times while standing were shorter than while sitting. Furthermore, walking simulation times in the standing position were closer to actual walking times to cover the same distances. The present findings extend to walking movements the notion that adopting a posture congruent with the movement to imagine facilitates the simulation process. They also suggest that, at least for simple walking tasks, this effect is maintained across the lifespan. The implication of our findings for optimizing MI training of locomotor-related activities is underlined.
  Neuroscience 07/2012; 222:49-57. · 3.38 Impact Factor