Michal Lavidor - Academia.edu (original) (raw)

Papers by Michal Lavidor

Neuropsychologia, 2020

Previous research has demonstrated that the Action-Observation Network (AON) is involved in both ... more Previous research has demonstrated that the Action-Observation Network (AON) is involved in both emotionalembodiment (empathy) and action-embodiment mechanisms. In the current study, we hypothesized that interfering with the AON will impair action recognition and that this impairment will be modulated by empathy levels. Fifty-two participants conducted a semantic decision task of hand gesture recognition, while we interfered with the AON by applying active (n ¼ 26) or sham (n ¼ 26) transcranial Direct Current Stimulation (tDCS) to the hand area of the primary motor cortex. We found that interfering with the AON impaired the performance of participants with high empathy levels and enhanced the performance of participants with low empathy. This finding suggests that the embodiment module may be flexible, and that it can be enhanced in individuals with low empathy by simple manipulation of motor activation.

Aggression and Violent Behavior, 2017

Martial arts are becoming a mainstream sport for energetic youth and their popularity extends glo... more Martial arts are becoming a mainstream sport for energetic youth and their popularity extends globally. Following a comprehensive search of martial arts research, a critical review of the field and the psychological implications was conducted. The resulting meta-analysis examined the effect of martial arts on problematic externalizing behavior (aggression, anger, and violence). The final meta-analysis included twelve studies, with 507 participants (ages 6 to 18), where study type was a moderator. For nine intervention and longitudinal studies, there was a homogenous effect size of 0.65 (95% CI: 0.11, 1.03) indicating a medium effect, where martial arts improved aggression among the practicing youth. The other three one-time comparisons studies did not yield a homogenous effect size. Based on these analyses, it appears that martial arts has a potential to reduce externalizing behaviors in youth, although further research is needed to determine the mechanisms of change and specify the most relevant population groups for targeted interventions.

Frontiers in Neuroscience, Feb 14, 2012

The process of evaluating risks and benefits involves a complex neural network that includes the ... more The process of evaluating risks and benefits involves a complex neural network that includes the dorsolateral prefrontal cortex (DLPFC). It has been proposed that in conflict and reward situations, theta-band (4-8 Hz) oscillatory activity in the frontal cortex may reflect an electrophysiological mechanism for coordinating neural networks monitoring behavior, as well as facilitating task-specific adaptive changes. The goal of the present study was to investigate the hypothesis that theta-band oscillatory balance between right and left frontal and prefrontal regions, with a predominance role to the right hemisphere (RH), is crucial for regulatory control during decision-making under risk. In order to explore this hypothesis, we used transcranial alternating current stimulation, a novel technique that provides the opportunity to explore the functional role of neuronal oscillatory activities and to establish a causal link between specific oscillations and functional lateralization in ri...

Clinical Neurophysiology, 2011

Symmetry, 2021

The AB refers to the performance impairment that occurs when visual selective attention is overlo... more The AB refers to the performance impairment that occurs when visual selective attention is overloaded through the very rapid succession of two targets (T1 and T2) among distractors by using the rapid serial visual presentation task (RSVP). Under these conditions, performance is typically impaired when T2 is presented within 200–500 ms from T1 (AB). Based on neuroimaging studies suggesting a role of top-down attention and working memory brain hubs in the AB, here we potentiated via anodal or sham tDCS the activity of the right DLPFC (F4) and of the right PPC (P4) during an AB task. The findings showed that anodal tDCS over the F4 and over P4 had similar effects on the AB. Importantly, potentiating the activity of the right frontoparietal network via anodal tDCS only benefitted poor performers, reducing the AB, whereas in good performers it accentuated the AB. The contribution of the present findings is twofold: it shows both top-down and bottom-up contributions of the right frontopar...

The Semantic Radical Combinability Effects in Chinese Character Recognition: an rTMS study Janet ... more The Semantic Radical Combinability Effects in Chinese Character Recognition: an rTMS study Janet Hui-wen Hsiao (h.hsiao@sms.ed.ac.uk) Richard Shillcock (rcs@inf.ed.ac.uk) School of Informatics, University of Edinburgh, 2 Buccleuch Place, Edinburgh EH8 9LW, UK Michal Lavidor (m.lavidor@hull.ac.uk) Department of Psychology, University of Hull, Cottingham Road, Hull HU6 7RX, UK Whether the human foveal representation is split along a vertical meridian and contralaterally projected to the two hemispheres has until recently been a controversial issue. Lavidor and Walsh (2003) applied repetitive Transcranial Magnetic Stimulation (rTMS) over left and right occipital cortex to disrupt visual input to the left and right hemispheres in a lexical decision task and examined the extent to which the split fovea claim can account for the recognition of English words controlled for lexical neighbourhoods. Here we describe a further rTMS investigation of the split fovea claim, examining semantic rad...

Symmetry, 2020

The fronto-parietal network is involved in top-down and bottom-up processes necessary to achieve ... more The fronto-parietal network is involved in top-down and bottom-up processes necessary to achieve cognitive control. We investigated the role of asymmetric enhancement of the left dorsolateral prefrontal cortex (lDLPFC) and right posterior parietal cortex (rPPC) in cognitive control under conditions of emotional conflict arising from emotional distractors. The effects of anodal tDCS over the lDLPFC/cathodal over the rPPC and the effects of anodal tDCS over the rPPC/cathodal over the lDLPFC were compared to sham tDCS in a double-blind design. The findings showed that anodal stimulation over the lDLPFC reduced interference from emotional distractors, but only when participants had already gained experience with the task. In contrast, having already performed the task only eliminated facilitation effects for positive stimuli. Importantly, anodal stimulation of the rPPC did not affect distractors’ interference. Therefore, the present findings indicate that the lDLPFC plays a crucial role...

Frontiers in Psychology, 2018

Brain and Cognition, 2002

CaSe AlTeRnAtIoN effects on the two cerebral hemispheres were studied in a lateralized visual lex... more CaSe AlTeRnAtIoN effects on the two cerebral hemispheres were studied in a lateralized visual lexical decision task with 32 right-handed participants. The study aimed to compare two well-known lateralization theories, the two processing modes and the abstractive/form-specific theories, that differ in the predictions regarding case alternation effects on the hemispheres. The experiment employed the masked priming paradigm, where prime and target words were presented in mixed case. The results of the experiment demonstrated no hemispheric differences in priming size when prime and target were similar in (mixed) case, thus were in line with the two modes theory. However, a new interpretation to the abstractive/form-specific model may also account for the results.

Experimental Brain Research, 2019

Transcranial direct current stimulation (tDCS) of 1 mA for 13 min was reported to create a linear... more Transcranial direct current stimulation (tDCS) of 1 mA for 13 min was reported to create a linear inter-dependency between the intensity and duration of the current and the effects of the stimulation. tDCS on the primary motor cortex (M1) has been shown to have an effect on both motor-evoked potential (MEP) and motor learning. However, recent findings have shown that the known linear effect is invalid in a 2 mA stimulation for 20 min, where cathodal stimulation led to excitability, rather than inhibition, as measured by MEP changes. Here we aim to replicate the non-linear effect of cathodal stimulation over the M1, using a cognitive task. Twenty-two healthy subjects participated in three sessions, where they were administered with a 2 mA anodal and cathodal stimulation for 20 min over the left M1, and a sham stimulation, while performing the serial reaction time task (SRTT). The overall analysis failed to show any effects of either polarity of tDCS on SRTT performance and hence did not replicate previous findings. However, given our goal to replicate the previously reported reversed polarity effects on MEP, we conducted an exploratory analysis to see whether there were any more subtle signs of a change in sign of the cathodal effect compared with anodal. Anodal stimulation led to faster performance than cathodal stimulation before 13 min of stimulation have passed, however, after 13 min, the pattern had switched, and performance under cathodal stimulation was faster. We conclude that cathodal tDCS has a non-linear effect, and the known polarity-dependent effects of tDCS shift after 13 min of stimulation, leading to an increased, rather than decreased, excitability.

Experimental psychology, 2017

Research suggests that the action-observation network is involved in both emotional-embodiment (e... more Research suggests that the action-observation network is involved in both emotional-embodiment (empathy) and action-embodiment (imitation) mechanisms. Here we tested whether empathy modulates action-embodiment, hypothesizing that restricting imitation abilities will impair performance in a hand gesture comprehension task. Moreover, we hypothesized that empathy levels will modulate the imitation restriction effect. One hundred twenty participants with a range of empathy scores performed gesture comprehension under restricted and unrestricted hand conditions. Empathetic participants performed better under the unrestricted compared to the restricted condition, and compared to the low empathy participants. Remarkably however, the latter showed the exactly opposite pattern and performed better under the restricted condition. This pattern was not found in a facial expression recognition task. The selective interaction of embodiment restriction and empathy suggests that empathy modulates t...

Social cognitive and affective neuroscience, 2018

Previous research has demonstrated that the Action-Observation Network (AON) is involved in both ... more Previous research has demonstrated that the Action-Observation Network (AON) is involved in both emotional-embodiment (empathy) and action-embodiment mechanisms. In this study, we hypothesized that interfering with the AON will impair action recognition and that this impairment will be modulated by empathy levels. In Experiment 1 (n = 90), participants were asked to recognize facial expressions while their facial motion was restricted. In Experiment 2 (n = 50), we interfered with the AON by applying transcranial Direct Current Stimulation to the motor cortex. In both experiments, we found that interfering with the AON impaired the performance of participants with high empathy levels; however, for the first time, we demonstrated that the interference enhanced the performance of participants with low empathy. This novel finding suggests that the embodiment module may be flexible, and that it can be enhanced in individuals with low empathy by simple manipulation of motor activation.

Brain topography, Jan 7, 2018

Schizophrenia (Sz) is a mental health disorder characterized by severe cognitive, emotional, soci... more Schizophrenia (Sz) is a mental health disorder characterized by severe cognitive, emotional, social, and perceptual deficits. Visual deficits are found in tasks relying on the magnocellular/dorsal stream. In our first experiment we established deficits in global motion processing in Sz patients compared to healthy controls. We used a novel task in which background optic flow produces a distortion of the apparent trajectory of a moving stimulus, leading control participants to provide biased estimates of the true motion trajectory under conditions of global stimulation. Sz patients were significantly less affected by the global background motion, and reported trajectories that were more veridically accurate than those of controls. In order to study the mechanism of this effect, we performed a second experiment where we applied transcranial electrical stimulation over area MT+ to selectively modify global motion processing of optic flow displays in healthy participants. Cathodal and h...

Neuropsychology review, Jan 27, 2017

Persons with Mild Cognitive Impairment (MCI) are at high Alzheimer's Disease (AD) risk but th... more Persons with Mild Cognitive Impairment (MCI) are at high Alzheimer's Disease (AD) risk but the development of sensitive measures to assess subtle cognitive decline in this population poses a major challenge for clinicians and researchers. Eye movement monitoring is a non-invasive, sensitive way to assess subtle cognitive processes in clinical populations. We conducted a critical review and a meta-analysis of the literature on pro and antisaccade paradigm in AD/MCI. The meta-analysis included 20 studies, all of which used the prosaccade paradigm and 13 of which studied the antisaccade paradigm as well. Our meta-analysis showed that AD but not MCI patients showed longer prosaccade latencies when compared to controls. While antisaccade latencies did not differentiate between patients from controls, antisaccade error rate were significantly increased among patients in comparison to controls in over 87% of the studies. These findings highlight antisaccade error rate as a reliable too...

Journal of family psychology : JFP : journal of the Division of Family Psychology of the American Psychological Association (Division 43), Jan 10, 2017

Empathic accuracy (EA; Ickes & Hodges, 2013) is the extent to which people accurately perceive th... more Empathic accuracy (EA; Ickes & Hodges, 2013) is the extent to which people accurately perceive their peers' thoughts, feelings, and other inner mental states. EA has particularly interested researchers in the context of romantic couples. Reviews of the literature suggest a possible link between romantic partners' EA and their relationship satisfaction (Ickes & Simpson, 2001; Sillars & Scott, 1983). To assess the magnitude of this association and examine possible moderators, we performed a meta-analytic review of 21 studies (total N = 2,739 participants) that examined the association between EA and satisfaction. We limited our review to studies measuring EA using the dyadic interaction paradigm (Ickes, Stinson, Bissonnette, & Garcia, 1990). We found a small but significant association between the two (r = .134, p < .05). Subsequent moderation analyses demonstrated that EA for negative emotions (one's accuracy when assessing a partner's negative emotions) was more c...

Neuropsychologia, Jan 20, 2016

For complex linguistic strings such as idioms, making a decision as to the correct meaning may re... more For complex linguistic strings such as idioms, making a decision as to the correct meaning may require complex top-down cognitive control such as the suppression of incorrect alternative meanings. In the study presented here, we used transcranial direct current stimulation to test the hypothesis that a domain general dorsolateral prefrontal cognitive control network is involved in constraining the complex processing involved. Specifically, we sought to test prominent theoretical stances on the division of labour across dorsolateral prefrontal cortex in the left- and right-hemispheres of the brain, including the role of salience and fine vs. coarse semantic coding. 32 healthy young adult participants were randomly allocated to one of two stimulation montage groups (LH anodal/RH cathodal or RH anodal/LH cathodal). Participants were tested twice, completing a semantic decision task after either receiving active or sham stimulation. The semantic decision task required participants to ju...

European Psychologist, 2016

. This paper is aimed at providing an introduction to up-to-date noninvasive brain stimulation to... more . This paper is aimed at providing an introduction to up-to-date noninvasive brain stimulation tools that have been successful in modulating higher-level cognitive functions in healthy individuals. The current review focuses on transcranial electrical stimulation (tES) studies aiming to explore cognitive models from an experimental rather than clinical viewpoint. It focuses primarily on major advances in language, working memory, learning, response inhibition, and other executive functions in healthy individuals, and the use of different methods of electrical brain stimulation such as transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS), and transcranial random noise stimulation (tRNS). The final section summarizes the scientific novelty of the reviewed papers and discusses the possible roles of brain stimulation in future experimental research and clinical applications.

Neural plasticity, 2016

Recently, transcranial alternating current stimulation (tACS) has emerged as a tool to enhance hu... more Recently, transcranial alternating current stimulation (tACS) has emerged as a tool to enhance human cognitive processes. Here, we provide a brief summary of the rationale behind tACS-induced effects on task-relevant brain oscillations and associated cognitive functions and review previous studies in young subjects that have applied tACS in cognitive paradigms. Additionally, we present pilot data where we administered theta-tACS (6 Hz) over the temporoparietal cortex and a supraorbital reference for 20 min during implicit language learning in healthy young (mean/SD age: 22/2) and older (mean/SD age: 66/4) adults, in a sham-controlled crossover design. Linear mixed models revealed significantly increased retrieval accuracy following tACS-accompanied associative learning, after controlling for session order and learning success. These data provide the first implementation of tACS during cognitive performance in older adults and support recent studies suggesting that tACS in the theta ...

Journal of cognitive neuroscience, Jan 17, 2016

The parietal cortex has been implicated in a variety of numerosity and numerical cognition tasks ... more The parietal cortex has been implicated in a variety of numerosity and numerical cognition tasks and was proposed to encompass dedicated neural populations that are tuned for analogue magnitudes as well as for symbolic numerals. Nonetheless, it remains unknown whether the parietal cortex plays a role in approximate numerical averaging (rapid, yet coarse computation of numbers' mean)-a process that is fundamental to preference formation and decision-making. To causally investigate the role of the parietal cortex in numerical averaging, we have conducted a transcranial direct current stimulation (tDCS) study, in which participants were presented with rapid sequences of numbers and asked to convey their intuitive estimation of each sequence's average. During the task, the participant underwent anodal (excitatory) tDCS (or sham), applied either on parietal or frontal region. We found that, although participants exhibit above-chance accuracy in estimating the average of numerical...

Neuropsychologia, 2020

Previous research has demonstrated that the Action-Observation Network (AON) is involved in both ... more Previous research has demonstrated that the Action-Observation Network (AON) is involved in both emotionalembodiment (empathy) and action-embodiment mechanisms. In the current study, we hypothesized that interfering with the AON will impair action recognition and that this impairment will be modulated by empathy levels. Fifty-two participants conducted a semantic decision task of hand gesture recognition, while we interfered with the AON by applying active (n ¼ 26) or sham (n ¼ 26) transcranial Direct Current Stimulation (tDCS) to the hand area of the primary motor cortex. We found that interfering with the AON impaired the performance of participants with high empathy levels and enhanced the performance of participants with low empathy. This finding suggests that the embodiment module may be flexible, and that it can be enhanced in individuals with low empathy by simple manipulation of motor activation.

Aggression and Violent Behavior, 2017

Martial arts are becoming a mainstream sport for energetic youth and their popularity extends glo... more Martial arts are becoming a mainstream sport for energetic youth and their popularity extends globally. Following a comprehensive search of martial arts research, a critical review of the field and the psychological implications was conducted. The resulting meta-analysis examined the effect of martial arts on problematic externalizing behavior (aggression, anger, and violence). The final meta-analysis included twelve studies, with 507 participants (ages 6 to 18), where study type was a moderator. For nine intervention and longitudinal studies, there was a homogenous effect size of 0.65 (95% CI: 0.11, 1.03) indicating a medium effect, where martial arts improved aggression among the practicing youth. The other three one-time comparisons studies did not yield a homogenous effect size. Based on these analyses, it appears that martial arts has a potential to reduce externalizing behaviors in youth, although further research is needed to determine the mechanisms of change and specify the most relevant population groups for targeted interventions.

Frontiers in Neuroscience, Feb 14, 2012

The process of evaluating risks and benefits involves a complex neural network that includes the ... more The process of evaluating risks and benefits involves a complex neural network that includes the dorsolateral prefrontal cortex (DLPFC). It has been proposed that in conflict and reward situations, theta-band (4-8 Hz) oscillatory activity in the frontal cortex may reflect an electrophysiological mechanism for coordinating neural networks monitoring behavior, as well as facilitating task-specific adaptive changes. The goal of the present study was to investigate the hypothesis that theta-band oscillatory balance between right and left frontal and prefrontal regions, with a predominance role to the right hemisphere (RH), is crucial for regulatory control during decision-making under risk. In order to explore this hypothesis, we used transcranial alternating current stimulation, a novel technique that provides the opportunity to explore the functional role of neuronal oscillatory activities and to establish a causal link between specific oscillations and functional lateralization in ri...

Clinical Neurophysiology, 2011

Symmetry, 2021

The AB refers to the performance impairment that occurs when visual selective attention is overlo... more The AB refers to the performance impairment that occurs when visual selective attention is overloaded through the very rapid succession of two targets (T1 and T2) among distractors by using the rapid serial visual presentation task (RSVP). Under these conditions, performance is typically impaired when T2 is presented within 200–500 ms from T1 (AB). Based on neuroimaging studies suggesting a role of top-down attention and working memory brain hubs in the AB, here we potentiated via anodal or sham tDCS the activity of the right DLPFC (F4) and of the right PPC (P4) during an AB task. The findings showed that anodal tDCS over the F4 and over P4 had similar effects on the AB. Importantly, potentiating the activity of the right frontoparietal network via anodal tDCS only benefitted poor performers, reducing the AB, whereas in good performers it accentuated the AB. The contribution of the present findings is twofold: it shows both top-down and bottom-up contributions of the right frontopar...

The Semantic Radical Combinability Effects in Chinese Character Recognition: an rTMS study Janet ... more The Semantic Radical Combinability Effects in Chinese Character Recognition: an rTMS study Janet Hui-wen Hsiao (h.hsiao@sms.ed.ac.uk) Richard Shillcock (rcs@inf.ed.ac.uk) School of Informatics, University of Edinburgh, 2 Buccleuch Place, Edinburgh EH8 9LW, UK Michal Lavidor (m.lavidor@hull.ac.uk) Department of Psychology, University of Hull, Cottingham Road, Hull HU6 7RX, UK Whether the human foveal representation is split along a vertical meridian and contralaterally projected to the two hemispheres has until recently been a controversial issue. Lavidor and Walsh (2003) applied repetitive Transcranial Magnetic Stimulation (rTMS) over left and right occipital cortex to disrupt visual input to the left and right hemispheres in a lexical decision task and examined the extent to which the split fovea claim can account for the recognition of English words controlled for lexical neighbourhoods. Here we describe a further rTMS investigation of the split fovea claim, examining semantic rad...

Symmetry, 2020

The fronto-parietal network is involved in top-down and bottom-up processes necessary to achieve ... more The fronto-parietal network is involved in top-down and bottom-up processes necessary to achieve cognitive control. We investigated the role of asymmetric enhancement of the left dorsolateral prefrontal cortex (lDLPFC) and right posterior parietal cortex (rPPC) in cognitive control under conditions of emotional conflict arising from emotional distractors. The effects of anodal tDCS over the lDLPFC/cathodal over the rPPC and the effects of anodal tDCS over the rPPC/cathodal over the lDLPFC were compared to sham tDCS in a double-blind design. The findings showed that anodal stimulation over the lDLPFC reduced interference from emotional distractors, but only when participants had already gained experience with the task. In contrast, having already performed the task only eliminated facilitation effects for positive stimuli. Importantly, anodal stimulation of the rPPC did not affect distractors’ interference. Therefore, the present findings indicate that the lDLPFC plays a crucial role...

Frontiers in Psychology, 2018

Brain and Cognition, 2002

CaSe AlTeRnAtIoN effects on the two cerebral hemispheres were studied in a lateralized visual lex... more CaSe AlTeRnAtIoN effects on the two cerebral hemispheres were studied in a lateralized visual lexical decision task with 32 right-handed participants. The study aimed to compare two well-known lateralization theories, the two processing modes and the abstractive/form-specific theories, that differ in the predictions regarding case alternation effects on the hemispheres. The experiment employed the masked priming paradigm, where prime and target words were presented in mixed case. The results of the experiment demonstrated no hemispheric differences in priming size when prime and target were similar in (mixed) case, thus were in line with the two modes theory. However, a new interpretation to the abstractive/form-specific model may also account for the results.

Experimental Brain Research, 2019

Transcranial direct current stimulation (tDCS) of 1 mA for 13 min was reported to create a linear... more Transcranial direct current stimulation (tDCS) of 1 mA for 13 min was reported to create a linear inter-dependency between the intensity and duration of the current and the effects of the stimulation. tDCS on the primary motor cortex (M1) has been shown to have an effect on both motor-evoked potential (MEP) and motor learning. However, recent findings have shown that the known linear effect is invalid in a 2 mA stimulation for 20 min, where cathodal stimulation led to excitability, rather than inhibition, as measured by MEP changes. Here we aim to replicate the non-linear effect of cathodal stimulation over the M1, using a cognitive task. Twenty-two healthy subjects participated in three sessions, where they were administered with a 2 mA anodal and cathodal stimulation for 20 min over the left M1, and a sham stimulation, while performing the serial reaction time task (SRTT). The overall analysis failed to show any effects of either polarity of tDCS on SRTT performance and hence did not replicate previous findings. However, given our goal to replicate the previously reported reversed polarity effects on MEP, we conducted an exploratory analysis to see whether there were any more subtle signs of a change in sign of the cathodal effect compared with anodal. Anodal stimulation led to faster performance than cathodal stimulation before 13 min of stimulation have passed, however, after 13 min, the pattern had switched, and performance under cathodal stimulation was faster. We conclude that cathodal tDCS has a non-linear effect, and the known polarity-dependent effects of tDCS shift after 13 min of stimulation, leading to an increased, rather than decreased, excitability.

Experimental psychology, 2017

Research suggests that the action-observation network is involved in both emotional-embodiment (e... more Research suggests that the action-observation network is involved in both emotional-embodiment (empathy) and action-embodiment (imitation) mechanisms. Here we tested whether empathy modulates action-embodiment, hypothesizing that restricting imitation abilities will impair performance in a hand gesture comprehension task. Moreover, we hypothesized that empathy levels will modulate the imitation restriction effect. One hundred twenty participants with a range of empathy scores performed gesture comprehension under restricted and unrestricted hand conditions. Empathetic participants performed better under the unrestricted compared to the restricted condition, and compared to the low empathy participants. Remarkably however, the latter showed the exactly opposite pattern and performed better under the restricted condition. This pattern was not found in a facial expression recognition task. The selective interaction of embodiment restriction and empathy suggests that empathy modulates t...

Social cognitive and affective neuroscience, 2018

Previous research has demonstrated that the Action-Observation Network (AON) is involved in both ... more Previous research has demonstrated that the Action-Observation Network (AON) is involved in both emotional-embodiment (empathy) and action-embodiment mechanisms. In this study, we hypothesized that interfering with the AON will impair action recognition and that this impairment will be modulated by empathy levels. In Experiment 1 (n = 90), participants were asked to recognize facial expressions while their facial motion was restricted. In Experiment 2 (n = 50), we interfered with the AON by applying transcranial Direct Current Stimulation to the motor cortex. In both experiments, we found that interfering with the AON impaired the performance of participants with high empathy levels; however, for the first time, we demonstrated that the interference enhanced the performance of participants with low empathy. This novel finding suggests that the embodiment module may be flexible, and that it can be enhanced in individuals with low empathy by simple manipulation of motor activation.

Brain topography, Jan 7, 2018

Schizophrenia (Sz) is a mental health disorder characterized by severe cognitive, emotional, soci... more Schizophrenia (Sz) is a mental health disorder characterized by severe cognitive, emotional, social, and perceptual deficits. Visual deficits are found in tasks relying on the magnocellular/dorsal stream. In our first experiment we established deficits in global motion processing in Sz patients compared to healthy controls. We used a novel task in which background optic flow produces a distortion of the apparent trajectory of a moving stimulus, leading control participants to provide biased estimates of the true motion trajectory under conditions of global stimulation. Sz patients were significantly less affected by the global background motion, and reported trajectories that were more veridically accurate than those of controls. In order to study the mechanism of this effect, we performed a second experiment where we applied transcranial electrical stimulation over area MT+ to selectively modify global motion processing of optic flow displays in healthy participants. Cathodal and h...

Neuropsychology review, Jan 27, 2017

Persons with Mild Cognitive Impairment (MCI) are at high Alzheimer's Disease (AD) risk but th... more Persons with Mild Cognitive Impairment (MCI) are at high Alzheimer's Disease (AD) risk but the development of sensitive measures to assess subtle cognitive decline in this population poses a major challenge for clinicians and researchers. Eye movement monitoring is a non-invasive, sensitive way to assess subtle cognitive processes in clinical populations. We conducted a critical review and a meta-analysis of the literature on pro and antisaccade paradigm in AD/MCI. The meta-analysis included 20 studies, all of which used the prosaccade paradigm and 13 of which studied the antisaccade paradigm as well. Our meta-analysis showed that AD but not MCI patients showed longer prosaccade latencies when compared to controls. While antisaccade latencies did not differentiate between patients from controls, antisaccade error rate were significantly increased among patients in comparison to controls in over 87% of the studies. These findings highlight antisaccade error rate as a reliable too...

Journal of family psychology : JFP : journal of the Division of Family Psychology of the American Psychological Association (Division 43), Jan 10, 2017

Empathic accuracy (EA; Ickes & Hodges, 2013) is the extent to which people accurately perceive th... more Empathic accuracy (EA; Ickes & Hodges, 2013) is the extent to which people accurately perceive their peers' thoughts, feelings, and other inner mental states. EA has particularly interested researchers in the context of romantic couples. Reviews of the literature suggest a possible link between romantic partners' EA and their relationship satisfaction (Ickes & Simpson, 2001; Sillars & Scott, 1983). To assess the magnitude of this association and examine possible moderators, we performed a meta-analytic review of 21 studies (total N = 2,739 participants) that examined the association between EA and satisfaction. We limited our review to studies measuring EA using the dyadic interaction paradigm (Ickes, Stinson, Bissonnette, & Garcia, 1990). We found a small but significant association between the two (r = .134, p < .05). Subsequent moderation analyses demonstrated that EA for negative emotions (one's accuracy when assessing a partner's negative emotions) was more c...

Neuropsychologia, Jan 20, 2016

For complex linguistic strings such as idioms, making a decision as to the correct meaning may re... more For complex linguistic strings such as idioms, making a decision as to the correct meaning may require complex top-down cognitive control such as the suppression of incorrect alternative meanings. In the study presented here, we used transcranial direct current stimulation to test the hypothesis that a domain general dorsolateral prefrontal cognitive control network is involved in constraining the complex processing involved. Specifically, we sought to test prominent theoretical stances on the division of labour across dorsolateral prefrontal cortex in the left- and right-hemispheres of the brain, including the role of salience and fine vs. coarse semantic coding. 32 healthy young adult participants were randomly allocated to one of two stimulation montage groups (LH anodal/RH cathodal or RH anodal/LH cathodal). Participants were tested twice, completing a semantic decision task after either receiving active or sham stimulation. The semantic decision task required participants to ju...

European Psychologist, 2016

. This paper is aimed at providing an introduction to up-to-date noninvasive brain stimulation to... more . This paper is aimed at providing an introduction to up-to-date noninvasive brain stimulation tools that have been successful in modulating higher-level cognitive functions in healthy individuals. The current review focuses on transcranial electrical stimulation (tES) studies aiming to explore cognitive models from an experimental rather than clinical viewpoint. It focuses primarily on major advances in language, working memory, learning, response inhibition, and other executive functions in healthy individuals, and the use of different methods of electrical brain stimulation such as transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS), and transcranial random noise stimulation (tRNS). The final section summarizes the scientific novelty of the reviewed papers and discusses the possible roles of brain stimulation in future experimental research and clinical applications.

Neural plasticity, 2016

Recently, transcranial alternating current stimulation (tACS) has emerged as a tool to enhance hu... more Recently, transcranial alternating current stimulation (tACS) has emerged as a tool to enhance human cognitive processes. Here, we provide a brief summary of the rationale behind tACS-induced effects on task-relevant brain oscillations and associated cognitive functions and review previous studies in young subjects that have applied tACS in cognitive paradigms. Additionally, we present pilot data where we administered theta-tACS (6 Hz) over the temporoparietal cortex and a supraorbital reference for 20 min during implicit language learning in healthy young (mean/SD age: 22/2) and older (mean/SD age: 66/4) adults, in a sham-controlled crossover design. Linear mixed models revealed significantly increased retrieval accuracy following tACS-accompanied associative learning, after controlling for session order and learning success. These data provide the first implementation of tACS during cognitive performance in older adults and support recent studies suggesting that tACS in the theta ...

Journal of cognitive neuroscience, Jan 17, 2016

The parietal cortex has been implicated in a variety of numerosity and numerical cognition tasks ... more The parietal cortex has been implicated in a variety of numerosity and numerical cognition tasks and was proposed to encompass dedicated neural populations that are tuned for analogue magnitudes as well as for symbolic numerals. Nonetheless, it remains unknown whether the parietal cortex plays a role in approximate numerical averaging (rapid, yet coarse computation of numbers' mean)-a process that is fundamental to preference formation and decision-making. To causally investigate the role of the parietal cortex in numerical averaging, we have conducted a transcranial direct current stimulation (tDCS) study, in which participants were presented with rapid sequences of numbers and asked to convey their intuitive estimation of each sequence's average. During the task, the participant underwent anodal (excitatory) tDCS (or sham), applied either on parietal or frontal region. We found that, although participants exhibit above-chance accuracy in estimating the average of numerical...