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ABSTRACT: The reinforcement sensitivity theory (RST) relates individual differences in reward sensitivity to the activation of the behavioral approach system (BAS). Dopamine-related brain structures have been repeatedly associated with reward processing, but also with cognitive processes such as task switching. In the present study, we examined the association between reward sensitivity and the event-related fMRI BOLD response with set switching in 31 males. As expected, the right inferior frontal cortex (rIFG) and the striatum (i.e. the left putamen) were involved in set-switching activity for the overall sample. Interindividual differences in Gray's reward sensitivity were related to stronger activity in the rIFG and the ventral striatum. Thus, trait reward sensitivity contributed to the modulation of brain responsiveness in set-switching tasks. Having considered previous research, we propose that higher BAS activity is associated with a stronger reward to process a better implementation of goal-directed tasks and the diminished processing of secondary cues.
Social Cognitive and Affective Neuroscience 07/2011; 7(4):423-30. · 6.13 Impact Factor
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ABSTRACT: The reinforcement sensitivity theory (RST) proposed the behavioral activation system (BAS) as a neurobehavioral system that is dependent on dopamine-irrigated structures and that mediates the individual differences in sensitivity and reactivity to appetitive stimuli associated with BAS-related personality traits. Theoretical developments propose that high BAS sensitivity is associated with both enhanced appetitive stimuli processing and the diminished processing of aversive stimuli. The objective of this study was to analyze how individual differences in BAS functioning were associated with brain activation during erotic and aversive picture processing while subjects were involved in a simple goal-directed task. Forty-five male participants took part in this study. The task activation results confirm the activation of the reward and punishment brain-related structures while viewing erotic and aversive pictures, respectively. The SR scores show a positive correlation with activation of the left lateral prefrontal cortex, the mesial prefrontal cortex and the right occipital cortex while viewing erotic pictures, and a negative correlation with the right lateral prefrontal cortex and the left occipital cortex while viewing aversive pictures. In summary, the SR scores modulate the activity of the cortical areas in the prefrontal and the occipital cortices that are proposed to modulate the BAS and the BIS-FFFS.
Social Cognitive and Affective Neuroscience 02/2010; 5(1):18-28. · 6.13 Impact Factor
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ABSTRACT: The Paced Auditory Serial Addition test (PASAT) is a sensitive task for evaluating cognitive impairment in patients with diffuse brain disorders, such as multiple sclerosis patients. Brain areas involved in this task have been investigated in diverse fMRI studies using different methodologies to control the subjects' responses during scanning. Here, we examined the possible differences between overt and covert responses during the PASAT task in 13 volunteers. Results showed similar activations in parietal and frontal brain areas during both versions of the task. The contrast between the two conditions (overt and covert) indicated that differences in these two methodologies were minimal. Unlike the covert condition, the overt version of the task obtained significant activations in the left superior and inferior frontal gyrus, bilateral occipital cortex, caudate nucleus and cerebellum. As expected, no significant overactivations were observed in the covert when compared with the overt condition. Discussion focuses on the lower cost of using verbal responses to monitor performance during the PASAT task, which might be generalisable to other frontal lobe tasks requiring discrete responses.
Human Brain Mapping 07/2008; 29(6):644-50. · 5.88 Impact Factor
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ABSTRACT: Recent fMRI studies have suggested that multiple sclerosis (MS) patients show adaptive cortical changes (i.e., compensatory mechanisms) during motor and cognitive tasks to limit the clinical impact of tissue injury. In this study, we investigated the activation pattern during the auditory n-back working memory (WM) paradigm in a group of 17 MS patients and 10 healthy controls with preserved performance in WM tasks. Compared with healthy controls, MS patients showed significantly greater bilateral activation in prefrontal cortex (BA 44), and the insula. These findings were similar to those obtained in previous studies showing that compensatory mechanisms during WM tasks in MS may be based on the use of prefrontal areas adjacent to those involved in the task.
Human Brain Mapping 06/2007; 28(5):424-30. · 5.88 Impact Factor
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ABSTRACT: We used fMRI to study brain activity associated with the performance of a pre-learned sequence of complex movements of the hand-made unimanually in a group of 13 Parkinson's disease patients and a group of 11 control volunteers. Patients were scanned "off" medication. In controls, sequential movements led to the activation of bilateral sensorimotor and premotor cortex, bilateral inferior parietal cortex, supplementary motor area, bilateral putamen and globus pallidus, and the left ventral lateral nucleus of the thalamus. Sequential movements in the Parkinson's disease group were associated with a similar pattern of activation, although relative decrease of activation in striatum and thalamic areas was observed. Patients in comparison with controls showed a hyperactivation in ipsilateral premotor areas and a hypoactivation in structures of the frontostriatal motor loop. Furthermore, patient scores in the motor scale of the UPDRS correlated positively with the activation thalamus and motor cortical areas during the sequential motor task. We concluded that in Parkinson's disease there is a compensatory mechanism of the dopamine deficit in frontostriatal motor circuits that increases participation in the execution of motor tasks of parietal-lateral premotor circuits.
Brain Research 06/2007; 1147:265-71. · 2.73 Impact Factor
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ABSTRACT: The present study deals with a right-handed female polyglot suffering from a Foreign Accent Syndrome (FAS) which affects her native language (L1), but not her other languages learnt since the age of 12. She had a small infarct in the left corona radiata as the result of a carotid occlusion. Her L1 was Spanish, but she also had a good command of French, English and Catalan (L2). Aphasia tests did not reveal any other significant alteration in any language. Analyses of pre-morbid and post-morbid voice recordings revealed that FAS affected Spanish dramatically, but no important changes were observed for French. Results were interpreted as showing that different brain areas control articulation of L1 and L2 learnt after a critical period.
Neuroreport 11/2004; 15(14):2267-70. · 1.66 Impact Factor
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ABSTRACT: Seven different laboratory measures of impulsivity were administered to a group of 165 school-aged boys. Parents' and teachers' ratings of Attention Deficit and Hyperactivity Disorder and Oppositional/Defiant Disorder were also obtained. Factor analyses of impulsivity measures revealed the existence of a strong Inhibitory Control Factor including measures derived from Stop Task, the Continuous Performance Test, the Matching Familiar Figures Test, and the Circle Tracing Task. Other forms of impulsivity like resistance to interference, the Wisconsin Card Sorting Test and efficiency in the DRL Task loaded on a second independent factor. The Inhibitory Control factor was correlated with ADHD ratings, whereas the second factor was slightly related to the presence of ODD symptoms. Discussion is focused on the relevance of inhibitory control in impulsivity and ADHD research.
Journal of Abnormal Child Psychology 07/2004; 32(3):295-304. · 3.09 Impact Factor
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Cognition & Emotion. 01/2003; 17:951-959.
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ABSTRACT: Word-finding difficulties observed in some patients with anomia have been attributed to an insufficient activation of phonology by semantics. There are, however, few direct tests of this hypothesis. This paper reports the case of FR, who presented with anomic aphasia following temporal lobe epilepsy and a cavernoma in the left superior temporal lobe. His anomic deficit was characterized by: (1) no apparent associated semantic impairment; (2) item consistency for accuracy and errors across different administrations; (3) accuracy strongly correlated with word frequency; and (4) a partial, albeit weak, knowledge of the gender of unnamed items. We conducted a naming experiment in which target pictures were implicitly primed by briefly presented masked words. Results showed that the prior presentation of the written target name improved accuracy. When compared with unprimed trials, the presence of the primes also increased phonological errors and decreased semantic errors. We argue that automatic phonological activation derived directly from the implicit written primes interacted with the remaining phonological input from the picture's semantic representation leading to increased accuracy and a change in the balance of error types.
Brain and Language 12/2001; · 3.12 Impact Factor
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ABSTRACT: The stop-signal task has become one of the most important paradigms for the study of general inhibitory problems in children and adults. The objective of this research has been to study the relationship between personality and performance in the stop-signal task in a sample of female undergraduates. Subjects completed the Sensitivity to Punishment and Sensitivity to Reward Questionnaire, the Eysenck Personality Questionnaire, and the Spielberger trait-anxiety measure. They also completed the stop-task using the tracking method to estimate stop-signal reaction time (SSRT). As expected, higher scores on the Sensitivity to Reward scale and lower scores on the Sensitivity to Punishment scale were associated with general inhibitory deficits. However, the other personality measures were not correlated with SSRT. Discussion concentrates on highlighting the importance of this task for measuring inhibitory deficits, and on the possibility of the existence of different pathways to demonstrate them.
Personality and Individual Differences.
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ABSTRACT: An identity negative priming task was employed to investigate cognitive inhibition in 245 undergraduates. The task presented consecutively a prime and a probe display that contained a target and a distractor. Negative priming is observed when subjects must respond to a target in the probe display that had been a distractor in the prime display. This task also served to study the Eriksen interference effect by comparing a condition in which the target and the distractor had the same identity with a condition in which they had different identities. Subjects completed the Sensitivity to Punishment and Sensitivity to Reward Questionnaire designed to measure Gray's anxiety and impulsivity dimensions. Results showed that impulsives had a lower cognitive inhibition than non-impulsives, whereas impulsive women also showed a greater Eriksen interference effect than non-impulsive women. Furthermore, no differences in task performance were found between anxious and non-anxious groups. Our discussion considers the importance of studying cognitive functioning in personality research.
Personality and Individual Differences.
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ABSTRACT: A Posner covert orienting task was developed to investigate the role of the anterior and posterior attentional networks described by Posner and Petersen (1990) (Posner, M. I., & Petersen, S. E. (1990). The attention system of the human brain. Annual Review of Neuroscience, 13, 25–42.) in attentional biases toward threat-related stimuli observed in non-clinical trait-anxious subjects. This task was administered in two different conditions depending on the informative value of the cue. Subjects had to detect an asterisk target that appeared 100 or 500 ms after the cue. As expected, the anxiety group (measured by the Sensitivity to Punishment scale) was related to a greater tendency to focus on locations where aversive and non-informative cues had appeared. This effect was observed at the 100 ms, but not at the 500 ms SOA, and disappears when cues were informative of target location. We have proposed that non-informative threat-related stimuli would activate the anterior network in anxious but not in non-anxious subjects.
Personality and Individual Differences.
