Psicologia
http://hdl.handle.net/11201/268
2024-03-29T06:07:39ZA randomized, double-blind, sham-controlled trial of transcranial direct current stimulation in attention-deficit/hyperactivity disorder
http://hdl.handle.net/11201/1710
A randomized, double-blind, sham-controlled trial of transcranial direct current stimulation in attention-deficit/hyperactivity disorder
Cosmo, Camila; Baptista, Abrahão Fontes; Araújo, Arão Nogueira de; Rosário, Raphael Silva do; Miranda, José Garcia Vivas; Montoya Jiménez, Pedro José; Sena, Eduardo Pondé de
BACKGROUND: Current standardized treatments for cognitive impairment in attention-deficit/hyperactivity disorder remain limited and their efficacy restricted. Transcranial direct current stimulation (tDCS) is a promising tool for enhancing cognitive performance in several neuropsychiatric disorders. Nevertheless, the effects of tDCS in reducing cognitive impairment in patients with attention-deficit/hyperactivity disorder (ADHD) have not yet been investigated. METHODS: A parallel, randomized, double-blind, sham-controlled trial was conducted to examine the efficacy of tDCS on the modulation of inhibitory control in adults with ADHD. Thirty patients were randomly allocated to each group and performed a go/no-go task before and after a single session of either anodal stimulation (1 mA) over the left dorsolateral prefrontal cortex or sham stimulation. RESULTS: A nonparametric two-sample Wilcoxon rank-sum (Mann-Whitney) test revealed no significant differences between the two groups of individuals with ADHD (tDCS vs. sham) in regard to behavioral performance in the go/no go tasks. Furthermore, the effect sizes of group differences after treatment for the primary outcome measures-correct responses, impulsivity and omission errors-were small. No adverse events resulting from stimulation were reported. CONCLUSION: According to these findings, there is no evidence in support of the use of anodal stimulation over the left dorsolateral prefrontal cortex as an approach for improving inhibitory control in ADHD patients. To the best of our knowledge, this is the first clinical study to assess the cognitive effects of tDCS in individuals with ADHD. Further research is needed to assess the clinical efficacy of tDCS in this population.
2015-08-12T00:00:00ZActive sampling in visual search is coupled to the cardiac cycle
http://hdl.handle.net/11201/156316
Active sampling in visual search is coupled to the cardiac cycle
Galvez-Pol, A.; McConnell, R.; Kilner, M. J
[eng] Recent research has demonstrated that perception and reasoning vary according to the phase of internal bodily signals such as heartbeat. This has been shown by locking the presentation of sensory events to distinct phases of the cardiac cycle. However, task-relevant information is not usually encountered in such a phase-locked manner nor passively accessed, but rather actively sampled at one's own pace. Moreover, if the phase of the cardiac cycle is an important modulator of perception and cognition, as previously proposed, then the way in which we actively sample the world should be similarly modulated by the phase of the cardiac cycle. Here we tested this by coregistration of eye movements and heartbeat signals while participants freely compared differences between two visual arrays. Across three different analyses, we found a significant coupling of saccades, subsequent fixations, and blinks with the cardiac cycle. More eye movements were generated during the systolic phase of the cardiac cycle, which has been reported as the period of maximal effect of the baroreceptors' activity upon cognition. Conversely, more fixations were found during the diastole phase (quiescent baroreceptors). Lastly, more blinks were generated in the later period of the cardiac cycle. These results suggest that interoceptive and exteroceptive processing do adjust to each other; in our case, by sampling the outer environment during quiescent periods of the inner organism.
Active tactile discrimination is coupled with and modulated by the cardiac cycle
http://hdl.handle.net/11201/160226
Active tactile discrimination is coupled with and modulated by the cardiac cycle
Galvez-Pol, A.; Pavandeep, V.; Villacampa, J.; Kilner, J.M.
[eng] Perception and cognition are modulated by the phase of the cardiac signal in which the stimuli are presented. This has been shown by locking the presentation of stimuli to distinct cardiac phases. However, in everyday life sensory information is not presented in this passive and phase-locked manner, instead we actively move and control our sensors to perceive the world. Whether active sensing is coupled and modulated with the cardiac cycle remains largely unknown. Here, we recorded the electrocardiograms of human participants while they actively performed a tactile grating orientation task. We show that the duration of subjects' touch varied as a function of the cardiac phase in which they initiated it. Touches initiated in the systole phase were held for longer periods of time than touches initiated in the diastole phase. This effect was most pronounced when elongating the duration of the touches to sense the most difficult gratings. Conversely, while touches in the control condition were coupled to the cardiac cycle, their length did not vary as a function of the phase in which these were initiated. Our results reveal that we actively spend more time sensing during systole periods, the cardiac phase associated with lower perceptual sensitivity (vs. diastole). In line with interoceptive inference accounts, these results indicate that we actively adjust the acquisition of sense data to our internal bodily cycles.
Adolescents' alcohol use in botellon and attitudes towards alcohol use and prevention policies
http://hdl.handle.net/11201/152683
Adolescents' alcohol use in botellon and attitudes towards alcohol use and prevention policies
Gervilla, Elena; Quigg, Zara; Duch, Mariàngels; Juan, Montse; Guimaraes, Clarisse
[eng] Alcohol is a common drug misused by young people worldwide. Previous studies have found that attitudes towards heavy consumption are stronger predictors than general norms concerning alcohol. This study aims to explore adolescents' alcohol use and drunkenness, to understand adolescents' attitudes towards alcohol use, drunkenness and prevention approaches, and to explore associations between attitudes and personal alcohol use and demographics. Methods: Cross-sectional face-to-face survey of 410 adolescents (61.2% women) who were socializing at night in the streets of Palma (Spain). Breath Alcohol Concentration (BrAC), self-reported measures of alcohol use and social variables were assessed. Results: 70.7% of respondents had a BrAC score higher than 0. The full sample reported having a mean of 3.9 drunk episodes in the last month, and a mean of 7.34 in Alcohol Use Disorders Identification Test (AUDIT). A total of 30.7% were under the minimum age limit for alcohol drinking in Spain and males showed higher BrAC than females. Bivariate analyses identified some differences in attitudes across participant demographics and personal alcohol use. In conclusion, we found high levels of alcohol use and drunkenness amongst adolescents, and adolescents' attitudes towards drunkenness and prevention approaches were associated with their alcohol consumption as well as with age.