Category: Brain and Cognition
Converging operations and the role of perceptual and decisional influences on the perception of faces: Neural and behavioral evidence
Published in: Brain and Cognition, Volume 122, April 2018, 59-75
“Theoretical analyses suggest that the regularities indicative of holistic processing can be obtained by combinations of perceptual and decisional factors. Kuefner and colleagues used electrophysiological results to suggest that the composite face effect is driven solely by perceptual factors. Two limitations of their approach are (a) it did not involve behavioral measures of perceptual sensitivity or bias, and (b) it is unclear how the measures used in that study are consistent with other measures of perceptual and decisional processing. Eight observers completed three tasks involving the stimuli used by Kuefner et al.. The first was a direct replication. The second was a complete identification task, associated with the perceptual and decisional distinctions formalized in general recognition theory. The third was an implementation of the Eriksen fianker task, which allows for a pattern of results that have been interpreted in terms of perceptual and decisional influences. While the empirical distinctions used by Kuefner et al. were not consistent with either the EEG data from the other tasks or the established behavioral measures of perceptual sensitivity and decisional bias, the inferences drawn from the EEG and behavioral data from those tasks were consistent with one another, underscoring the importance of converging operations.”
Written by: Rebecca J. Von Der Heide, Michael J. Wenger, Jennifer L. Bittner, Daniel Fitousi
For full text: https://doi.org/10.1016/j.bandc.2018.01.007
Published in: Brain and Cognition, Volume 122, April 2018, 52-58
“Functional connectivity using task-residual data capitalizes on remaining variance after mean task-related signal is removed from a time series. The degree of network specificity in language and attention domains featured by task-residual and resting-state data types were compared. Functional connectivity based on task-residual data evidenced stronger laterality of the language and attention connections and thus greater network specificity compared to resting-state functional connectivity of the same connections. Covariance between network nodes of task-residuals may thus reflect the degree to which two regions are coordinated in their specific activity, rather than a general shared co-activation. Task-residual functional connectivity provides complementary data to that of resting-state, emphasizing network relationships during task engagement.”
Written by: Stella M. Tran, Keith M. McGregor, George Andrew James, Kaundinya Gopinath, Venkatagiri Krishnamurthy, Lisa C. Krishnamurthy, Bruce Crosson
For full text: https://doi.org/10.1016/j.bandc.2018.02.003
Published in: Brain and Cognition, Volume 122, April 2018, 45-51
Obstacle negotiation is a daily activity that requires the integration of sensorimotor and cognitive information. Recent studies provide evidence for the important role of prefrontal cortex during obstacle negotiation. We aimed to explore the effects of obstacle height and available response time on prefrontal activation.
Twenty healthy young adults (age: 30.1 ± 1.0 years; 50% women) walked in an obstacle course while negotiating anticipated and unanticipated obstacles at heights of 50 mm and 100 mm. Prefrontal activation was measured using a functional near-infrared spectroscopy system. Kinect cameras measured the obstacle negotiation strategy. Prefrontal activation was defined based on mean level of HbO2 before, during and after obstacle negotiation and the HbO2 slope from gait initiation and throughout the task. Changes between types of obstacles were assessed using linear-mix models and partial correlation analyses evaluated the relationship between prefrontal activation and the distance between the feet as the subjects traversed the obstacles.
Different obstacle heights showed similar changes in prefrontal activation measures (p > 0.210). However, during unanticipated obstacles, the slope of the HbO2 response was steeper (p = 0.048), as compared to anticipated obstacles. These changes in prefrontal activation during negotiation of unanticipated obstacles were correlated with greater distance of the leading foot after the obstacles (r = 0.831, p = 0.041).
These findings are the first to show that the pattern of prefrontal activation depends on the nature of the obstacle. More specifically, during unanticipated obstacles the recruitment of the prefrontal cortex is faster and greater than during negotiating anticipated obstacles. These results provide evidence of the important role of the prefrontal cortex and the ability of healthy young adults to tailor the activation pattern to different types of obstacles.”
Written by: Inbal Maidan, Shiran Shustak, Topaz Sharon, Hagar Bernad-Elazari, Nimrod Geffen, Nir Giladi, Jeffrey M. Hausdorff, Anat Mirelman
For full text: https://doi.org/10.1016/j.bandc.2018.02.006
More far is more right: Manual and ocular line bisections, but not the Judd illusion, depend on radial space
Published in: Brain and Cognition, Volume 122, April 2018, 34-43
“Line bisection studies generally find a left-to-right shift in bisection bias with increasing distance between the observer and the target line, which may be explained by hemispheric differences in the processing of proximo-distal information. In the present study, the segregation between near and far space was further characterized across the motor system and contextual cues. To this aim, 20 right-handed participants were required to perform a manual bisection task of simple lines presented at three different distances (60, 90, 120 cm). Importantly, the horizontal spatial location of the line was manipulated along with the viewing distance to investigate more deeply the hemispheric engagement in the transition from near to far space. As the motoric component of the manual task producing activations of left premotor and motor areas may be partially responsible for the observed transition, participants were also involved in an ocular bisection task. Further, participants were required to bisect Judd variants of the target lines, which are known to elicit a Müller-Lyer-type illusion. Since the Judd illusion depends on areas in the ventral visual stream, we predicted that line bisections of Judd-type lines would be unaffected by viewing distance. Results showed that manual bisection of simple lines was modulated separately by viewing distance and the hemispace of presentation, with this pattern being similar for ocular bisection. Critically, bisections in the Judd illusion task were not modulated by viewing distance, whether performed by hand or by eye. Overall, these findings support the hypothesis that the right hemisphere plays a dominant role in the processing of space close to the body. They also present novel evidence for a general reduction of this dominance at farther distances, whether hand motor actions are involved or not. Finally, our study documents a dissociation between the processing of pure visuospatial information and that of a visual illusion as a function of viewing distance, supporting more generally the dorsal/near space and the ventral/far space segregation.”
Written by: Luca Rinaldi, Giovanni Bertolini, Christopher J. Bockisch, Angelo Maravita, Luisa Girelli, Peter Brugger
For full text: https://doi.org/10.1016/j.bandc.2018.01.009
Published in: Brain and Cognition, Volume 122, April 2018, 26-33
“One of the most important structural changes that occur in the brain during the course of life relates to the corpus callosum, the largest neural pathway that connects the two cerebral hemispheres. It has been shown that the corpus callosum, and in particular its anterior sections, endures a process of degeneration in ageing. Hence, a primary question is whether such structural changes in the brain of older adults have functional consequences on inter-hemispheric communication. In particular, whether the atrophy of the corpus callosum in ageing may lead to a higher or lower level of inter-hemispheric interference is currently unknown. To investigate this question, we asked young and healthy older adults to perform modified versions of the classic Stroop paradigm in which the target and distracter were spatially separated. Across two experiments, we found that the Stroop effect was significantly reduced in older adults when the two stimuli were distributed in two different hemifields as opposed to the same single hemifield. This new finding suggests that age-related callosal thinning reduces inter-hemispheric interference by facilitating the two hemispheres to process information in parallel.”
Written by: Jean-François Delvenne, Julie Castronovo
For full text: https://doi.org/10.1016/j.bandc.2018.01.008
Association of the N100 TMS-evoked potential with attentional processes: A motor cortex TMS–EEG study
Published in: Brain and Cognition, Volume 122, April 2018, 9-16
“The most thoroughly studied transcranial magnetic stimulation (TMS)-evoked electroencephalogram (EEG) potential (TEP), N100, is often defined as a measure of cortical inhibition.
Aerobic exercise is more effective than goal-based exercise for the treatment of cognition in Parkinson’s disease
Published in: Brain and Cognition, Volume 122, April 2018, 1-8