Category: Brain and Cognition

Converging operations and the role of perceptual and decisional influences on the perception of faces: Neural and behavioral evidence

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

Abstract
“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

Task-residual functional connectivity of language and attention networks

Task-residual functional connectivity of language and attention networks

Published in: Brain and Cognition, Volume 122, April 2018, 52-58

Abstract
“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

Prefrontal cortex activation during obstacle negotiation: What’s the effect size and timing?

Prefrontal cortex activation during obstacle negotiation: What’s the effect size and timing?

Published in: Brain and Cognition, Volume 122, April 2018, 45-51

Abstract
“Background

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.

Methods

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.

Results

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).

Conclusions

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

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

Abstract
“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

Reduced inter-hemispheric interference in ageing: Evidence from a divided field Stroop paradigm

Reduced inter-hemispheric interference in ageing: Evidence from a divided field Stroop paradigm

Published in: Brain and Cognition, Volume 122, April 2018, 26-33

Abstract
“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

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

Abstract
“The most thoroughly studied transcranial magnetic stimulation (TMS)-evoked electroencephalogram (EEG) potential (TEP), N100, is often defined as a measure of cortical inhibition.

We explored the association of the N100 amplitude with attention in 51 young healthy adults. Navigated TMS with simultaneous EEG registering was applied over the left primary motor cortex at the intensity of 110% of the resting motor threshold. Attention was assessed with the Paced Auditory Serial Addition Test (PASAT).

We found a negative Pearson correlation (p = .023, r = −0.317) between the left centroparietal N100 amplitude and the PASAT score. Of the participants, the 17 with the highest PASAT scores and 17 with the lowes scores were selected for further analysis, in which a significant between-group difference in the left centroparietal N100 was found (p = .017). The topographic specificity of this finding was further confirmed with linear mixed model (LMM) analysis, in which significant differences were detected in the N100 amplitude; most prominently in the left centroparietal region (p = .001). A smaller N100 amplitude was associated with better performance in the attention task.

Our findings suggest that the GABA-B-ergic TEP N100 is associated with attentional processes and thus represents cortical inhibition beyond motor inhibition.”

Written by: Outi Kaarre, Marja Aikia, Elisa Kallioniemi, Mervi Kononen, Virve Kekkonen, Noora Heikkinen, Petri Kivimaki, Tommi Tolmunen, Sara Maatta, Eila Laukkanen
For full text: https://doi.org/10.1016/j.bandc.2018.01.004

The impact of perceptual changes to studied items on ERP correlates of familiarity and recollection is subject to hemispheric asymmetries

The impact of perceptual changes to studied items on ERP correlates of familiarity and recollection is subject to hemispheric asymmetries

Published in: Brain and Cognition, Volume 122, April 2018, 17-25

Abstract
“It is still unclear which role the right hemisphere (RH) preference for perceptually specific and the left hemisphere (LH) bias towards abstract memory representations play at the level of episodic memory retrieval. When stimulus characteristics hampered the retrieval of abstract memory representations, these hemispheric asymmetries have previously only modulated event-related potential (ERP) correlates of recollection (late positive complex, LPC), but not of familiarity (FN400). In the present experiment, we used stimuli which facilitated the retrieval of abstract memory representations. With the divided visual field technique, new items, identical repetitions and color-modified versions of incidentally studied object pictures were presented in either the right (RVF) or the left visual field (LVF). Participants performed a memory inclusion task, in which they had to categorize both identically repeated and color-modified study items as ‘old’. Only ERP, but not behavioral data showed hemispheric asymmetries: Compared to identical repetitions, FN400 and LPC old/new effects for color-modified items were equivalent with RVF/LH presentation, but reduced with LVF/RH presentation. By promoting the use of abstract stimulus information for memory retrieval, we were thus able to show that hemispheric asymmetries in accessing abstract or specific memory representations can modulate ERP correlates of familiarity as well as recollection processes.”

Written by: Kristina Kuper, Hubert D. Zimmer
For full text: https://doi.org/10.1016/j.bandc.2018.01.006

Aerobic exercise is more effective than goal-based exercise for the treatment of cognition in Parkinson’s disease

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

Abstract

Background

Little is known about how different exercise modalities influence cognition in Parkinson’s disease (PD). Moreover, the focus of previous investigations on examining the effects of exercise mainly on executive functions and the exclusion of individuals with cognitive impairment may limit the potential to define exercise as a treatment for cognitive decline in PD.

Objective

The aim of this study was to compare the effects of aerobic and goal-based exercise on five cognitive domains in cognitively normal and impaired individuals with PD.

Methods

Seventy-six individuals with PD were randomly allocated into three groups: Aerobic, Goal-based, and Control. Participants in the exercise groups attended 1-h sessions 3x/week for 12 weeks, while those in the Control group carried on with their regular activities. Changes in cognitive domains were assessed using paper-based neuropsychological tests.

Results

Inhibitory control improved only in the Aerobic group (p = .04), irrespective of participants cognitive status at baseline. Moreover, participants with cognitive impairment in Aerobic group maintained their set-shifting ability, whereas those in the Control group were worse at post-test (p = .014).

Conclusion

This is the first study to show that aerobic exercise is more effective than goal-based exercise for the treatment of cognition in PD with and without cognitive impairment.”

Written by: Carolina R.A. Silveira, Eric A. Roy, Brittany N. Intzandt, Quincy J. Almeida
For full text: https://doi.org/10.1016/j.bandc.2018.01.002

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