Activity In Dorsolateral Prefrontal Cortex Research Articles

Resting-State Brain Activity Dysfunctions in Schizophrenia and Their Associations with Negative Symptom Domains: An fMRI Study.

The aim of the present study was to examine the neurobiological correlates of the two negative symptom domains of schizophrenia, the Motivational Deficit domain (including avolition, anhedonia, and asociality) and the Expressive Deficit domain (including blunted affect and alogia), focusing on brain areas that are most commonly found to be associated with negative symptoms in previous literature. Resting-state (rs) fMRI data were analyzed in 62 subjects affected by schizophrenia (SZs) and 46 healthy controls (HCs). The SZs, compared to the HCs, showed higher rs brain activity in the right inferior parietal lobule and the right temporoparietal junction, and lower rs brain activity in the right dorsolateral prefrontal cortex, the bilateral anterior dorsal cingulate cortex, and the ventral and dorsal caudate. Furthermore, in the SZs, the rs brain activity in the left orbitofrontal cortex correlated with negative symptoms (r = -0.436, p = 0.006), in particular with the Motivational Deficit domain (r = -0.424, p = 0.002), even after controlling for confounding factors. The left ventral caudate correlated with negative symptoms (r = -0.407, p = 0.003), especially with the Expressive Deficit domain (r = -0.401, p = 0.003); however, these results seemed to be affected by confounding factors. In line with the literature, our results demonstrated that the two negative symptom domains might be underpinned by different neurobiological mechanisms.

Enhancement of Visuospatial Working Memory by Transcranial Direct Current Stimulation on Prefrontal and Parietal Cortices.

Previous studies have reported dorsolateral prefrontal cortex (DLPFC) and posterior parietal cortex (PPC) activation during the performance of spatial working memory (SWM), therefore this study aims to compare the effect of transcranial direct current stimulation (tDCS) between these two areas. Fifty-four healthy right-handed students (27 women, 27 men; age=24.3±0.2 years) were randomly assigned to an anodal group (n=27) and a sham group (n=27), each of these groups was divided into F4 (representing right DLPFC) or P4 (representing right PPC) subgroups, respectively. A computerized Corsi block tapping (CBT) task was used to measure SWM. The tDCS intervention consisted of five daily sessions with a direct current of 1.5 mA for 15 minutes on the F4 or P4 area of the brain at 24-hour intervals. Significant enhancement of the SWM span as well as a faster response was observed after anodal tDCS in both the anterior and posterior direction. Moreover, stimulation of the left DLPFC induced a faster reaction time compared to the right PPC. Stimulation DLPFC and PPC, as an element of the frontoparietal network, showed SWM enhancement, with the DLPFC being more affected. Our finding provides new evidence to compare the effect of stimulation on the two main activated cortical areas during visual SWM.

Working memory deficit in schizophrenia: a systematic review and meta-analysis of fMRI studies examining frontal and parietal brain activity.

The role of functional magnetic resonance imaging (fMRI) findings in investigation of working memory (WM) deficit in schizophrenia patients is still debatable. The aim of the study was to investigate the role of fMRI findings of the frontal and parietal brain activity in investigation of WM deficit in schizophrenia patients. We used Medline, Embase, and the Cochrane Database to conduct a comprehensive search up to January 2023. Functional MRI findings of schizophrenia patients were compared with healthy patients in comparative studies for assessing their WM capacity in terms of dorsolateral prefrontal cortex and parietal region activation. The Cochrane Risk of Bias Assessment Tool was used to evaluate the research quality. Ten trials and 676 schizophrenia patients were included in our analysis. For the comparative assessment of primary outcome - alteration in dorsolateral prefrontal cortex and parietal region activity in schizophrenic patients versus healthy controls - we found the pooled odds ratio (OR) of 1.58 [95% CI: 1.09-2.29], I 2 = 61% and p = 0.01 and risk ratio (RR) was 1.27 [95% CI: 1.06-1.53], I 2 = 55% and p = 0.01. The AUC value of 0.944 indicates a favourable overall diagnostic performance of fMRI for the diagnosis of schizophrenia. fMRI findings showing abnormalities in the parietal and frontal regions can be used to study schizophrenia patients' WM deficits.

Clinical Practice Guidelines for the Therapeutic Use of Repetitive Transcranial Magnetic Stimulation in Neuropsychiatric Disorders.

Clinical Practice Guidelines for the Therapeutic Use of Repetitive Transcranial Magnetic Stimulation in Neuropsychiatric Disorders.

Effects of Personalized Cognitive Training Using Mental Workload Monitoring on Executive Function in Older Adults With Mild Cognitive Impairment.

Although a variety of cognitive training has been performed, its optimally personalized delivery is still unknown. This study established the mental workload classification model using a convolutional neural network based on functional near-infrared spectroscopy-derived data. The dorsolateral prefrontal cortex (DLPFC) while thirty individuals with mild cognitive impairment (MCI) performed spatial working memory testing was found to be a considerable indicator to classify 3 levels of mental workload with an accuracy of over 86%. In the next step, forty subjects with MCI were randomly allocated into the experimental group (EG) that received cognitive training with mental workload-based difficulty adjustment or the control group (CG) that received conventional cognitive training. To compare both groups, the Trail Making Test Part B (TMT-B) and hemodynamic responses in the DLPFC during the TMT-B were measured. After the 16 training sessions, the EG subjects achieved a greater improvement in the TMT-B than the CG subjects (p < 0.05). Also, the EG subject showed a significantly lower DLPFC activity during the TMT-B than the CG subject (p < 0.05). In sum, the EG subjects better performed executive function with lower energy from the DLPFC. These findings imply that the importance of mental workload monitoring to provide personalized cognitive training.

Effects of nonsocial and circumscribed interest images on neural mechanisms of emotion regulation in autistic adults.

Emotion dysregulation is commonly reported among autistic individuals. Prior work investigating the neurofunctional mechanisms of emotion regulation (ER) in autistic adults has illustrated alterations in dorsolateral prefrontal cortex (dlPFC) activity, as well as concurrent atypical patterns of activation in subcortical regions related to affect during cognitive reappraisal of social images. Whereas most research examining ER in autism has focused on regulation of negative emotions, the effects of regulating positive emotions has been generally understudied. This is surprising given the relevance of positive motivational states to understanding circumscribed interests (CI) in autism. Accordingly, the purpose of this study was to use fMRI with simultaneous eye-tracking and pupillometry to investigate the neural mechanisms of ER during passive viewing and cognitive reappraisal of a standardized set of nonsocial images and personalized (self-selected) CI images. The autistic group demonstrated comparatively reduced modulation of posterior cingulate cortex (PCC) activation during cognitive reappraisal of CI images compared to viewing of CI, although no eye-tracking/pupillometry differences emerged between-groups. Further, the autistic group demonstrated increased PCC connectivity with left lateral occipital and right supramarginal areas when engaging in cognitive reappraisal vs. viewing CI. In autistic adults, CI may be differentially modulated via PCC. Considering the documented role of the PCC as a core hub of the default mode network, we further postulate that ER of CI could potentially be related to self-referential cognition.

Neural Correlates of Cognitive Load While Playing an Emergency Simulation Game: A Functional Near-Infrared Spectroscopy (fNIRS) Study

Functional near-infrared spectroscopy (fNIRS) provides reliable results for determining cognitive load based on averaged cortical blood flow during multiple repetitions of short cognitive tasks. At the same time, it remains unclear how to use this technique for assessing cognitive load during prolonged single-trial activity. In this study, we used a computer-based emergency simulation game for inducing different levels of cognitive load. We propose a novel approach to measure cognitive load using specific time slots, determined based on simulation log-data interpreted in light of Barrouillet's time-based resource-sharing model. To validate this approach, we compared cortical activity in dorsolateral prefrontal cortex (DLPFC) and left inferior frontal gyrus (IFG) regions measured at four specific time slots during a simulation. We found significant associations between cognitive load and neuronal activity within the DLPFC depending on the chosen time slot, whereas no such dependencies were found for the IFG. These results illustrate how knowledge of task structure could be used advantageously for the identification of cognitive load. Although requiring further investigation in terms of reliability and generalizability, the presented approach can be considered promising evidence that fNIRS might be suitable for more general reliable assessments of cognitive load during prolonged single-trial activities and for real-time adaptations in simulation-based learning environments.

Modulating the Activity of the Right Dorsolateral Prefrontal Cortex Alters Altruism in Situations of Advantageous Inequity

Altruism is highly valued and cherished by human society. However, human preferences and behavior are sensitive to inequality considerations. Currently, remarkably little is known about the neurobiological mechanisms underlying the process of altruistic acts in inequity situations. Therefore, to clarify the causal role of the right dorsolateral prefrontal cortex (rDLPFC) in altruism during situations of advantageous and disadvantageous inequity, we applied transcranial direct current stimulation (tDCS) to demonstrate the involvement of the rDLPFC in altruism in situations of inequity. A total of 71 participants (38 female and 33 male) received anodal tDCS at 1.5 mA over the rDLPFC (n = 38) or the primary visual cortex (n = 33) and subsequently participated in a modified dictator game that measures altruism. We found that anodal tDCS over the rDLPFC decreased subjects’ sensitivity to altruistic efficiency and cost in situations of advantageous inequity. Our results suggested that the rDLPFC plays an important role in overriding self-interest to enforce altruism in situations of advantageous inequity.

The Neural Signature of Impaired Inhibitory Control in Individuals with Heroin Use Disorder.

Heroin addiction imposes a devastating toll on society, with little known about its neurobiology. Excessive salience attribution to drug over nondrug cues/reinforcers, with concomitant inhibitory control decreases, are common mechanisms underlying drug addiction. Although inhibitory control alterations generally culminate in prefrontal cortex (PFC) hypoactivations across drugs of abuse, patterns in individuals with heroin addiction (iHUDs) remain unknown. We used a stop-signal fMRI task designed to meet recent consensus guidelines in mapping inhibitory control in 41 iHUDs and 24 age- and sex-matched healthy controls (HCs). Despite group similarities in the stop-signal response time (SSRT; the classic inhibitory control measure), compared with HCs, iHUDs exhibited impaired target detection sensitivity (proportion of hits in go vs false alarms in stop trials; p = 0.003). Additionally, iHUDs exhibited lower right anterior PFC (aPFC) and dorsolateral PFC (dlPFC) activity during successful versus failed stops (the hallmark inhibitory control contrast). Lower left dlPFC/supplementary motor area (SMA) activity was associated with slower SSRT specifically in iHUDs and lower left aPFC activity with worse target sensitivity across all participants (p < 0.05 corrected). Importantly, in iHUDs, lower left SMA and aPFC activity during inhibitory control was associated with shorter time since last use and higher severity of dependence, respectively (p < 0.05 corrected). Together, results revealed lower perceptual sensitivity and hypoactivations during inhibitory control in cognitive control regions (e.g., aPFC, dlPFC, SMA) as associated with task performance and heroin use severity measures in iHUDs. Such neurobehavioral inhibitory control deficits may contribute to self-control lapses in heroin addiction, constituting targets for prevention and intervention efforts to enhance recovery.SIGNIFICANCE STATEMENT Heroin addiction continues its deadly impact, with little known about the neurobiology of this disorder. Although behavioral and prefrontal cortical impairments in inhibitory control characterize addiction across drugs of abuse, these patterns remain underexplored in heroin addiction. Here, we illustrate a significant behavioral impairment in target discrimination in individuals with heroin addiction compared with matched healthy controls. We further show lower engagement during inhibitory control in the anterior and dorsolateral prefrontal cortex (key regions that regulate cognitive control) as associated with slower stopping, worse discrimination, and heroin use measures. Mapping the neurobiology of inhibitory control in heroin addiction for the first time, we identify potential treatment targets inclusive of prefrontal cortex-mediated cognitive control amenable for neuromodulation en route to recovery.

Differences in right hemisphere fNIRS activation associated with executive network during performance of the lateralized attention network tast by elite, expert and novice ice hockey athletes

ObjectiveWe investigated brain activity associated with executive control attention network in elite, expert, and novice female ice hockey athletes during the revised lateralized attention network tast to determine whether the neural correlates of performance differ by skill level. MethodsWe collected and analyzed functional near-infrared spectroscopy data of 38 participants while performing the revised lateralized attention network tast. ResultsElite players were significantly faster than novices (p = .005), and the experts’ overall accuracy rate (ACC) was higher than that of novices (p = .001). The effect of the executive network on reaction time was higher in novices than in elite players (p = .008) and experts (p = .004). The effect of the executive network on the ACC was lower in elite players than in experts (p = .009) and novices (p = .010). Finally, elite player had higher flanker conflict effects on RT (p = .005) under the invalid cue condition. the effect of the alertness network and orientation on the ACC was lower in elite players than in novices (p = .000) and experts (p = .022). Changes in the blood oxygen level-dependent signal related to the flanker effect were significantly different in the right dorsolateral prefrontal cortex (F=3.980, p = .028) and right inferior frontal gyrus (F=3.703, p = .035) among the three groups. Elit players showed more efficient executive control (reduced conflict effect on ACC) (p = .006)in the RH.The changes related to the effect of blood oxygen level on orienting were significantly different in the right frontal eye fields (F=3.883, p = .030) among the three groups, Accompanied by significant activation of the right dorsolateral prefrontal cortex(p = .026). ConclusionOur findings provide partial evidence of the superior cognitive performance and high neural efficiency of elite ice hockey players during cognitive tasks. These results demonstrate the right hemisphere superiority for executive control.We also found that specific brain activation in hockey players does not show a clear and linear relationship with skill level.

Relationship between Moral Values for Driving Behavior and Brain Activity: An NIRS Study.

Although there are clear moral components to traffic violations and risky and aggressive driving behavior, few studies have examined the relationship between moral values and risky driving. This study aimed to examine the relationship between moral views of driving behavior and brain activity. Twenty healthy drivers participated in this study. A questionnaire regarding their moral values concerning driving behavior was administered to the participants. Brain activity was measured using near-infrared spectroscopy while eliciting moral emotions. Based on the results of the questionnaire, the participants were divided into two groups: one with high moral values and the other with low moral values. Brain activity was statistically compared between the two groups. Both groups had significantly lower activity in the prefrontal cortex during the self-risky driving task. The low moral group had significantly lower activity in the left dorsolateral prefrontal cortex than the high moral group, while it had lower activity in the right dorsolateral prefrontal cortex in the self-risky driving task than in the safe driving task. Regardless of their moral values, the participants were less susceptible to moral emotions during risky driving. Furthermore, our findings suggest that drivers with lower moral values may be even less susceptible to moral emotions.

Neurohemodynamic correlates of BDNF gene expression in schizophrenia patients with working memory deficits: A functional MRI study.

Brain-derived neurotrophic factor (BDNF) is involved in neuroplasticity underlying cognitive deficits, including working memory deficits (WMD), in schizophrenia. Methodological challenges and inconsistencies are reported with peripheral BDNF levels. Left dorsolateral prefrontal cortex (DLPFC) is proposed to underlie WMD, though inconsistently. We aimed to explore the correlations between brain activation during working memory task-based functional Magnetic Resonance Imaging (fMRI) and BDNF gene expression in schizophrenia patients with WMD. 26 patients with schizophrenia with established WMD were recruited for the study. Blood samples were collected to study lymphocyte BDNF gene expression. Patients underwent task-based fMRI to examine the working memory performance and related brain activation. Whole-brain analysis was performed with 2-back >0-back and 2-back >rest contrast. The peak intensity values of the activation were used for correlation analysis. Whole brain analysis with 2-back >rest contrast revealed maximum activation in left DLPFC, Brodmann area 9 (t=10.54, FWE corrected p<0.05). The baseline BDNF gene expression correlated positively with the peak intensity of brain activation in left DLPFC (r=0.365, p=0.033). Negative symptom score negatively correlated with BDNF gene expression (r=-0.499, p=0.005) and left DLPFC fMRI activation (r=-0.393, p=0.023) respectively. We found a significant positive association between BDNF gene expression and the activation of the DLPFC during the working memory task. This novel observation needs further systematic evaluation to establish the potential role of peripheral BDNF expression in WMD in schizophrenia.

Dissociable neural mechanisms of cognition and well-being in youth versus healthy aging.

Mental health, cognition, and their underlying neural processes in healthy aging are rarely studied simultaneously. Here, in a sample of healthy younger (n = 62) and older (n = 54) adults, we compared subjective mental health as well as objective global cognition across several core cognitive domains with simultaneous electroencephalography (EEG). We found significantly greater symptoms of anxiety, depression, and loneliness in youth and in contrast, greater mental well-being in older adults. Yet, global performance across core cognitive domains was significantly worse in older adults. EEG-based source imaging of global cognitive task-evoked processing showed reduced suppression of activity in the anterior medial prefrontal default mode network (DMN) region in older adults relative to youth. Global cognitive performance efficiency was predicted by greater activity in the right dorsolateral prefrontal cortex in younger adults and in contrast, by greater activity in right inferior frontal cortex in older adults. Furthermore, greater mental well-being in older adults related to lesser global task-evoked activity in the posterior DMN. Overall, these results suggest dissociated neural mechanisms underlying global cognition and mental well-being in youth versus healthy aging. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Non-invasive brain stimulation modulates GABAergic activity in neurofibromatosis 1

Neurofibromatosis 1 (NF1) is a single-gene disorder associated with cognitive phenotypes common to neurodevelopmental conditions such as autism. GABAergic dysregulation underlies working memory impairments seen in NF1. This mechanistic experimental study investigates whether application of anodal transcranial direct current stimulation (atDCS) can modulate GABA and working memory in NF1. Thirty-one NF1 adolescents 11–18 years, were recruited to this single-blind sham-controlled cross-over randomized trial. AtDCS or sham stimulation was applied to the left Dorsolateral Prefrontal Cortex (DLPFC) and MR Spectroscopy was collected before and after intervention in the left DLPFC and occipital cortex. Task-related functional MRI was collected before, during, and after stimulation. Higher baseline GABA+ in the left DLPFC was associated with faster response times on baseline working memory measures. AtDCS was seen to significantly reduced GABA+ and increase brain activation in the left DLPFC as compared to sham stimulation. Task performance was worse in the aTDCS group during stimulation but no group differences in behavioural outcomes were observed at the end of stimulation. Although our study suggests aTDCS modulates inhibitory activity in the DLPFC, further work is needed to determine whether repeated sessions of atDCS and strategies such as alternating current stimulation offer a better therapeutic approach.

Medial Prefrontal Cortex Dysfunction Mediates Working Memory Deficits in Patients With Schizophrenia

BackgroundSchizophrenia (SCZ) is marked by working memory (WM) deficits, which predict poor functional outcome. While most functional magnetic resonance imaging studies of WM in SCZ have focused on the dorsolateral prefrontal cortex (PFC), some recent work suggests that the medial PFC (mPFC) may play a role. We investigated whether task-evoked mPFC deactivation is associated with WM performance and whether it mediates deficits in SCZ. In addition, we investigated associations between mPFC deactivation and cortical dopamine release. MethodsPatients with SCZ (n = 41) and healthy control participants (HCs) (n = 40) performed a visual object n-back task during functional magnetic resonance imaging. Dopamine release capacity in mPFC was quantified with [11C]FLB457 in a subset of participants (9 SCZ, 14 HCs) using an amphetamine challenge. Correlations between task-evoked deactivation and performance were assessed in mPFC and dorsolateral PFC masks and were further examined for relationships with diagnosis and dopamine release. ResultsmPFC deactivation was associated with WM task performance, but dorsolateral PFC activation was not. Deactivation in the mPFC was reduced in patients with SCZ relative to HCs and mediated the relationship between diagnosis and WM performance. In addition, mPFC deactivation was significantly and inversely associated with dopamine release capacity across groups and in HCs alone, but not in patients. ConclusionsReduced WM task-evoked mPFC deactivation is a mediator of, and potential substrate for, WM impairment in SCZ, although our study design does not rule out the possibility that these findings could relate to cognition in general rather than WM specifically. We further present preliminary evidence of an inverse association between deactivation during WM tasks and dopamine release capacity in the mPFC.

The associations between suicide-related behaviors, prefrontal dysfunction in emotional cognition, and personality traits in mood disorders

Suicide is a serious public health problem, and it is urgent to identify biomarkers associated with suicide to prevent it. We aimed to clarify the association across suicidal behavior, personality traits, and brain activation by emotional stimulation tasks using near-infrared spectroscopy (NIRS) in patients with mood disorders. 11 mood disorder patients with a history of suicide attempt (MDSA), 18 mood disorder patients with no history of suicide attempt (MDNSA), and 17 healthy individuals were studied. The MDSA patients showed significantly high impulsivity and hopeless compared to healthy subjects, great response to the thread word task in the orbitofrontal cortex (OFC) and dorsolateral prefrontal cortex (DLPFC) compared to MDNSA patients, and the significant correlation between the personality traits and brain activation. The MDNSA did not show the trend. The results suggest that the personality traits and the activation of OFC and DLPFC during the negative emotional cognitive stimuli is associated with suicidal behavior, indicating the findings are involved in the pathophysiology of suicidality in mood disorders.

Pesticide exposure and cortical brain activation among farmworkers in Costa Rica

BackgroundPrevious epidemiological studies have reported associations of pesticide exposure with poor cognitive function and behavioral problems. However, these findings have relied primarily on neuropsychological assessments. Questions remain about the neurobiological effects of pesticide exposure, specifically where in the brain pesticides exert their effects and whether compensatory mechanisms in the brain may have masked pesticide-related associations in studies that relied purely on neuropsychological measures. MethodsWe conducted a functional neuroimaging study in 48 farmworkers from Zarcero County, Costa Rica, in 2016. We measured concentrations of 13 insecticide, fungicide, or herbicide metabolites or parent compounds in urine samples collected during two study visits (approximately 3–5 weeks apart). We assessed cortical brain activation in the prefrontal cortex during tasks of working memory, attention, and cognitive flexibility using functional near-infrared spectroscopy (fNIRS). We estimated associations of pesticide exposure with cortical brain activation using multivariable linear regression models adjusted for age and education level. ResultsWe found that higher concentrations of insecticide metabolites were associated with reduced activation in the prefrontal cortex during a working memory task. For example, 3,5,6-trichloro-2-pyridinol (TCPy; a metabolite of the organophosphate chlorpyrifos) was associated with reduced activation in the left dorsolateral prefrontal cortex (β = −2.3; 95% CI: −3.9, −0.7 per two-fold increase in TCPy). Similarly, 3-phenoxybenzoic acid (3-PBA; a metabolite of pyrethroid insecticides) was associated with bilateral reduced activation in the dorsolateral prefrontal cortices (β = −3.1; 95% CI: −5.0, −1.2 and −2.3; 95% CI: −4.5, −0.2 per two-fold increase in 3-PBA for left and right cortices, respectively). These associations were similar, though weaker, for the attention and cognitive flexibility tasks. We observed null associations of fungicide and herbicide biomarker concentrations with cortical brain activation during the three tasks that were administered. ConclusionOur findings suggest that organophosphate and pyrethroid insecticides may impact cortical brain activation in the prefrontal cortex – neural dynamics that could potentially underlie previously reported associations with cognitive and behavioral function. Furthermore, our study demonstrates the feasibility and utility of fNIRS in epidemiological field studies.

Disrupted network switching in euthymic bipolar disorder: Working memory and self-referential paradigms

BackgroundPatients with bipolar disorder (BD) frequently suffer from neurocognitive deficits that can persist during periods of clinical stability. Specifically, impairments in executive functioning such as working memory and in self-processing have been identified as the main components of the neurocognitive profile observed in euthymic BD patients. The study of the neurobiological correlates of these state-independent alterations may be a prerequisite to develop reliable biomarkers in BD. MethodsA sample of 27 euthymic BD patients and 25 healthy participants (HC) completed working memory and self-referential functional Magnetic Resonance Imaging (fMRI) tasks. Activation maps obtained for each group and contrast images (i.e., 2-back > 1-back/self > control) were used for comparisons between patients and HC. ResultsEuthymic BD patients, in comparison to HC, showed a higher ventromedial prefrontal cortex activation during working memory, a result driven by the lack of deactivation in BD patients. In addition, euthymic BD patients displayed a greater dorsomedial and dorsolateral prefrontal cortex activation during self-reference processing. LimitationsPharmacotherapy was described but not included as a confounder in our models. Sample size was modest. ConclusionOur findings revealed a lack of deactivation in the anterior default mode network (aDMN) during a working memory task, a finding consistent with prior research in BD patients, but also a higher activation in frontal regions within the central executive network (CEN) during self-processing. These results suggest that an imbalance of neural network dynamics underlying external/internal oriented cognition (the CEN and the aDMN, respectively) may be one of the first reliable biomarkers in euthymic bipolar patients.

Age differences in brain activity in dorsolateral prefrontal cortex and supplementary motor areas during three different walking speed tasks.

Functional Near-Infrared Spectrometry (fNIRS) is a novel neuroimaging method that can detect brain activity during functional activities. The prefrontal cortex and supplemental motor area (SMA) are active during normal and fast speed walking. However, it is unclear how age difference affects brain activity in the dorsolateral prefrontal cortex (DLPFC) and SMA when walking at different speeds. The purpose of this study was to investigate the age differences in DLPFC and SMA activation during different walking speeds. 10 younger (5F; 25±8 y.o.) and 10 older adults (5F; 73±6 y.o.) completed three visits in this study. Functional Near-Infrared Spectroscopy was used to detect hemodynamic changes on right and left hemispheres over the DLPFC and SMA during self-selected slow, preferred, and fast walking speeds. The results showed significantly increased DLPFC and SMA activity in older adults compared to younger adults when walking at preferred normal, fast, and slow speeds. Older adults also had a higher left DLPFC activation during preferred fast walking speed than younger adults. The results suggest that there are age differences in the DLPFC and SMA activation, with older adults demonstrating increased DLPFC and SMA activity across all walk conditions compared to younger adults. This may indicate older adults require higher cognitive demand and need to recruit indirect motor pathways when changing gait speed by increasing SMA activation.

The neural correlates and the underlying processes of weak brand choices

Despite the advantages of strong brands over weak brands, consumers often choose weak brands. The authors test two competing explanations that can explain weak brand choices, by exploring the underlying strong/weak brand choice processes. We test these explanations in a simultaneous evaluation and choice-based scenario, using brands from several product categories. Through an fMRI study (and related behavioural studies), we found significant activation in Rostral Anterior Cingulate Cortex (ACC), Dorsal ACC and Right Dorsolateral Prefrontal Cortex (DLPFC) for weak brand choices. Our results suggest that weak brand choice involves an assessment of value/worth, including cognitive control over feelings of conflict, error-commission, and regret. Brain-behaviour correlation analyses, response times in a lexical-decision task, and choice responses in behavioural studies support these inferences. We contribute to the understanding of consumer-based brand equity, brand-affect associations, and joint/separate product evaluations, and also suggest actionable insights for firms/managers to leverage weak brands’ position.