An Alternative to the Traditional Cold Pressor Test: The Cold Pressor Arm Wrap

Recently research on the relationship between stress and cognition, emotion, and behavior has greatly increased. These advances have yielded insights into important questions ranging from the nature of stress'' influence on addiction¹ to the role of stress in neural changes associated with alterations in decision-making^2,3. As topics being examined by the field evolve, however, so too must the methodologies involved. In this article a practical and effective alternative to a classic stress induction technique, the cold pressor test (CPT), is presented: the cold pressor arm wrap (CPAW). CPT typically involves immersion of a participant''s dominant hand in ice-cold water for a period of time⁴. The technique is associated with robust activation of the sympatho-adrenomedullary (SAM) axis (and release of catecholamines; e.g. adrenaline and noradrenaline) and mild-to-moderate activation of the hypothalamic-pituitary-adrenal (HPA) axis with associated glucocorticoid (e.g. cortisol) release. While CPT has been used in a wide range of studies, it can be impractical to apply in some research environments. For example use of water during, rather than prior to, magnetic resonance imaging (MRI) has the potential to damage sensitive and expensive equipment or interfere with acquisition of MRI signal. The CPAW is a practical and effective alternative to the traditional CPT. Composed of a versatile list of inexpensive and easily acquired components, CPAW makes use of MRI-safe gelpacs cooled to a temperature similar to CPT rather than actual water. Importantly CPAW is associated with levels of SAM and HPA activation comparable to CPT, and can easily be applied in a variety of research contexts. While it is important to maintain specific safety protocols when using the technique, these are easy to implement if planned for. Creation and use of the CPAW will be discussed.     

The PPARδ agonist GW0742 inhibits neuroinflammation,but does not restore neurogenesis or prevent early delayed hippocampal-dependent cognitive impairment after whole-brain irradiation

Brain tumor patients often develop cognitive impairment months to years after partial or fractionated whole-brain irradiation (WBI). Studies suggest that neuroinflammation and decreased hippocampal neurogenesis contribute to the pathogenesis of radiation-induced brain injury. In this study, we determined if the peroxisomal proliferator-activated receptor (PPAR) δ agonist GW0742 can prevent radiation-induced brain injury in C57Bl/6 wild-type (WT) and PPARδ knockout (KO) mice. Dietary GW0742 prevented the acute increase in IL-1β mRNA and ERK phosphorylation measured at 3 h after a single 10-Gy dose of WBI; it also prevented the increase in the number of activated hippocampal microglia 1 week after WBI. In contrast, dietary GW074 failed to prevent the radiation-induced decrease in hippocampal neurogenesis determined 2 months after WBI in WT mice or to mitigate their hippocampal-dependent spatial memory impairment measured 3 months after WBI using the Barnes maze task. PPARδ KO mice exhibited defects including decreased numbers of astrocytes in the dentate gyrus/hilus of the hippocampus and a failure to exhibit a radiation-induced increase in activated hippocampal microglia. Interestingly, the number of astrocytes in the dentate gyrus/hilus was reduced in WT mice, but not in PPARδ KO mice 2 months after WBI. These results demonstrate that, although dietary GW0742 prevents the increase in inflammatory markers and hippocampal microglial activation in WT mice after WBI, it does not restore hippocampal neurogenesis or prevent early delayed hippocampal-dependent cognitive impairment after WBI. Thus, the exact relationship between radiation-induced neuroinflammation, neurogenesis, and cognitive impairment remains elusive.     

The Environments of Our Hominin Ancestors, Tool-usage, and Scenario Visualization

In this paper, I give an account of how our hominin ancestors evolved a conscious ability I call scenario visualization that enabled them to manufacture novel tools so as to survive and flourish in the ever-changing and complex environments in which they lived. I first present the ideas and arguments put forward by evolutionary psychologists that the mind evolved certain mental capacities as adaptive responses to environmental pressures. Specifically, Steven Mithen thinks that the mind has evolved cognitive fluidity, viz., an ability to exchange information flexibly between and among mental modules. Showing the deficiency in Mithen’s view, I then argue that the flexible exchange of information between and among modules together with scenario visualization is what explains the ability to construct the novel tools needed to survive and flourish in the environments in which our hominin ancestors resided. Finally, I trace the development of the multi-purposed javelin, from its meager beginnings as a stick, in order to illustrate scenario visualization in novel tool manufacturing.     

Duelo anticipado en familiares de personas con demencia. Variables psicosociales asociadas y su impacto sobre la salud del cuidador. Una revisión de literatura

IntroductionTaking care of a relative with dementia may be linked to negative consequences for the caregiver. One of the processes that can be experienced is anticipatory grief, that is defined as the feelings of pain and loss that appear in the caregiver before the death of the person cared for.ObjectivesThe review aimed to conceptualize anticipatory grief in this population, to study the related psychosocial variables, and to know the repercussions for the health of the caregiver.MethodA systematic search was made under the directives of PRISMA statement in the ProQuest, PubMed, Web of Science (WOS), and Scopus databases, including studies published in the last 10 years (2013–2023).ResultsA total of 160 articles were obtained, 15 being finally selected. It is observed that anticipatory grief is defined as an ambiguous process since it appeared before the death of the sick family member. Being a female caregiver, spouse of a family member with dementia, having a closer relationship with him and/or having an important responsibility in care, are associated with a greater chance of experiencing anticipatory grief. In relation to the person cared for, if he or she is in a severe phase of the disease, is younger, and/or presents problematic behaviours, there is also greater anticipatory grief in the family caregiver.Anticipatory grief has a significant impact on caregivers’ physical, psychological, and social health, being associated with greater burden, depressive symptomatology, and social isolation.ConclusionsAnticipatory grief turns out to be a relevant concept in the context of dementia, being necessary to include it in intervention programs for this population.     

Epac: new emerging cAMP-binding protein

The well-known second messenger cyclic adenosine monophosphate (cAMP) regulates the morphology and physiology of neurons and thus higher cognitive brain functions. The discovery of exchange protein activated by cAMP (Epac) as a guanine nucleotide exchange factor for Rap GTPases has shed light on protein kinase A (PKA)-independent functions of cAMP signaling in neural tissues. Studies of cAMP-Epac-mediated signaling in neurons under normal and disease conditions also revealed its diverse contributions to neurodevelopment, synaptic remodeling, and neurotransmitter release, as well as learning, memory, and emotion. In this mini-review, the various roles of Epac isoforms, including Epac1 and Epac2, highly expressed in neural tissues are summarized, and controversies or issues are highlighted that need to be resolved to uncover the critical functions of Epac in neural tissues and the potential for a new therapeutic target of mental disorders.     

Multi-dimensional modulations of α and γ cortical dynamics following mindfulness-based cognitive therapy in Major Depressive Disorder

To illuminate candidate neural working mechanisms of Mindfulness-Based Cognitive Therapy (MBCT) in the treatment of recurrent depressive disorder, parallel to the potential interplays between modulations in electro-cortical dynamics and depressive symptom severity and self-compassionate experience. Linear and nonlinear α and γ EEG oscillatory dynamics were examined concomitant to an affective Go/NoGo paradigm, pre-to-post MBCT or natural wait-list, in 51 recurrent depressive patients. Specific EEG variables investigated were; (1) induced event-related (de-) synchronisation (ERD/ERS), (2) evoked power, and (3) inter-/intra-hemispheric coherence. Secondary clinical measures included depressive severity and experiences of self-compassion. MBCT significantly downregulated α and γ power, reflecting increased cortical excitability. Enhanced α-desynchronisation/ERD was observed for negative material opposed to attenuated α-ERD towards positively valenced stimuli, suggesting activation of neural networks usually hypoactive in depression, related to positive emotion regulation. MBCT-related increase in left-intra-hemispheric α-coherence of the fronto-parietal circuit aligned with these synchronisation dynamics. Ameliorated depressive severity and increased self-compassionate experience pre-to-post MBCT correlated with α-ERD change. The multi-dimensional neural mechanisms of MBCT pertain to task-specific linear and non-linear neural synchronisation and connectivity network dynamics. We propose MBCT-related modulations in differing cortical oscillatory bands have discrete excitatory (enacting positive emotionality) and inhibitory (disengaging from negative material) effects, where mediation in the α and γ bands relates to the former.     

Mental content and evolutionary explanation

Cognitive ethology is the comparative study of animal cognition from an evolutionary perspective. As a sub-discipline of biology it shares interest in questions concerning the immediate causes and development of behavior. As a part of ethology it is also concerned with questions about the function and evolution of behavior. I examine some recent work in cognitive ethology, and I argue that the notions of mental content and representation are important to enable researchers to answer questions and state generalizations about the function and volution of behavior.I would like to thank Dorothy Cheney, Keith Donnellan, Alan Nelson, and Robert Seyfarth for their help.     

Traumatic Brain Injury Rehabilitation: QEEG Biofeedback Treatment Protocols

Interventions for improvement of cognitive problems in patients with traumatic brain injury (TBI) include electroencephalography biofeedback, also known as neurofeedback. Quantitative electroencephalography (QEEG) patterns are assessed in TBI patients and then compared to a database obtained from a normative population. Deviations in QEEG patterns from the normative group are the basis for an intervention plan. While QEEG patterns, obtained under an eyes closed, resting condition, provide information about deviations at rest, QEEG patterns obtained while the patient engages in cognitive tasks reflect specific deficiencies in brain functioning. This paper reviews and assesses QEEG patterns collected under both resting conditions as well as cognitive tasks. The article provides a theoretical and empirical base for QEEG interventions with TBI.     

Sweet or not: Using information and cognitive dissonance to nudge children toward healthier food choices

In the interest of public health, it is important to nudge children toward healthier food choices (e.g., beverages with less added sugar). We conducted a field experiment in a peri-urban region in Vietnam to evaluate the effects of information and cognitive dissonance on the food choices of children. Our sample consisted of more than 1200 primary school children, randomly assigned into three groups: control, health information, and health information plus hypocrisy inducement. The third group was intended to raise cognitive dissonance by illustrating the gap between what people know they should do (socially desired behaviors) and what they actually do (transgressions). The results indicate that health information increased the likelihood of selecting milk with less sugar by around 30 %, as compared to the control group. Hypocrisy inducement did not make any additional contribution to healthier food choices. The treatment effects declined when there was a delay between the treatment and the behavioral choice. We discuss the practical implications of our findings for short-term intervention field studies.