Cognitive and Behavioral Neurology最新文献

Philosophical theories have attempted to shed light on the intricate relationships between consciousness and memory since long before this became a major theme in psychology and neuroscience. In the December 2022 issue of Cognitive and Behavioral Neurology , Budson, Richman, and Kensinger (2022) introduced a comprehensive theoretical framework pertaining to the origins of consciousness in relation to the memory system, its implications on our real-time perception of the world, and the neuroanatomical correlates underlying these phenomena. Throughout their paper, Budson et al (2022) focus on their theory's explanatory value regarding several clinical syndromes and experimental findings. In this commentary, we first summarize the theory presented by Budson and colleagues (2022). Then, we suggest a complementary approach of studying the relationships between consciousness and memory through the concept of the human self and its protracted representation through time (so-called mental time travel). Finally, we elaborate on Budson and colleagues' (2022) neuroanatomical explanation to their theory and suggest that adding the concepts of brain networks and cortical gradients may contribute to their theory's interpretability.

The dehumanization of others is a major scourge of mankind; however, despite its significance, physicians have little understanding of the neurobiological mechanisms for this behavior. We can learn much about dehumanization from its brain-behavior localization and its manifestations in people with brain disorders. Dehumanization as an act of denying to others human qualities includes two major forms. Animalistic dehumanization (also called infrahumanization) results from increased inhibition of prepotent tendencies for emotional feelings and empathy for others. The mechanism may be increased activity in the inferior frontal gyrus. In contrast, mechanistic dehumanization results from a loss of perception of basic human nature and decreased mind-attribution. The mechanism may be hypofunction of a mentalization network centered in the ventromedial prefrontal cortex and adjacent subgenual anterior cingulate cortex. Whereas developmental factors may promote animalistic dehumanization, brain disorders, such as frontotemporal dementia, primarily promote mechanistic dehumanization. The consideration of these two processes as distinct, with different neurobiological origins, could help guide efforts to mitigate expression of this behavior.

Sensory impairments such as age-related hearing loss and poor eyesight have been associated with a negative impact on cognitive screening test scores. Many researchers use cognitive tests and consider factors such as vision and cardiac issues but do not account for hearing loss. We reviewed published literature in the field of gerontology to determine if hearing loss was considered in human subjects research that involved the administration of a cognitive battery or screening test. We present evidence for the need to consider hearing loss when administering cognitive screening tests, as well as recommendations for practitioners and researchers.

Background: Alzheimer disease dementia may be preceded by cognitive stages during which behavioral and psychological changes can occur. More precisely, behavioral symptoms may be observed during the subjective cognitive decline (SCD) or the mild cognitive impairment (MCI) stages; these symptoms can be measured using the Mild Behavioral Impairment Checklist (MBI-C).

Objective: To validate the French-Quebec version of the MBI-C in individuals ages 60-85 years.

Method: The sample included 60 participants (20 MCI, 20 SCD, 20 cognitively healthy) and their informants. To assess the discriminant validity of the MBI-C, a Kruskal-Wallis analysis with a multiple comparisons test was performed on the MBI-C Total score. To determine convergent validity, Spearman correlations were calculated between the MBI-C subscales and a set of validation tools. Finally, test-retest reliability was assessed with Spearman correlations of MBI-C scores between two test sessions.

Results: All of the analyses indicated satisfactory psychometric properties for the French-Quebec version of the MBI-C.

Conclusion: This validation study reveals that the MBI-C can be used successfully in dementia risk assessments. From now on, the use of a validated MBI-C will be possible in the French-Quebec population.

Background: Emotional distress can lead to suicidal ideation and potentially suicide completion, yet there is very little literature on suicidal ideation in individuals with a diagnosis of neurofibromatosis (NF; NF1, NF2, and schwannomatosis).

Objective: To examine the baseline occurrence, severity, and clinical correlates of suicidal ideation in adults with NF.

Method: Individuals with NF (N = 220) completed assessments measuring depression (Patient Health Questionnaire-9), anxiety (Generalized Anxiety Disorder-7), perceived stress (Perceived Stress Scale-10), pain (Graded Chronic Pain Scale and PROMIS Pain Interference Short Form 8a), and general quality of life (World Health Organization Quality of Life-Brief version) before beginning a two-arm, single-blind randomized control trial of a live-video mind-body program for stress management and resiliency.

Results: Nineteen percent (n = 42) of the individuals experienced suicidal ideation (ie, >0; ideation present several days or greater). More individuals with NF2 experienced suicidal ideation compared with those with NF1 or schwannomatosis. All of the clinical variables except pain intensity were significantly correlated ( P < 0.01) with greater suicidal ideation. Suicidal ideation in individuals with NF was comparable to or higher than that in other medical populations (eg, cancer, dermatological, neurologic). Depression and poor psychological quality of life significantly increased the risk for suicidal ideation.

Conclusion: Suicidal ideation was relatively prevalent in individuals with NF seeking participation in a mind-body randomized controlled trial. NF clinicians should be prepared to discuss these concerns and provide resources when suicidal ideation is present.

Clinical trial registration: ClinicalTrials.gov (Identifier NCT03406208).

Consciouness is a phenomenon that has eluded explanation by generations of physicians and scientists. Many discussions, experiments, and theories about consciousness have been published, but none has adequately explained the phenomenon. In the previous issue, Budson and colleagues (2022) present a theory of consciousness based on explicit memory processes, with consciousness developing in the context of memory function. In the authors' view, consciousness accompanying other cortical processes such as language or visual-spatial function developed only later in evolution. The evidence presented for this evolutionary sequence, however, is very limited. Furthermore, no discussion is directed toward the theory that consciousness involves the intersection between external perceptions and internal bodily states. The authors also develop the concept that most of our actions, and even our personality, are conscious only after the fact; immediate decisions are taken by the unconscious mind-the "horse" rather than the "rider." There is empirical evidence that rapid decisions and responses occur before they become conscious. However, Budson and colleagues (2022) extend the concept of unconscious decision-making to virtually all actions; in so doing, not only do they minimize the phenomenon of self-conscious awareness, but their theory has disturbing ethical implications for personal responsibility, criminal law, free will, and personality.

In the previous issue, Budson, Richman, and Kensinger (2022) put forth the intriguing proposal that consciousness may have evolved from the episodic memory system. In addition to providing a possible evolutionary trajectory for consciousness, I believe that viewing consciousness as an extension of memory in this way is particularly useful for understanding some of the puzzling temporal complexities that are inherent to consciousness. For example, due to neural transmission delays, our conscious experience must necessarily lag the outside world, which creates a paradox for both conscious perception (Do we see the past, rather than the present?) and action (How can we make rapid decisions if it takes so long to become conscious of something?). These paradoxes can be elegantly solved by treating consciousness as a memory system. Finally, the proposal put forth by Budson and colleagues (2022) aligns with the emerging perspective that consciousness, like memory, represents a narrative time line of events rather than any single instant. However, I believe that this conceptualization can be further extended to include not only the past, but also the future. In this way, consciousness can be provocatively viewed as the remembered past, present, and future.

We suggest that there is confusion between why consciousness developed and what additional functions, through continued evolution, it has co-opted. Consider episodic memory. If we believe that episodic memory evolved solely to accurately represent past events, it seems like a terrible system-prone to forgetting and false memories. However, if we believe that episodic memory developed to flexibly and creatively combine and rearrange memories of prior events in order to plan for the future, then it is quite a good system. We argue that consciousness originally developed as part of the episodic memory system-quite likely the part needed to accomplish that flexible recombining of information. We posit further that consciousness was subsequently co-opted to produce other functions that are not directly relevant to memory per se, such as problem-solving, abstract thinking, and language. We suggest that this theory is compatible with many phenomena, such as the slow speed and the after-the-fact order of consciousness, that cannot be explained well by other theories. We believe that our theory may have profound implications for understanding intentional action and consciousness in general. Moreover, we suggest that episodic memory and its associated memory systems of sensory, working, and semantic memory as a whole ought to be considered together as the conscious memory system in that they, together, give rise to the phenomenon of consciousness. Lastly, we suggest that the cerebral cortex is the part of the brain that makes consciousness possible, and that every cortical region contributes to this conscious memory system.

Background: Co-occurring somatoform symptoms complicate the diagnosis and treatment of Parkinson disease (PD).

Objective: To learn more about the relationship between somatoform symptoms and PD by comparing demographic and clinical features across PD groups differing in somatoform symptom severity.

Method: Using standardized Brief Symptom Inventory-18 (BSI-18) scores to measure somatoform symptom severity, we assigned 1093 individuals with PD to one of four subgroups using comparisons to normative means: low (M < -½ SD), average (M ± ½ SD), high (M +½ SD to +1 SD), very high (M > +1 SD). We used demographics and disease severity measures to assess each subgroup.

Results: Most of the individuals with PD (56%) had high or very high somatoform symptom levels. Increased somatoform symptom levels were associated with female gender, lower socioeconomic status, greater disease duration, increased PD severity (Total Unified Parkinson's Disease Rating Scale), greater disability (Older Americans Resource and Services Disability subscale), increased BSI-18 Depression and Anxiety subscale scores, lower cognitive function (Mini-Mental State Examination), lower self-efficacy scores (Self-Efficacy to Manage Chronic Disease Scale), lower quality of life scores (SF-12 Health Status Survey), and greater medical comorbidity (Cumulative Illness Rating Scale-Geriatrics) (all comparisons: P < 0.001). We found no significant between-group differences for age, race, or marital status.

Conclusion: Somatoform symptom severity in individuals with PD is associated with greater PD severity and disability and is more common in females and in individuals with low socioeconomic status. Greater awareness of somatoform symptoms should help improve PD treatment.