Face Processing and Autism at Multiple Stages of Life

    When talking about autism, the conversation is mainly dominated by thoughts about behaviors associated with autism. These behaviors include many stereotypes, such as making less eye contact, decreased sociability, and problems with reading social cues to name a few. Many studies concerning autism look into these associated traits to try to find a cognitive difference to better help kids and adults with autism. Research like this can help people get diagnosed earlier in life and get support for their needs in a world that can be difficult without it. 

    In "Cortical Source Analysis of the Face Sensitive N290 ERP Component in Infants at High Risk for Autism" by M. W. Guy, et al., the researchers aimed to find evidence linking the connecting between different N290 event-related potential (ERP) components in infants that have siblings with diagnosed autism (ASIB) and infants diagnosed with Fragile-X syndrome (FXS) which has links to autism. The rates for a later autism diagnosis in these groups are 20% and 60% respectively due to their previous studies. There was also the control group labeled as Low-Risk control (LRC) the ERP component N290 is thought to be a precursor to the adult N170 and has shown relations to face-processing differences in infants. The study uses Cortical source analysis, electrophysiological data measured on the scalp combined with a model of the head of the infant, to study the neural sources of this face-processing ERP. Obtaining these head models from the infant from MRI scans allows an easier approach to obtaining the data than with typical fMRI and EEG studies. Overall they found that all groups had greater responses to faces than toys and that the FXS group showed the greatest difference between toys and faces. FXS also showed a preference for familiar stimuli rather than unfamiliar ones, which was not present for either the ASIB or LRC groups. For the different head models, the Self (real infant head models) and the Infant Brain Imaging Study (IBIS), or group-specific MRI scans were used in times when Self caps were unable to be used. Each type was analyzed over different regions of interest (ROI). Overall, they found that both the Self and IBIS models could accurately show the processing differences between toys and faces. Using this ERP component data and the accuracy of the head models, this kind of testing could potentially diagnose children with autism as early as 12 months old, especially those who fall into the ASIB and FXS categories. 

    In "Face processing in young adults with autism and ADHD: An event related potentials study" by U. Aydin, et al., they aimed to help see the effects of autism and ADHD diagnosis in early adults using the same mechanism of studying face-processing ERP components but using the adult N170 ERP. Though a meta-analysis of many studies showed a small to non-significant difference between autistic adults and non-autistic adults, there is still shown that there is a sensitivity to the N170 ERP in autistic adults comparatively. For their study, they uses EGG technology to obtain information during the ERP tasks. The adults were put through two passive-viewing tasks, one showing upright and inverted faces with either direct or adverted gaze and a second task with faces expressing different emotions. Results showed that there were in fact differences in latency among those with autism- (without autism diagnosis) and those with autism+ (with autism diagnosis) along with differences between sexes as well. Overall, inverted faces had longer latency than upright faces, and "negative" emotions such as disgust, anger, and fear had longer latency than joy or neutral expressions for all groups. The N170 amplitude, autism- had higher amplitudes than those with autism, but the opposite was found for the N170 latency, with the same pattern showing with ADHD+ individuals. 

    Using these two studies, there is a clear difference between individuals with and without an autism diagnosis. Using technology to study ERP components in infants, children, and adults can be an accurate way to diagnose and study the effects of autism in relation to social behavior. If infants are diagnosed earlier due to this technology there can be more resources allocated to them. With studies in adults, we can see the effects of face-processing differences related to behavior such as why eye contact tends to be harder to maintain in older individuals with diagnosed autism. Hopefully, research like this can help people to better understand peers and people that have autism. 

References

Guy, Maggie W., et al. “Cortical Source Analysis of the Face Sensitive N290 ERP Component in

    Infants at High Risk for Autism.” Brain Sciences, vol. 12, no. 9, 2022, p. 1129.,

    https://doi.org/10.3390/brainsci12091129. 

Aydin Ü, Cañigueral R, Tye C and McLoughlin G (2023) "Face processing in young adults with autism     and ADHD: An event related potentials study. Front. Psychiatry" 14:1080681. doi:    

    10.3389/fpsyt.2023.1080681

Role of Hormone Therapy in Perimenopausal Women on Enhanced Hippocampal Function and Memory in Later Life

    In this blog, I will be connecting a study conducted by Pauline Maki et al. entitled “Perimenopausal use of hormone therapy is associated with enhanced memory and hippocampal function later in life” with another study by Yuko Hara et al. entitled "Estrogen Effects on Cognitive and Synaptic Health over the Lifecourse." I will begin by explaining the hypotheses and findings of each study and then explain their implications as well as how they relate to one another and the field of neuroscience as a whole.

    In the study by Maki et al., researchers examined the effects of Hormone Therapy (HT) usage on the cognitive function and memory of women undergoing perimenopause and postmenopause. To conduct their experiment, the researchers studied 17 women in the perimenopausal stage who used HT continuously and 17 others in the perimenopausal stage who had never used HT. The results showed that perimenopausal women who were using HT continuously scored higher on tests for verbal imaging tasks and increased activation of the left hippocampus. Furthermore, those individuals who had used HT continuously performed better on image-based memory tasks, suggesting that continuous HT usage may correlate with increased verbal memory and cognition function.

    The study by Hara et al. sought to study the impact of Estrogen on cognitive functions and better synaptic health in later life. They studied these effects by examining clinical trials of women undergoing therapies for hormone replacement and how their cognitive symptoms were impacted. They also discussed summaries related to the effects of hormone replacement therapy in females going through menopause. The implications of the study are that hormone replacement therapy through Estrogen can have a beneficial impact on cognitive performance and synaptic health in later life for females experiencing menopause.

    Both studies demonstrate a correlation between hormone therapy and increased cognitive function and better performance on verbal imaging and memory-related tasks. The first study examined brain areas that were stimulated as a result of continuous dosage of hormone therapy which resulted in improved cognitive function, while the second study examined the role of hormone replacement therapy through Estrogen on cognitive performance and synaptic health for women experiencing menopause. Further research in this field is necessary to determine how hormone therapy can effect other areas of the brain and to what extent. Furthermore, the impact of dosage and duration of hormone therapy must also be further studied to maximize benefit for peri and post-menopausal women. 

Autism Rates Spike

         

        Autism Spectrum Disorder (ASD) is a neurological and developmental disorder that affects communication, social interaction, and behavior. In the past decade, CDC reports have shown autism rates to have risen threefold. Prior to 2001, the condition was estimated to be diagnosed in one out of a hundred fifty children. But now, CDC reports evaluate one in fifty-four children to be diagnosed with autism. An article written by NBC News discusses the reasons behind the increased number of autism diagnoses. The article speculates that a greater awareness of the disorder and advancement in the approaches to diagnosing the condition must've led to an upsurge in the numbers. However, the article also mentions that other factors, such as genetics and environment, might contribute to the trend. 

        All things considered, increased research scope on autism are uncovering better methods of diagnosing the condition early. While also discovering new genetic mechanisms to allow for a better understanding of how the disorder is cultivated. Dr. Maggie W. Guy and her colleagues work in one of the research laboratories that are striving to find better ways of diagnosing autism spectrum disorder. In the article "Cortical Source Analysis of the Face Sensitive N290 ERP Component in Infants at High Risk for Autism," they explain their research and how it could diagnose autism earlier. The study's findings highlight the need for group-specific head templates for accurate source analysis in infants at high risk for ASD. The study's results have implications for the development of measures aiding in the early identification of ASD in infancy and for promoting an increased understanding of cortical development associated with social information processing in neurodevelopmental disorders, including FXS and ASD. Continued research in this area is important to better understand the neural bases of ASD and to develop effective interventions.

    Overall Autism Spectrum Disorder is a complex condition that affects individuals in different ways. Early intervention and treatment can greatly improve outcomes for individuals with ASD. It is important to seek out resources and support from healthcare providers, educators, and community organizations to help individuals with ASD reach their full potential.

Taste Sensation and Neurological Theory

    Understanding the neurological nuances of taste requires an in-depth analysis of the neural pathways,

brain anatomy, and proteins that make sensory functions possible. Such concepts are discussed in the papers

of Ephrin-B/EphB Signaling Is Required for Normal Innervation of Lingual Gustatory Papillae by

Bill Rochlin and Encoding Taste: From Receptors to Perception by Stephen D. Roper. Thus, this paper

will compare the works described in order to discuss the relationship between neural pathways,

brain anatomy, proteins and cognitive taste functions.

Rochlin’s work Ephrin-B/EphB Signaling Is Required for Normal Innervation of Lingual Gustatory

Papillae, evaluates the proteins of Ephrin-B (EphB) in relation to speech. Specifically, he describes that the

protein EphB uses signaling in order to regulate growth of gustatory neurites. Gustatory neurons are sensory

neurons within the peripheral nervous system that aid the brain in identifying taste. Specifically, the gustatory

neurites function to transport sensory information via neural pathways from the tongue and throughout the

primary gustatory cortex. The primary gustatory complex is the region of the brain that recognizes taste itself.

As such, the hypothesis of this study was to verify if Ephrin-B is essential to the regulation of taste sensation

in the brain as well the development of taste buds. Given their presented results, the researchers were able

to fail to reject their hypothesis confirming that EphB is infact a required variable for taste sensory

transduction and transportation.

In reference to Roper’s work, Encoding Taste: From Receptors to Perception, he assesses the nature

of taste receptor cells and their relationship to taste sensory functions. The hypothesis of his study is to

confirm the degree to which tongue cells aid in transducing sensory signals within periphery sensory

organs and transporting signals to the brain. In order to evaluate his theory, he analyzes the role of taste

receptor acting as conductors in an active circuit that carry electrical impulses two and frm the brain.

After making such assessment of his research he was able to conclude that his research was indeed

confirming the tongue’s cell receptors as imperative variables to the brain receiving and providing

feedback signals for taste sensory functions.

The common denominator between these two pieces of work is that they both tell the relationshi

between neural anatomy, pathways, proteins, and taste sensory functions. Rochlins work does so by

analyzing thereltionship between taste proteins. By contrast, Roper’s work accomplishes the same via the

relationship between tongue cells and the brain’s anatomy.

Link: https://morebrainpoints.blogspot.com/2023/05/taste-sensation-and-neurological-theory.html

References

SD;, R. (n.d.). Encoding taste: From receptors to perception. Handbook of experimental pharmacology. https://pubmed.ncbi.nlm.nih.gov/34796381/ 

Treffy RW;Collins D;Hoshino N;Ton S;Katsevman GA;Oleksiak M;Runge EM;Cho D;Russo M;Spec A;Gomulka J;Henkemeyer M;Rochlin MW; (n.d.). Ephrin-B/EPHB signaling is required for normal innervation of lingual gustatory papillae. Developmental neuroscience. https://pubmed.ncbi.nlm.nih.gov/27035151/

The Body is More Like a Machine Than You Think

According to the Center for Disease Control and Prevention, approximately 795,000 individuals have a stroke in the United States each year, and out of this alarming large population, nearly 80 percent experience motor dysfunction and impairments. As the diagnoses rates of both acute and chronic stroke symptoms continue to increase globally, reform of existing therapies and search for new methods of neurorehabilitation have long been in the call for. The greater population often overlook or do not appreciate the vast interconnectedness of neural pathways that construct the privilege of motor abilities. Motor functions depend on a wide array of ascending and descending pathways including sensory and proprioceptive devices, and the immensely complex engagement of higher brain regions such as the premotor and primary cortex along with the cerebellum and each of their distinctly different upper motor neuron activity. On an extensively micro molecular level understanding of the nervous system’s control of motor capabilities, each of these regions depend on specific neurotransmitters and their respective receptors to initiate a cascade of events that work to activate motor abilities and visual-spatial awareness. Acetylcholine and their respective ionotropic (nicotinic acetylcholine receptors) and G-coupled protein receptor (muscarinic acetylcholine receptors), work to construct a mural of peripheral activity at neuromuscular junctions in order to facilitate distal and proximal extremity muscular functions. Additionally, glutamate and its respective receptors NMDAR (N-methyl-D-aspartate) and AMPAR (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) habituate a variety of locations in the upper regions of the brain and heavily contribute to the upper motor neuron functions. When injuries to the central nervous system occur as a response to the extremities of stroke effects, a number of inhibitions to previously stated pathways and their molecular components that influence symptoms of motor impairments occur. Classical training-based interventions such as physical, occupational, or language therapy as well as novel multimodal approaches like, e.g., mirror therapy or music-based therapy, have all been shown to enhance functional recovery, albeit to variable degrees.2 Though it has been shown that physical therapies have been successful in functionally reorganizing motor functions in stroke patients most significant improvements occur in the first few weeks post-stroke, often reaching a relative plateau after 3 months with less significant recovery subsequently.2 The imitations of physical methods of enhancing motor impairments has pushed physician and neurophysiological researchers, alike, to seek out new approaches to combat symptoms of motor dysfunction. One effective mechanism has been the practice of non-invasive brain stimulation techniques like transcranial magnetic stimulation (TMS) or transcranial direct current stimulation (TDCS) which can be used to modulate neural plasticity, in which motor improvements upon TMS-evoked inactivation of contralesional M1 can be observed in the first week post-stroke in patients with mild motor deficits.2 These methods rely heavily on the concept of central nervous system stimulation in which certain regions of the brain that specifically regulate the mechanisms of motor abilities are excited in order to induce forms of positive neuroplasticity. Codependently, these forms of neurorehabilitation have been combined with methods of physical therapies to form a comorbid conditioning in the attempt to generate more successful outcomes. 

In addition to the array of methods that primarily concentrate on the stimulation of central nervous system components, research such as that of Vincent Chen and his colleague’s amaze the world of neurobiology by proposing the influence of stimulating peripheral sensory and proprioceptive receptors in order to elicit a form of mirror and feedforward mechanisms to perhaps enhance motor functions. In this study subjects received electrical intervention twice a week for eight weeks and finished all assessment sessions including follow-up. The electrical signal group received 40-minute sensory level electrical stimulus prior to motor training and the control group received sham-electrical signaling instead.1 Though this research remains in the infancy stage, it has shown remarkable outcomes in which they reported an increase in corticomuscular activity in beta band which suggested that during motor relearning, the motor cortex has stronger connectivity between the central nervous system and muscles at the periphery.1 Research in neurophysiology calls for pioneers such as those aforementioned in order to further advance universal understanding of methods that could combat not just impairments induced by stroke but, ultimately, all forms of neurologic motor impediments. 

Works Cited 

1. Chen, Vincent; Chou, Li-Wei; Fregni, Felipe; Kao, Chung-Lan; Pan, Li-Ling; Tsai, Mei-Wun; Wei, Shun-Hwa; Yang, Wen-Wen. (2018). Effects of 8-Week Sensory Electrical stimulation combined with motor training on EEG-EMG Coherence and Motor Function in Individuals with Stroke, Scientific Reports. 

2. Grefkes, C., Fink, G.R. Recovery from Stroke: Current Concepts and Future perspectives. Neurol. Res. Pract. 2, 17 (2020). https://doi.org/10.1186/s42466-020-00060-6

The Potential Utility of Beauty

 If you were suddenly asked “What makes something beautiful?”, you would probably find yourself stumped. Yes, you can give examples of things you find beautiful: your baby’s smile, sunflowers towering in a field, the latte art you get at the local coffee shop, etc. If you’re given a moment to seriously think about why you find such things to be beautiful, even if they seem to have nothing in common, you might come up with reasonings like these: your baby is the most important thing in the world to you, sunflowers are yellow and that is your favorite color, you find the latte art beautiful because you have no idea how they’re able to create those images so pristinely. So what if those things have little to do with each other; perhaps the very idea that such a question can be answered is flawed to its core. Can a concept such as beauty be quantified or pinned down at all? 

The research paper, “Is Beauty in the Eye of the Beholder or an Objective Truth? A Neuroscientific answer” seeks to answer such a query. The writers open up the article with the very same question, “What makes something beautiful?” and goes on to say, “For philosophers, short of defining beauty, the principal question has been to discover where it lies. Specifically, is beauty a quality of objects (objectivist view) or does it come from within the beholder (subjectivist view)?” (Aleem et al., 2019). 

The paper then goes on to state that there is strong support throughout the scientific community for an objective definition of beauty. Features such as symmetry, balance, color, fractality, complexity, and curvature have been shown to be appealing across cultures, genders, and age groups. However, there are plenty of subjective differences on an individual and socio-cultural level that point to subjectivity. How can both the subjective and objective aspects of beauty be explained? 

These researchers establish that the answer is multifaceted. When it comes to objectivity in beauty, they discuss the processing fluency theory, evolution, and various brain functions as a suitable explanation. The processing fluency theory states that “the easier it is for a perciever to process the properties of a stimulus, the greater its aesthetic response will be…the processing fluency theory assumes that objects differ in their fluency…[and] that fluency is hedonistically marked, so objects are perceived more positively than are those with lower fluency” (Aleem et al., 2019). This theory has a clear relationship to evolution. Since we rely on our senses to perceive anything that can threaten or sustain our survival, any amount of visual imbalance would attract our visual attention (e.g. noticing that a certain plant has three leaves can help distinguish poison ivy from a harmless vine). 

However, it does not explain the subjectivity in beauty. After all, there are undeniable cultural differences in what is perceived to be beautiful. Understanding how these differences present neurologically is challenging for the very same reason that is highlighted in the beginning of this article. A facial expression, flower, and food can all have their own aesthetic response. Does the brain respond in the same way to each of them? An fMRI study referenced in the paper revealed that “aesthetic appraisal may be a special case of generalized appraisal mechanisms in the brain” (Aleem et al., 2019). The brain regions that activated during generalized appraisal were the orbitofrontal cortex (OFC), anterior insula, and the ventral basal ganglia. These combined brain regions facilitate reward based learning, which further supports evolution’s role in our perception of beauty. If we eat a red apple and find it to be sweet, we are rewarded and learn that those two traits might be connected. If we find an apple that is an even brighter red than the last, and it tastes even sweeter, our learning is updated. This could translate to that individual enjoying paintings of red apples over paintings of tart, bitter apples. The fact that reward based learning provides an explanation for cultural differences in perception of beauty, since the same stimuli and result will not be present in all environments. The paper also proposes that learning under different motivations can explain a variance in an individual’s aesthetic preferences. 

This article concludes that “objectivity [in beauty] may have arisen in part to our evolutionary history and principles captured by the processing fluency theory…[but] while all of us may be born with similar aesthetic biases, over time these biases are shaped by our experience through learning” (Aleem et all., 2019). 

You may be thinking that while this is interesting, perhaps, what real world benefit results from this study? From understanding how we perceive beauty? Just because we know what brain regions are involved or what role evolution or reward based learning plays into our aesthetic preferences does not erase the frivolity of beauty. 

However, there is a wealth of research that suggests that the perceived beauty of our environment provides a genuine impact on patient outcomes and satisfaction. For example, “A New Tool in Treating Mental Illness: Building Design” discusses the newfound effort to create more beautiful, welcoming hospitals to reduce stress and aggression. Understanding the mechanisms of beauty, how we perceive it, why we perceive it the way we do, lends legitimacy to the objectionist view of beauty. If beauty is something that can be defined by generally universal standards, adjusting to the learned cultural perceptions of beauty of their desired patient population, then it is something that can be pinned down and clearly implemented. If beauty is shown to be something with a biological basis (evolution, brain processes), then it lends legitimacy to the concept of beauty in general, and potentially increases support and funding to improve patient outcomes. 

https://www.nytimes.com/2021/01/05/business/mental-health-facilities-design.html

Memories are Always in Our Mind

 Memories are Always in Our Mind  

Memories are a curtail part of our identity, they guide our behavior and remind us of past events such as birthdays, vacations, and other past actions. Memories are constantly being formed but many of them are forgotten. Individuals whose ability to form memories have been disrupted often feel isolated and life becomes difficult for them. Many debilitating diseases such as Alzheimer's disease, diabetes, Parkinson’s disease, and again in general cause cognitive dysfunctions such as memory loss. The visual system and working memory work hand in hand to enhance our ability to retrieve visual information. As people age, there is an ongoing quest for memory enhancement across the globe. In the article “Mechanisms of Memory Enhancement” Sarah A. Stern and Cristian M. Alberini discuss how targeting mechanisms such as “CREB activation, AMPA/NMDA receptor trafficking, neuromodulation (e.g., via dopamine, adrenaline, cortisol or acetylcholine) and metabolic processes (e.g., via glucose and insulin)” can lead to the enhancement of memory. In their study, Stern and Alberini capitalize on the “knowledge gained by the biological study of long-term memory formation storage” to identify how cellular and molecular mechanisms play a role in memory formation and in learning. Their research shows that memories can be enhanced after they are consolidated. This is beginning to open new avenues for developing treatments for conditions disorders. This shows that “Memory enhancement can be in fact promoted via pharmacological manipulations given in concert with reconsolidation.” Memories can be enhanced when retrieval-induced reconsolidation is targeted. This occurs by repeating retrieval session where memories can return to a labile state.  

This work connects to the work done by Sven Vanneste and other colleagues in “The peripheral effect of direct current stimulation on brain circuits involving memory”. They also studied memories but were testing how direct transcranial electrical stimulation can “activate the greater occipital nerve (ON-tDCS) and up-regulate memory performance via activation of the LC-NA pathway.” Their work focused on how activity changes enhance communication between different brain regions.  

Both articles emphasize how morphological modifications at the synapse are connected to memory formation and enhancement. Although there is little data on how the increase in NMDAR/AMPAR subunits are increased at the different stages of memory, it has been proven that they are responsible for memory enhancement.  

As science advances, there is now more information due to scientists like the ones disguised above that are interested in finding molecular pathways and the targets that enhance memories. It is important to note that there are multiple ways to enhance memories such cognitive enhancement therapies. Emotional events are better remembered than events with non-emotional significance due to the stress hormones released during the events. Memory enhancement studies have the potential to change many lives by treating diseases of the mind and aiding in the development of strategies for better leading and cognitive functions.  

 

 

 

References:  

Stern, Sarah A., and Cristina M. Alberini. “Mechanisms of Memory Enhancement.” WIREs Systems Biology and Medicine, no. 1, Wiley, Nov. 2012, pp. 37–53. Crossref, doi:10.1002/wsbm.1196. 
 

Vanneste, Sven, et al. “The Peripheral Effect of Direct Current Stimulation on Brain Circuits Involving Memory.” Science Advances, no. 45, American Association for the Advancement of Science (AAAS), Nov. 2020. Crossref, doi:10.1126/sciadv.aax9538.