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Wednesday, February 7, 2018

Vision & Audition

Vision & Audition


Beginner neuroscientists will often start with shedding light on perception. After all, sensation and perception are the steps preceding interpretation. While human are generally believed to possess a total of five sense, only two will be discussed in the present short entry.

The parallels between audition and vision lie in the trajectory undertaken by the sensory stimuli. Waves (whether light or sound) first encounter the receptors, then the respective carrying nerves. In the case of vision, the receptors are the rods and cones located on the retina (the lining at the back of the eye. In the case of auditory cells, these are hair cells or stereocilia, inner and outer. The transmitting nerves in question are the optic nerve for vision, and the auditory nerve for audition.

Interestingly, a blind spot is formed at the exact location where the optic nerve leaves the eye. Also, the signal then travels to the thalamus, sometimes called the relay station of the brain, where it is further adjourned to the visual cortex at the back of the cranium, or the occipital lobe. The temporal lobe is most often associated with hearing.

Branches’ Speech. Audititon and Vision. Photo by Megan Jorgensen (Elena)

An artificial blue eye. Albino eyes are red or purple because of a complete lack of melanin. Eye color is believed to be largely due to genetics (e.g. recessive [blue, green, hazel] and dominant [brown] alleles). However, researchers in Australia have challenged that notion as too simplistic. Also, while eye color is permanent, companies such as Lumineyes claim that they can change the amount of melanin, and thus the coloring, of human eyes. Is it safe? Image: Copyright © Megan Jorgensen (Elena)

Sport Psychology

Sport Psychology


In some circles, sports psychology can be seen as a controversial field, although related branch health psychology gets slightly more recognition. Of course, that may be because health psychology lays closer to medicine, a fact many feel conveys scientific prestige and soundness.

Nonetheless, psychologists have often looked at the interaction of sports and individuals’ lives. Needless to say, psychologists study the mind and behavior, and both get an important place in sports. Aside from the interpersonal dynamics critical to any team sport, and the obvious motivational effects of (good) coaches and trainers, physical activity may have some physiologically based benefits to it as well, such as endorphin release and fitness and wellness advantages.

Balls, elliptical spheres and pokes are used in many sports (bowling, hockey, golf, American football, soccer or football, billiards or pool, basketball, tennis, volleyball and so on). As can be seen from the picture, image: Copyright © Megan Jorgensen (Elena)

For example, studies have found that in competitive environments monkeys who won had hormone (testosterone) and neurotransmitter (serotonin) levels fluctuate. Furthermore, the outcome could be determined by the initial levels of these chemical substances naturally produced by the body prior to the events.

Finally, as previously stated, contrary reasons aside, sport may help in keeping healthy and fit, keeping a positive mood and even improve cognitive abilities. While many researchers have documented the beneficial effects of regular exercise, it may even contribute to neurogenesis. Along these lines, in laboratory mice hippocampal neurons were noticed to regenerate in mice who exercised. The work in question looked at the impact of cortisol, released as a response to stress, on the hippocampus and memory.

Social Psychology

Social Psychology


The document below underscores some key issues in psychology today. Psychology is a social science subdivided into many branches, each studying the human mind and behavior from different perspectives. Thus, while neuroscience focuses on study of the brain anatomy (or neuroanatomy), social psychologists look at the interpersonal and interactive psychology of social events and the emotions they entail. For instance, the constitution of the United States of America, secures, among other things, the right to pursue happiness for individuals. But what is happiness? Clearly, the subject matter has constantly been debated by philosophers and artists alike, but medicine has also its take on the subject. Indeed, the medical specialization related most closely to psychology is psychiatry. However, unlike psychologists, who are usually required to have earned a doctoral degree and are thus Doctors of Philosophy, psychiatrists are (medical) doctors in the sense that they are physicians. Consequently, psychologists are mental health professionals who treat conditions with psychotherapy, but are typically unlicensed to prescribe medication in most jurisdictions.

Along these lines, both the American Psychiatric Association (APA) and the World Health Organization (WHO) publish manuals designed to help diagnose mental illnesses and other psychological disorders for practitioners. Perhaps one of the better known such diseases is depression (depressive symptoms can manifest in a number of disturbances, including Major Depressive Disorder – MDD, Seasonal Affective Disorder – SAD, Dysthymic Disorder, Bipolar Disorder and Schizoaffective Disorder). But what causes depression? Academic and institutional research on the issue in abundant.

Social psychologists study interpersonal interactions and the social world. Image: Megan Jorgensen (Elena)

Nevertheless, on the unscientific side, many people feel depressed or sad occasionally; it is the recurrence, persistence, intensity and duration of the symptomatology which may lead to a professional diagnosis. Clearly, if one suffers from disfunction, there are a variety of sources of help, including family doctors and general practitioners, psychiatrists, hospitals, clinics, group support centres and other therapeutic establishments.

Notwithstanding, several simple steps seem to contribute to good mood in general, in most individuals. To illustrate, a healthy lifestyle, eating a balanced diet and exercising, in addition to, a fulfilling vocational, as well as, a social and personal life, contribute to an end result of happiness. Also a healthy lifestyle, good nutrition and exercise are likely to contribute to both health and well-being. To illustrate, physical activity releases endorphins (the body’s natural feel good chemicals) and there appears to be a consensus in the academic literature on regular exercising health benefits. Further, a spirit free from either eating disorders (EDs) or other health concerns associated with obesity, seem to be good predictors of sustained contentment. Conversely, other factors, such as quitting smoking or extensive stress (due to even positive changes!) may negatively impact one’s disposition and mood.

Social competence is defined as the ability to get what one wants in relationships, while still maintaining positive relationships with others. Image: Megan Jorgensen (Elena)

Additionally, people often turn to friendly and trusted others in times of trouble, but depression is different in that respect. For example, while having a reliable circle of close friends and a large network of acquaintances facilitates coveys social and emotional support from peers, persons with depression withdraw as a coping mechanism, which paradoxically, could then further exacerbate symptoms.

As an extroverted but disappointed loner once suggested – after unsuccessfully using the “How to pick up girls in bars?” tips from an attraction pick up artist – loneliness can be quite depressive. Although, social psychologists argue that loneliness and solitude are two different concepts, with only loneliness implying dissatisfaction with the state of being alone. Finally, this sums up the arguments hereby presented, showcasing some of the topics portrayed in psychology papers.

Cognitive Behavioral Therapy (CBT)

Cognitive Behavioral Therapy (CBT)


Together with hypnotherapy, psychoanalysis, commitment and acceptance therapy, and many others, it is hard to find a therapy which is not debated by scholars and clinicians alike. However, CBT or cognitive behavioural therapy remains among one of the most widely taught, and whose benefits have been most closely associated with remission from depression. For example, psychological studies have shown that in conjunction with medication, CBT use was more likely to lead to positive results and recovery from depression than use of medication alone.

Art has a lot to do with how we perceive the environment. Image: Megan Jorgensen (Elena)

So what is CBT? CBT operates on the notion that our feelings, thoughts and behaviours are interrelated. Cognitions or thoughts influence our feelings and our behaviours, while emotions and actions in turn influence and reinforce the way we think. Thus, according to CBT the cycle of negative emotions, thoughts and behaviour may be broken by introducing positivity at any stage of the interrelated circle. However, it may be difficult to change the way one feels, so thoughts and behaviours may be better targets to a healthier lifestyle.

Hypothalamus Influence on Food

Hypothalamus Influence on Food

By Dr. Megan Jorgensen


The major inhibitory neurotransmitter GABA (γ-Aminobutyric acid or Gamma-AminoButyricAcid) is often associated with energy regulation and eating. So is the hypothalamus, located at the base of the brain. For instance, hypophagia and resultant weight loss caused by cobalt protoporphyrin in mice, is related to diminished activity of nitric oxide synthase in that part of the brain (Li et al., 2006). Further, the link (via the pituitary gland) between the endocrine and nervous systems is also hypothalamic in nature.

Moreover, Williams & Elmquist (2011) write that the optogenetic placement of nutrition intake related actions, corresponds to the arcuate nucleus of the hypothalamus. More precisely, the pro-opiomelanocortin (POMC) and agouti-related peptide (AGRP) neurons would be responsible for this regulating mechanism. Furthermore, the roles played by the two cell types appear contradictory. POMC activity decreases food intake, while AGRP elevates it.

Very thin individuals are sometimes called ‘stick thin’. mysterious room: stick figures. Image: Copyright © Megan Jorgensen (Elena)

Along these lines, leptin orOBprotein expression in the hypothalamus, has also been said to reduce appetite in rats (Schwartz et al., 1996). Clearly, the structure is crucial for metabolism.

References:

  • Li, M., Vizzard, M. A., Jaworski, D. M. & Galbraith, R. A. (2006). The weight loss elicited by cobalt protoporphyrin is related to decreased activity of nitric oxide synthase in the hypothalamus. J. Appl. Physiol., 100: 1983–9
  • Schwartz, M. W., Seeley, R. J., Campfield, L. A., Burn, P. & Baskin, D. G. (1996). Identification of targets of leptin action in rat hypothalamus. J. Clin. Invest., 98 (5): 1101-6.
  • Williams, K. W. & Elmquist, J. K. (2011). Lighting up the hypothalamus: Coordinated control of feeding behavior. Nat. Neurosci.: News and Views, 14 (3): 277-8.

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