12/4/23 test

ASSUMPTIONS OF THE BIOLOGICAL PERSPECTIVE

• All that is psychological is first physiological. 

• The mind resides in the brain and therefore all thoughts, feelings and behaviors ultimately have a physical/biological cause. 

• Human genes have evolved over millions of years to adapt physiology and behavior to the environment. Therefore, much behavior will have a genetic basis. 

BIOLOGICAL PERSPECTIVE METHODS OF INVESTIGATION 

• There are various methods of investigation in the biological perspective. 

• The most common methods of investigation include the following: 

• Laboratory experimentation (which can entail stimulating, giving drugs, removing parts of the brain, lesioning, all to see what effects it has on behavior)

• Laboratory observations (controlled observations of physical processes. Example: scanning the structure and activity of a sleeping brain)

• Correlational studies (between twins and adopted family members to discover the genetic influence on intelligence or mental disorders) 

POSITIVE CONTRIBUTIONS OF THE BIOLOGICAL PERSPECTIVE TO SOCIETY

• The biological perspective has been applied to therapy. It has helped with drug treatment, psychosurgery, electroconvulsive therapy and treatment protocols for schizophrenia, depression and other disorders. 

• It has also been applied to health: research on the causes and effects of stress have enabled physicians to counsel and assist in the management of stress. 

• It has led to more research on sleep and sleep deprivation’s effect on jet lag and shift work. 

• It has led to a better understanding of the genetic basis of intellectual ability, disorders, diseases etc. 

• It had led to a better understanding of sports, including the effect of arousal on performance and the use of techniques to enhance performance. 

PHINEAS GAGE
- “The man who lived with a hole in his head” 

General Information 

• Name: Phinease Gage

• Age: 25 years old

• Occupation: 25 year old foreman employed on the Rutland and Burlington Railroad

• Height/weight: N/A 

• Condition: Orbital Frontal Syndrome

What Happened? 

• Phineas was working on the railroad when a tamping iron was set in motion. 

• Ths iron penetrated below his left cheek and exited near the top middle of his skull, near the coronal and sagittal sutures. 

• The rod was launched with such force that it landed 30 meters away from him. 

• Although Gage was knocked flat, he was able to get up and walk to the Ox cart on which he sat while he was driven into town. 

• During the ride, he was able to talk and write in his logbook. This was an anomaly because he did not lose consciousness. 

BEFORE THE ACCIDENT (pre-morbid)

• Gage held a job as a foreman prior to the accident. 

• He had friends and was seen as healthy both mentally and physically. 

• He was capable of making good decisions. 

• He was seen as well balanced emotions  

AFTER THE ACCIDENT (post-morbid) 

• Immediate changes: nothing significant was observed. Could converse, walk, was able to recognize friends/family, appeared rational and appeared to have survived post-injury infection. 

• First changes: He became aggressive, had temper outbursts. 

• Was impulsive, could not inhibit (keep himself from doing something), used foul language, 

• had no boundaries, was kept away from women because of his behavior, could not make rational decision or solve problems, he was stubborn. 

• All of these changes are correlated to a location in the brain that was affected. 

• Became aggressive: right frontal lobe

• Had temper outbursts: right frontal lobe

• Inhibit: left frontal lobe

• Foul language: right frontal lobe

• Any executive functioning is in the left frontal lobe 

• Stubbornness: right frontal lobe

THE DR. JILL BOLTE CASE STUDY

• Dr. Jill Bolte Taylor was a neuroanatomist who suffered a hemorrhagic stroke.

• This stroke cause the loss of various functions in her body, including the ability to speak, the ability to comprehend language, the ability to read and understand words and numbers and her right side of her body going limp.

• As a result of the stroke, she experienced strange findings.

• Her physical presenting symptoms included: her right side going limp, being unable to separate herself from the space in which she was, and feeling a huge rush of expansiveness.

• Her physiological symptoms (on a functional level) included: a severe headache in the left frontal region above her left eye, a pounding, caustic pain that appeared in waves, pain in the eye, blurring/loss of vision; lack of clarity (could not read numbers or letters), impaired, slurred speech and impaired hearing.

• Her Broca’s area (responsible for expressive language) and Wernicke’s area (responsible for receptive language) were affected.

• She suffered internal bleeding in the left frontal temporal area and was diagnosed with a hemorrhagic stroke.

NEUROTRANSMITTERS + NEUROHORMONES

• Neurotransmitters are chemical messengers that can be excitatory (stimulatory) or inhibitory (hindering). 

• They are manufactured in the cell body, transported down the axon and stored in little pockets in the terminal buttons called vesicles. 

• The neurotransmitter released from the vesicle travels across the synapse and binds to the receptors of dendrites or axons on a postsynaptic neuron. 

• This only happens if there is a goodness of fit between the neurotransmitter and the receptors. 

• A neurohormone is any hormone that is produced and released into the bloodstream by neuroendocrine cells. 

• Hormones are secreted into the circulation for systemic effect, but they can also function as neurotransmitters or in other roles such as autocrine or also as paracrine messengers. 

• Oxytocin (love hormone) is an example of a neuro-hormone. 

SPECIFIC NEUROTRANSMITTERS

• Glutamate is a nonessential amino acid that does not cross the blood brain barrier and must be synthesized in neurons from local precursors. 

• Glutamate is an excitatory neurotransmitter found in the hippocampus and it plays a crucial role in cognition, learning and memory 

• Glutamate must be present in the right concentrations, both too much and too little is harmful. 

BRAIN 

• The Cerebral Cortex makes up 80% of the brain’s total weight.

• Responsible for regulation of a broad range of cognitive, emotional, and motor functions.

• Cerebral cortex is divided into two hemispheres: and the Left Cerebral Hemispheres are connected by a large bundle fibers called the Corpus Collosum.

• The Corpus Collosum allows information sent from one hemisphere to be available to the other.  If severed, the two hemispheres operate as separate and independent brains.

• For most sensory and motor functions the cortex exhibits contralateral representation……the left hemisphere controls the right side of the body and vice versa.

• An exception to this rule is the passage of Olfactory information.

• Olfactory signals from the right nostril go directly to the right hemisphere and signals from the left nostril to the left hemisphere.

• Visual Information from each eye goes to both sides of the brain…..Information from the Right visual field of each eye goes to the left hemisphere and information from left visual field of both eyes goes to the right hemisphere.

• Although both hemispheres of the brain play a role in most behaviors, each hemisphere tends to specialize.

• In 90-95% of right-handed individuals and 50-60% of left-handed individuals, written and spoken language and logical thinking is lateralized to the left hemisphere (dominant hemisphere); 

• While the understanding of spatial relationships and facial recognition are lateralized to the right hemisphere (non-dominant) for the remaining left-handed people, language is controlled by the right hemisphere or bilaterally.

• This type of brain lateralization is also referred to as hemispheric specialization which is apparent to some degree at birth.