Oct12

Oct 12 Lateralization

lateralized in the right hemisphere: Spatial processing, melody perception, imagery and negative emotion

lateralized in the left hemisphere: Language, logic, and positive emotion tend to be

Split brain patients no longer have an intact corpus callosum

This provides a research opportunity

Can restrict presentation of stimuli to a specific hemisphere in these patients

Because fibres cross over in the optic nerve (contralateral wiring), the left visual field is processed in the right hemisphere and vice verse.

Procedures were done in an attempt to reduce seizure in response to stimuli, so regardless of which side process something only one hemisphere is forced to process it.

If someone looks at a word with left eye while having split brain, they might not be able to properly process that word because the language processing part of the left hemisphere isn't seeing it Genes, evolution, and behaviour

Nature vs nurture debate: is actually a false dichotomy, rarely one or the other but almost always a complex and multidirectional relationship between genetics, environment, and behaviour

Genotype: the specific genetic makeup of an individual, present from birth and never changes

Phenotype: the observable characteristics produced by genetic commands, can be altered by genes and environment

Genotypes code for phenotypes.

Every cell has 46 chromosomes arranged in 23 pairs, one of each pair from the mother and the other from the father.

The egg/sperm cells are an execption (each only has 23, then are combined at conception)

Each chromosome is a tightly coiled molecule of deoxyribonucleic acid DNA partially covered by protein, Dna from a single human cell would be

Genes carry codes for protein manufacture, encoded in combinations of 4 bases

4 bases: Adenine, thymine, guanine, and cytosine.

Allele: an alternative form of a gene that produces different characteristics

At various times, certain genes may be turned on or off

Epigenetic: genes can be turned on or off at various times that are often related to environmental factors.

How do genes typically exert their effects? Genes carry codes for protein manufacture, estimates of 70 000 different proteins in humans

Approximately half are though to code for brain structure/function

Figuring out how all of these interact is a massive challenge and not something we're close to completely understanding.

Dominant genes will show whether or not a recessive gene is present

For recessive genes, the particular characteristics controlled by the gene will only be displayed if the partner genes inherited by both parent are recessive

Polygenetic transmission: a given characteristic is controlled by two or more genes. Greatly complicates the relationship between genes and behaviour

Remember punnett squares

The human genome project: involved identifing/mapping all known human genes with the goal of understanding both structure and functions

Identified 3.1 billion letters in the human genome

Humans have about 25000 genes (less than expected?)

200 genes may come from bacteria

Recombinant DNA procedures: enzymes cut/combine DNA from different organisms

Gene knockout procedures: particular genes are disbaled

Major limitation of these procedures is that few behaviours are controlled by a single gene.

hungry i have pumpkin bread in my bag im very excited for it but the wait. ohhg the wait

Heredity: passage of characteristics from parents to offspring via genes

Heritability: how much variation in something can be attributed to genetic differences

Heritability cooefficient: statistical estimate of the extent to which variation in a characteristic among a group of people can be attributed to genetic factors, expressed with a numberic value from the froms of 0-1 These values do not apply in individuals, but rather the variance in a trait across individuals within a specific group

Weight having a heritability coefficient of .6 doesn't mean that 60% of a given person's weight is due to genetics Rather, this suggests that within a certain group 60 % of the variance in weight can be attributed to genetic factors

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New heritability coefficients need to be calculated for each new group being observed.

In other words we need to be making independent estimates