¡Descarga Psychobiology I. Module I. y más Apuntes en PDF de Psicología solo en Docsity!
- Concept of pshychobiology.
1.1.
Levels of organization:
Psychobiology can be explained as the scientific area that studies behavioural and psychological processes biology.
A basic concept of biology is that organisms and their environment have to be explained as systems that are formed by components that are organised in hierarchical levels. What is so distinctive is that these biological levels of organisation range from a single organelle all the way up to the biosphere in a highly structured hierarchy. This organisation is hierarchic because there are units of different order and its inclusive because some of the units are contained inside other units of a higher order.
Infra-organismic level : cell and molecular biology.
Organismic level : organismic biology.
Supra
- organi smic : popula tional biolog y.
Mean while molec ular and cellula r biolog ists (reductionists/narrow sense) usually focus on the study of the processes defined on the higher levels of the hierarchy, organismal and population biologists (organicists/broad sense) also analyse variables defined on the lower levels of the hierarchy, they focus on multiple levels and emphasize on crossing and re-crossing levels of organization. Horizontal causal relations, located on the elemental levels of organization are more studied in molecular and celular biology , meanwhile on the organismic and populational biology , more attention is given on vertical causal relations.
1.2. Reductionism vs Organicism:
Reductionism ( provintial biology/narrow sense) consists on explaining the cause-effect relation by stating that the effects are always at the top of the hierarchy and the causes are always at the bottom of the hierarchy. In other words, this means that the processes that take place in the higher levels of the hierarchy are explained according to the processes that control the functioning of the more elemental levels. The causal relations established tend to be vertical and ascendant ( Horizontal upward causation ). On the other hand, organicism (autonomous biology/broad sense) states that the information flows on both directions, which means that the same variable can be at the same time cause and effects (Vertical two-way causation).
Horizontal causal relations search for cause-effect relations between processes that take place on the same level, the dependent and the independent variables are located on the same level. Vertical causal relations establish cause-effect relations between processes that happen on different levels of organisation, the dependent and the independent variables are located on different levels.
Provincial biology tends to relie on explanations of behaviour based just on physiological processes, in other words, in ascendant vertical causal relations. Autonomous biology defend that every organism has something special that can’t be explained by physics or chemistry. Provincial biology accepts constitutive , explanatory and theory reductionism and Autonomous biology accepts constitutive reductionism but rejects explanatory and theory reductionism.
Constitutive reductionism states that the material composition of which living beings are formed is exactly the same as of the elements of the inorganic world. The processes that can be observed in the inanimate world aren’t incompatible with the physical and chemical processes found at an atomic and molecular level.
Explanatory reductionism states that the explanation to the processes that happen on the higher levels of the organisation of a living being have to be searched for on the lower and more elemental levels of the hierarchy, which are the molecular and cellular levels.
Theory reductionism states that explanations that are given on certain branches of science can be considered as specific or particular cases of theories and laws formulated I other sciences that are considered more general and mature, in other words, biological laws can be deduced from the laws of physics.
1.3. Proximate vs Ultimate causes:
A very important concept in biology has to do with the temporal scale in which causal
relations are looked for and established. Proximate causes ( functional biology ) explain
effects by studying their relations to relatively close timing, in other words, the effect is
always caused by something that has not happened too long ago and that has happened
The ladder perspective shows evolution as a linear process. We assume that humans
are at the top of the ladder, and the other species are on the lower levels, ordered by the
similarities they share with our species. For example, chimpanzees would be in the next
lower level. This view of evolution is incorrect. Following an arbitrary idea of
complexity. Animal model. Anthropocentric.
The tree view of evolution focuses on a not directional and ramified nature of evolutive
change. In different branches, each specie is sophisticated and adapted the best
depending on the specific niche in which it has developed. Comparing species in their
environments, they are superior than humans. (At the ocean, fish are better adapted than
humans). Model animal. Biological approach.
1.8. Model approach (model animals and biological approach):
The animal model has as main objective understanding humans, related to an
anthropocentric approach , so it is based on using animals as models that are simpler,
more economic and more ethically acceptable in order to understand human kind.
On the other hand, the model animal is related to a biological approach. The relevant
about the model animal used, in which there is not a specie more important than the
other, is that they are studied the similarities and the differences between different
species and thanks to this comparative perspective, there are obtained relevant results
that are used in order to formulate general principles that can be applied to any kind of
specie.
1.9. Organisms and environment (interpretation and niche construction):
There are two views when studying the relation between organisms and environment:
- Conventional model (post Darwinian orthodox theory) : The casual
relationship between the environment and organisms is that organisms propose
and make offers and the environment approves or not the proposal and will
select what organism will survive and will make their characteristics temporally
immortal and what organism will be erased, as well as their characteristics.
Causal relationship is from environment to organism always. Organisms are
passive. This happens in every generation, the only information passed on is the
genetic information from the alleles we receive from our parents, this is the
traditional view.
- Extended model (Lewontin) : Organisms interact with the environment and vice
versa, Lewontin explains that organisms and their environments are
interpenetrated , which means that there is no environment without organisms,
and no organisms without environment, they are inseparable. It emphasizes how
important is to understand that organisms are part of their environment. Arrows
tend to be two ways, relationships are bidirectional. Niche construction :
everything we do have consequences on our environment. And what
environment produces will affect us. Organisms are not passive, we actively
change the environment and produce the environment that will select us.
Everything around us is the outcome of human actions. We have created an
environment which is extremely hostile for us. We don’t only inherit genes, but
we inherit the environment too.
Interpenetration is the concept ; niche construction formalizes this concept.
We create an scenario where our offspring has to survive, we inherit the habitat that our previous generation created, and in each new generation we create new habitat and add to the previous construction.
1.10. Inheritance (genetic and nongenetic):
Genetic inheritance, epigenetic inheritance, ecological inheritance, cultural inheritance.
The experiences that organisms have during their vital live leave ….
There is nongenetic information that is also inhibited, this is something new that scientists are trying to explain.
Oblique ecological inheritance : Information you get from adults of other generation that are not your parents.
Horizontal arrow : generation passed between members of the same generation, from your siblings or friend, keen or not keen. This information will enrich your knowledge.
Vertical arrow : information only flows from parents to you
Genetic inheritance and parental effect: the information can only be inherited from your parents, arrow always vertical.
Epigenetic inheritance: inhibit sets that contain genomes that are epigenetically marked epialleles you inherit from your parents, this affects whether these alleles will be active or silenced. Vertical
- epialleles: Change the expression of the DNA, control of how the genome will contribute to the construction of the organism.
- Genomic imprinting : when one of the alleles you receive from your parents is silenced, only one allele is expressed
- epigenome: something above genetics. This can be reversed and turned on and off continuously.
Parental effect : consequence of mother’s behaviour, exposed to factors that might affect the expression of your genome. It has to do with things that our parents do that might affect the expression of our genes. Ex. The rat mom licks their babes, the consequence varies on how much time moms lick their new-borns, this affects a gene which manufactures oestrogen receptors, which are important for many chemicals to produce physiological effects, facilitate lactation, and maternal care.
What you acquire can be in the genes (alleles) you inherit from your parents, can be in the epigenome (epigenetic marks) you inherit from your parents, can be the outcome of the way your parents reared/nurtured you (parental effects), can be in the environment you inherit from your parents, from other members of your parents' generation or even from individuals from your own generation (ecological inheritance), or can be in the culture that your inherit from parents, other elders and your peers (cultural inheritance).
1.11. Biologies:
predisposed you to behave that way. The environment contributed to design your psychological profile in a certain direction. Something that happened long ago also contributes in how you behave now. Ex. People who developed an insecure-type of attachment when they were infants tend to establish conflicting romantic relationships when they reach adulthood
- Ultimate causes : you are crossing the intergeneration boundary. - Function or adaptive value (Current factor) : the third why : it is adaptive. Any consequence which impacts in survival and reproduction will be favoured in natural selection. A particular behaviour is adaptive: these are biological fitness increasing, we do things because they will benefit us as biological systems. Ex. People choose mating partners that are resourceful because it may increase their biological fitness. - Evolution (Historical factor) : the fourth why. Evolution of behaviour. Is there any other organism that may have some incipient kind of morality so we can trace the origin of this adaptation? We investigate whether the kind of adaptation is related to a common ancestor on the tree. The building blocks of human morality are already present in our ancestors. Studying whether something is ancient or modern adaptation. Ex. Try to understand which species of birds will sing and at what extent they developed independently this ability or if there was a common ancestor that was able to sing. Ex. Play is practiced by human individuals (and also by many other warm-blooded species) because it helped our ancestors and our lineage’s ancestors to maximize their fitness
Female birds choose male birds when they are attracted to them is proximate cause. Ultimate cause is because in the past male birds that sing had more babies
1.12. Psychologies:
1.5. Psychobiology:
Development and inheritance:
-Previous view of development: Process of just quantitative change, just growth. Ex. Embrio just growing. Development understood as everything we see in an adult form is already present in one of the gametes, already present on the sperm. You just inflate the cell, the zygote.
- Epigenesis : Process with continuous interaction between organism and environment.
Gottlieb distinguishes between two kinds of epigenesis; predetermined epigenesis and probabilistic epigenesis.
Predetermined epigenesis: Development of behaviour is controlled by genes located in the nervous system. Arrows only one way. Reductionist approach.
genes structure Function (behaviour)
Probabilistic epigenesis : Development is the result of horizontal and vertical constraints between processes that take place on the same level and on different levels of organisation. The development of an organism is far more unpredictable. Arrows are bidirectional. Interaction that goes on both directions. All information is operating during the whole lifetime of the organism. Everything can be cause and effect at the same time. There is no agent more important than the function of another agent.
Genes structure Function (behaviour)
1.6. Psychobiological disciplines:
- Evolutionary psychology : It has three evolutionary approximations; evolutionary psychology , ecology of behaviour and dual inheritance. Any of the three evolutionary approximations has the main idea that any empirical phenomenon is the result of natural selection and constitutes an adaptation for the main biological problems of survival and reproduction. Main ideas of evolutionary psychology are: it isn´t the observable behaviour what matters but the cognitive processes that lead to that behaviour and that aren’t accessible directly; the hypothesis that these cognitive systems are specific of each biological domain; that most of the psychological characteristics that can be observed on a human species have been forced in an environment much different than the actual one, this is called the environment of evolutionary adaptedness (EEA).
- Physiological psychology : Study of neural mechanisms of behaviour by manipulating the nervous system of nonhuman animal in controlled experiments. Anthropocentric and reductionist approach. Experimental method.
- (^) Neuropsychology: Study of the psychological effects of brain damage in human patients. They see to what extent those brain areas are relevant to the psychological functions studied. Anthropocentric and proximate causes.
- Psychophysiology: Study of the relation between physiological activity and psychological processes in human subjects by non-invasive physiological recording. Anthropocentric and proximate causes.
- Cognitive neuroscience: They rely on new image techniques; these techniques are equipment able to take information from the brain and produce the image on real time on which areas are being activated. Metabolism, x-rays absorbed, oxygen, all this information can be taken.
- (^) Psychopharmacology: Study of the effects of drugs on the brain and behaviour. Narrow sense approach.
- Cognitive neuroscience: Study of the neuronal mechanisms of human cognition, largely through the use of functional brain imaging.
- Comparative psychology: Study of the evolution, genetics, and adaptiveness of behaviour, largely through the use of the comparative method.
1.7. What is psychobiology’s main contribution to the other psychologies?
- The integrative perspective with regards to the levels of organization (infra-organismic, organismic and supra-organismic).
- The study of ultimate causes (evolution) and its integration with the information on the proximate causes.
- The history of planet Earth is a history of change. Its main elements, the atmosphere, the lithosphere, the hydrosphere, and the biosphere have all changed ever since the Earth formed, 4500 million years ago.
- The changes that define the Earth’s history have not been driven by any supernatural entity. They are the result of natural processes.
- Creationism vs Evolutionism
- Creationism: line vertical, no change. Every organism has changed since it was created but there is no relation between them, there are not connected (Lammar).
- Evolutionism: lines oblique, there have been change. Every organism has changes since it was created and there is relation between them. Lines split into new levels, this branched process on one hand there will be events o speciation and branching, this defines the concept of tree. The tree becomes a web, there are connections between different branches of the tree. There are patterns of branching and diversifying. The information comes via ancestors, every time they have branched off they have innovated and acquired new properties that separate them from the common ancestor and from other branches on the tree. You can also get information not only from your ancestors but from other guys in the tree.
Evolutionism is just another religion.
From essentialism to Darwinian evolutionism
- Typological thinking (essentialism): Things are essentially different from each other except if they share the same properties and essences, this is how things were seen at that time.
-transmutation/saltationism : from time to time there is a transmutation, someone who was in category A changes suddenly and dramatically into something completely different category without going into anything intermediate, nature was essentially discontinuous, there is no relation between two different categories. Change from one particular state into another different without any series of intermediate forms.
- transformationism/uniformitarianism (external causes, internal causes ): things can become other things all the time through the process of making small changes constant so that you can see the transition from one form to another. External causes : external environment, if the environment is challenging in a particular direction the organism tend to adapt and change into that direction. If you use something very often you will grow that organ. Internal cause: phenolism, every living organism was built so that there was a tendency to get better and improve over time. The way you are designed is prominent to become better and to change in the direction of being a better design.
- Populational thinking/variational thinking (Darwinian evolutionism): evolution I spossible and has taken place because the variation is not something you have to try to hide, it’s the essence of species. This is a real change in the way we see evolution. The better adapted will spread within the population.
- Evidence for evolution:
- (^) Fossil record
- Homologous traits
- Analogous traits
- (^) Molecular similarities
- Vestigial traits
- Embryo development
- Biogeography.
- Homologous vs Analogous traits:
- (^) Homologous traits: shared because of common ancestry
- Analogous traits: they owe their similarity for the fact that they have evolved independently by the process of ecological convergence. They have solved the problems independently but they come to the same solution and develop same traits.
-Vestigial and atavistic traits:
- (^) Vestigial traits: species have vestigial organs because they are no longer functional, this body plan they have inherited from a common ancestor, but once you have acquired a certain trait its hard to get rid or that organs or traits which is no longer necessary for the kind of life they live therefore this leads to a vestigious presence. This tell as that we have developed. Ex. Wisdom teeth and goose bumps
- (^) Atavistic traits: our ancestors we tailed organisms that used that tail to move arung, humans are now tailess but they still have that essence. An example of an atavistic trait is that only a very low proportion of the species are born with that atavistic trait. Both are non functional but in the case of vestigial traits all species have them but in atavistic traits only few have them.
-Darwinian theory:
- Fact 1: superfecundity:
- Fact 2: stable population size: despite superfecundity the size of population tends to be very stable
- Fact 3: resources are limited: resources on which our life depends are limited.
- (^) Fact 4: uniqueness: this uniqueness might have to do with the fact that some individuals are better adapted for the struggle of existence.
- Fact 5: Darwin reasoned that individuals resembelded their parents more than anything, parents transmit something to their offspring there was some material bases for whatever is transmited from parents to offspring so natural selection is the mechanis that would explain difference between different kinds of genets etc. by selecting individuals in the basis of for example intelligence to the extent that that particular trait is genetically based, natural selection is selecting the phenotype and by doing that its dragging the genotype. Those who where better adapted produced more copies of them selves and passed genotipes associates with that phenotipes.
1 st^ principle: people struggle for the limited resources and as a result if there are more organisms than resources then people have to live or be eliminated, since you have to fight for live some individuals have to be eliminated.
2 nd^ principle: natural selection: this means that any time we see in a population that there is survival then that is a proof that natural selection is operating. Those individuals better adapted will be favoured for natural selection, the worst adapted will be disfavoured.
