Learning is changing of attitudes and behaviors with the time due to influences. This is a feature which has distinguished living from non-living and has accounted for the pattern of organization of species in the environment. Learning is a process which facilitates thinking via memory. Therefore behavioral and survival acts are depending on learning and determine the fitness of an organism to survive in the environment. Even though the core concept of learning is equal to every organism, capacities and methods of learning are different among species and among individuals of the same species. Due to these differences learning has become a critical factor in the natural process of evolution.
All individuals in a population exhibit virtually the same behavior, despite individual and environmental variables during development and throughout life. These types of behaviors that are fixed to a population are known as Innate behaviors. But always entire population does not show the exact same behavior. Behavior is a variable depending on experiences and environment can influence behaviors through experience based learning. Modification of behavior is triggered by specific stimuli which are known as motivations. However there are several types of learning associated with behaviors.
Imprinting
This is a phenomenon of phase sensitive learning which has both fixed-innate and dynamic-learning components. This usually happen during a specific age or a phase in life and result a rapid, long lasting response in a particular individual or an object. This is different from other types of learning by having a sensitive period (critical period) which is a limited developmental period when certain behaviors can be learned.
For example during this sensitive period via imprinting, offspring recognize parents, parents recognize their offspring and offspring learn basic behaviors of their specie.
How does a young know what or who to imprint? Sometimes tendency to respond to imprinting stimuli is innate. But some species do not have innate recognition. So they respond to the first stimuli they encounter. These stimuli should have certain key characters. Otherwise subject will try to imprint behaviors which are irrelevant in terms of evolution and beyond their capabilities. In some cases the key character of the imprinting stimuli is mobility. The subject will imprint the first moving object that it encounters. There are specificities in these characters such as in the case of mobility as the key character, specificity of character would be moving away from the subject which is requiring imprinting.
Habituation & Sensitization
This is a type of learning which explains changes in the degree of responsiveness according to the nature and frequency of stimuli.
Habituation is decrease in responsiveness to a stimuli that is frequent and conveying a little or no new information. This allows an animal to ignore unimportant stimuli.
Sensitization is increase in responsiveness to stimuli that is frequent and conveying important information. With this, nervous system of a animal can be focused on important stimuli which are critical for survival, such as food, danger or harmful substances.
Collective action of habituation and sensitization allow an animal to focus on important stimuli while ignoring others as unimportant. This will prevent waste of time and energy on information that are less important to the animal's survival and reproduction. This way habituation and sensitization may increase individual fitness and increase the chance of contributing to the gene pool of next generation.
Spatial Learning
Animals with certain higher nervous system can establish memory that corresponds to the spatial structure of the environment. Most of the activities of an animal such as finding food, building nests or mating are related to the arrangement of environment around it. Every environment has its own features with possible variations.
When developing the spatial memory it is always related to the constant, major and sensible objects in the environment. For example some birds learn to locate their nests by learning its position in relation to visible landmarks and location indicators. Since spatial memory is partially important for the survival of the organism, fitness of an organism is proportional to the capacity of spatial learning.
Cognition & Cognitive Maps
Cognition is the knowing in terms of awareness, recollection, reasoning, recognition and adjustment. This higher nervous function is involved with the intellectual ability of an individual and involve with the logical thinking and sequential planning. This helps to act without the interruption of emotions in particular situations.
There is a representation in the nervous system of spatial relationship between objects in the surrounding environment which is known as Cognitive Maps. Everything we experience and identify by the means of touch, vision or any other stimuli make a stamp on the nervous arrangement, giving rise to a pattern of neurons and their firing rates relative to the environment. These patterns build the cognitive map, the neuronal layout of the environment.
Cognitive map is a higher stage of spatial learning. In cognitive maps rather than simply memorizing objects in the environment, certain rules are applied in order to form a unique map. Therefore organism would be able to navigate more efficiently by relating location indicators to one another.
Clark's Nutcracker (Nucifraga columbiana) place pine seeds in thousands of hiding places covering a large area as 35 km2 around its nest. It uses these pine seeds as landmarks to find the position of the nest accurately. It can identify halfway between these landmarks and this act as an abstract geometric rule in their cognitive maps. Such rules are fundamental properties of cognitive maps and they will reduce the amount of details required to remember. By applying these rules with the help of cognition they can easily locate a specific object and ensure it with recognition.
Associative Learning
Some organisms have ability to associate one environmental factor (color) with another (taste). Learning related to this association is known as associative learning. This is a very strong type of learning and requires a higher nervous system, because associations between experiences should be established. In associative learning always there is a modification of existing behavior in response to an experience. There are two main types of associative learning namely; Classical conditioning and Operant conditioning.
1) Classical Conditioning
In classical conditioning, a behavior which is produced by a stimulus becomes linked with another, probably unrelated stimuli which ultimately result the same outcome after conditioning.
Russian physiologist Ivan Pavlov was the first scientist to demonstrate and explain classical conditioning. In his experiment he used the salivation of a dog, in response to presence of food in mouth, as the unconditioned behavior. During the experiment, each time he gave food to the dog he rang a bell simultaneously and always salivation could be observed. After a certain period he stopped giving food and just rang the bell and observed that the dog is still salivating as it was provided with food. In here salivation had linked with the sound of a ringing bell and had become a conditioned behavior. The process by which these two unrelated stimuli are associated is known as conditioning. There could be other factors which influence classical conditioning for instance, as in this case smell of food, taste of food, vision of food and thinking of food.
2) Operant Conditioning
This is a type of trial and error learning. In operant conditioning behaviors are modified in association with reward or punishment. Organisms tend to repeat behaviors which are rewarded and avoid behaviors which are responded with punishments. Complex neuronal systems are associated with the perception of rewards and punishments.
B.F. Skinner experimented operant conditioning using the Skinner's box. He took a special box and put a rat inside it. The box was equipped with a lever, when pushed release a food pallet in to a plate and another lever when pushed give a mild sub lethal electric shock to the rat which is inside the box. Initially rat pushed both levers by chance and experienced both reward and punishment. Eventually it learned that pushing a one lever will give a electric shock, the punishment and pushing the other lever will release food, the reward. As a result of neural association in between pressing levers and different outcomes, after some time rat evaded pressing the lever which gave an electric shock and kept on pressing the lever which released food pallets.
Even though some stimuli can be linked with a particular behavior instead of the original stimuli, animals cannot learn to link any stimuli with a given behavior. Sometimes organization of the nervous system restricts associations that can be formed. Therefore associative learning is a highly selective type of learning.
Logical Thinking & Problem Solving
Thinking is the outcome of memory, which is the result of learning. Logical thinking is a neuronal activity which is involved with cognition. To be logical, organism should be mentally sound and able to reason out things. Only a organized nervous system can perform problem solving. Because it requires many aspects such as learning, memory, thinking, associating and sequencing. Organisms have to face obstacles throughout their life to survive in the environment. Cognitive activity of creating methods to proceed from one state to another in order to overcome real or apparent obstacles is known as problem solving.
Different animal species have different capacities of problem solving depending on the complexity of the organization and development of their neuronal system. Even within the same specie success of problem solving vary due to individual experiences and abilities. In higher animal species individuals can learn to solve problems by observing the behavior of other individuals at the presence of such problem. They also have the ability to modify the method of problem solving that they have learned, according to the situation of appliance. Ability of problem solving is positively related to the evolutionary fitness of an individual.
Learning appears to be controlled by individual preferences. Therefore individuals among the same specie learn different things and master different abilities giving the intellectual diversity to the population. Individual preference to learn could be either genetically predisposed or acquired after birth, with the influence of the behavior of surrounding adults. Learning preferences apparently depend on the individual ability to capture information and the type of captured information.
Organisms have to confront many challenges for their own survival and to ensure existence of their specie. In order to surmount these challenges, they require experience based behavioral modification (learning), memory and logical thinking. Most of the organisms on the planet demonstrate some way of learning. Learning could be either innate or develop at a some stage of life. Some animals have a restricted learning period while some learn throughout their life span.
Shivantha Withanage is a science student. Since 2009 he is publishing on various fields of science. In 2010, he came up with his debut science project, "Traditional Ways of Water Purification", where he attempted to evaluate the scientific basis of traditional wisdom of water purification in Sri Lanka.
