EVOLUTIONARY PSYCHOLOGY SUBHOJIT CHAKLADAR

CONTENTS The Transition Biofeedback Brain Stimulation Brain Imaging Brain: Structure and Function Brain based Approach to Learning

QUESTIONS What is Biofeedback? Why does Cocaine cause extremely pleasurable experience? What is the Principle of Opposite Control?

THE TRANSITION Social behavior may have biological (more specifically Evolutionary) bases. Behavior that favor the survival of the individual (and the species) are learned more spontaneously (like a pigeon learning to peck to obtain food). What was called Sociobiology earlier is now Evolutionary Psychology

BIOFEEDBACK Biofeedback is a procedure by which an individual is given information about his/her biological functioning. It can be used to provide individuals with some control over behaviors that are normally autonomic or involuntary. In humans, heart rate (Inoue and Sadamoto, 2002), specific brain activity (Vernon et al, 2003) can be controlled by the individual using biofeedback.

BIOFEEDBACK Biofeedback has many practical applications like attempts to alleviate migraine headaches, reduce blood pressure and heart rate, control asthma. Neurofeedback is a specific Biofeedback which involves neurological functioning. It has been used to treat attention deficit disorders or learning abilities. Thus in effect, biofeedback, makes the individual “learn”, how to avoid these disorders (which are normally thought to be beyond conscious control).

BRAIN STIMULATION Electrical Stimulation of brain is used to map brain functions. It involves implanting electrodes or stimulating the brain in an electromagnetic field. One of the very early studies was done by Olds (1956) using implanted electrodes in rat brain.

BRAIN STIMULATION Mood altering drugs are a good example of Chemical Stimulation of the brain. A neurotransmitter called Dopamine, is involved in activity of some neurons associated with pleasure and motivation. Drugs like Cocaine, prevent immediate recapture of dopamine, released upon neural stimulation.

BRAIN STIMULATION This causes high levels of dopamine leading to intensely pleasurable experience. So, getting HIGH on cocaine is actually caused by HIGH levels of dopamine.

BRAIN IMAGING Electroencephalogram (EEG) – Detect actual electrical discharges in the brain using surface electrodes.

BRAIN IMAGING Positron Emission Tomography (PET) – Record blood flow change by studying distribution of radioactive particles injected in bloodstream.

BRAIN IMAGING Functional Magnetic Resonance Imaging (fMRI) – Detecting extremely subtle changes in magnetic field that accompany changes in blood flow levels.

BRAIN: STRUCTURE AND FUNCTION Evolution of different parts of human brain: Hindbrain – Oldest and most primitive structure. Physically the lowest part of the brain in humans. It is present and well developed in non-human animals. Midbrain. Forebrain – Most recent and the most advanced structure. It is also the largest part of the human brain.

BRAIN: STRUCTURE AND FUNCTION Forebrain Midbrain Hindbrain Function Regulating physiological functions. Relay station for sensory information. Emotion. Learning, thinking, remembering. Vision, speech, hearing, orientation. Regulating waking and sleeping. Controlling general arousal. Respiration, heart rate. Locomotion and balance

BRAIN: STRUCTURE AND FUNCTION Forebrain: A closer look Hypothalamus Location – Deep within the brain, near the top of brain stem. Function – Regulating physiological functions of ANS and the glands.

BRAIN: STRUCTURE AND FUNCTION Thalamus Location – Top of brain stem. Function – All sensory information, except for smell, are routed through the thalamus.

BRAIN: STRUCTURE AND FUNCTION The Limbic System Amygdala – Process emotional information for long term storage. Hippocampus – Long term memory of facts.

BRAIN: STRUCTURE AND FUNCTION Cerebrum The largest and most complex brain structure. The outer covering is the Cerebral Cortex – the seat of most advanced mental activities like learning, thinking and remembering. Frontal lobes – Involved in motor activity and higher thought processes. Temporal lobes – Hearing, Language and Speech. Parietal lobes – Physical sensation, movement, recognition, orientation. Occipital lobes – Vision.

BRAIN: STRUCTURE AND FUNCTION

BRAIN: STRUCTURE AND FUNCTION Cerebral Hemispheres Principle of Opposite Control

BRAIN: STRUCTURE AND FUNCTION Left brain (hemisphere) is supposed to control logical and verbal skills, so “left-brained” people are better in these skills. Right brain (hemisphere) is supposed to control emotion, spatial and temporal things, so “right-brained” people are better in music and art. However, there is no concrete evidence for this and this is highly debated.

BRAIN BASED APPROACH TO LEARNING Brain development is highly dependent on experience – especially early experience. Brain is the main learning center. Learning occurs by means of sensory information entering the brain.

SUMMARY Learning is often motivated by Evolutionary factors. Tasks that help the individual (and/or the species as a whole) to survive are learnt more easily. Learning is essentially adaptive or malleable, subject to certain biological constraints.

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