Psychobiology - Historical Psychology - Lecture Slides, Slides of History of Psychology

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Psychobiology

Psychobiology

 Psychobiology: The field of study that attempts to explain psychological phenomena in terms of their biological foundations.  Behaviorism had discouraged the search for internal causes of behavior.

Physiological psychology Psychopharmacology Neuropsychology Psychophysiology Cognitive neuroscience Comparative psychology Docsity.com

Summary of

Biopsychology

Karl S. Lashley

 Attended University of West Virginia, University of Pittsburgh, and Johns Hopkins University  While at Johns Hopkins he met and was highly influenced by Watson  Lashley was interested in finding the neurophysiological bases of conditioned reflexes, Watson was not.  Professor at University of Minnesota, University of Chicago, and Harvard  Director of Yerkes Primate Laboratory

Karl S. Lashley

In Search of the Engram

 Engram: The supposed neurophysiological locus of memory and learning. Lashley sought the engram in vain, as have subsequent researchers.  “ This series of experiments has yielded a good bit of information about what and where the memory trace is not. It has discovered nothing directly of the real nature of the engram. I sometimes feel, in reviewing the evidence on the localization of the memory trace, that the necessary conclusion is that learning is just not possible .”

Karl S. Lashley

In Search of the Engram

Modern Research

 Rats and mice can be trained to solve simple tasks. For example, if a mouse is placed in a pool of murky water, it will swim about until it finds a hidden platform to climb out on. With repetition, the mouse soon learns to locate the platform more quickly. Presumably it does so with the aid of visual cues placed around the perimeter of the pool because it cannot see or smell the platform itself.  Rats or mice who have had a part of their brain called the hippocampus damaged, cannot learn this task, although they continue to solve it quickly if they were trained before their brain damage. This suggests that neurons in the hippocampus are needed for new learning to occur.  New neurons are produced in the hippocampus throughout life. They arise from a pool of stem cells in the brain.

Donald O. Hebb

 Graduated from Dalhousie University with the lowest GPA you could get!  Despite this, he went to McGill University for Graduate work (Hebb’s mom knew the chair of the Psychology Department!)  Went to the University of Chicago and worked with Lashley and took a seminar with Kohler.  “ I had all the fervor of the reformed drunk at a temperance meeting; having been a fully convinced Pavlonian, I was now a fully convinced Gestalt-cum- Lashleyan .”  Lashley took a professorship at Harvard and Hebb went with him, receiving his PhD from Harvard.

Donald O. Hebb

 Worked with Neurosurgeon Wilder Penfield at the Montreal Neurological Institute.  Hebb was to evaluate patients following neurosurgery.  Consistently found little or no loss of intelligence despite loss of brain tissue.  “ Experience in childhood normally develops concepts, modes of thought, and ways of perceiving that constitute intelligence. Injury to the infant brain interferes with that process, but the same injury at maturity does not reverse it .”  Went with Lashley to the Yerkes Primate Laboratory  Took Professor position at McGill University

Donald O. Hebb

Cell Assemblies and Phase Sequences

 The interconnections between neurons in an infant brain are essentially random.  Experience causes this network of neurons to become organized.  Every environmental object we encounter fires a complex package of neurons called a cell assembly.  Though initially unconnected, reverberating neural activity connects the various parts of an object to each other.  A phase sequence is a “temporally integrated series of assembly activities; it amounts to one current in the stream of thought” Docsity.com

Donald O. Hebb

Cell Assemblies and Phase Sequences

 When one component of a phase sequence fires, they all tend to fire.  When the phase sequence fires we experience a “stream of consciousness”

 Childhood learning involves the building up of cell assemblies and phase sequences ( Associationistic ).

 Adult learning involves creativity and insight from rearrangement of existing cell assemblies and phase sequences ( Gestalt ). Docsity.com

Roger W. Sperry

 BA from Oberlin College

 PhD in Zoology from the University of Chicago

 Studied with Lashley at the Yerkes Laboratory

 Professor at University of Chicago and California Institute of Technology

Roger W. Sperry

The Split-Brain

Preparation

 Split-brain Preparation: A brain that has had its corpus callosum and optic chiasm ablated. Corpus Callosum

Methods of Psychobiology

 Many techniques exist to measure cognitive functioning.

 Lesions, Electrophysiology, and Neuroimaging (to be discussed) are only a few.

 Recording of neurons-Feature detectors

 Brain dissections-Weight of various areas

 Behavioral measures

Methods of Psychobiology

Lesions

 Double Dissociation: Refers to situations in which an independent variable affects Task A but not Task B and in which a different variable affects Task B but not Task A.  If damage to one part of the brain leads to decreases in verbal performance, but not spatial performance while damage to a different part leads to decreases in spatial performance but not verbal performance, we can more be more able to say the damage to the areas “cause” the changes in performance.