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HF9 (3000 BC (500BC (130-200 BC. (Renaissance1500-1800 AD (Breakthrough in…

- - - - Galen
        
        Started to experiment with animals six
        centuries after Aristotle and found in one of his experiments that
        after severing nerves in the throat, a pig would stop screaming
        but not breathing, which suggested that the voice comes from
        the brain
        o He dissected brains and published drawings of them
        o The brain was not important for reason or emotion but
        residence for the soul
        o How did the brain communicate with the body?
        ▪ The soul lived in the solid parts of the brain and
        produced and stored animal spirits (= spirits that were
        thought to travel over the nerves between the ventricles
        in the brain and the body)
        ▪ The ventricles were an apertures in the middle of the
        brain which for a long time were thought to contain
        perceptions, memories and thoughts
      - Renaissance
        
        1500-1800 AD
        
        Andreas Vesalius (1514-1564)
        
        resumed Galen’s view and extended it onto
        humans. He found three ventricles which functions became differentiated
        
        Front ventricle: Receives information from the senses (“common sense”)
        
        Second ventricle: In the middle and comprised thought and judgment
        
        Third ventricle: At the back and contains memory
        
        With the discovery of Galen’s texts researcher also regained interest in the
        relationship between injuries and behavior. The physician von Grafenberg for
        example concluded that brain damage can lead to speech problems.
        
        The focus gradually turned to the
        solid parts
        of the brain rather than the ventricles
        
        In the 17 th century they started to pay attention to the difference between the
        outer layer or the cerebral hemispheres and the layer underneath
        
        Thomas Willis (1664)
        was one of the first researchers
        to implicate the grey part
        of the brain in the functions of memory
        
        Around the same time scholars started to doubt the existence of spirits in the
        nerves and hypothesized that fluid flows in them
        
        Increased Interest in Reflexes:
        That some behaviors were elicited automatically
        without voluntary intervention became the focus of interest.
        o Galen had already discovered the same in animals and had ascribed
        “sympathy” between the various body parts ( sympathetic nervous system)
        
        Descartes
        was also interested in reflexes because
        they fitted within his mechanistic view of the body.
        He argued that a reflex consisted of a sensory
        impression which rushed to the brain and was
        reflected back into a motor command. This process
        was unconscious and involuntary. (1633)
        
        Procháska
        published a book in 1784 in which the
        argued that reflexes were not controlled by the
        brain but involved the spinal cord
        
        Breakthrough in the 19 th Century
        
        1800s
        
        2. Growing Focus on Reflexes
        • Research started to pay more attention to the nature and function of reflexes
        • Marshall Hall (1790-1857) introduced the notion of the reflex arc to refer to
        the mechanisms involve in involuntary movements elicited by sensory stimuli
        o His claim profited from the discovery shortly made before that there exist
        two different types of nerves (afferent and efferent nerves)
        o He further extended his concept from a simple physiological phenomenon
        to a biological principle and insisted that all muscular function, with a small
        number of exceptions, depend on reflexes controlled by the spinal cord
        • Ivan Sechenov was one of some scholars who extended Hall’s reflex arc from
        the spinal cord to the complete brain – he was Pavlov’s teacher
        • Still, there was some doubt among some scholars (e.g. William James and
        John Dewey’s) but Watson did not share their hesitation when he introduced
        behaviorism as the science of the S-R reflex arc.
        
        1. The Discovery of the Cerebrospinal Axis
        • The view since Galen was that the spinal cord functioned as a transmission
        channel of the spirits and later the brain fluid
        • This view became questioned when researchers began to realize that a body
        remained functioning in a vegetative state when the hemispheres were taken
        away or disconnected from the top of the spinal cord
        
        3. Localization of
        
        Brain Functions
        Are different psychological functions localized in different parts of the brain?
        
        Brain Equipotentiality Theory:
        states that all brain parts have equal
        significance and are involved in each task – view till 19 th century
        
        Localization Theory:
        states that brain processes are localized, meaning that
        only part of the brain underlies a particular mental function • In
        1825 Jean-Baptiste Bouillaud
        presented evidence which according to him proved that speech was controlled by the frontal part of the brain
        
        In contrast,
        Marie Jean Pierre Flourens
        defended the equpotentiality of he cerebral hemispheres, even though he agreed that the big structures of the nervous system have divergent functions
        
        1861
        
        In
        Paul Broca
        repeated and extended Bouillaud’s
        work and presented evidence that speech production was
        only controlled by the left frontal lobe
        
        1874
        Stimulated by these findings Karl Wernicke presented
        evidence in 1874 that language problems could also occur
        after damage to the rear part of the brain. But the
        problems had more to do with speech comprehension.
        
        In general, research on the localization of brain functions was
        partly motivated by the claims of Gall and Spurzheim
        regarding Phrenology.
        
        o Its view was part of a much wieder and earlier belief that
        an individual’s personality could be deduced from his or
        her appearance in general, in particular from the head and
        the face (Physiognomy)
        
        Gall and Spurzheim were convinced that the brain was
        composes of many organs, each dedicated to a particular skill`
        
        1800s
        
        5. Disentangling Communication in the Nervous System
        • Was the network a continuous structure or did it
        consist of individual cells?
        • Golgi favored for the former and it took nearly half a
        century before it became generally accepted that the network was composed of individual neurons which communicated with each other without being
        
        attached to one another ( 1906 Nobel Price for Golgi and Ramón y Cajal)
        
        The next challenge was to explain how they exchange and store information
        
        After animal spirits and brain fluid a new idea emerged, namely that the
        nervous system might resemble the transmission of electrical signals
        
        that was inspired by the first electricity generator in 1650 followed by the
        Leyden Jar, the first useable device to store electricity
        
        1786: Luigi Galvani
        was the first to find clear empirical evidence for the
        involvement of electricity in the nervous system of frogs
        • But how could the brain generate electricity? It would take another 50 years
        before Emil du Bois-Reymond would establish that nerve signals indeed
        involve electricity ( he used electric fishes)
        1852: Helmholtz
        measured the speed of signal transmission in nerves and
        found that they are based on chemical processes
        • In the 20 th century the exact mechanisms of signal transmission would be
        unraveled largely on the basis of the neurons of the giant squid
        • Around the same time neurotransmitter were discovered, which opened the
        door to the creation of medicines that have an impact on brain related
        disorders like epilepsy or depression
        
        4. The Discovery of the Nerve Cell
        • The fourth big finding was that the gray matter of the
        cerebral hemispheres consisted of billions of cells and
        that the white matter were the “tails”
        • Technical innovations like better microscopes and
        colors to stain the brain tissue were needed to make
        this discovery
        Camillo Golgi
        used silver stain that made neurons
        stand out against the surrounding cells and revealed
        that they not only consisted of cell bodies but in
        addition compromised a highly interconnected network
        
        Neuropsychology in the 20 th Century
        
        1900s
        
        Most of the research so far was based on animals because there is great similarity
        between the brain functioning in humans and in animals.
        
        After the world wars localization studies continued in the 20 th century
        o Gordon Holmes examined the consequences of small-scale wounds at the
        back of the head after World War I (shot wounds)
        o Joachim Bodamer (1947) described soldiers who lost their ability to
        recognize faces after World War II (prosopagnosia)
        
        In the second half of the 20 th century psychologists rather than physicians
        became involved in studying behavioral consequences of brain injury
        o Neuropsychology: The branch of psychology that looks at the relationship
        between brain and behavior. Research traditionally focused on understanding
        the consequences of brain damage and localizing affected tissue
        
        Around 1970/1980 a number of neuropsychologists became dissatisfied with
        the way in which the subject matter was investigated
        
        It was hard to localize the issue, because all that could be done was to
        establish a correlation between symptoms and post-mortem brain analysis
        
        The damage caused by brain injuries was most of the time widespread,
        making it difficult to decide which part of the damage caused the symptoms
        
        Results of examinations rarely went beyond the list of symptoms and case-
        studies were more common than formulating theories in general
        
        A landmark publication was a book on Deep Dyslexia that referred to reading
        problems either caused by developmental factors or brain damage
        
        Morton and Patterson (1980) postulated a distinction between a logogen
        system (lexicon) and a cognitive system (meaning of the word). They argued
        that there were three different
        logogen systems (for visual, auditory
        and spoken words)
        
        Grapheme conversion route:
        converts letters into sounds
        
        The second route had a direct
        connection between the visual
        logogen system and the output
        logogen system
        
        The third route was important to
        name written words via the visual
        logogen system, through the
        cognitive system and then to the logogen output o In patients with dyslexia only the last route is still functioning
        
        To emphasize the difference between the new type of research and the
        neuropsychological approach a new name was coined
        
        o Cognitive Neuropsychology: A part of neuropsychology aimed at
        understanding and treating behavioral consequences of brain damage within
        information processing models proposed by cognitive psychologists
        
        o By relating consequence of brain damage to theories of normal functioning
        they explicitly aimed to increase the impact of their research
        
        Brain Imaging and the
        
        Turn to Neuroscience
        
        single-cell recording
        EEG
        ERP
        MEG
        PET
        fMRI
        TMS
        
        The availability to measure human brain activity while participants are performing
        mental operations opened a completely new field: Cognitive Neuroscience, the
        scientific study of the biological mechanisms underlying cognition.
        
        However, not everyone was is convinced that brain imaging allow researcher to
        really test information processing models
        o Kihlstrom (2007): Argued that the conclusions based on brain imaging have a
        strong resemblance to the claims made by phrenology in the 19 th century
        
        But despite the doubts there are also some arguments for its usefulness
        o There is a difference between empirically showing the brain regions involved
        in a particular task and speculating about them
        o The low resolution of current methods are likely to be improved for example by
        combining different techniques
        o Localization of brain activity while a person is performing a task does provide
        information about the processes involved
        
        Focus On: Can Delusion be Investigated with the Cognitive
        
        Neuropsychological Approach?
        
        Delusions:
        Strong erroneous beliefs that are not supported by empirical evidence
        o They are present in app. 75% of people diagnosed with schizophrenia but also
        happen sometimes after brain injury
        o Examples: Presecutory (e.g. someone is trying to harm me), Body/Mind
        Control (e.g. my thoughts are controlled by aliens)
        • The subfield that tries to understand delusions and other consequences of mental
        disorders is called Cognitive Neuropsychiatry
        • Case Study of Joseph Capgras (1873-1950)
        o Mme. M. was a patient of Caprgras suffering from delusions
        o He was struck by the strength of this woman’s conviction that her child and her
        husband had been replaced by imposters
        o Capgras published several papers on that case and starts to interpret the
        delusions in terms of Freudian thinking
        • The Cognitive Neuropsychiatry Alternative: They got interested in delusions when
        it became clear that delusions sometimes started after a brain injury
        o Ellis and Young (1990) put forward the hypothesis that what might be
        happening in the Capgras delusion is that the unconscious, emotion-based
        face processing route that has been severed
        o Such a disconnection would result in the patients still recognizing the person
        at a conscious level but failing to experience the emotional response
        
        1 more item...
    - - He divided the soul into three parts (Tripartite Soul)
        
        The highest part is situated in the brain and responsible for reasoning. It
        directly came from the soul of the universe and was immortal.
        
        The second part dealt with sensation, mortal and situated in the heart
        
        The lower part dealt with appetite and was place in the liver