University of Split Danica Škara, PhD Office hours: Tuesday, 14:00-15:00h PSYCHOLINGUISTICS AND COGNITIVE ASPECTS OF LANGUAGE Week 2: LANGUAGE AND THE BRAIN

THE HUMAN BRAIN The human brain is the center of the human nervous system and is a highly complex organ. It has the same general structure as the brains of other mammals, but is over three times as large as the brain of a typical mammal. Especially expanded are the frontal lobes, which are involved in executive functions such as self-control, planning, reasoning, and abstract thought. The human brain is the center of the human nervous system and is a highly complex organ. It has the same general structure as the brains of other mammals, but is over three times as large as the brain of a typical mammal. Especially expanded are the frontal lobes, which are involved in executive functions such as self-control, planning, reasoning, and abstract thought. nervous system mammals frontal lobesexecutive functions nervous system mammals frontal lobesexecutive functions The portion of the brain devoted to vision is also greatly enlarged in human beings. The portion of the brain devoted to vision is also greatly enlarged in human beings.

Neurons The human brain has been estimated to contain 50–100 billion (1011) neurons, of which about 10 billion (1010) are cells. These cells pass signals to each other via approximately 100 trillion (1014)synaptic connections. The human brain has been estimated to contain 50–100 billion (1011) neurons, of which about 10 billion (1010) are cells. These cells pass signals to each other via approximately 100 trillion (1014)synaptic connections.neuronscellsneuronscells What does the brain do? What does the brain do? It receives and transmits messages to other parts of our body. It accepts a fllod of information about the world around your various senses (seeing, hearing, smelling, tasting and touching). It receives and transmits messages to other parts of our body. It accepts a fllod of information about the world around your various senses (seeing, hearing, smelling, tasting and touching).

Neuron structure Millions of sensory receptors detect changes, called stimuli, which occur inside and outside the body. They monitor such things as temperature, light, and sound from the external environment. Millions of sensory receptors detect changes, called stimuli, which occur inside and outside the body. They monitor such things as temperature, light, and sound from the external environment. Sensory input is converted into electrical signals called nerve impulses that are transmitted to the brain. There the signals are brought together to create sensations, to produce thoughts, or to add to memory. Sensory input is converted into electrical signals called nerve impulses that are transmitted to the brain. There the signals are brought together to create sensations, to produce thoughts, or to add to memory.

Each neuron has three basic parts: cell body (soma), one or more dendrites, and a single axon.

Neurons transmit nerve messages.

Brain message travel between neurons in just one thousandth of a second. Each time you have a new thought or memory, a new brain connection is made between two or more brain cells. Brain message travel between neurons in just one thousandth of a second. Each time you have a new thought or memory, a new brain connection is made between two or more brain cells.

The neural network in the human brain is formed by the genetic code acting as a framework, and by individual development. Long-term memory is either achieved by changes on the synapses (more strength connections) or by changes of functional units (new cell assemblies). A connection can become stronger when the same path is used often, the other way round a connection that is rarely used will weaken.

LANGUAGE IN THE BRAIN The ability of humans to speak and to understand speech requires an enormous amount of brain resources. These resources have to manage information about many thousands of words and many syntactic constructions and their interconnections. The ability of humans to speak and to understand speech requires an enormous amount of brain resources. These resources have to manage information about many thousands of words and many syntactic constructions and their interconnections. This complex combination of brain structure can be called the brain’s linguistic system. This complex combination of brain structure can be called the brain’s linguistic system.

We use language to talk about an enormous range of different kinds and aspects of human experience, all of which also have representations in the brain. We use language to talk about an enormous range of different kinds and aspects of human experience, all of which also have representations in the brain. The linguistic system must therefore occupy a central position in mental structure, connected to the cognitive systems that register all those other experiences. The linguistic system must therefore occupy a central position in mental structure, connected to the cognitive systems that register all those other experiences.

Lateralization Left-brain/Right-brain The human brain is split into two hemispheres. The left hemisphere controls any muscular activity on the right side of the human body and the right hemisphere operates vice versa. We know that there are small differences in the sizes of some regions in the two hemispheres. We know that there are small differences in the sizes of some regions in the two hemispheres. These differences may form the basis for the first major brain specialization for language – lateralization of language to the left hemisphere. These differences may form the basis for the first major brain specialization for language – lateralization of language to the left hemisphere.

Functions of hemispheres The two hemispheres are thought to contribute to the processing and understanding of language: The two hemispheres are thought to contribute to the processing and understanding of language: the left hemisphere: rapid language processing, lexical, syntactic processing, phonemic processing the left hemisphere: rapid language processing, lexical, syntactic processing, phonemic processing the right hemisphere: higher level processing, discourse processing, prosodic information the right hemisphere: higher level processing, discourse processing, prosodic information

Location of two brain areas that play a critical role in language: Broca’s area and Wernicke’s area

Broca’s area The first language area within the left hemisphere to be discovered is Broca's area, named after Paul Broca, who discovered the area while studying patients with aphasia, a language disorder. The first language area within the left hemisphere to be discovered is Broca's area, named after Paul Broca, who discovered the area while studying patients with aphasia, a language disorder.Broca's areaPaul Broca aphasiaBroca's areaPaul Broca aphasia Deficits associates with brain damage: Deficits associates with brain damage: Broca’s area Disturbance of speech production Disturbance of speech production Agrammatic speech Agrammatic speech

For example, in the following passage, a Broca's aphasic patient is trying to explain how he came to the hospital for dental surgery: For example, in the following passage, a Broca's aphasic patient is trying to explain how he came to the hospital for dental surgery: Yes... ah... Monday... er... Dad and Peter H... (his own name), and Dad.... er... hospital... and ah... Wednesday... Wednesday, nine o'clock... and oh... Thursday... ten o'clock, ah doctors... two... an' doctors... and er... teeth... yah.[ Yes... ah... Monday... er... Dad and Peter H... (his own name), and Dad.... er... hospital... and ah... Wednesday... Wednesday, nine o'clock... and oh... Thursday... ten o'clock, ah doctors... two... an' doctors... and er... teeth... yah.[[

Wernicke's area Wernicke's area The second language area to be discovered is called Wernicke's area, after Carl Wernicke, a German neurologist who discovered the area while studying patients who had similar symptoms to Broca's area patients but damage to a different part of their brain. The second language area to be discovered is called Wernicke's area, after Carl Wernicke, a German neurologist who discovered the area while studying patients who had similar symptoms to Broca's area patients but damage to a different part of their brain.Wernicke's areaCarl WernickeWernicke's areaCarl Wernicke

Individuals with Wernicke's aphasia may speak in long sentences that have no meaning, add unnecessary words, and even create new "words" (neologisms). Individuals with Wernicke's aphasia may speak in long sentences that have no meaning, add unnecessary words, and even create new "words" (neologisms).neologisms For example, someone with Wernicke's aphasia may say, "You know that smoodle pinkered and that I want to get him round and take care of him like you want before", meaning "The dog needs to go out so I will take him for a walk". For example, someone with Wernicke's aphasia may say, "You know that smoodle pinkered and that I want to get him round and take care of him like you want before", meaning "The dog needs to go out so I will take him for a walk". They have poor auditory and reading comprehension, and fluent, but nonsensical, oral and written expression. Individuals with Wernicke's aphasia usually have great difficulty understanding the speech of both themselves and others and are therefore often unaware of their mistakes. They have poor auditory and reading comprehension, and fluent, but nonsensical, oral and written expression. Individuals with Wernicke's aphasia usually have great difficulty understanding the speech of both themselves and others and are therefore often unaware of their mistakes.