Post on 14-Jan-2016
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PHYSIOLOGICAL UNDERPINNINGS OF LANGUAGE, PROBLEM SOLVING, AND REASONING
Thinking vs. Language
Is there a difference between thinking and language? In other words, do you “think” language and thinking should be studied separately or together?
Language
Arbitrary system of communication that combines symbols, such as words or gestural signs, in rule-based ways to create meaning
Allows for communication of information, as well as social and emotional functions
Features of Language
Highly practiced and automatic process
Four levels of analysis that must coordinate Phonemes Morphemes Syntax Extralinguistic information
Nonhuman Animal Communication
Animal species differ in the complexity and type of communication
Most communication is geared towards mating and aggression
Honeybees and vervet monkeys
Teaching Human Language
Many attempts to teach non-humans our language, with mixed results Chimpanzees Bonobos
Humans appear unique in our ability to use language in a sophisticated way
Aphasias Paved the Way
What is an aphasia? 2 important discoveries from aphasias
Left hemisphere is dominant in language Two key cortical areas have different roles
in language Broca’s Area Wernicke’s Area**arcuate fasciculus is bidirectional
Modern Framework
3 large systems interact closely in language perception and production Language implementation system
Broca and Wernicke Analyzes incoming signals and ensures
articulatory control Mediational system
Temporal, parietal, occipital, and frontal association cortices
Conceptual system Remainder of higher-order association cortices
Problem Solving and Reasoning
Involves reliable planning, judgment, and decision-making Requires monitoring of external world,
attention to information, retrieval from long-term memory, manipulation/integration of information, and output of appropriate information.
Also, suppression of unnecessary information and inappropriate actions.
Altogether, this is called executive function.
Problem Solving and Reasoning
“Executive control”– mechanism or system responsible for the coordinated operation of various systems.
Prefrontal cortex is considered the important structure for executive control Numerous studies on damage of the
prefrontal cortex Studies indicate a sensitivity, not a
specificity for executive function
Prefrontal Damage
Normal IQ Normal long-term memory Normal perceptual and motor skills Deficits when intellectual operations
demand creation of a program of action Difficulties when a choice needs to be made
between several equally probable alternatives
Coordination of perceptual, motor, and memory processes is deficient
3 divisions of prefrontal cortex
Dorsolateral Prefrontal Cortex Anterior Cingulate Cortex Orbitofrontal Cortex
Dorsolateral Prefrontal Cortex
Involved with on-line processing such as integrating different dimensions of cognition and behavior
Verbal fluency, maintain and shift set, planning, response inhibition, working memory, organizational skills, reasoning, problem solving, abstract thinking.
Anterior Cingulate
Involved in emotional drives, experience, and integration
Responsible for inhibition of inappropriate responses, decision making, and motivated behavior. Lesions related to low drive states
Orbitofrontal Cortex
Involved in impulse control, maintenance of set, monitoring ongoing behavior and socially appropriate behavior
Role in representing the value of rewards based on sensory stimuli and evaluating subjective emotional experiences Lesions lead to impulsivity, aggressive
outbursts, sexual promiscuity, antisocial behavior.
The role of working memory
Involved with temporary storage of information
Also a mechanism of for manipulating and processing stored information
This is an indication that working memory can be considered a “workspace” for information processing
3 Features of Prefrontal Mechanism
1. Represent and process any kind of new information
2. Access any kind of necessary information
3. Provide information to various neuronal systems to direct information processing
**The prefrontal mechanism must have flexible and dynamic input-output relationships with various brain systems