-Each hemisphere controls contralateral side of body.

-Functional asymmetries of the brain. -No corpus collosum

a. left hemisphere only reacts to right side of body

b. need damage to see lateralization Damage to corpus callosum interferes with exchange of information

-Corpus callosum matures through first 5 to 10 years

-Young children have difficulty comparing information from left and right hand

-Incomplete development of corpus callosum increases development of anterior and hippocampal commisures

-Immediately after surgery, each hemisphere responds quickly and accurately only to information presented directly

-Brain learns use smaller connections

-Difficulty integrating information remains

a. repeated excessive synchronized neural activity.

b. decreased release of GABA

-sodium amytal (wada) test

a. anesthetize one hemisphere and check language function

b. dichotic listening: report more digits heard by dominant half  

c. functional brain imaging: fMRI and PET

-split-brain patients: those who have undergone damage to the corpus callosum

-normal intellect and motivation

-use hands independently in a way others cannot Respond differently to stimuli presented to only one side of the body

-right hemisphere is better

-damage to parts of right hemisphere causes difficulty perceiving other's emotions, failure to understand humor and sarcasm, and monotone voice deficiency.

-Left hemisphere damage increases ability to accurately judge emotion

-Decreased left hemisphere interference

-Right hemisphere better at spatial relationships

-Left hemisphere generally focuses on visual details, right hemisphere usually focuses on visual pattern.

-Left side may be specialized for language from birth.

-Human language likely modification of behavior found in other species

-Studies of nonhuman language abilities Insight to how best to teach language to those who do not learn it easily

-Illustrate ambiguity of our concept of language -Recovery of language after damage

-Location of damage (left vs. right)

-Initial lateralization of language in patient

-Age affects extent of recovery...Brain is more plastic at an early age

-Language Damage to left hemisphere often results in language deficiencies

-Left side may be specialized for language from birth

-Planum temporale asymmetry seems related to language function

-Two theories of human ability to learn language:

1. Language a by-product of overall brain development

2. Language as an extra part of brain

-Tendency to ignore left side of objects

-Associated with right hemisphere damage

-Location of damage determines neglect

-Damage to right inferior parietal cortex leads to neglect of everything to left of own body

-Damage to right superior temporal cortex leads to neglect of left side of objects, regardless of location

-Serious impairment in language production, usually due to brain damage

-Serious impairment in language production, usually due to brain damage

-Omission of most pronouns, prepositions, conjunctions, auxiliary verbs, tense and number endings during speech production

-People have trouble understanding same class of words they omit (prepositions and conjunctions)

-Accompanied by comprehension deficits

-Sentence meaning depends on prepositions, word endings or unusual word order

-Sentence structure is complicated

-Impaired ability to remember names of objects (anomia)

-Impaired language comprehension

-Recognition of items often not impaired; ability to find word is impaired

-Depression: Similar symptoms result from hormonal problems, head injuries, brain tumors Often comorbid with schizophrenia, substance abuse, anxiety or Parkinson’s

-Absence of happiness more reliable symptom than increased sadness

-Twice as common in women About 10% lifetime prevalence

-Moderate degree of heritability

-Genetic Factors:

a. Gene for serotonin transporter protein controls ability to reabsorb neurotransmitter

b. Presence of two “short forms” associated with increased chance of depression after stressful events may alter how people react to stressful events

c. Childhood depression equally common in boys and girls

d. After puberty, depression twice as common in females

e. Consistent across cultures, suggesting biological factor

-Tricyclic Antidepressants (TCAs) Block reuptake of 5HT, DA,NE

-Selective Serotonin Reuptake Inhibitors (SSRIs) Block reuptake of 5-HT

-Monoamine Oxidase Inhibitors (MAOIs) Block enzymatic breakdown of 5-HT

-Atypical Antidepressants: Antidepressant effects with fewer side effects

-Monoamine Oxidase Inhibitors (MAOIs) Block enzymatic breakdown of 5-HT

-Atypical Antidepressants: Antidepressant effects with fewer side effects

-Electroconvulsive Therapy (ECT): Used when antidepressants are ineffective...Side effects include memory loss Increases neuron production in hippocampus Alters expression of 120+ genes

-Repetitive Transcranial Magnetic Stimulation

-Sleep Deprivation Quickest method of relieving depression

-Short term solution: Regular Exercise

-Depression that regularly occurs during particular season

-Patients have phase-delayed sleep and temperature rhythms

-Most depressed people have phase-advanced patterns.

-Treatment often includes bright lights

-Light affects serotonin synapses and alters circadian rhythms

positive symptoms- behaviors that are present that should be absent

negative symptoms-behaviors that are absent that should be present

-Schizophrenia results from excess activity at dopamine synapses in certain brain areas

-Dopamine turnover faster in schizophrenia, especially in basal ganglia Substance-induced psychotic disorder characterized by hallucinations and delusions resulting from repeated large doses of amphetamine

-Prolong activity of dopamine Supports dopamine hypothesis

-Increased activity specifically at D2 receptor

-Limitations: Dopamine concentration not abnormal

-Antipsychotic drugs block dopamine within minutes but effects on behavior gradually build over 2 to 3 weeks

-Deficient activity at glutamate receptors

-Dopamine inhibits glutamate release or glutamate stimulates neurons that inhibit dopamine release

-Increased dopamine produces same effects as decreased glutamate

-Lower than normal release of glutamate

-Fewer receptors in prefrontal cortex and hippocampus

-Effects of phencyclidine (PCP/angel dust): Inhibits NMDA glutamate receptors

Produces positve and negative symptoms at high doses Does not produce symptoms in preadolescents

Cannot treat with glutamate due to excitotoxicity, but glycine enhances effects of glutamate

-Inhibits NMDA glutamate receptors

-Produces positve and negative symptoms at high doses Does not produce symptoms in preadolescents

-Cannot treat with glutamate due to excitotoxicity, but glycine enhances effects of glutamate

-block D2 receptors

-treat positive symptoms

-mesolimbocortical system

-block dopamine in mesostriatal system

a. tardive dyskinesia- tremors and involuntary movements

-Reading difficulties not due to other deficit More common in boys Probable genetic factor

-Cultural influence (related to number of phonemes?)

-Subtle visual, auditory and motor deficits

-include weak social interactions, emotional expression, speech, and working memory.

-usually stable over time and difficult to treat.

-positive symptoms fall into two clusters: psychotic and disorganized.

-the psychotic cluster consists of delusions (unfounded beliefs, such as the conviction that one is being persecuted or that outer space aliens are trying to control one's behavior) and hallucinations.

-PET scans have showed that hallucinations occur during periods of increased activity in the thalamus, hippocampus, and parts of the cortex, including many of the areas activated by actual hearing.

-The disorganized cluster of positive symptoms consists of inappropriate emotional displays, bizarre behaviors, incoherent speech, and thought disorder.

-Overall intelligence varies considerably, but on the average, IQ scores are a few points below those of the rest of the population.

-The most typical type of thought disorder of schizophrenia is a difficulty understanding and using abstract concepts...related symptoms include deficits in attention and working memory