Temporal+Lobes

** The temporal lobes are unique. These are the only regions of the brain that subserves personalized, subjective emotional and social experience and can store and recall this information from memory. The temporal lobes also contains the core structures of the limbic system involved in emotion and memory, the amygdala and hippocampus. ** The temporal lobe/limbic allocortex is responsive to complex auditory and visual stimuli, comprehending, in humans, complex speech, and contains the highest density and the greatest diversity of peptides and neurotransmitters as compared to all other brain regions.

AUDITORY NEOCORTEX
THE AUDITORY ASSOCIATION AREAS WERNICKE'S AREA THE MELODIC-INTONATIONAL AXIS MIDDLE TEMPORAL LOBE INFERIOR TEMPORAL LOBE THE AMYGDALA.

Lesions/Damage

 * HALLUCINATIONS **

-Cortical Deafness
 * Bilateral Primary Auditory Zone**

-Pure Word Deafness -Difficulty with perception of real words, word lists, numbers, backwards speech, morse code, consonants, consonant vowel syllables, nonsense syllables, transitional elements of speech, single phonemes, rhymes, activity significantly increases in the left hemisphere during language tasks including reading
 * Left Primary Auditory Zone **

AUDITORY AGNOSIA -Difficulty with acoustically related sounds, non-verbal environmental acoustics (e.g. wind, rain, animal noises), prosodic-melodic nuances, sounds which convey emotional meaning, most aspects of music including tempo and meter
 * Right Primary Auditory zone **

RECEPTIVE APHASIA
 * Left Auditory Association Area (including Wernicke's Zone)**

-Associated Visual Agnosia -Word finding difficulty -possible aphasic abnormalities -Confrontive naming deficits -Abnormalities in the maintanance of temporal order and sequence -Verbal memory impairments -Reading and naming deficits (phonological alexia) <span style="background-color: #ffffff; font-family: 'Times New Roman',serif;">patients with developmental dyslexia have been found to have abnormalities in this area
 * Middle Temporal Lobe**

VISUAL ATTENTION - loss of the ability to recognize faces (prosopagnosia) -Severe disturbances involving visual discrimination learning and retention -Difficulty performing visual closure and recognizing incomplete figural stimuli (different shapes and patterns and objects which differ in regard to size or color)
 * Inferior Temporal Lobe**

MEMORY DREAMING TEMPORAL LOBE (PARTIAL COMPLEX) SEIZURES & EPILEPSY -Ability to sing affected (right amygdala) -Ability to properly intonate altered (right amygdala)
 * Inferior Temporal Lobe/Amydala/Hippocampus**

Electrical Stimulation:
<span style="color: #000000; font-family: 'Times New Roman',serif;">Of all brain regions, only stimulation or activation of the temporal lobe or underlying limbic structures, gives rise to personalized, subjective, emotional, and sexual experiences. Although direct electrical stimulation of the frontal motor cortex can induce twitching of the lips, flexion or extension of a single finger joint, protrusion of the tongue or elevation of the palate, patients never claim to have willed these movements. That is, <span style="color: #000000; font-family: 'Times New Roman',serif;">stimulation of the frontal lobes evokes behavior that seems outside the control of the patient. <span style="color: #000000; font-family: 'Times New Roman',serif;">By contrast, electrode stimulation of the temporal lobes <span style="color: #000000; font-family: 'Times New Roman',serif;">There is no subjective sensations with frontal or parietal or occipital stimulation. In fact, with stimulation to these other brain areas the patient <span style="color: #000000; font-family: 'Times New Roman',serif;">only becomes aware of the stimulation when they attempt to speak or move, or if a finger begins to twitch or if they feel <span style="color: #000000; font-family: 'Times New Roman',serif;">painful tingling or see flashes of light. Although damage to the frontal lobe can produce the "frontal lobe personality" it is the temporal lobe which subserves those aspects of experience which are experienced as personal and subjective, of pertaining to the self and one's personal and even spiritual identity. Indeed, stimulation of the temporal lobe can give rise to profound personal, emotional, sexual, and even religious feelings which are experienced as personally, spiritually and philosphically meaningful, including even sensations of having the "truth" revealed and of receiving knowledge regarding the meaning of life and death.evokes experiences which become part of the subjective stream of consciousness, embedded into the very fabric of the personality, such that the personality, and even sexual orientation may be altered. Moreover, patients may experience profound visual and auditory hallucinations and even feel as if they have left their bodies and are floating in space or soaring across the heavens.

<span style="color: #000000; font-family: 'Times New Roman',serif;">The temporal lobe is the most heterogenous of the four lobes of the human brain, as it consists of six layered neocortex, four to five layered mesocortex, and 3 layered allocortex, with the hippocampus and amygdala forming its limbic core. <span style="color: #000000; font-family: 'Times New Roman',serif;">Because so much of the temporal lobe evolved from limbic nuclei, unlike the other lobes, it consists of a mixture of allocortex, mesocortex, and neocortex, with allocortex and mesocortex being especially prominent in and around the medial-anterior inferiorally located uncus, beneath which and which abuts the amygdala and hippocampus. <span style="color: #000000; font-family: 'Times New Roman',serif;">Broadly considered, the neocortical surface of the temporal lobes can be subdivided into three main convolutions, the superior, middle, and inferior temporal gyri, which in turn are separated and distinguished by the sylvian fissure and the superior, middle, and inferior temporal sulci. Each of these subdivision performs different (albeit overlapping) functions, i.e. auditory, visual, and auditory-visual-affective perception including memory storage.
 * <span style="color: #000000; font-family: 'Times New Roman',serif;">TEMPORAL TOPOGRAPHY **

<span style="color: #000000; font-family: 'Times New Roman',serif;">The temporal lobes perform complex <span style="color: #000000; font-family: 'Times New Roman',serif;">analysis of visual stimuli, including the recognition of <span style="color: #000000; font-family: 'Times New Roman',serif;">faces, animals, tools, houses, and other complex geometric forms. <span style="color: #000000; font-family: 'Times New Roman',serif;">The inferior and medial temporal lobe harbors the amygdala and hippocampus, performs complex visual integrative activities including visual closure, and contains neurons which respond selectively to faces and to the sight of complex objects. <span style="color: #000000; font-family: 'Times New Roman',serif;">The inferior and middle temporal lobes, are the recipients of one two diverging (dorsal and ventral) streams of visual input arising from within the occipital lobe and thalamus; i.e. the pulvinar and dorsal medial nucleus of the thalamus. The dorsal stream is more concerned with the detection of motion and movement, orientation, binocular disparity, whereas the ventral stream is concerned with the discrimination of shapes, textures, objects and faces, including individual faces. This information flows from the primary visual to visual association areas and is received and processed in the temporal lobes and is then shunted to parietal lobe, and to the amygdala and entorhinal cortex (the gateway to the hippocampus) where it may then be learned and stored in memory. <span style="color: #000000; font-family: 'Times New Roman',serif;">The temporal lobes, however, also receive extensive projections from the somesthetic and visual association areas, and processes gustatory, visceral, and olfactory sensations including the feeling of hunger. Hence, the temporal lobes perform an exceedingly complex array of divergent and interrelated functions.
 * <span style="color: #000000; font-family: 'Times New Roman',serif;">Vision and the Temporal Lobes **

[[image:http://brainmind.com/images/visualstreams768.jpg width="75" height="38" align="RIGHT"]]**<span style="color: #000000; font-family: 'Times New Roman',serif;">FUNCTIONAL OVERVIEW **
<span style="color: #000000; font-family: 'Times New Roman',serif;">The right and left temporal lobe are functionally lateralized

<span style="color: #000000; font-family: 'Times New Roman',serif;">more concerned with non-emotional language functions, including, via the inferior-medial and basal temporal lobes reading and verbal (as verbal-visual) memory. e.g.when reading and speaking the left posterior temporal lobe becomes highly active, due, presumably to its involvement in lexical processing. The superior temporal lobe (and supramarginal gyrus) also becomes more active when reading aloud than when reading silently, and becomes active during semantic processing as does the left angular gyrus. <span style="color: #000000; font-family: 'Times New Roman',serif;">-Word generation <span style="color: #000000; font-family: 'Times New Roman',serif;">-Sentence comprehension tasks <span style="color: #000000; font-family: 'Times New Roman',serif;">-Retrieving the meaning of words during semantic processing and semantic decision tasks (in conjunction with the angular gyrus); see phomemes <span style="color: #000000; font-family: 'Times New Roman',serif;">Auditory areas: neurons become activated in response to speech, including the sound of the patient's own voice.
 * <span style="color: #000000; font-family: 'Times New Roman',serif;">Left Temporal Lobe: **

<span style="color: #000000; font-family: 'Times New Roman',serif;">more concerned with perceiving emotional and melodic auditory signals and is dominant for storing and recalling emotional and visual memories <span style="color: #000000; font-family: 'Times New Roman',serif;">-Interpreting the figurative aspects of language <span style="color: #000000; font-family: 'Times New Roman',serif;">-More prominent in discerning location of sounds
 * <span style="color: #000000; font-family: 'Times New Roman',serif;">Right Temporal Lobe: **

<span style="color: #000000; font-family: 'Times New Roman',serif;">However, there is considerable functional overlap and these structures often become simultaneously activated when performing various tasks. For example, the right posterior temporal cortex also becomes highly active, and when making semantic decisions (involving reading words with similar meanings), there is increased activity bilaterally. Presumably, in part, both temporal lobes become activated when speaking and reading, due to the left temporal lobe's specialization for extracting the semantic, temporal, sequential, and the syntactic elements of speech, thereby making language comprehension possible. By contrast, the right temporal lobe becomes active as it attempts to perceive, extract and comprehend the emotional (as well as the semantic) and gestalt aspects of speech and written language.

<span style="font-family: Times New Roman,serif;">TEMPORAL LOBE INJURY SUSCEPTIBILITY
<span style="color: #000000; font-family: 'Times New Roman',serif;">The temporal lobes are highly susceptible to injury from a variety of causes, including head injury, stroke, tumor, and epilepsy. In part, this susceptibility is due to the position of the temporal lobe within the skull. With whiplash injuries, or if the skull is struck from the back or the front, the temporal lobes will slam into the inside of the skull and may be ripped, torn, and sheared. These are called coup and contra coupe injuries.

<span style="color: #000000; font-family: 'Times New Roman',serif;">The inferior temporal lobes are also slow to mature which in turn increases the likelihood that abnormal neural networks may be formed in response to adverse early experience. Hence, not surprisingly, abnormal early environmental influences, including profound traumatic stress, can induce language, emotional, and memory disorders including repression for childhood experiences, as well as severe psychiatric abnormalities including schizophrenia and dissociative phenomenon; disturbances which implicate the temporal lobes as well as the amygdala and hippocampus.